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Diffstat (limited to 'contrib/gcc/stmt.c')
| -rw-r--r-- | contrib/gcc/stmt.c | 6130 |
1 files changed, 0 insertions, 6130 deletions
diff --git a/contrib/gcc/stmt.c b/contrib/gcc/stmt.c deleted file mode 100644 index f55b2c955ded..000000000000 --- a/contrib/gcc/stmt.c +++ /dev/null @@ -1,6130 +0,0 @@ -/* Expands front end tree to back end RTL for GNU C-Compiler - Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc. - -This file is part of GNU CC. - -GNU CC is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU CC is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU CC; see the file COPYING. If not, write to -the Free Software Foundation, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - - -/* This file handles the generation of rtl code from tree structure - above the level of expressions, using subroutines in exp*.c and emit-rtl.c. - It also creates the rtl expressions for parameters and auto variables - and has full responsibility for allocating stack slots. - - The functions whose names start with `expand_' are called by the - parser to generate RTL instructions for various kinds of constructs. - - Some control and binding constructs require calling several such - functions at different times. For example, a simple if-then - is expanded by calling `expand_start_cond' (with the condition-expression - as argument) before parsing the then-clause and calling `expand_end_cond' - after parsing the then-clause. */ - -#include "config.h" -#include "system.h" - -#include "rtl.h" -#include "tree.h" -#include "flags.h" -#include "except.h" -#include "function.h" -#include "insn-flags.h" -#include "insn-config.h" -#include "insn-codes.h" -#include "expr.h" -#include "hard-reg-set.h" -#include "obstack.h" -#include "loop.h" -#include "recog.h" -#include "machmode.h" -#include "toplev.h" -#include "output.h" - -#define obstack_chunk_alloc xmalloc -#define obstack_chunk_free free -struct obstack stmt_obstack; - -/* Assume that case vectors are not pc-relative. */ -#ifndef CASE_VECTOR_PC_RELATIVE -#define CASE_VECTOR_PC_RELATIVE 0 -#endif - -/* Filename and line number of last line-number note, - whether we actually emitted it or not. */ -char *emit_filename; -int emit_lineno; - -/* Nonzero if within a ({...}) grouping, in which case we must - always compute a value for each expr-stmt in case it is the last one. */ - -int expr_stmts_for_value; - -/* Each time we expand an expression-statement, - record the expr's type and its RTL value here. */ - -static tree last_expr_type; -static rtx last_expr_value; - -/* Each time we expand the end of a binding contour (in `expand_end_bindings') - and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here. - This is used by the `remember_end_note' function to record the endpoint - of each generated block in its associated BLOCK node. */ - -static rtx last_block_end_note; - -/* Number of binding contours started so far in this function. */ - -int block_start_count; - -/* Functions and data structures for expanding case statements. */ - -/* Case label structure, used to hold info on labels within case - statements. We handle "range" labels; for a single-value label - as in C, the high and low limits are the same. - - An AVL tree of case nodes is initially created, and later transformed - to a list linked via the RIGHT fields in the nodes. Nodes with - higher case values are later in the list. - - Switch statements can be output in one of two forms. A branch table - is used if there are more than a few labels and the labels are dense - within the range between the smallest and largest case value. If a - branch table is used, no further manipulations are done with the case - node chain. - - The alternative to the use of a branch table is to generate a series - of compare and jump insns. When that is done, we use the LEFT, RIGHT, - and PARENT fields to hold a binary tree. Initially the tree is - totally unbalanced, with everything on the right. We balance the tree - with nodes on the left having lower case values than the parent - and nodes on the right having higher values. We then output the tree - in order. */ - -struct case_node -{ - struct case_node *left; /* Left son in binary tree */ - struct case_node *right; /* Right son in binary tree; also node chain */ - struct case_node *parent; /* Parent of node in binary tree */ - tree low; /* Lowest index value for this label */ - tree high; /* Highest index value for this label */ - tree code_label; /* Label to jump to when node matches */ - int balance; -}; - -typedef struct case_node case_node; -typedef struct case_node *case_node_ptr; - -/* These are used by estimate_case_costs and balance_case_nodes. */ - -/* This must be a signed type, and non-ANSI compilers lack signed char. */ -static short *cost_table; -static int use_cost_table; - -/* Stack of control and binding constructs we are currently inside. - - These constructs begin when you call `expand_start_WHATEVER' - and end when you call `expand_end_WHATEVER'. This stack records - info about how the construct began that tells the end-function - what to do. It also may provide information about the construct - to alter the behavior of other constructs within the body. - For example, they may affect the behavior of C `break' and `continue'. - - Each construct gets one `struct nesting' object. - All of these objects are chained through the `all' field. - `nesting_stack' points to the first object (innermost construct). - The position of an entry on `nesting_stack' is in its `depth' field. - - Each type of construct has its own individual stack. - For example, loops have `loop_stack'. Each object points to the - next object of the same type through the `next' field. - - Some constructs are visible to `break' exit-statements and others - are not. Which constructs are visible depends on the language. - Therefore, the data structure allows each construct to be visible - or not, according to the args given when the construct is started. - The construct is visible if the `exit_label' field is non-null. - In that case, the value should be a CODE_LABEL rtx. */ - -struct nesting -{ - struct nesting *all; - struct nesting *next; - int depth; - rtx exit_label; - union - { - /* For conds (if-then and if-then-else statements). */ - struct - { - /* Label for the end of the if construct. - There is none if EXITFLAG was not set - and no `else' has been seen yet. */ - rtx endif_label; - /* Label for the end of this alternative. - This may be the end of the if or the next else/elseif. */ - rtx next_label; - } cond; - /* For loops. */ - struct - { - /* Label at the top of the loop; place to loop back to. */ - rtx start_label; - /* Label at the end of the whole construct. */ - rtx end_label; - /* Label before a jump that branches to the end of the whole - construct. This is where destructors go if any. */ - rtx alt_end_label; - /* Label for `continue' statement to jump to; - this is in front of the stepper of the loop. */ - rtx continue_label; - } loop; - /* For variable binding contours. */ - struct - { - /* Sequence number of this binding contour within the function, - in order of entry. */ - int block_start_count; - /* Nonzero => value to restore stack to on exit. */ - rtx stack_level; - /* The NOTE that starts this contour. - Used by expand_goto to check whether the destination - is within each contour or not. */ - rtx first_insn; - /* Innermost containing binding contour that has a stack level. */ - struct nesting *innermost_stack_block; - /* List of cleanups to be run on exit from this contour. - This is a list of expressions to be evaluated. - The TREE_PURPOSE of each link is the ..._DECL node - which the cleanup pertains to. */ - tree cleanups; - /* List of cleanup-lists of blocks containing this block, - as they were at the locus where this block appears. - There is an element for each containing block, - ordered innermost containing block first. - The tail of this list can be 0, - if all remaining elements would be empty lists. - The element's TREE_VALUE is the cleanup-list of that block, - which may be null. */ - tree outer_cleanups; - /* Chain of labels defined inside this binding contour. - For contours that have stack levels or cleanups. */ - struct label_chain *label_chain; - /* Number of function calls seen, as of start of this block. */ - int function_call_count; - /* Nonzero if this is associated with a EH region. */ - int exception_region; - /* The saved target_temp_slot_level from our outer block. - We may reset target_temp_slot_level to be the level of - this block, if that is done, target_temp_slot_level - reverts to the saved target_temp_slot_level at the very - end of the block. */ - int target_temp_slot_level; - /* True if we are currently emitting insns in an area of - output code that is controlled by a conditional - expression. This is used by the cleanup handling code to - generate conditional cleanup actions. */ - int conditional_code; - /* A place to move the start of the exception region for any - of the conditional cleanups, must be at the end or after - the start of the last unconditional cleanup, and before any - conditional branch points. */ - rtx last_unconditional_cleanup; - /* When in a conditional context, this is the specific - cleanup list associated with last_unconditional_cleanup, - where we place the conditionalized cleanups. */ - tree *cleanup_ptr; - } block; - /* For switch (C) or case (Pascal) statements, - and also for dummies (see `expand_start_case_dummy'). */ - struct - { - /* The insn after which the case dispatch should finally - be emitted. Zero for a dummy. */ - rtx start; - /* A list of case labels; it is first built as an AVL tree. - During expand_end_case, this is converted to a list, and may be - rearranged into a nearly balanced binary tree. */ - struct case_node *case_list; - /* Label to jump to if no case matches. */ - tree default_label; - /* The expression to be dispatched on. */ - tree index_expr; - /* Type that INDEX_EXPR should be converted to. */ - tree nominal_type; - /* Number of range exprs in case statement. */ - int num_ranges; - /* Name of this kind of statement, for warnings. */ - const char *printname; - /* Used to save no_line_numbers till we see the first case label. - We set this to -1 when we see the first case label in this - case statement. */ - int line_number_status; - } case_stmt; - } data; -}; - -/* Chain of all pending binding contours. */ -struct nesting *block_stack; - -/* If any new stacks are added here, add them to POPSTACKS too. */ - -/* Chain of all pending binding contours that restore stack levels - or have cleanups. */ -struct nesting *stack_block_stack; - -/* Chain of all pending conditional statements. */ -struct nesting *cond_stack; - -/* Chain of all pending loops. */ -struct nesting *loop_stack; - -/* Chain of all pending case or switch statements. */ -struct nesting *case_stack; - -/* Separate chain including all of the above, - chained through the `all' field. */ -struct nesting *nesting_stack; - -/* Number of entries on nesting_stack now. */ -int nesting_depth; - -/* Allocate and return a new `struct nesting'. */ - -#define ALLOC_NESTING() \ - (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting)) - -/* Pop the nesting stack element by element until we pop off - the element which is at the top of STACK. - Update all the other stacks, popping off elements from them - as we pop them from nesting_stack. */ - -#define POPSTACK(STACK) \ -do { struct nesting *target = STACK; \ - struct nesting *this; \ - do { this = nesting_stack; \ - if (loop_stack == this) \ - loop_stack = loop_stack->next; \ - if (cond_stack == this) \ - cond_stack = cond_stack->next; \ - if (block_stack == this) \ - block_stack = block_stack->next; \ - if (stack_block_stack == this) \ - stack_block_stack = stack_block_stack->next; \ - if (case_stack == this) \ - case_stack = case_stack->next; \ - nesting_depth = nesting_stack->depth - 1; \ - nesting_stack = this->all; \ - obstack_free (&stmt_obstack, this); } \ - while (this != target); } while (0) - -/* In some cases it is impossible to generate code for a forward goto - until the label definition is seen. This happens when it may be necessary - for the goto to reset the stack pointer: we don't yet know how to do that. - So expand_goto puts an entry on this fixup list. - Each time a binding contour that resets the stack is exited, - we check each fixup. - If the target label has now been defined, we can insert the proper code. */ - -struct goto_fixup -{ - /* Points to following fixup. */ - struct goto_fixup *next; - /* Points to the insn before the jump insn. - If more code must be inserted, it goes after this insn. */ - rtx before_jump; - /* The LABEL_DECL that this jump is jumping to, or 0 - for break, continue or return. */ - tree target; - /* The BLOCK for the place where this goto was found. */ - tree context; - /* The CODE_LABEL rtx that this is jumping to. */ - rtx target_rtl; - /* Number of binding contours started in current function - before the label reference. */ - int block_start_count; - /* The outermost stack level that should be restored for this jump. - Each time a binding contour that resets the stack is exited, - if the target label is *not* yet defined, this slot is updated. */ - rtx stack_level; - /* List of lists of cleanup expressions to be run by this goto. - There is one element for each block that this goto is within. - The tail of this list can be 0, - if all remaining elements would be empty. - The TREE_VALUE contains the cleanup list of that block as of the - time this goto was seen. - The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */ - tree cleanup_list_list; -}; - -static struct goto_fixup *goto_fixup_chain; - -/* Within any binding contour that must restore a stack level, - all labels are recorded with a chain of these structures. */ - -struct label_chain -{ - /* Points to following fixup. */ - struct label_chain *next; - tree label; -}; - - -/* Non-zero if we are using EH to handle cleanus. */ -static int using_eh_for_cleanups_p = 0; - - -static int n_occurrences PROTO((int, const char *)); -static void expand_goto_internal PROTO((tree, rtx, rtx)); -static int expand_fixup PROTO((tree, rtx, rtx)); -static rtx expand_nl_handler_label PROTO((rtx, rtx)); -static void expand_nl_goto_receiver PROTO((void)); -static void expand_nl_goto_receivers PROTO((struct nesting *)); -static void fixup_gotos PROTO((struct nesting *, rtx, tree, - rtx, int)); -static void expand_null_return_1 PROTO((rtx, int)); -static void expand_value_return PROTO((rtx)); -static int tail_recursion_args PROTO((tree, tree)); -static void expand_cleanups PROTO((tree, tree, int, int)); -static void check_seenlabel PROTO((void)); -static void do_jump_if_equal PROTO((rtx, rtx, rtx, int)); -static int estimate_case_costs PROTO((case_node_ptr)); -static void group_case_nodes PROTO((case_node_ptr)); -static void balance_case_nodes PROTO((case_node_ptr *, - case_node_ptr)); -static int node_has_low_bound PROTO((case_node_ptr, tree)); -static int node_has_high_bound PROTO((case_node_ptr, tree)); -static int node_is_bounded PROTO((case_node_ptr, tree)); -static void emit_jump_if_reachable PROTO((rtx)); -static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree)); -static int add_case_node PROTO((tree, tree, tree, tree *)); -static struct case_node *case_tree2list PROTO((case_node *, case_node *)); - -void -using_eh_for_cleanups () -{ - using_eh_for_cleanups_p = 1; -} - -void -init_stmt () -{ - gcc_obstack_init (&stmt_obstack); - init_eh (); -} - -void -init_stmt_for_function () -{ - /* We are not currently within any block, conditional, loop or case. */ - block_stack = 0; - stack_block_stack = 0; - loop_stack = 0; - case_stack = 0; - cond_stack = 0; - nesting_stack = 0; - nesting_depth = 0; - - block_start_count = 0; - - /* No gotos have been expanded yet. */ - goto_fixup_chain = 0; - - /* We are not processing a ({...}) grouping. */ - expr_stmts_for_value = 0; - last_expr_type = 0; - - init_eh_for_function (); -} - -void -save_stmt_status (p) - struct function *p; -{ - p->block_stack = block_stack; - p->stack_block_stack = stack_block_stack; - p->cond_stack = cond_stack; - p->loop_stack = loop_stack; - p->case_stack = case_stack; - p->nesting_stack = nesting_stack; - p->nesting_depth = nesting_depth; - p->block_start_count = block_start_count; - p->last_expr_type = last_expr_type; - p->last_expr_value = last_expr_value; - p->expr_stmts_for_value = expr_stmts_for_value; - p->emit_filename = emit_filename; - p->emit_lineno = emit_lineno; - p->goto_fixup_chain = goto_fixup_chain; - save_eh_status (p); -} - -void -restore_stmt_status (p) - struct function *p; -{ - block_stack = p->block_stack; - stack_block_stack = p->stack_block_stack; - cond_stack = p->cond_stack; - loop_stack = p->loop_stack; - case_stack = p->case_stack; - nesting_stack = p->nesting_stack; - nesting_depth = p->nesting_depth; - block_start_count = p->block_start_count; - last_expr_type = p->last_expr_type; - last_expr_value = p->last_expr_value; - expr_stmts_for_value = p->expr_stmts_for_value; - emit_filename = p->emit_filename; - emit_lineno = p->emit_lineno; - goto_fixup_chain = p->goto_fixup_chain; - restore_eh_status (p); -} - -/* Emit a no-op instruction. */ - -void -emit_nop () -{ - rtx last_insn; - - last_insn = get_last_insn (); - if (!optimize - && (GET_CODE (last_insn) == CODE_LABEL - || (GET_CODE (last_insn) == NOTE - && prev_real_insn (last_insn) == 0))) - emit_insn (gen_nop ()); -} - -/* Return the rtx-label that corresponds to a LABEL_DECL, - creating it if necessary. */ - -rtx -label_rtx (label) - tree label; -{ - if (TREE_CODE (label) != LABEL_DECL) - abort (); - - if (DECL_RTL (label)) - return DECL_RTL (label); - - return DECL_RTL (label) = gen_label_rtx (); -} - -/* Add an unconditional jump to LABEL as the next sequential instruction. */ - -void -emit_jump (label) - rtx label; -{ - do_pending_stack_adjust (); - emit_jump_insn (gen_jump (label)); - emit_barrier (); -} - -/* Emit code to jump to the address - specified by the pointer expression EXP. */ - -void -expand_computed_goto (exp) - tree exp; -{ - rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); - -#ifdef POINTERS_EXTEND_UNSIGNED - x = convert_memory_address (Pmode, x); -#endif - - emit_queue (); - /* Be sure the function is executable. */ - if (current_function_check_memory_usage) - emit_library_call (chkr_check_exec_libfunc, 1, - VOIDmode, 1, x, ptr_mode); - - do_pending_stack_adjust (); - emit_indirect_jump (x); - - current_function_has_computed_jump = 1; -} - -/* Handle goto statements and the labels that they can go to. */ - -/* Specify the location in the RTL code of a label LABEL, - which is a LABEL_DECL tree node. - - This is used for the kind of label that the user can jump to with a - goto statement, and for alternatives of a switch or case statement. - RTL labels generated for loops and conditionals don't go through here; - they are generated directly at the RTL level, by other functions below. - - Note that this has nothing to do with defining label *names*. - Languages vary in how they do that and what that even means. */ - -void -expand_label (label) - tree label; -{ - struct label_chain *p; - - do_pending_stack_adjust (); - emit_label (label_rtx (label)); - if (DECL_NAME (label)) - LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); - - if (stack_block_stack != 0) - { - p = (struct label_chain *) oballoc (sizeof (struct label_chain)); - p->next = stack_block_stack->data.block.label_chain; - stack_block_stack->data.block.label_chain = p; - p->label = label; - } -} - -/* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos - from nested functions. */ - -void -declare_nonlocal_label (label) - tree label; -{ - rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); - - nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels); - LABEL_PRESERVE_P (label_rtx (label)) = 1; - if (nonlocal_goto_handler_slots == 0) - { - emit_stack_save (SAVE_NONLOCAL, - &nonlocal_goto_stack_level, - PREV_INSN (tail_recursion_reentry)); - } - nonlocal_goto_handler_slots - = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots); -} - -/* Generate RTL code for a `goto' statement with target label LABEL. - LABEL should be a LABEL_DECL tree node that was or will later be - defined with `expand_label'. */ - -void -expand_goto (label) - tree label; -{ - tree context; - - /* Check for a nonlocal goto to a containing function. */ - context = decl_function_context (label); - if (context != 0 && context != current_function_decl) - { - struct function *p = find_function_data (context); - rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label)); - rtx temp, handler_slot; - tree link; - - /* Find the corresponding handler slot for this label. */ - handler_slot = p->nonlocal_goto_handler_slots; - for (link = p->nonlocal_labels; TREE_VALUE (link) != label; - link = TREE_CHAIN (link)) - handler_slot = XEXP (handler_slot, 1); - handler_slot = XEXP (handler_slot, 0); - - p->has_nonlocal_label = 1; - current_function_has_nonlocal_goto = 1; - LABEL_REF_NONLOCAL_P (label_ref) = 1; - - /* Copy the rtl for the slots so that they won't be shared in - case the virtual stack vars register gets instantiated differently - in the parent than in the child. */ - -#if HAVE_nonlocal_goto - if (HAVE_nonlocal_goto) - emit_insn (gen_nonlocal_goto (lookup_static_chain (label), - copy_rtx (handler_slot), - copy_rtx (p->nonlocal_goto_stack_level), - label_ref)); - else -#endif - { - rtx addr; - - /* Restore frame pointer for containing function. - This sets the actual hard register used for the frame pointer - to the location of the function's incoming static chain info. - The non-local goto handler will then adjust it to contain the - proper value and reload the argument pointer, if needed. */ - emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label)); - - /* We have now loaded the frame pointer hardware register with - the address of that corresponds to the start of the virtual - stack vars. So replace virtual_stack_vars_rtx in all - addresses we use with stack_pointer_rtx. */ - - /* Get addr of containing function's current nonlocal goto handler, - which will do any cleanups and then jump to the label. */ - addr = copy_rtx (handler_slot); - temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx, - hard_frame_pointer_rtx)); - - /* Restore the stack pointer. Note this uses fp just restored. */ - addr = p->nonlocal_goto_stack_level; - if (addr) - addr = replace_rtx (copy_rtx (addr), - virtual_stack_vars_rtx, - hard_frame_pointer_rtx); - - emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX); - - /* USE of hard_frame_pointer_rtx added for consistency; not clear if - really needed. */ - emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); - emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx)); - emit_indirect_jump (temp); - } - } - else - expand_goto_internal (label, label_rtx (label), NULL_RTX); -} - -/* Generate RTL code for a `goto' statement with target label BODY. - LABEL should be a LABEL_REF. - LAST_INSN, if non-0, is the rtx we should consider as the last - insn emitted (for the purposes of cleaning up a return). */ - -static void -expand_goto_internal (body, label, last_insn) - tree body; - rtx label; - rtx last_insn; -{ - struct nesting *block; - rtx stack_level = 0; - - if (GET_CODE (label) != CODE_LABEL) - abort (); - - /* If label has already been defined, we can tell now - whether and how we must alter the stack level. */ - - if (PREV_INSN (label) != 0) - { - /* Find the innermost pending block that contains the label. - (Check containment by comparing insn-uids.) - Then restore the outermost stack level within that block, - and do cleanups of all blocks contained in it. */ - for (block = block_stack; block; block = block->next) - { - if (INSN_UID (block->data.block.first_insn) < INSN_UID (label)) - break; - if (block->data.block.stack_level != 0) - stack_level = block->data.block.stack_level; - /* Execute the cleanups for blocks we are exiting. */ - if (block->data.block.cleanups != 0) - { - expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1); - do_pending_stack_adjust (); - } - } - - if (stack_level) - { - /* Ensure stack adjust isn't done by emit_jump, as this - would clobber the stack pointer. This one should be - deleted as dead by flow. */ - clear_pending_stack_adjust (); - do_pending_stack_adjust (); - emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX); - } - - if (body != 0 && DECL_TOO_LATE (body)) - error ("jump to `%s' invalidly jumps into binding contour", - IDENTIFIER_POINTER (DECL_NAME (body))); - } - /* Label not yet defined: may need to put this goto - on the fixup list. */ - else if (! expand_fixup (body, label, last_insn)) - { - /* No fixup needed. Record that the label is the target - of at least one goto that has no fixup. */ - if (body != 0) - TREE_ADDRESSABLE (body) = 1; - } - - emit_jump (label); -} - -/* Generate if necessary a fixup for a goto - whose target label in tree structure (if any) is TREE_LABEL - and whose target in rtl is RTL_LABEL. - - If LAST_INSN is nonzero, we pretend that the jump appears - after insn LAST_INSN instead of at the current point in the insn stream. - - The fixup will be used later to insert insns just before the goto. - Those insns will restore the stack level as appropriate for the - target label, and will (in the case of C++) also invoke any object - destructors which have to be invoked when we exit the scopes which - are exited by the goto. - - Value is nonzero if a fixup is made. */ - -static int -expand_fixup (tree_label, rtl_label, last_insn) - tree tree_label; - rtx rtl_label; - rtx last_insn; -{ - struct nesting *block, *end_block; - - /* See if we can recognize which block the label will be output in. - This is possible in some very common cases. - If we succeed, set END_BLOCK to that block. - Otherwise, set it to 0. */ - - if (cond_stack - && (rtl_label == cond_stack->data.cond.endif_label - || rtl_label == cond_stack->data.cond.next_label)) - end_block = cond_stack; - /* If we are in a loop, recognize certain labels which - are likely targets. This reduces the number of fixups - we need to create. */ - else if (loop_stack - && (rtl_label == loop_stack->data.loop.start_label - || rtl_label == loop_stack->data.loop.end_label - || rtl_label == loop_stack->data.loop.continue_label)) - end_block = loop_stack; - else - end_block = 0; - - /* Now set END_BLOCK to the binding level to which we will return. */ - - if (end_block) - { - struct nesting *next_block = end_block->all; - block = block_stack; - - /* First see if the END_BLOCK is inside the innermost binding level. - If so, then no cleanups or stack levels are relevant. */ - while (next_block && next_block != block) - next_block = next_block->all; - - if (next_block) - return 0; - - /* Otherwise, set END_BLOCK to the innermost binding level - which is outside the relevant control-structure nesting. */ - next_block = block_stack->next; - for (block = block_stack; block != end_block; block = block->all) - if (block == next_block) - next_block = next_block->next; - end_block = next_block; - } - - /* Does any containing block have a stack level or cleanups? - If not, no fixup is needed, and that is the normal case - (the only case, for standard C). */ - for (block = block_stack; block != end_block; block = block->next) - if (block->data.block.stack_level != 0 - || block->data.block.cleanups != 0) - break; - - if (block != end_block) - { - /* Ok, a fixup is needed. Add a fixup to the list of such. */ - struct goto_fixup *fixup - = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); - /* In case an old stack level is restored, make sure that comes - after any pending stack adjust. */ - /* ?? If the fixup isn't to come at the present position, - doing the stack adjust here isn't useful. Doing it with our - settings at that location isn't useful either. Let's hope - someone does it! */ - if (last_insn == 0) - do_pending_stack_adjust (); - fixup->target = tree_label; - fixup->target_rtl = rtl_label; - - /* Create a BLOCK node and a corresponding matched set of - NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at - this point. The notes will encapsulate any and all fixup - code which we might later insert at this point in the insn - stream. Also, the BLOCK node will be the parent (i.e. the - `SUPERBLOCK') of any other BLOCK nodes which we might create - later on when we are expanding the fixup code. - - Note that optimization passes (including expand_end_loop) - might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED - as a placeholder. */ - - { - register rtx original_before_jump - = last_insn ? last_insn : get_last_insn (); - rtx start; - - start_sequence (); - pushlevel (0); - start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); - fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED); - last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); - fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */ - end_sequence (); - emit_insns_after (start, original_before_jump); - } - - fixup->block_start_count = block_start_count; - fixup->stack_level = 0; - fixup->cleanup_list_list - = ((block->data.block.outer_cleanups - || block->data.block.cleanups) - ? tree_cons (NULL_TREE, block->data.block.cleanups, - block->data.block.outer_cleanups) - : 0); - fixup->next = goto_fixup_chain; - goto_fixup_chain = fixup; - } - - return block != 0; -} - - - -/* Expand any needed fixups in the outputmost binding level of the - function. FIRST_INSN is the first insn in the function. */ - -void -expand_fixups (first_insn) - rtx first_insn; -{ - fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0); -} - -/* When exiting a binding contour, process all pending gotos requiring fixups. - THISBLOCK is the structure that describes the block being exited. - STACK_LEVEL is the rtx for the stack level to restore exiting this contour. - CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. - FIRST_INSN is the insn that began this contour. - - Gotos that jump out of this contour must restore the - stack level and do the cleanups before actually jumping. - - DONT_JUMP_IN nonzero means report error there is a jump into this - contour from before the beginning of the contour. - This is also done if STACK_LEVEL is nonzero. */ - -static void -fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) - struct nesting *thisblock; - rtx stack_level; - tree cleanup_list; - rtx first_insn; - int dont_jump_in; -{ - register struct goto_fixup *f, *prev; - - /* F is the fixup we are considering; PREV is the previous one. */ - /* We run this loop in two passes so that cleanups of exited blocks - are run first, and blocks that are exited are marked so - afterwards. */ - - for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) - { - /* Test for a fixup that is inactive because it is already handled. */ - if (f->before_jump == 0) - { - /* Delete inactive fixup from the chain, if that is easy to do. */ - if (prev != 0) - prev->next = f->next; - } - /* Has this fixup's target label been defined? - If so, we can finalize it. */ - else if (PREV_INSN (f->target_rtl) != 0) - { - register rtx cleanup_insns; - - /* Get the first non-label after the label - this goto jumps to. If that's before this scope begins, - we don't have a jump into the scope. */ - rtx after_label = f->target_rtl; - while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL) - after_label = NEXT_INSN (after_label); - - /* If this fixup jumped into this contour from before the beginning - of this contour, report an error. */ - /* ??? Bug: this does not detect jumping in through intermediate - blocks that have stack levels or cleanups. - It detects only a problem with the innermost block - around the label. */ - if (f->target != 0 - && (dont_jump_in || stack_level || cleanup_list) - /* If AFTER_LABEL is 0, it means the jump goes to the end - of the rtl, which means it jumps into this scope. */ - && (after_label == 0 - || INSN_UID (first_insn) < INSN_UID (after_label)) - && INSN_UID (first_insn) > INSN_UID (f->before_jump) - && ! DECL_ERROR_ISSUED (f->target)) - { - error_with_decl (f->target, - "label `%s' used before containing binding contour"); - /* Prevent multiple errors for one label. */ - DECL_ERROR_ISSUED (f->target) = 1; - } - - /* We will expand the cleanups into a sequence of their own and - then later on we will attach this new sequence to the insn - stream just ahead of the actual jump insn. */ - - start_sequence (); - - /* Temporarily restore the lexical context where we will - logically be inserting the fixup code. We do this for the - sake of getting the debugging information right. */ - - pushlevel (0); - set_block (f->context); - - /* Expand the cleanups for blocks this jump exits. */ - if (f->cleanup_list_list) - { - tree lists; - for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists)) - /* Marked elements correspond to blocks that have been closed. - Do their cleanups. */ - if (TREE_ADDRESSABLE (lists) - && TREE_VALUE (lists) != 0) - { - expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); - /* Pop any pushes done in the cleanups, - in case function is about to return. */ - do_pending_stack_adjust (); - } - } - - /* Restore stack level for the biggest contour that this - jump jumps out of. */ - if (f->stack_level) - emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump); - - /* Finish up the sequence containing the insns which implement the - necessary cleanups, and then attach that whole sequence to the - insn stream just ahead of the actual jump insn. Attaching it - at that point insures that any cleanups which are in fact - implicit C++ object destructions (which must be executed upon - leaving the block) appear (to the debugger) to be taking place - in an area of the generated code where the object(s) being - destructed are still "in scope". */ - - cleanup_insns = get_insns (); - poplevel (1, 0, 0); - - end_sequence (); - emit_insns_after (cleanup_insns, f->before_jump); - - - f->before_jump = 0; - } - } - - /* For any still-undefined labels, do the cleanups for this block now. - We must do this now since items in the cleanup list may go out - of scope when the block ends. */ - for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) - if (f->before_jump != 0 - && PREV_INSN (f->target_rtl) == 0 - /* Label has still not appeared. If we are exiting a block with - a stack level to restore, that started before the fixup, - mark this stack level as needing restoration - when the fixup is later finalized. */ - && thisblock != 0 - /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it - means the label is undefined. That's erroneous, but possible. */ - && (thisblock->data.block.block_start_count - <= f->block_start_count)) - { - tree lists = f->cleanup_list_list; - rtx cleanup_insns; - - for (; lists; lists = TREE_CHAIN (lists)) - /* If the following elt. corresponds to our containing block - then the elt. must be for this block. */ - if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups) - { - start_sequence (); - pushlevel (0); - set_block (f->context); - expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); - do_pending_stack_adjust (); - cleanup_insns = get_insns (); - poplevel (1, 0, 0); - end_sequence (); - if (cleanup_insns != 0) - f->before_jump - = emit_insns_after (cleanup_insns, f->before_jump); - - f->cleanup_list_list = TREE_CHAIN (lists); - } - - if (stack_level) - f->stack_level = stack_level; - } -} - -/* Return the number of times character C occurs in string S. */ -static int -n_occurrences (c, s) - int c; - const char *s; -{ - int n = 0; - while (*s) - n += (*s++ == c); - return n; -} - -/* Generate RTL for an asm statement (explicit assembler code). - BODY is a STRING_CST node containing the assembler code text, - or an ADDR_EXPR containing a STRING_CST. */ - -void -expand_asm (body) - tree body; -{ - if (current_function_check_memory_usage) - { - error ("`asm' cannot be used with `-fcheck-memory-usage'"); - return; - } - - if (TREE_CODE (body) == ADDR_EXPR) - body = TREE_OPERAND (body, 0); - - emit_insn (gen_rtx_ASM_INPUT (VOIDmode, - TREE_STRING_POINTER (body))); - last_expr_type = 0; -} - -/* Generate RTL for an asm statement with arguments. - STRING is the instruction template. - OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. - Each output or input has an expression in the TREE_VALUE and - a constraint-string in the TREE_PURPOSE. - CLOBBERS is a list of STRING_CST nodes each naming a hard register - that is clobbered by this insn. - - Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. - Some elements of OUTPUTS may be replaced with trees representing temporary - values. The caller should copy those temporary values to the originally - specified lvalues. - - VOL nonzero means the insn is volatile; don't optimize it. */ - -void -expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line) - tree string, outputs, inputs, clobbers; - int vol; - char *filename; - int line; -{ - rtvec argvec, constraints; - rtx body; - int ninputs = list_length (inputs); - int noutputs = list_length (outputs); - int ninout = 0; - int nclobbers; - tree tail; - register int i; - /* Vector of RTX's of evaluated output operands. */ - rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); - int *inout_opnum = (int *) alloca (noutputs * sizeof (int)); - rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); - enum machine_mode *inout_mode - = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode)); - /* The insn we have emitted. */ - rtx insn; - - /* An ASM with no outputs needs to be treated as volatile, for now. */ - if (noutputs == 0) - vol = 1; - - if (current_function_check_memory_usage) - { - error ("`asm' cannot be used with `-fcheck-memory-usage'"); - return; - } - - /* Count the number of meaningful clobbered registers, ignoring what - we would ignore later. */ - nclobbers = 0; - for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) - { - char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); - i = decode_reg_name (regname); - if (i >= 0 || i == -4) - ++nclobbers; - else if (i == -2) - error ("unknown register name `%s' in `asm'", regname); - } - - last_expr_type = 0; - - /* Check that the number of alternatives is constant across all - operands. */ - if (outputs || inputs) - { - tree tmp = TREE_PURPOSE (outputs ? outputs : inputs); - int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp)); - tree next = inputs; - - if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES) - { - error ("too many alternatives in `asm'"); - return; - } - - tmp = outputs; - while (tmp) - { - char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp)); - if (n_occurrences (',', constraint) != nalternatives) - { - error ("operand constraints for `asm' differ in number of alternatives"); - return; - } - if (TREE_CHAIN (tmp)) - tmp = TREE_CHAIN (tmp); - else - tmp = next, next = 0; - } - } - - for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) - { - tree val = TREE_VALUE (tail); - tree type = TREE_TYPE (val); - char *constraint; - char *p; - int c_len; - int j; - int is_inout = 0; - int allows_reg = 0; - int allows_mem = 0; - - /* If there's an erroneous arg, emit no insn. */ - if (TREE_TYPE (val) == error_mark_node) - return; - - /* Make sure constraint has `=' and does not have `+'. Also, see - if it allows any register. Be liberal on the latter test, since - the worst that happens if we get it wrong is we issue an error - message. */ - - c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; - constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail)); - - /* Allow the `=' or `+' to not be at the beginning of the string, - since it wasn't explicitly documented that way, and there is a - large body of code that puts it last. Swap the character to - the front, so as not to uglify any place else. */ - switch (c_len) - { - default: - if ((p = strchr (constraint, '=')) != NULL) - break; - if ((p = strchr (constraint, '+')) != NULL) - break; - case 0: - error ("output operand constraint lacks `='"); - return; - } - - if (p != constraint) - { - j = *p; - bcopy (constraint, constraint+1, p-constraint); - *constraint = j; - - warning ("output constraint `%c' for operand %d is not at the beginning", j, i); - } - - is_inout = constraint[0] == '+'; - /* Replace '+' with '='. */ - constraint[0] = '='; - /* Make sure we can specify the matching operand. */ - if (is_inout && i > 9) - { - error ("output operand constraint %d contains `+'", i); - return; - } - - for (j = 1; j < c_len; j++) - switch (constraint[j]) - { - case '+': - case '=': - error ("operand constraint contains '+' or '=' at illegal position."); - return; - - case '%': - if (i + 1 == ninputs + noutputs) - { - error ("`%%' constraint used with last operand"); - return; - } - break; - - case '?': case '!': case '*': case '&': - case 'E': case 'F': case 'G': case 'H': - case 's': case 'i': case 'n': - case 'I': case 'J': case 'K': case 'L': case 'M': - case 'N': case 'O': case 'P': case ',': -#ifdef EXTRA_CONSTRAINT - case 'Q': case 'R': case 'S': case 'T': case 'U': -#endif - break; - - case '0': case '1': case '2': case '3': case '4': - case '5': case '6': case '7': case '8': case '9': - error ("matching constraint not valid in output operand"); - break; - - case 'V': case 'm': case 'o': - allows_mem = 1; - break; - - case '<': case '>': - /* ??? Before flow, auto inc/dec insns are not supposed to exist, - excepting those that expand_call created. So match memory - and hope. */ - allows_mem = 1; - break; - - case 'g': case 'X': - allows_reg = 1; - allows_mem = 1; - break; - - case 'p': case 'r': - default: - allows_reg = 1; - break; - } - - /* If an output operand is not a decl or indirect ref and our constraint - allows a register, make a temporary to act as an intermediate. - Make the asm insn write into that, then our caller will copy it to - the real output operand. Likewise for promoted variables. */ - - real_output_rtx[i] = NULL_RTX; - if ((TREE_CODE (val) == INDIRECT_REF - && allows_mem) - || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd' - && (allows_mem || GET_CODE (DECL_RTL (val)) == REG) - && ! (GET_CODE (DECL_RTL (val)) == REG - && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) - || ! allows_reg - || is_inout) - { - if (! allows_reg) - mark_addressable (TREE_VALUE (tail)); - - output_rtx[i] - = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, - EXPAND_MEMORY_USE_WO); - - if (! allows_reg && GET_CODE (output_rtx[i]) != MEM) - error ("output number %d not directly addressable", i); - if (! allows_mem && GET_CODE (output_rtx[i]) == MEM) - { - real_output_rtx[i] = protect_from_queue (output_rtx[i], 1); - output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i])); - if (is_inout) - emit_move_insn (output_rtx[i], real_output_rtx[i]); - } - } - else - { - output_rtx[i] = assign_temp (type, 0, 0, 0); - TREE_VALUE (tail) = make_tree (type, output_rtx[i]); - } - - if (is_inout) - { - inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))); - inout_opnum[ninout++] = i; - } - } - - ninputs += ninout; - if (ninputs + noutputs > MAX_RECOG_OPERANDS) - { - error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS); - return; - } - - /* Make vectors for the expression-rtx and constraint strings. */ - - argvec = rtvec_alloc (ninputs); - constraints = rtvec_alloc (ninputs); - - body = gen_rtx_ASM_OPERANDS (VOIDmode, - TREE_STRING_POINTER (string), "", 0, argvec, - constraints, filename, line); - - MEM_VOLATILE_P (body) = vol; - - /* Eval the inputs and put them into ARGVEC. - Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ - - i = 0; - for (tail = inputs; tail; tail = TREE_CHAIN (tail)) - { - int j; - int allows_reg = 0, allows_mem = 0; - char *constraint, *orig_constraint; - int c_len; - rtx op; - - /* If there's an erroneous arg, emit no insn, - because the ASM_INPUT would get VOIDmode - and that could cause a crash in reload. */ - if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) - return; - - /* ??? Can this happen, and does the error message make any sense? */ - if (TREE_PURPOSE (tail) == NULL_TREE) - { - error ("hard register `%s' listed as input operand to `asm'", - TREE_STRING_POINTER (TREE_VALUE (tail)) ); - return; - } - - c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; - constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail)); - orig_constraint = constraint; - - /* Make sure constraint has neither `=', `+', nor '&'. */ - - for (j = 0; j < c_len; j++) - switch (constraint[j]) - { - case '+': case '=': case '&': - if (constraint == orig_constraint) - { - error ("input operand constraint contains `%c'", constraint[j]); - return; - } - break; - - case '%': - if (constraint == orig_constraint - && i + 1 == ninputs - ninout) - { - error ("`%%' constraint used with last operand"); - return; - } - break; - - case 'V': case 'm': case 'o': - allows_mem = 1; - break; - - case '<': case '>': - case '?': case '!': case '*': - case 'E': case 'F': case 'G': case 'H': case 'X': - case 's': case 'i': case 'n': - case 'I': case 'J': case 'K': case 'L': case 'M': - case 'N': case 'O': case 'P': case ',': -#ifdef EXTRA_CONSTRAINT - case 'Q': case 'R': case 'S': case 'T': case 'U': -#endif - break; - - /* Whether or not a numeric constraint allows a register is - decided by the matching constraint, and so there is no need - to do anything special with them. We must handle them in - the default case, so that we don't unnecessarily force - operands to memory. */ - case '0': case '1': case '2': case '3': case '4': - case '5': case '6': case '7': case '8': case '9': - if (constraint[j] >= '0' + noutputs) - { - error - ("matching constraint references invalid operand number"); - return; - } - - /* Try and find the real constraint for this dup. */ - if ((j == 0 && c_len == 1) - || (j == 1 && c_len == 2 && constraint[0] == '%')) - { - tree o = outputs; - for (j = constraint[j] - '0'; j > 0; --j) - o = TREE_CHAIN (o); - - c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1; - constraint = TREE_STRING_POINTER (TREE_PURPOSE (o)); - j = 0; - break; - } - - /* ... fall through ... */ - - case 'p': case 'r': - default: - allows_reg = 1; - break; - - case 'g': - allows_reg = 1; - allows_mem = 1; - break; - } - - if (! allows_reg && allows_mem) - mark_addressable (TREE_VALUE (tail)); - - op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); - - if (asm_operand_ok (op, constraint) <= 0) - { - if (allows_reg) - op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op); - else if (!allows_mem) - warning ("asm operand %d probably doesn't match constraints", i); - else if (CONSTANT_P (op)) - op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), - op); - else if (GET_CODE (op) == REG - || GET_CODE (op) == SUBREG - || GET_CODE (op) == CONCAT) - { - tree type = TREE_TYPE (TREE_VALUE (tail)); - rtx memloc = assign_temp (type, 1, 1, 1); - - emit_move_insn (memloc, op); - op = memloc; - } - else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op)) - /* We won't recognize volatile memory as available a - memory_operand at this point. Ignore it. */ - ; - else if (queued_subexp_p (op)) - ; - else - /* ??? Leave this only until we have experience with what - happens in combine and elsewhere when constraints are - not satisfied. */ - warning ("asm operand %d probably doesn't match constraints", i); - } - XVECEXP (body, 3, i) = op; - - XVECEXP (body, 4, i) /* constraints */ - = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), - orig_constraint); - i++; - } - - /* Protect all the operands from the queue, - now that they have all been evaluated. */ - - for (i = 0; i < ninputs - ninout; i++) - XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0); - - for (i = 0; i < noutputs; i++) - output_rtx[i] = protect_from_queue (output_rtx[i], 1); - - /* For in-out operands, copy output rtx to input rtx. */ - for (i = 0; i < ninout; i++) - { - static char match[9+1][2] - = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}; - int j = inout_opnum[i]; - - XVECEXP (body, 3, ninputs - ninout + i) /* argvec */ - = output_rtx[j]; - XVECEXP (body, 4, ninputs - ninout + i) /* constraints */ - = gen_rtx_ASM_INPUT (inout_mode[j], match[j]); - } - - /* Now, for each output, construct an rtx - (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT - ARGVEC CONSTRAINTS)) - If there is more than one, put them inside a PARALLEL. */ - - if (noutputs == 1 && nclobbers == 0) - { - XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs)); - insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body)); - } - else if (noutputs == 0 && nclobbers == 0) - { - /* No output operands: put in a raw ASM_OPERANDS rtx. */ - insn = emit_insn (body); - } - else - { - rtx obody = body; - int num = noutputs; - if (num == 0) num = 1; - body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers)); - - /* For each output operand, store a SET. */ - - for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) - { - XVECEXP (body, 0, i) - = gen_rtx_SET (VOIDmode, - output_rtx[i], - gen_rtx_ASM_OPERANDS (VOIDmode, - TREE_STRING_POINTER (string), - TREE_STRING_POINTER (TREE_PURPOSE (tail)), - i, argvec, constraints, - filename, line)); - MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; - } - - /* If there are no outputs (but there are some clobbers) - store the bare ASM_OPERANDS into the PARALLEL. */ - - if (i == 0) - XVECEXP (body, 0, i++) = obody; - - /* Store (clobber REG) for each clobbered register specified. */ - - for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) - { - char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); - int j = decode_reg_name (regname); - - if (j < 0) - { - if (j == -3) /* `cc', which is not a register */ - continue; - - if (j == -4) /* `memory', don't cache memory across asm */ - { - XVECEXP (body, 0, i++) - = gen_rtx_CLOBBER (VOIDmode, - gen_rtx_MEM (BLKmode, - gen_rtx_SCRATCH (VOIDmode))); - continue; - } - - /* Ignore unknown register, error already signaled. */ - continue; - } - - /* Use QImode since that's guaranteed to clobber just one reg. */ - XVECEXP (body, 0, i++) - = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j)); - } - - insn = emit_insn (body); - } - - /* For any outputs that needed reloading into registers, spill them - back to where they belong. */ - for (i = 0; i < noutputs; ++i) - if (real_output_rtx[i]) - emit_move_insn (real_output_rtx[i], output_rtx[i]); - - free_temp_slots (); -} - -/* Generate RTL to evaluate the expression EXP - and remember it in case this is the VALUE in a ({... VALUE; }) constr. */ - -void -expand_expr_stmt (exp) - tree exp; -{ - /* If -W, warn about statements with no side effects, - except for an explicit cast to void (e.g. for assert()), and - except inside a ({...}) where they may be useful. */ - if (expr_stmts_for_value == 0 && exp != error_mark_node) - { - if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused) - && !(TREE_CODE (exp) == CONVERT_EXPR - && TREE_TYPE (exp) == void_type_node)) - warning_with_file_and_line (emit_filename, emit_lineno, - "statement with no effect"); - else if (warn_unused) - warn_if_unused_value (exp); - } - - /* If EXP is of function type and we are expanding statements for - value, convert it to pointer-to-function. */ - if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE) - exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp); - - last_expr_type = TREE_TYPE (exp); - last_expr_value = expand_expr (exp, - (expr_stmts_for_value - ? NULL_RTX : const0_rtx), - VOIDmode, 0); - - /* If all we do is reference a volatile value in memory, - copy it to a register to be sure it is actually touched. */ - if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM - && TREE_THIS_VOLATILE (exp)) - { - if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode) - ; - else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) - copy_to_reg (last_expr_value); - else - { - rtx lab = gen_label_rtx (); - - /* Compare the value with itself to reference it. */ - emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ, - expand_expr (TYPE_SIZE (last_expr_type), - NULL_RTX, VOIDmode, 0), - BLKmode, 0, - TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT, - lab); - emit_label (lab); - } - } - - /* If this expression is part of a ({...}) and is in memory, we may have - to preserve temporaries. */ - preserve_temp_slots (last_expr_value); - - /* Free any temporaries used to evaluate this expression. Any temporary - used as a result of this expression will already have been preserved - above. */ - free_temp_slots (); - - emit_queue (); -} - -/* Warn if EXP contains any computations whose results are not used. - Return 1 if a warning is printed; 0 otherwise. */ - -int -warn_if_unused_value (exp) - tree exp; -{ - if (TREE_USED (exp)) - return 0; - - switch (TREE_CODE (exp)) - { - case PREINCREMENT_EXPR: - case POSTINCREMENT_EXPR: - case PREDECREMENT_EXPR: - case POSTDECREMENT_EXPR: - case MODIFY_EXPR: - case INIT_EXPR: - case TARGET_EXPR: - case CALL_EXPR: - case METHOD_CALL_EXPR: - case RTL_EXPR: - case TRY_CATCH_EXPR: - case WITH_CLEANUP_EXPR: - case EXIT_EXPR: - /* We don't warn about COND_EXPR because it may be a useful - construct if either arm contains a side effect. */ - case COND_EXPR: - return 0; - - case BIND_EXPR: - /* For a binding, warn if no side effect within it. */ - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case SAVE_EXPR: - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case TRUTH_ORIF_EXPR: - case TRUTH_ANDIF_EXPR: - /* In && or ||, warn if 2nd operand has no side effect. */ - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case COMPOUND_EXPR: - if (TREE_NO_UNUSED_WARNING (exp)) - return 0; - if (warn_if_unused_value (TREE_OPERAND (exp, 0))) - return 1; - /* Let people do `(foo (), 0)' without a warning. */ - if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) - return 0; - return warn_if_unused_value (TREE_OPERAND (exp, 1)); - - case NOP_EXPR: - case CONVERT_EXPR: - case NON_LVALUE_EXPR: - /* Don't warn about values cast to void. */ - if (TREE_TYPE (exp) == void_type_node) - return 0; - /* Don't warn about conversions not explicit in the user's program. */ - if (TREE_NO_UNUSED_WARNING (exp)) - return 0; - /* Assignment to a cast usually results in a cast of a modify. - Don't complain about that. There can be an arbitrary number of - casts before the modify, so we must loop until we find the first - non-cast expression and then test to see if that is a modify. */ - { - tree tem = TREE_OPERAND (exp, 0); - - while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR) - tem = TREE_OPERAND (tem, 0); - - if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR - || TREE_CODE (tem) == CALL_EXPR) - return 0; - } - goto warn; - - case INDIRECT_REF: - /* Don't warn about automatic dereferencing of references, since - the user cannot control it. */ - if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) - return warn_if_unused_value (TREE_OPERAND (exp, 0)); - /* ... fall through ... */ - - default: - /* Referencing a volatile value is a side effect, so don't warn. */ - if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' - || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r') - && TREE_THIS_VOLATILE (exp)) - return 0; - warn: - warning_with_file_and_line (emit_filename, emit_lineno, - "value computed is not used"); - return 1; - } -} - -/* Clear out the memory of the last expression evaluated. */ - -void -clear_last_expr () -{ - last_expr_type = 0; -} - -/* Begin a statement which will return a value. - Return the RTL_EXPR for this statement expr. - The caller must save that value and pass it to expand_end_stmt_expr. */ - -tree -expand_start_stmt_expr () -{ - int momentary; - tree t; - - /* Make the RTL_EXPR node temporary, not momentary, - so that rtl_expr_chain doesn't become garbage. */ - momentary = suspend_momentary (); - t = make_node (RTL_EXPR); - resume_momentary (momentary); - do_pending_stack_adjust (); - start_sequence_for_rtl_expr (t); - NO_DEFER_POP; - expr_stmts_for_value++; - return t; -} - -/* Restore the previous state at the end of a statement that returns a value. - Returns a tree node representing the statement's value and the - insns to compute the value. - - The nodes of that expression have been freed by now, so we cannot use them. - But we don't want to do that anyway; the expression has already been - evaluated and now we just want to use the value. So generate a RTL_EXPR - with the proper type and RTL value. - - If the last substatement was not an expression, - return something with type `void'. */ - -tree -expand_end_stmt_expr (t) - tree t; -{ - OK_DEFER_POP; - - if (last_expr_type == 0) - { - last_expr_type = void_type_node; - last_expr_value = const0_rtx; - } - else if (last_expr_value == 0) - /* There are some cases where this can happen, such as when the - statement is void type. */ - last_expr_value = const0_rtx; - else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value)) - /* Remove any possible QUEUED. */ - last_expr_value = protect_from_queue (last_expr_value, 0); - - emit_queue (); - - TREE_TYPE (t) = last_expr_type; - RTL_EXPR_RTL (t) = last_expr_value; - RTL_EXPR_SEQUENCE (t) = get_insns (); - - rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain); - - end_sequence (); - - /* Don't consider deleting this expr or containing exprs at tree level. */ - TREE_SIDE_EFFECTS (t) = 1; - /* Propagate volatility of the actual RTL expr. */ - TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value); - - last_expr_type = 0; - expr_stmts_for_value--; - - return t; -} - -/* Generate RTL for the start of an if-then. COND is the expression - whose truth should be tested. - - If EXITFLAG is nonzero, this conditional is visible to - `exit_something'. */ - -void -expand_start_cond (cond, exitflag) - tree cond; - int exitflag; -{ - struct nesting *thiscond = ALLOC_NESTING (); - - /* Make an entry on cond_stack for the cond we are entering. */ - - thiscond->next = cond_stack; - thiscond->all = nesting_stack; - thiscond->depth = ++nesting_depth; - thiscond->data.cond.next_label = gen_label_rtx (); - /* Before we encounter an `else', we don't need a separate exit label - unless there are supposed to be exit statements - to exit this conditional. */ - thiscond->exit_label = exitflag ? gen_label_rtx () : 0; - thiscond->data.cond.endif_label = thiscond->exit_label; - cond_stack = thiscond; - nesting_stack = thiscond; - - do_jump (cond, thiscond->data.cond.next_label, NULL_RTX); -} - -/* Generate RTL between then-clause and the elseif-clause - of an if-then-elseif-.... */ - -void -expand_start_elseif (cond) - tree cond; -{ - if (cond_stack->data.cond.endif_label == 0) - cond_stack->data.cond.endif_label = gen_label_rtx (); - emit_jump (cond_stack->data.cond.endif_label); - emit_label (cond_stack->data.cond.next_label); - cond_stack->data.cond.next_label = gen_label_rtx (); - do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); -} - -/* Generate RTL between the then-clause and the else-clause - of an if-then-else. */ - -void -expand_start_else () -{ - if (cond_stack->data.cond.endif_label == 0) - cond_stack->data.cond.endif_label = gen_label_rtx (); - - emit_jump (cond_stack->data.cond.endif_label); - emit_label (cond_stack->data.cond.next_label); - cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */ -} - -/* After calling expand_start_else, turn this "else" into an "else if" - by providing another condition. */ - -void -expand_elseif (cond) - tree cond; -{ - cond_stack->data.cond.next_label = gen_label_rtx (); - do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); -} - -/* Generate RTL for the end of an if-then. - Pop the record for it off of cond_stack. */ - -void -expand_end_cond () -{ - struct nesting *thiscond = cond_stack; - - do_pending_stack_adjust (); - if (thiscond->data.cond.next_label) - emit_label (thiscond->data.cond.next_label); - if (thiscond->data.cond.endif_label) - emit_label (thiscond->data.cond.endif_label); - - POPSTACK (cond_stack); - last_expr_type = 0; -} - - - -/* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this - loop should be exited by `exit_something'. This is a loop for which - `expand_continue' will jump to the top of the loop. - - Make an entry on loop_stack to record the labels associated with - this loop. */ - -struct nesting * -expand_start_loop (exit_flag) - int exit_flag; -{ - register struct nesting *thisloop = ALLOC_NESTING (); - - /* Make an entry on loop_stack for the loop we are entering. */ - - thisloop->next = loop_stack; - thisloop->all = nesting_stack; - thisloop->depth = ++nesting_depth; - thisloop->data.loop.start_label = gen_label_rtx (); - thisloop->data.loop.end_label = gen_label_rtx (); - thisloop->data.loop.alt_end_label = 0; - thisloop->data.loop.continue_label = thisloop->data.loop.start_label; - thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0; - loop_stack = thisloop; - nesting_stack = thisloop; - - do_pending_stack_adjust (); - emit_queue (); - emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); - emit_label (thisloop->data.loop.start_label); - - return thisloop; -} - -/* Like expand_start_loop but for a loop where the continuation point - (for expand_continue_loop) will be specified explicitly. */ - -struct nesting * -expand_start_loop_continue_elsewhere (exit_flag) - int exit_flag; -{ - struct nesting *thisloop = expand_start_loop (exit_flag); - loop_stack->data.loop.continue_label = gen_label_rtx (); - return thisloop; -} - -/* Specify the continuation point for a loop started with - expand_start_loop_continue_elsewhere. - Use this at the point in the code to which a continue statement - should jump. */ - -void -expand_loop_continue_here () -{ - do_pending_stack_adjust (); - emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); - emit_label (loop_stack->data.loop.continue_label); -} - -/* Finish a loop. Generate a jump back to the top and the loop-exit label. - Pop the block off of loop_stack. */ - -void -expand_end_loop () -{ - rtx start_label = loop_stack->data.loop.start_label; - rtx insn = get_last_insn (); - int needs_end_jump = 1; - - /* Mark the continue-point at the top of the loop if none elsewhere. */ - if (start_label == loop_stack->data.loop.continue_label) - emit_note_before (NOTE_INSN_LOOP_CONT, start_label); - - do_pending_stack_adjust (); - - /* If optimizing, perhaps reorder the loop. - First, try to use a condjump near the end. - expand_exit_loop_if_false ends loops with unconditional jumps, - like this: - - if (test) goto label; - optional: cleanup - goto loop_stack->data.loop.end_label - barrier - label: - - If we find such a pattern, we can end the loop earlier. */ - - if (optimize - && GET_CODE (insn) == CODE_LABEL - && LABEL_NAME (insn) == NULL - && GET_CODE (PREV_INSN (insn)) == BARRIER) - { - rtx label = insn; - rtx jump = PREV_INSN (PREV_INSN (label)); - - if (GET_CODE (jump) == JUMP_INSN - && GET_CODE (PATTERN (jump)) == SET - && SET_DEST (PATTERN (jump)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF - && (XEXP (SET_SRC (PATTERN (jump)), 0) - == loop_stack->data.loop.end_label)) - { - rtx prev; - - /* The test might be complex and reference LABEL multiple times, - like the loop in loop_iterations to set vtop. To handle this, - we move LABEL. */ - insn = PREV_INSN (label); - reorder_insns (label, label, start_label); - - for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev)) - { - /* We ignore line number notes, but if we see any other note, - in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*, - NOTE_INSN_LOOP_*, we disable this optimization. */ - if (GET_CODE (prev) == NOTE) - { - if (NOTE_LINE_NUMBER (prev) < 0) - break; - continue; - } - if (GET_CODE (prev) == CODE_LABEL) - break; - if (GET_CODE (prev) == JUMP_INSN) - { - if (GET_CODE (PATTERN (prev)) == SET - && SET_DEST (PATTERN (prev)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE - && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1)) - == LABEL_REF) - && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label) - { - XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) - = start_label; - emit_note_after (NOTE_INSN_LOOP_END, prev); - needs_end_jump = 0; - } - break; - } - } - } - } - - /* If the loop starts with a loop exit, roll that to the end where - it will optimize together with the jump back. - - We look for the conditional branch to the exit, except that once - we find such a branch, we don't look past 30 instructions. - - In more detail, if the loop presently looks like this (in pseudo-C): - - start_label: - if (test) goto end_label; - body; - goto start_label; - end_label: - - transform it to look like: - - goto start_label; - newstart_label: - body; - start_label: - if (test) goto end_label; - goto newstart_label; - end_label: - - Here, the `test' may actually consist of some reasonably complex - code, terminating in a test. */ - - if (optimize - && needs_end_jump - && - ! (GET_CODE (insn) == JUMP_INSN - && GET_CODE (PATTERN (insn)) == SET - && SET_DEST (PATTERN (insn)) == pc_rtx - && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)) - { - int eh_regions = 0; - int num_insns = 0; - rtx last_test_insn = NULL_RTX; - - /* Scan insns from the top of the loop looking for a qualified - conditional exit. */ - for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn; - insn = NEXT_INSN (insn)) - { - if (GET_CODE (insn) == NOTE) - { - if (optimize < 2 - && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG - || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) - /* The code that actually moves the exit test will - carefully leave BLOCK notes in their original - location. That means, however, that we can't debug - the exit test itself. So, we refuse to move code - containing BLOCK notes at low optimization levels. */ - break; - - if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) - ++eh_regions; - else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) - { - --eh_regions; - if (eh_regions < 0) - /* We've come to the end of an EH region, but - never saw the beginning of that region. That - means that an EH region begins before the top - of the loop, and ends in the middle of it. The - existence of such a situation violates a basic - assumption in this code, since that would imply - that even when EH_REGIONS is zero, we might - move code out of an exception region. */ - abort (); - } - - /* We must not walk into a nested loop. */ - if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) - break; - - /* We already know this INSN is a NOTE, so there's no - point in looking at it to see if it's a JUMP. */ - continue; - } - - if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN) - num_insns++; - - if (last_test_insn && num_insns > 30) - break; - - if (eh_regions > 0) - /* We don't want to move a partial EH region. Consider: - - while ( ( { try { - if (cond ()) 0; - else { - bar(); - 1; - } - } catch (...) { - 1; - } )) { - body; - } - - This isn't legal C++, but here's what it's supposed to - mean: if cond() is true, stop looping. Otherwise, - call bar, and keep looping. In addition, if cond - throws an exception, catch it and keep looping. Such - constructs are certainy legal in LISP. - - We should not move the `if (cond()) 0' test since then - the EH-region for the try-block would be broken up. - (In this case we would the EH_BEG note for the `try' - and `if cond()' but not the call to bar() or the - EH_END note.) - - So we don't look for tests within an EH region. */ - continue; - - if (GET_CODE (insn) == JUMP_INSN - && GET_CODE (PATTERN (insn)) == SET - && SET_DEST (PATTERN (insn)) == pc_rtx) - { - /* This is indeed a jump. */ - rtx dest1 = NULL_RTX; - rtx dest2 = NULL_RTX; - rtx potential_last_test; - if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE) - { - /* A conditional jump. */ - dest1 = XEXP (SET_SRC (PATTERN (insn)), 1); - dest2 = XEXP (SET_SRC (PATTERN (insn)), 2); - potential_last_test = insn; - } - else - { - /* An unconditional jump. */ - dest1 = SET_SRC (PATTERN (insn)); - /* Include the BARRIER after the JUMP. */ - potential_last_test = NEXT_INSN (insn); - } - - do { - if (dest1 && GET_CODE (dest1) == LABEL_REF - && ((XEXP (dest1, 0) - == loop_stack->data.loop.alt_end_label) - || (XEXP (dest1, 0) - == loop_stack->data.loop.end_label))) - { - last_test_insn = potential_last_test; - break; - } - - /* If this was a conditional jump, there may be - another label at which we should look. */ - dest1 = dest2; - dest2 = NULL_RTX; - } while (dest1); - } - } - - if (last_test_insn != 0 && last_test_insn != get_last_insn ()) - { - /* We found one. Move everything from there up - to the end of the loop, and add a jump into the loop - to jump to there. */ - register rtx newstart_label = gen_label_rtx (); - register rtx start_move = start_label; - rtx next_insn; - - /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note, - then we want to move this note also. */ - if (GET_CODE (PREV_INSN (start_move)) == NOTE - && (NOTE_LINE_NUMBER (PREV_INSN (start_move)) - == NOTE_INSN_LOOP_CONT)) - start_move = PREV_INSN (start_move); - - emit_label_after (newstart_label, PREV_INSN (start_move)); - - /* Actually move the insns. Start at the beginning, and - keep copying insns until we've copied the - last_test_insn. */ - for (insn = start_move; insn; insn = next_insn) - { - /* Figure out which insn comes after this one. We have - to do this before we move INSN. */ - if (insn == last_test_insn) - /* We've moved all the insns. */ - next_insn = NULL_RTX; - else - next_insn = NEXT_INSN (insn); - - if (GET_CODE (insn) == NOTE - && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG - || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) - /* We don't want to move NOTE_INSN_BLOCK_BEGs or - NOTE_INSN_BLOCK_ENDs because the correct generation - of debugging information depends on these appearing - in the same order in the RTL and in the tree - structure, where they are represented as BLOCKs. - So, we don't move block notes. Of course, moving - the code inside the block is likely to make it - impossible to debug the instructions in the exit - test, but such is the price of optimization. */ - continue; - - /* Move the INSN. */ - reorder_insns (insn, insn, get_last_insn ()); - } - - emit_jump_insn_after (gen_jump (start_label), - PREV_INSN (newstart_label)); - emit_barrier_after (PREV_INSN (newstart_label)); - start_label = newstart_label; - } - } - - if (needs_end_jump) - { - emit_jump (start_label); - emit_note (NULL_PTR, NOTE_INSN_LOOP_END); - } - emit_label (loop_stack->data.loop.end_label); - - POPSTACK (loop_stack); - - last_expr_type = 0; -} - -/* Generate a jump to the current loop's continue-point. - This is usually the top of the loop, but may be specified - explicitly elsewhere. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_continue_loop (whichloop) - struct nesting *whichloop; -{ - last_expr_type = 0; - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label, - NULL_RTX); - return 1; -} - -/* Generate a jump to exit the current loop. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_loop (whichloop) - struct nesting *whichloop; -{ - last_expr_type = 0; - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX); - return 1; -} - -/* Generate a conditional jump to exit the current loop if COND - evaluates to zero. If not currently inside a loop, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_loop_if_false (whichloop, cond) - struct nesting *whichloop; - tree cond; -{ - rtx label = gen_label_rtx (); - rtx last_insn; - last_expr_type = 0; - - if (whichloop == 0) - whichloop = loop_stack; - if (whichloop == 0) - return 0; - /* In order to handle fixups, we actually create a conditional jump - around a unconditional branch to exit the loop. If fixups are - necessary, they go before the unconditional branch. */ - - - do_jump (cond, NULL_RTX, label); - last_insn = get_last_insn (); - if (GET_CODE (last_insn) == CODE_LABEL) - whichloop->data.loop.alt_end_label = last_insn; - expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, - NULL_RTX); - emit_label (label); - - return 1; -} - -/* Return nonzero if the loop nest is empty. Else return zero. */ - -int -stmt_loop_nest_empty () -{ - return (loop_stack == NULL); -} - -/* Return non-zero if we should preserve sub-expressions as separate - pseudos. We never do so if we aren't optimizing. We always do so - if -fexpensive-optimizations. - - Otherwise, we only do so if we are in the "early" part of a loop. I.e., - the loop may still be a small one. */ - -int -preserve_subexpressions_p () -{ - rtx insn; - - if (flag_expensive_optimizations) - return 1; - - if (optimize == 0 || loop_stack == 0) - return 0; - - insn = get_last_insn_anywhere (); - - return (insn - && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label) - < n_non_fixed_regs * 3)); - -} - -/* Generate a jump to exit the current loop, conditional, binding contour - or case statement. Not all such constructs are visible to this function, - only those started with EXIT_FLAG nonzero. Individual languages use - the EXIT_FLAG parameter to control which kinds of constructs you can - exit this way. - - If not currently inside anything that can be exited, - return 0 and do nothing; caller will print an error message. */ - -int -expand_exit_something () -{ - struct nesting *n; - last_expr_type = 0; - for (n = nesting_stack; n; n = n->all) - if (n->exit_label != 0) - { - expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX); - return 1; - } - - return 0; -} - -/* Generate RTL to return from the current function, with no value. - (That is, we do not do anything about returning any value.) */ - -void -expand_null_return () -{ - struct nesting *block = block_stack; - rtx last_insn = 0; - - /* Does any pending block have cleanups? */ - - while (block && block->data.block.cleanups == 0) - block = block->next; - - /* If yes, use a goto to return, since that runs cleanups. */ - - expand_null_return_1 (last_insn, block != 0); -} - -/* Generate RTL to return from the current function, with value VAL. */ - -static void -expand_value_return (val) - rtx val; -{ - struct nesting *block = block_stack; - rtx last_insn = get_last_insn (); - rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); - - /* Copy the value to the return location - unless it's already there. */ - - if (return_reg != val) - { -#ifdef PROMOTE_FUNCTION_RETURN - tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); - int unsignedp = TREE_UNSIGNED (type); - enum machine_mode old_mode - = DECL_MODE (DECL_RESULT (current_function_decl)); - enum machine_mode mode - = promote_mode (type, old_mode, &unsignedp, 1); - - if (mode != old_mode) - val = convert_modes (mode, old_mode, val, unsignedp); -#endif - emit_move_insn (return_reg, val); - } - if (GET_CODE (return_reg) == REG - && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) - emit_insn (gen_rtx_USE (VOIDmode, return_reg)); - /* Handle calls that return values in multiple non-contiguous locations. - The Irix 6 ABI has examples of this. */ - else if (GET_CODE (return_reg) == PARALLEL) - { - int i; - - for (i = 0; i < XVECLEN (return_reg, 0); i++) - { - rtx x = XEXP (XVECEXP (return_reg, 0, i), 0); - - if (GET_CODE (x) == REG - && REGNO (x) < FIRST_PSEUDO_REGISTER) - emit_insn (gen_rtx_USE (VOIDmode, x)); - } - } - - /* Does any pending block have cleanups? */ - - while (block && block->data.block.cleanups == 0) - block = block->next; - - /* If yes, use a goto to return, since that runs cleanups. - Use LAST_INSN to put cleanups *before* the move insn emitted above. */ - - expand_null_return_1 (last_insn, block != 0); -} - -/* Output a return with no value. If LAST_INSN is nonzero, - pretend that the return takes place after LAST_INSN. - If USE_GOTO is nonzero then don't use a return instruction; - go to the return label instead. This causes any cleanups - of pending blocks to be executed normally. */ - -static void -expand_null_return_1 (last_insn, use_goto) - rtx last_insn; - int use_goto; -{ - rtx end_label = cleanup_label ? cleanup_label : return_label; - - clear_pending_stack_adjust (); - do_pending_stack_adjust (); - last_expr_type = 0; - - /* PCC-struct return always uses an epilogue. */ - if (current_function_returns_pcc_struct || use_goto) - { - if (end_label == 0) - end_label = return_label = gen_label_rtx (); - expand_goto_internal (NULL_TREE, end_label, last_insn); - return; - } - - /* Otherwise output a simple return-insn if one is available, - unless it won't do the job. */ -#ifdef HAVE_return - if (HAVE_return && use_goto == 0 && cleanup_label == 0) - { - emit_jump_insn (gen_return ()); - emit_barrier (); - return; - } -#endif - - /* Otherwise jump to the epilogue. */ - expand_goto_internal (NULL_TREE, end_label, last_insn); -} - -/* Generate RTL to evaluate the expression RETVAL and return it - from the current function. */ - -void -expand_return (retval) - tree retval; -{ - /* If there are any cleanups to be performed, then they will - be inserted following LAST_INSN. It is desirable - that the last_insn, for such purposes, should be the - last insn before computing the return value. Otherwise, cleanups - which call functions can clobber the return value. */ - /* ??? rms: I think that is erroneous, because in C++ it would - run destructors on variables that might be used in the subsequent - computation of the return value. */ - rtx last_insn = 0; - register rtx val = 0; - register rtx op0; - tree retval_rhs; - int cleanups; - - /* If function wants no value, give it none. */ - if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) - { - expand_expr (retval, NULL_RTX, VOIDmode, 0); - emit_queue (); - expand_null_return (); - return; - } - - /* Are any cleanups needed? E.g. C++ destructors to be run? */ - /* This is not sufficient. We also need to watch for cleanups of the - expression we are about to expand. Unfortunately, we cannot know - if it has cleanups until we expand it, and we want to change how we - expand it depending upon if we need cleanups. We can't win. */ -#if 0 - cleanups = any_pending_cleanups (1); -#else - cleanups = 1; -#endif - - if (TREE_CODE (retval) == RESULT_DECL) - retval_rhs = retval; - else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR) - && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) - retval_rhs = TREE_OPERAND (retval, 1); - else if (TREE_TYPE (retval) == void_type_node) - /* Recognize tail-recursive call to void function. */ - retval_rhs = retval; - else - retval_rhs = NULL_TREE; - - /* Only use `last_insn' if there are cleanups which must be run. */ - if (cleanups || cleanup_label != 0) - last_insn = get_last_insn (); - - /* Distribute return down conditional expr if either of the sides - may involve tail recursion (see test below). This enhances the number - of tail recursions we see. Don't do this always since it can produce - sub-optimal code in some cases and we distribute assignments into - conditional expressions when it would help. */ - - if (optimize && retval_rhs != 0 - && frame_offset == 0 - && TREE_CODE (retval_rhs) == COND_EXPR - && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR - || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR)) - { - rtx label = gen_label_rtx (); - tree expr; - - do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX); - start_cleanup_deferral (); - expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), - DECL_RESULT (current_function_decl), - TREE_OPERAND (retval_rhs, 1)); - TREE_SIDE_EFFECTS (expr) = 1; - expand_return (expr); - emit_label (label); - - expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), - DECL_RESULT (current_function_decl), - TREE_OPERAND (retval_rhs, 2)); - TREE_SIDE_EFFECTS (expr) = 1; - expand_return (expr); - end_cleanup_deferral (); - return; - } - - /* Attempt to optimize the call if it is tail recursive. */ - if (optimize_tail_recursion (retval_rhs, last_insn)) - return; - -#ifdef HAVE_return - /* This optimization is safe if there are local cleanups - because expand_null_return takes care of them. - ??? I think it should also be safe when there is a cleanup label, - because expand_null_return takes care of them, too. - Any reason why not? */ - if (HAVE_return && cleanup_label == 0 - && ! current_function_returns_pcc_struct - && BRANCH_COST <= 1) - { - /* If this is return x == y; then generate - if (x == y) return 1; else return 0; - if we can do it with explicit return insns and branches are cheap, - but not if we have the corresponding scc insn. */ - int has_scc = 0; - if (retval_rhs) - switch (TREE_CODE (retval_rhs)) - { - case EQ_EXPR: -#ifdef HAVE_seq - has_scc = HAVE_seq; -#endif - case NE_EXPR: -#ifdef HAVE_sne - has_scc = HAVE_sne; -#endif - case GT_EXPR: -#ifdef HAVE_sgt - has_scc = HAVE_sgt; -#endif - case GE_EXPR: -#ifdef HAVE_sge - has_scc = HAVE_sge; -#endif - case LT_EXPR: -#ifdef HAVE_slt - has_scc = HAVE_slt; -#endif - case LE_EXPR: -#ifdef HAVE_sle - has_scc = HAVE_sle; -#endif - case TRUTH_ANDIF_EXPR: - case TRUTH_ORIF_EXPR: - case TRUTH_AND_EXPR: - case TRUTH_OR_EXPR: - case TRUTH_NOT_EXPR: - case TRUTH_XOR_EXPR: - if (! has_scc) - { - op0 = gen_label_rtx (); - jumpifnot (retval_rhs, op0); - expand_value_return (const1_rtx); - emit_label (op0); - expand_value_return (const0_rtx); - return; - } - break; - - default: - break; - } - } -#endif /* HAVE_return */ - - /* If the result is an aggregate that is being returned in one (or more) - registers, load the registers here. The compiler currently can't handle - copying a BLKmode value into registers. We could put this code in a - more general area (for use by everyone instead of just function - call/return), but until this feature is generally usable it is kept here - (and in expand_call). The value must go into a pseudo in case there - are cleanups that will clobber the real return register. */ - - if (retval_rhs != 0 - && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode - && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) - { - int i, bitpos, xbitpos; - int big_endian_correction = 0; - int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); - int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; - int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), - (unsigned int)BITS_PER_WORD); - rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs); - rtx result_reg, src = NULL_RTX, dst = NULL_RTX; - rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); - enum machine_mode tmpmode, result_reg_mode; - - /* Structures whose size is not a multiple of a word are aligned - to the least significant byte (to the right). On a BYTES_BIG_ENDIAN - machine, this means we must skip the empty high order bytes when - calculating the bit offset. */ - if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD) - big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) - * BITS_PER_UNIT)); - - /* Copy the structure BITSIZE bits at a time. */ - for (bitpos = 0, xbitpos = big_endian_correction; - bitpos < bytes * BITS_PER_UNIT; - bitpos += bitsize, xbitpos += bitsize) - { - /* We need a new destination pseudo each time xbitpos is - on a word boundary and when xbitpos == big_endian_correction - (the first time through). */ - if (xbitpos % BITS_PER_WORD == 0 - || xbitpos == big_endian_correction) - { - /* Generate an appropriate register. */ - dst = gen_reg_rtx (word_mode); - result_pseudos[xbitpos / BITS_PER_WORD] = dst; - - /* Clobber the destination before we move anything into it. */ - emit_insn (gen_rtx_CLOBBER (VOIDmode, dst)); - } - - /* We need a new source operand each time bitpos is on a word - boundary. */ - if (bitpos % BITS_PER_WORD == 0) - src = operand_subword_force (result_val, - bitpos / BITS_PER_WORD, - BLKmode); - - /* Use bitpos for the source extraction (left justified) and - xbitpos for the destination store (right justified). */ - store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, - extract_bit_field (src, bitsize, - bitpos % BITS_PER_WORD, 1, - NULL_RTX, word_mode, - word_mode, - bitsize / BITS_PER_UNIT, - BITS_PER_WORD), - bitsize / BITS_PER_UNIT, BITS_PER_WORD); - } - - /* Find the smallest integer mode large enough to hold the - entire structure and use that mode instead of BLKmode - on the USE insn for the return register. */ - bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); - for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); - tmpmode != MAX_MACHINE_MODE; - tmpmode = GET_MODE_WIDER_MODE (tmpmode)) - { - /* Have we found a large enough mode? */ - if (GET_MODE_SIZE (tmpmode) >= bytes) - break; - } - - /* No suitable mode found. */ - if (tmpmode == MAX_MACHINE_MODE) - abort (); - - PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode); - - if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) - result_reg_mode = word_mode; - else - result_reg_mode = tmpmode; - result_reg = gen_reg_rtx (result_reg_mode); - - emit_queue (); - for (i = 0; i < n_regs; i++) - emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), - result_pseudos[i]); - - if (tmpmode != result_reg_mode) - result_reg = gen_lowpart (tmpmode, result_reg); - - expand_value_return (result_reg); - } - else if (cleanups - && retval_rhs != 0 - && TREE_TYPE (retval_rhs) != void_type_node - && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) - { - /* Calculate the return value into a pseudo reg. */ - val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl))); - val = expand_expr (retval_rhs, val, GET_MODE (val), 0); - val = force_not_mem (val); - emit_queue (); - /* Return the calculated value, doing cleanups first. */ - expand_value_return (val); - } - else - { - /* No cleanups or no hard reg used; - calculate value into hard return reg. */ - expand_expr (retval, const0_rtx, VOIDmode, 0); - emit_queue (); - expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl))); - } -} - -/* Return 1 if the end of the generated RTX is not a barrier. - This means code already compiled can drop through. */ - -int -drop_through_at_end_p () -{ - rtx insn = get_last_insn (); - while (insn && GET_CODE (insn) == NOTE) - insn = PREV_INSN (insn); - return insn && GET_CODE (insn) != BARRIER; -} - -/* Test CALL_EXPR to determine if it is a potential tail recursion call - and emit code to optimize the tail recursion. LAST_INSN indicates where - to place the jump to the tail recursion label. Return TRUE if the - call was optimized into a goto. - - This is only used by expand_return, but expand_call is expected to - use it soon. */ - -int -optimize_tail_recursion (call_expr, last_insn) - tree call_expr; - rtx last_insn; -{ - /* For tail-recursive call to current function, - just jump back to the beginning. - It's unsafe if any auto variable in this function - has its address taken; for simplicity, - require stack frame to be empty. */ - if (optimize && call_expr != 0 - && frame_offset == 0 - && TREE_CODE (call_expr) == CALL_EXPR - && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR - && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl - /* Finish checking validity, and if valid emit code - to set the argument variables for the new call. */ - && tail_recursion_args (TREE_OPERAND (call_expr, 1), - DECL_ARGUMENTS (current_function_decl))) - { - if (tail_recursion_label == 0) - { - tail_recursion_label = gen_label_rtx (); - emit_label_after (tail_recursion_label, - tail_recursion_reentry); - } - emit_queue (); - expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn); - emit_barrier (); - return 1; - } - - return 0; -} - -/* Emit code to alter this function's formal parms for a tail-recursive call. - ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs). - FORMALS is the chain of decls of formals. - Return 1 if this can be done; - otherwise return 0 and do not emit any code. */ - -static int -tail_recursion_args (actuals, formals) - tree actuals, formals; -{ - register tree a = actuals, f = formals; - register int i; - register rtx *argvec; - - /* Check that number and types of actuals are compatible - with the formals. This is not always true in valid C code. - Also check that no formal needs to be addressable - and that all formals are scalars. */ - - /* Also count the args. */ - - for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++) - { - if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a))) - != TYPE_MAIN_VARIANT (TREE_TYPE (f))) - return 0; - if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode) - return 0; - } - if (a != 0 || f != 0) - return 0; - - /* Compute all the actuals. */ - - argvec = (rtx *) alloca (i * sizeof (rtx)); - - for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) - argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0); - - /* Find which actual values refer to current values of previous formals. - Copy each of them now, before any formal is changed. */ - - for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) - { - int copy = 0; - register int j; - for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++) - if (reg_mentioned_p (DECL_RTL (f), argvec[i])) - { copy = 1; break; } - if (copy) - argvec[i] = copy_to_reg (argvec[i]); - } - - /* Store the values of the actuals into the formals. */ - - for (f = formals, a = actuals, i = 0; f; - f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++) - { - if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i])) - emit_move_insn (DECL_RTL (f), argvec[i]); - else - convert_move (DECL_RTL (f), argvec[i], - TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)))); - } - - free_temp_slots (); - return 1; -} - -/* Generate the RTL code for entering a binding contour. - The variables are declared one by one, by calls to `expand_decl'. - - EXIT_FLAG is nonzero if this construct should be visible to - `exit_something'. */ - -void -expand_start_bindings (exit_flag) - int exit_flag; -{ - struct nesting *thisblock = ALLOC_NESTING (); - rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); - - /* Make an entry on block_stack for the block we are entering. */ - - thisblock->next = block_stack; - thisblock->all = nesting_stack; - thisblock->depth = ++nesting_depth; - thisblock->data.block.stack_level = 0; - thisblock->data.block.cleanups = 0; - thisblock->data.block.function_call_count = 0; - thisblock->data.block.exception_region = 0; - thisblock->data.block.target_temp_slot_level = target_temp_slot_level; - - thisblock->data.block.conditional_code = 0; - thisblock->data.block.last_unconditional_cleanup = note; - thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups; - - if (block_stack - && !(block_stack->data.block.cleanups == NULL_TREE - && block_stack->data.block.outer_cleanups == NULL_TREE)) - thisblock->data.block.outer_cleanups - = tree_cons (NULL_TREE, block_stack->data.block.cleanups, - block_stack->data.block.outer_cleanups); - else - thisblock->data.block.outer_cleanups = 0; - thisblock->data.block.label_chain = 0; - thisblock->data.block.innermost_stack_block = stack_block_stack; - thisblock->data.block.first_insn = note; - thisblock->data.block.block_start_count = ++block_start_count; - thisblock->exit_label = exit_flag ? gen_label_rtx () : 0; - block_stack = thisblock; - nesting_stack = thisblock; - - /* Make a new level for allocating stack slots. */ - push_temp_slots (); -} - -/* Specify the scope of temporaries created by TARGET_EXPRs. Similar - to CLEANUP_POINT_EXPR, but handles cases when a series of calls to - expand_expr are made. After we end the region, we know that all - space for all temporaries that were created by TARGET_EXPRs will be - destroyed and their space freed for reuse. */ - -void -expand_start_target_temps () -{ - /* This is so that even if the result is preserved, the space - allocated will be freed, as we know that it is no longer in use. */ - push_temp_slots (); - - /* Start a new binding layer that will keep track of all cleanup - actions to be performed. */ - expand_start_bindings (0); - - target_temp_slot_level = temp_slot_level; -} - -void -expand_end_target_temps () -{ - expand_end_bindings (NULL_TREE, 0, 0); - - /* This is so that even if the result is preserved, the space - allocated will be freed, as we know that it is no longer in use. */ - pop_temp_slots (); -} - -/* Mark top block of block_stack as an implicit binding for an - exception region. This is used to prevent infinite recursion when - ending a binding with expand_end_bindings. It is only ever called - by expand_eh_region_start, as that it the only way to create a - block stack for a exception region. */ - -void -mark_block_as_eh_region () -{ - block_stack->data.block.exception_region = 1; - if (block_stack->next - && block_stack->next->data.block.conditional_code) - { - block_stack->data.block.conditional_code - = block_stack->next->data.block.conditional_code; - block_stack->data.block.last_unconditional_cleanup - = block_stack->next->data.block.last_unconditional_cleanup; - block_stack->data.block.cleanup_ptr - = block_stack->next->data.block.cleanup_ptr; - } -} - -/* True if we are currently emitting insns in an area of output code - that is controlled by a conditional expression. This is used by - the cleanup handling code to generate conditional cleanup actions. */ - -int -conditional_context () -{ - return block_stack && block_stack->data.block.conditional_code; -} - -/* Mark top block of block_stack as not for an implicit binding for an - exception region. This is only ever done by expand_eh_region_end - to let expand_end_bindings know that it is being called explicitly - to end the binding layer for just the binding layer associated with - the exception region, otherwise expand_end_bindings would try and - end all implicit binding layers for exceptions regions, and then - one normal binding layer. */ - -void -mark_block_as_not_eh_region () -{ - block_stack->data.block.exception_region = 0; -} - -/* True if the top block of block_stack was marked as for an exception - region by mark_block_as_eh_region. */ - -int -is_eh_region () -{ - return block_stack && block_stack->data.block.exception_region; -} - -/* Given a pointer to a BLOCK node, save a pointer to the most recently - generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given - BLOCK node. */ - -void -remember_end_note (block) - register tree block; -{ - BLOCK_END_NOTE (block) = last_block_end_note; - last_block_end_note = NULL_RTX; -} - -/* Emit a handler label for a nonlocal goto handler. - Also emit code to store the handler label in SLOT before BEFORE_INSN. */ - -static rtx -expand_nl_handler_label (slot, before_insn) - rtx slot, before_insn; -{ - rtx insns; - rtx handler_label = gen_label_rtx (); - - /* Don't let jump_optimize delete the handler. */ - LABEL_PRESERVE_P (handler_label) = 1; - - start_sequence (); - emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label)); - insns = get_insns (); - end_sequence (); - emit_insns_before (insns, before_insn); - - emit_label (handler_label); - - return handler_label; -} - -/* Emit code to restore vital registers at the beginning of a nonlocal goto - handler. */ -static void -expand_nl_goto_receiver () -{ -#ifdef HAVE_nonlocal_goto - if (! HAVE_nonlocal_goto) -#endif - /* First adjust our frame pointer to its actual value. It was - previously set to the start of the virtual area corresponding to - the stacked variables when we branched here and now needs to be - adjusted to the actual hardware fp value. - - Assignments are to virtual registers are converted by - instantiate_virtual_regs into the corresponding assignment - to the underlying register (fp in this case) that makes - the original assignment true. - So the following insn will actually be - decrementing fp by STARTING_FRAME_OFFSET. */ - emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); - -#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM - if (fixed_regs[ARG_POINTER_REGNUM]) - { -#ifdef ELIMINABLE_REGS - /* If the argument pointer can be eliminated in favor of the - frame pointer, we don't need to restore it. We assume here - that if such an elimination is present, it can always be used. - This is the case on all known machines; if we don't make this - assumption, we do unnecessary saving on many machines. */ - static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS; - size_t i; - - for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++) - if (elim_regs[i].from == ARG_POINTER_REGNUM - && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) - break; - - if (i == sizeof elim_regs / sizeof elim_regs [0]) -#endif - { - /* Now restore our arg pointer from the address at which it - was saved in our stack frame. - If there hasn't be space allocated for it yet, make - some now. */ - if (arg_pointer_save_area == 0) - arg_pointer_save_area - = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); - emit_move_insn (virtual_incoming_args_rtx, - /* We need a pseudo here, or else - instantiate_virtual_regs_1 complains. */ - copy_to_reg (arg_pointer_save_area)); - } - } -#endif - -#ifdef HAVE_nonlocal_goto_receiver - if (HAVE_nonlocal_goto_receiver) - emit_insn (gen_nonlocal_goto_receiver ()); -#endif -} - -/* Make handlers for nonlocal gotos taking place in the function calls in - block THISBLOCK. */ - -static void -expand_nl_goto_receivers (thisblock) - struct nesting *thisblock; -{ - tree link; - rtx afterward = gen_label_rtx (); - rtx insns, slot; - rtx label_list; - int any_invalid; - - /* Record the handler address in the stack slot for that purpose, - during this block, saving and restoring the outer value. */ - if (thisblock->next != 0) - for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1)) - { - rtx save_receiver = gen_reg_rtx (Pmode); - emit_move_insn (XEXP (slot, 0), save_receiver); - - start_sequence (); - emit_move_insn (save_receiver, XEXP (slot, 0)); - insns = get_insns (); - end_sequence (); - emit_insns_before (insns, thisblock->data.block.first_insn); - } - - /* Jump around the handlers; they run only when specially invoked. */ - emit_jump (afterward); - - /* Make a separate handler for each label. */ - link = nonlocal_labels; - slot = nonlocal_goto_handler_slots; - label_list = NULL_RTX; - for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1)) - /* Skip any labels we shouldn't be able to jump to from here, - we generate one special handler for all of them below which just calls - abort. */ - if (! DECL_TOO_LATE (TREE_VALUE (link))) - { - rtx lab; - lab = expand_nl_handler_label (XEXP (slot, 0), - thisblock->data.block.first_insn); - label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list); - - expand_nl_goto_receiver (); - - /* Jump to the "real" nonlocal label. */ - expand_goto (TREE_VALUE (link)); - } - - /* A second pass over all nonlocal labels; this time we handle those - we should not be able to jump to at this point. */ - link = nonlocal_labels; - slot = nonlocal_goto_handler_slots; - any_invalid = 0; - for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1)) - if (DECL_TOO_LATE (TREE_VALUE (link))) - { - rtx lab; - lab = expand_nl_handler_label (XEXP (slot, 0), - thisblock->data.block.first_insn); - label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list); - any_invalid = 1; - } - - if (any_invalid) - { - expand_nl_goto_receiver (); - emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0, - VOIDmode, 0); - emit_barrier (); - } - - nonlocal_goto_handler_labels = label_list; - emit_label (afterward); -} - -/* Generate RTL code to terminate a binding contour. - - VARS is the chain of VAR_DECL nodes for the variables bound in this - contour. There may actually be other nodes in this chain, but any - nodes other than VAR_DECLS are ignored. - - MARK_ENDS is nonzero if we should put a note at the beginning - and end of this binding contour. - - DONT_JUMP_IN is nonzero if it is not valid to jump into this contour. - (That is true automatically if the contour has a saved stack level.) */ - -void -expand_end_bindings (vars, mark_ends, dont_jump_in) - tree vars; - int mark_ends; - int dont_jump_in; -{ - register struct nesting *thisblock; - register tree decl; - - while (block_stack->data.block.exception_region) - { - /* Because we don't need or want a new temporary level and - because we didn't create one in expand_eh_region_start, - create a fake one now to avoid removing one in - expand_end_bindings. */ - push_temp_slots (); - - block_stack->data.block.exception_region = 0; - - expand_end_bindings (NULL_TREE, 0, 0); - } - - /* Since expand_eh_region_start does an expand_start_bindings, we - have to first end all the bindings that were created by - expand_eh_region_start. */ - - thisblock = block_stack; - - if (warn_unused) - for (decl = vars; decl; decl = TREE_CHAIN (decl)) - if (TREE_CODE (decl) == VAR_DECL - && ! TREE_USED (decl) - && ! DECL_IN_SYSTEM_HEADER (decl) - && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl)) - warning_with_decl (decl, "unused variable `%s'"); - - if (thisblock->exit_label) - { - do_pending_stack_adjust (); - emit_label (thisblock->exit_label); - } - - /* If necessary, make handlers for nonlocal gotos taking - place in the function calls in this block. */ - if (function_call_count != thisblock->data.block.function_call_count - && nonlocal_labels - /* Make handler for outermost block - if there were any nonlocal gotos to this function. */ - && (thisblock->next == 0 ? current_function_has_nonlocal_label - /* Make handler for inner block if it has something - special to do when you jump out of it. */ - : (thisblock->data.block.cleanups != 0 - || thisblock->data.block.stack_level != 0))) - expand_nl_goto_receivers (thisblock); - - /* Don't allow jumping into a block that has a stack level. - Cleanups are allowed, though. */ - if (dont_jump_in - || thisblock->data.block.stack_level != 0) - { - struct label_chain *chain; - - /* Any labels in this block are no longer valid to go to. - Mark them to cause an error message. */ - for (chain = thisblock->data.block.label_chain; chain; chain = chain->next) - { - DECL_TOO_LATE (chain->label) = 1; - /* If any goto without a fixup came to this label, - that must be an error, because gotos without fixups - come from outside all saved stack-levels. */ - if (TREE_ADDRESSABLE (chain->label)) - error_with_decl (chain->label, - "label `%s' used before containing binding contour"); - } - } - - /* Restore stack level in effect before the block - (only if variable-size objects allocated). */ - /* Perform any cleanups associated with the block. */ - - if (thisblock->data.block.stack_level != 0 - || thisblock->data.block.cleanups != 0) - { - /* Only clean up here if this point can actually be reached. */ - int reachable = GET_CODE (get_last_insn ()) != BARRIER; - - /* Don't let cleanups affect ({...}) constructs. */ - int old_expr_stmts_for_value = expr_stmts_for_value; - rtx old_last_expr_value = last_expr_value; - tree old_last_expr_type = last_expr_type; - expr_stmts_for_value = 0; - - /* Do the cleanups. */ - expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable); - if (reachable) - do_pending_stack_adjust (); - - expr_stmts_for_value = old_expr_stmts_for_value; - last_expr_value = old_last_expr_value; - last_expr_type = old_last_expr_type; - - /* Restore the stack level. */ - - if (reachable && thisblock->data.block.stack_level != 0) - { - emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, - thisblock->data.block.stack_level, NULL_RTX); - if (nonlocal_goto_handler_slots != 0) - emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, - NULL_RTX); - } - - /* Any gotos out of this block must also do these things. - Also report any gotos with fixups that came to labels in this - level. */ - fixup_gotos (thisblock, - thisblock->data.block.stack_level, - thisblock->data.block.cleanups, - thisblock->data.block.first_insn, - dont_jump_in); - } - - /* Mark the beginning and end of the scope if requested. - We do this now, after running cleanups on the variables - just going out of scope, so they are in scope for their cleanups. */ - - if (mark_ends) - last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); - else - /* Get rid of the beginning-mark if we don't make an end-mark. */ - NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED; - - /* If doing stupid register allocation, make sure lives of all - register variables declared here extend thru end of scope. */ - - if (obey_regdecls) - for (decl = vars; decl; decl = TREE_CHAIN (decl)) - if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl)) - use_variable (DECL_RTL (decl)); - - /* Restore the temporary level of TARGET_EXPRs. */ - target_temp_slot_level = thisblock->data.block.target_temp_slot_level; - - /* Restore block_stack level for containing block. */ - - stack_block_stack = thisblock->data.block.innermost_stack_block; - POPSTACK (block_stack); - - /* Pop the stack slot nesting and free any slots at this level. */ - pop_temp_slots (); -} - -/* Generate RTL for the automatic variable declaration DECL. - (Other kinds of declarations are simply ignored if seen here.) */ - -void -expand_decl (decl) - register tree decl; -{ - struct nesting *thisblock = block_stack; - tree type; - - type = TREE_TYPE (decl); - - /* Only automatic variables need any expansion done. - Static and external variables, and external functions, - will be handled by `assemble_variable' (called from finish_decl). - TYPE_DECL and CONST_DECL require nothing. - PARM_DECLs are handled in `assign_parms'. */ - - if (TREE_CODE (decl) != VAR_DECL) - return; - if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) - return; - - /* Create the RTL representation for the variable. */ - - if (type == error_mark_node) - DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx); - else if (DECL_SIZE (decl) == 0) - /* Variable with incomplete type. */ - { - if (DECL_INITIAL (decl) == 0) - /* Error message was already done; now avoid a crash. */ - DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1); - else - /* An initializer is going to decide the size of this array. - Until we know the size, represent its address with a reg. */ - DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)); - MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type)); - } - else if (DECL_MODE (decl) != BLKmode - /* If -ffloat-store, don't put explicit float vars - into regs. */ - && !(flag_float_store - && TREE_CODE (type) == REAL_TYPE) - && ! TREE_THIS_VOLATILE (decl) - && ! TREE_ADDRESSABLE (decl) - && (DECL_REGISTER (decl) || ! obey_regdecls) - /* if -fcheck-memory-usage, check all variables. */ - && ! current_function_check_memory_usage) - { - /* Automatic variable that can go in a register. */ - int unsignedp = TREE_UNSIGNED (type); - enum machine_mode reg_mode - = promote_mode (type, DECL_MODE (decl), &unsignedp, 0); - - DECL_RTL (decl) = gen_reg_rtx (reg_mode); - mark_user_reg (DECL_RTL (decl)); - - if (POINTER_TYPE_P (type)) - mark_reg_pointer (DECL_RTL (decl), - (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))) - / BITS_PER_UNIT)); - } - - else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST - && ! (flag_stack_check && ! STACK_CHECK_BUILTIN - && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0 - || (TREE_INT_CST_LOW (DECL_SIZE (decl)) - > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT)))) - { - /* Variable of fixed size that goes on the stack. */ - rtx oldaddr = 0; - rtx addr; - - /* If we previously made RTL for this decl, it must be an array - whose size was determined by the initializer. - The old address was a register; set that register now - to the proper address. */ - if (DECL_RTL (decl) != 0) - { - if (GET_CODE (DECL_RTL (decl)) != MEM - || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG) - abort (); - oldaddr = XEXP (DECL_RTL (decl), 0); - } - - DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1); - MEM_SET_IN_STRUCT_P (DECL_RTL (decl), - AGGREGATE_TYPE_P (TREE_TYPE (decl))); - - /* Set alignment we actually gave this decl. */ - DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT - : GET_MODE_BITSIZE (DECL_MODE (decl))); - - if (oldaddr) - { - addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); - if (addr != oldaddr) - emit_move_insn (oldaddr, addr); - } - - /* If this is a memory ref that contains aggregate components, - mark it as such for cse and loop optimize. */ - MEM_SET_IN_STRUCT_P (DECL_RTL (decl), - AGGREGATE_TYPE_P (TREE_TYPE (decl))); -#if 0 - /* If this is in memory because of -ffloat-store, - set the volatile bit, to prevent optimizations from - undoing the effects. */ - if (flag_float_store && TREE_CODE (type) == REAL_TYPE) - MEM_VOLATILE_P (DECL_RTL (decl)) = 1; -#endif - - MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl); - } - else - /* Dynamic-size object: must push space on the stack. */ - { - rtx address, size; - - /* Record the stack pointer on entry to block, if have - not already done so. */ - if (thisblock->data.block.stack_level == 0) - { - do_pending_stack_adjust (); - emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION, - &thisblock->data.block.stack_level, - thisblock->data.block.first_insn); - stack_block_stack = thisblock; - } - - /* Compute the variable's size, in bytes. */ - size = expand_expr (size_binop (CEIL_DIV_EXPR, - DECL_SIZE (decl), - size_int (BITS_PER_UNIT)), - NULL_RTX, VOIDmode, 0); - free_temp_slots (); - - /* Allocate space on the stack for the variable. Note that - DECL_ALIGN says how the variable is to be aligned and we - cannot use it to conclude anything about the alignment of - the size. */ - address = allocate_dynamic_stack_space (size, NULL_RTX, - TYPE_ALIGN (TREE_TYPE (decl))); - - /* Reference the variable indirect through that rtx. */ - DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address); - - /* If this is a memory ref that contains aggregate components, - mark it as such for cse and loop optimize. */ - MEM_SET_IN_STRUCT_P (DECL_RTL (decl), - AGGREGATE_TYPE_P (TREE_TYPE (decl))); - - /* Indicate the alignment we actually gave this variable. */ -#ifdef STACK_BOUNDARY - DECL_ALIGN (decl) = STACK_BOUNDARY; -#else - DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; -#endif - } - - if (TREE_THIS_VOLATILE (decl)) - MEM_VOLATILE_P (DECL_RTL (decl)) = 1; -#if 0 /* A variable is not necessarily unchanging - just because it is const. RTX_UNCHANGING_P - means no change in the function, - not merely no change in the variable's scope. - It is correct to set RTX_UNCHANGING_P if the variable's scope - is the whole function. There's no convenient way to test that. */ - if (TREE_READONLY (decl)) - RTX_UNCHANGING_P (DECL_RTL (decl)) = 1; -#endif - - /* If doing stupid register allocation, make sure life of any - register variable starts here, at the start of its scope. */ - - if (obey_regdecls) - use_variable (DECL_RTL (decl)); -} - - - -/* Emit code to perform the initialization of a declaration DECL. */ - -void -expand_decl_init (decl) - tree decl; -{ - int was_used = TREE_USED (decl); - - /* If this is a CONST_DECL, we don't have to generate any code, but - if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL - to be set while in the obstack containing the constant. If we don't - do this, we can lose if we have functions nested three deep and the middle - function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while - the innermost function is the first to expand that STRING_CST. */ - if (TREE_CODE (decl) == CONST_DECL) - { - if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl))) - expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode, - EXPAND_INITIALIZER); - return; - } - - if (TREE_STATIC (decl)) - return; - - /* Compute and store the initial value now. */ - - if (DECL_INITIAL (decl) == error_mark_node) - { - enum tree_code code = TREE_CODE (TREE_TYPE (decl)); - - if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE - || code == POINTER_TYPE || code == REFERENCE_TYPE) - expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node), - 0, 0); - emit_queue (); - } - else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST) - { - emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl)); - expand_assignment (decl, DECL_INITIAL (decl), 0, 0); - emit_queue (); - } - - /* Don't let the initialization count as "using" the variable. */ - TREE_USED (decl) = was_used; - - /* Free any temporaries we made while initializing the decl. */ - preserve_temp_slots (NULL_RTX); - free_temp_slots (); -} - -/* CLEANUP is an expression to be executed at exit from this binding contour; - for example, in C++, it might call the destructor for this variable. - - We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the - CLEANUP multiple times, and have the correct semantics. This - happens in exception handling, for gotos, returns, breaks that - leave the current scope. - - If CLEANUP is nonzero and DECL is zero, we record a cleanup - that is not associated with any particular variable. */ - -int -expand_decl_cleanup (decl, cleanup) - tree decl, cleanup; -{ - struct nesting *thisblock = block_stack; - - /* Error if we are not in any block. */ - if (thisblock == 0) - return 0; - - /* Record the cleanup if there is one. */ - - if (cleanup != 0) - { - tree t; - rtx seq; - tree *cleanups = &thisblock->data.block.cleanups; - int cond_context = conditional_context (); - - if (cond_context) - { - rtx flag = gen_reg_rtx (word_mode); - rtx set_flag_0; - tree cond; - - start_sequence (); - emit_move_insn (flag, const0_rtx); - set_flag_0 = get_insns (); - end_sequence (); - - thisblock->data.block.last_unconditional_cleanup - = emit_insns_after (set_flag_0, - thisblock->data.block.last_unconditional_cleanup); - - emit_move_insn (flag, const1_rtx); - - /* All cleanups must be on the function_obstack. */ - push_obstacks_nochange (); - resume_temporary_allocation (); - - cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1)); - DECL_RTL (cond) = flag; - - /* Conditionalize the cleanup. */ - cleanup = build (COND_EXPR, void_type_node, - truthvalue_conversion (cond), - cleanup, integer_zero_node); - cleanup = fold (cleanup); - - pop_obstacks (); - - cleanups = thisblock->data.block.cleanup_ptr; - } - - /* All cleanups must be on the function_obstack. */ - push_obstacks_nochange (); - resume_temporary_allocation (); - cleanup = unsave_expr (cleanup); - pop_obstacks (); - - t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups); - - if (! cond_context) - /* If this block has a cleanup, it belongs in stack_block_stack. */ - stack_block_stack = thisblock; - - if (cond_context) - { - start_sequence (); - } - - /* If this was optimized so that there is no exception region for the - cleanup, then mark the TREE_LIST node, so that we can later tell - if we need to call expand_eh_region_end. */ - if (! using_eh_for_cleanups_p - || expand_eh_region_start_tree (decl, cleanup)) - TREE_ADDRESSABLE (t) = 1; - /* If that started a new EH region, we're in a new block. */ - thisblock = block_stack; - - if (cond_context) - { - seq = get_insns (); - end_sequence (); - if (seq) - thisblock->data.block.last_unconditional_cleanup - = emit_insns_after (seq, - thisblock->data.block.last_unconditional_cleanup); - } - else - { - thisblock->data.block.last_unconditional_cleanup - = get_last_insn (); - thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups; - } - } - return 1; -} - -/* Like expand_decl_cleanup, but suppress generating an exception handler - to perform the cleanup. */ - -int -expand_decl_cleanup_no_eh (decl, cleanup) - tree decl, cleanup; -{ - int save_eh = using_eh_for_cleanups_p; - int result; - - using_eh_for_cleanups_p = 0; - result = expand_decl_cleanup (decl, cleanup); - using_eh_for_cleanups_p = save_eh; - - return result; -} - -/* Arrange for the top element of the dynamic cleanup chain to be - popped if we exit the current binding contour. DECL is the - associated declaration, if any, otherwise NULL_TREE. If the - current contour is left via an exception, then __sjthrow will pop - the top element off the dynamic cleanup chain. The code that - avoids doing the action we push into the cleanup chain in the - exceptional case is contained in expand_cleanups. - - This routine is only used by expand_eh_region_start, and that is - the only way in which an exception region should be started. This - routine is only used when using the setjmp/longjmp codegen method - for exception handling. */ - -int -expand_dcc_cleanup (decl) - tree decl; -{ - struct nesting *thisblock = block_stack; - tree cleanup; - - /* Error if we are not in any block. */ - if (thisblock == 0) - return 0; - - /* Record the cleanup for the dynamic handler chain. */ - - /* All cleanups must be on the function_obstack. */ - push_obstacks_nochange (); - resume_temporary_allocation (); - cleanup = make_node (POPDCC_EXPR); - pop_obstacks (); - - /* Add the cleanup in a manner similar to expand_decl_cleanup. */ - thisblock->data.block.cleanups - = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); - - /* If this block has a cleanup, it belongs in stack_block_stack. */ - stack_block_stack = thisblock; - return 1; -} - -/* Arrange for the top element of the dynamic handler chain to be - popped if we exit the current binding contour. DECL is the - associated declaration, if any, otherwise NULL_TREE. If the current - contour is left via an exception, then __sjthrow will pop the top - element off the dynamic handler chain. The code that avoids doing - the action we push into the handler chain in the exceptional case - is contained in expand_cleanups. - - This routine is only used by expand_eh_region_start, and that is - the only way in which an exception region should be started. This - routine is only used when using the setjmp/longjmp codegen method - for exception handling. */ - -int -expand_dhc_cleanup (decl) - tree decl; -{ - struct nesting *thisblock = block_stack; - tree cleanup; - - /* Error if we are not in any block. */ - if (thisblock == 0) - return 0; - - /* Record the cleanup for the dynamic handler chain. */ - - /* All cleanups must be on the function_obstack. */ - push_obstacks_nochange (); - resume_temporary_allocation (); - cleanup = make_node (POPDHC_EXPR); - pop_obstacks (); - - /* Add the cleanup in a manner similar to expand_decl_cleanup. */ - thisblock->data.block.cleanups - = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups); - - /* If this block has a cleanup, it belongs in stack_block_stack. */ - stack_block_stack = thisblock; - return 1; -} - -/* DECL is an anonymous union. CLEANUP is a cleanup for DECL. - DECL_ELTS is the list of elements that belong to DECL's type. - In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ - -void -expand_anon_union_decl (decl, cleanup, decl_elts) - tree decl, cleanup, decl_elts; -{ - struct nesting *thisblock = block_stack; - rtx x; - - expand_decl (decl); - expand_decl_cleanup (decl, cleanup); - x = DECL_RTL (decl); - - while (decl_elts) - { - tree decl_elt = TREE_VALUE (decl_elts); - tree cleanup_elt = TREE_PURPOSE (decl_elts); - enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); - - /* Propagate the union's alignment to the elements. */ - DECL_ALIGN (decl_elt) = DECL_ALIGN (decl); - - /* If the element has BLKmode and the union doesn't, the union is - aligned such that the element doesn't need to have BLKmode, so - change the element's mode to the appropriate one for its size. */ - if (mode == BLKmode && DECL_MODE (decl) != BLKmode) - DECL_MODE (decl_elt) = mode - = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)), - MODE_INT, 1); - - /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we - instead create a new MEM rtx with the proper mode. */ - if (GET_CODE (x) == MEM) - { - if (mode == GET_MODE (x)) - DECL_RTL (decl_elt) = x; - else - { - DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0))); - MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x); - RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x); - } - } - else if (GET_CODE (x) == REG) - { - if (mode == GET_MODE (x)) - DECL_RTL (decl_elt) = x; - else - DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0); - } - else - abort (); - - /* Record the cleanup if there is one. */ - - if (cleanup != 0) - thisblock->data.block.cleanups - = temp_tree_cons (decl_elt, cleanup_elt, - thisblock->data.block.cleanups); - - decl_elts = TREE_CHAIN (decl_elts); - } -} - -/* Expand a list of cleanups LIST. - Elements may be expressions or may be nested lists. - - If DONT_DO is nonnull, then any list-element - whose TREE_PURPOSE matches DONT_DO is omitted. - This is sometimes used to avoid a cleanup associated with - a value that is being returned out of the scope. - - If IN_FIXUP is non-zero, we are generating this cleanup for a fixup - goto and handle protection regions specially in that case. - - If REACHABLE, we emit code, otherwise just inform the exception handling - code about this finalization. */ - -static void -expand_cleanups (list, dont_do, in_fixup, reachable) - tree list; - tree dont_do; - int in_fixup; - int reachable; -{ - tree tail; - for (tail = list; tail; tail = TREE_CHAIN (tail)) - if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do) - { - if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST) - expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable); - else - { - if (! in_fixup) - { - tree cleanup = TREE_VALUE (tail); - - /* See expand_d{h,c}c_cleanup for why we avoid this. */ - if (TREE_CODE (cleanup) != POPDHC_EXPR - && TREE_CODE (cleanup) != POPDCC_EXPR - /* See expand_eh_region_start_tree for this case. */ - && ! TREE_ADDRESSABLE (tail)) - { - cleanup = protect_with_terminate (cleanup); - expand_eh_region_end (cleanup); - } - } - - if (reachable) - { - /* Cleanups may be run multiple times. For example, - when exiting a binding contour, we expand the - cleanups associated with that contour. When a goto - within that binding contour has a target outside that - contour, it will expand all cleanups from its scope to - the target. Though the cleanups are expanded multiple - times, the control paths are non-overlapping so the - cleanups will not be executed twice. */ - - /* We may need to protect fixups with rethrow regions. */ - int protect = (in_fixup && ! TREE_ADDRESSABLE (tail)); - - if (protect) - expand_fixup_region_start (); - - expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0); - if (protect) - expand_fixup_region_end (TREE_VALUE (tail)); - free_temp_slots (); - } - } - } -} - -/* Mark when the context we are emitting RTL for as a conditional - context, so that any cleanup actions we register with - expand_decl_init will be properly conditionalized when those - cleanup actions are later performed. Must be called before any - expression (tree) is expanded that is within a conditional context. */ - -void -start_cleanup_deferral () -{ - /* block_stack can be NULL if we are inside the parameter list. It is - OK to do nothing, because cleanups aren't possible here. */ - if (block_stack) - ++block_stack->data.block.conditional_code; -} - -/* Mark the end of a conditional region of code. Because cleanup - deferrals may be nested, we may still be in a conditional region - after we end the currently deferred cleanups, only after we end all - deferred cleanups, are we back in unconditional code. */ - -void -end_cleanup_deferral () -{ - /* block_stack can be NULL if we are inside the parameter list. It is - OK to do nothing, because cleanups aren't possible here. */ - if (block_stack) - --block_stack->data.block.conditional_code; -} - -/* Move all cleanups from the current block_stack - to the containing block_stack, where they are assumed to - have been created. If anything can cause a temporary to - be created, but not expanded for more than one level of - block_stacks, then this code will have to change. */ - -void -move_cleanups_up () -{ - struct nesting *block = block_stack; - struct nesting *outer = block->next; - - outer->data.block.cleanups - = chainon (block->data.block.cleanups, - outer->data.block.cleanups); - block->data.block.cleanups = 0; -} - -tree -last_cleanup_this_contour () -{ - if (block_stack == 0) - return 0; - - return block_stack->data.block.cleanups; -} - -/* Return 1 if there are any pending cleanups at this point. - If THIS_CONTOUR is nonzero, check the current contour as well. - Otherwise, look only at the contours that enclose this one. */ - -int -any_pending_cleanups (this_contour) - int this_contour; -{ - struct nesting *block; - - if (block_stack == 0) - return 0; - - if (this_contour && block_stack->data.block.cleanups != NULL) - return 1; - if (block_stack->data.block.cleanups == 0 - && block_stack->data.block.outer_cleanups == 0) - return 0; - - for (block = block_stack->next; block; block = block->next) - if (block->data.block.cleanups != 0) - return 1; - - return 0; -} - -/* Enter a case (Pascal) or switch (C) statement. - Push a block onto case_stack and nesting_stack - to accumulate the case-labels that are seen - and to record the labels generated for the statement. - - EXIT_FLAG is nonzero if `exit_something' should exit this case stmt. - Otherwise, this construct is transparent for `exit_something'. - - EXPR is the index-expression to be dispatched on. - TYPE is its nominal type. We could simply convert EXPR to this type, - but instead we take short cuts. */ - -void -expand_start_case (exit_flag, expr, type, printname) - int exit_flag; - tree expr; - tree type; - const char *printname; -{ - register struct nesting *thiscase = ALLOC_NESTING (); - - /* Make an entry on case_stack for the case we are entering. */ - - thiscase->next = case_stack; - thiscase->all = nesting_stack; - thiscase->depth = ++nesting_depth; - thiscase->exit_label = exit_flag ? gen_label_rtx () : 0; - thiscase->data.case_stmt.case_list = 0; - thiscase->data.case_stmt.index_expr = expr; - thiscase->data.case_stmt.nominal_type = type; - thiscase->data.case_stmt.default_label = 0; - thiscase->data.case_stmt.num_ranges = 0; - thiscase->data.case_stmt.printname = printname; - thiscase->data.case_stmt.line_number_status = force_line_numbers (); - case_stack = thiscase; - nesting_stack = thiscase; - - do_pending_stack_adjust (); - - /* Make sure case_stmt.start points to something that won't - need any transformation before expand_end_case. */ - if (GET_CODE (get_last_insn ()) != NOTE) - emit_note (NULL_PTR, NOTE_INSN_DELETED); - - thiscase->data.case_stmt.start = get_last_insn (); - - start_cleanup_deferral (); -} - - -/* Start a "dummy case statement" within which case labels are invalid - and are not connected to any larger real case statement. - This can be used if you don't want to let a case statement jump - into the middle of certain kinds of constructs. */ - -void -expand_start_case_dummy () -{ - register struct nesting *thiscase = ALLOC_NESTING (); - - /* Make an entry on case_stack for the dummy. */ - - thiscase->next = case_stack; - thiscase->all = nesting_stack; - thiscase->depth = ++nesting_depth; - thiscase->exit_label = 0; - thiscase->data.case_stmt.case_list = 0; - thiscase->data.case_stmt.start = 0; - thiscase->data.case_stmt.nominal_type = 0; - thiscase->data.case_stmt.default_label = 0; - thiscase->data.case_stmt.num_ranges = 0; - case_stack = thiscase; - nesting_stack = thiscase; - start_cleanup_deferral (); -} - -/* End a dummy case statement. */ - -void -expand_end_case_dummy () -{ - end_cleanup_deferral (); - POPSTACK (case_stack); -} - -/* Return the data type of the index-expression - of the innermost case statement, or null if none. */ - -tree -case_index_expr_type () -{ - if (case_stack) - return TREE_TYPE (case_stack->data.case_stmt.index_expr); - return 0; -} - -static void -check_seenlabel () -{ - /* If this is the first label, warn if any insns have been emitted. */ - if (case_stack->data.case_stmt.line_number_status >= 0) - { - rtx insn; - - restore_line_number_status - (case_stack->data.case_stmt.line_number_status); - case_stack->data.case_stmt.line_number_status = -1; - - for (insn = case_stack->data.case_stmt.start; - insn; - insn = NEXT_INSN (insn)) - { - if (GET_CODE (insn) == CODE_LABEL) - break; - if (GET_CODE (insn) != NOTE - && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE)) - { - do - insn = PREV_INSN (insn); - while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0)); - - /* If insn is zero, then there must have been a syntax error. */ - if (insn) - warning_with_file_and_line (NOTE_SOURCE_FILE(insn), - NOTE_LINE_NUMBER(insn), - "unreachable code at beginning of %s", - case_stack->data.case_stmt.printname); - break; - } - } - } -} - -/* Accumulate one case or default label inside a case or switch statement. - VALUE is the value of the case (a null pointer, for a default label). - The function CONVERTER, when applied to arguments T and V, - converts the value V to the type T. - - If not currently inside a case or switch statement, return 1 and do - nothing. The caller will print a language-specific error message. - If VALUE is a duplicate or overlaps, return 2 and do nothing - except store the (first) duplicate node in *DUPLICATE. - If VALUE is out of range, return 3 and do nothing. - If we are jumping into the scope of a cleanup or var-sized array, return 5. - Return 0 on success. - - Extended to handle range statements. */ - -int -pushcase (value, converter, label, duplicate) - register tree value; - tree (*converter) PROTO((tree, tree)); - register tree label; - tree *duplicate; -{ - tree index_type; - tree nominal_type; - - /* Fail if not inside a real case statement. */ - if (! (case_stack && case_stack->data.case_stmt.start)) - return 1; - - if (stack_block_stack - && stack_block_stack->depth > case_stack->depth) - return 5; - - index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); - nominal_type = case_stack->data.case_stmt.nominal_type; - - /* If the index is erroneous, avoid more problems: pretend to succeed. */ - if (index_type == error_mark_node) - return 0; - - /* Convert VALUE to the type in which the comparisons are nominally done. */ - if (value != 0) - value = (*converter) (nominal_type, value); - - check_seenlabel (); - - /* Fail if this value is out of range for the actual type of the index - (which may be narrower than NOMINAL_TYPE). */ - if (value != 0 && ! int_fits_type_p (value, index_type)) - return 3; - - /* Fail if this is a duplicate or overlaps another entry. */ - if (value == 0) - { - if (case_stack->data.case_stmt.default_label != 0) - { - *duplicate = case_stack->data.case_stmt.default_label; - return 2; - } - case_stack->data.case_stmt.default_label = label; - } - else - return add_case_node (value, value, label, duplicate); - - expand_label (label); - return 0; -} - -/* Like pushcase but this case applies to all values between VALUE1 and - VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest - value of the index type and ends at VALUE2. If VALUE2 is NULL, the range - starts at VALUE1 and ends at the highest value of the index type. - If both are NULL, this case applies to all values. - - The return value is the same as that of pushcase but there is one - additional error code: 4 means the specified range was empty. */ - -int -pushcase_range (value1, value2, converter, label, duplicate) - register tree value1, value2; - tree (*converter) PROTO((tree, tree)); - register tree label; - tree *duplicate; -{ - tree index_type; - tree nominal_type; - - /* Fail if not inside a real case statement. */ - if (! (case_stack && case_stack->data.case_stmt.start)) - return 1; - - if (stack_block_stack - && stack_block_stack->depth > case_stack->depth) - return 5; - - index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr); - nominal_type = case_stack->data.case_stmt.nominal_type; - - /* If the index is erroneous, avoid more problems: pretend to succeed. */ - if (index_type == error_mark_node) - return 0; - - check_seenlabel (); - - /* Convert VALUEs to type in which the comparisons are nominally done - and replace any unspecified value with the corresponding bound. */ - if (value1 == 0) - value1 = TYPE_MIN_VALUE (index_type); - if (value2 == 0) - value2 = TYPE_MAX_VALUE (index_type); - - /* Fail if the range is empty. Do this before any conversion since - we want to allow out-of-range empty ranges. */ - if (value2 && tree_int_cst_lt (value2, value1)) - return 4; - - value1 = (*converter) (nominal_type, value1); - - /* If the max was unbounded, use the max of the nominal_type we are - converting to. Do this after the < check above to suppress false - positives. */ - if (!value2) - value2 = TYPE_MAX_VALUE (nominal_type); - value2 = (*converter) (nominal_type, value2); - - /* Fail if these values are out of range. */ - if (TREE_CONSTANT_OVERFLOW (value1) - || ! int_fits_type_p (value1, index_type)) - return 3; - - if (TREE_CONSTANT_OVERFLOW (value2) - || ! int_fits_type_p (value2, index_type)) - return 3; - - return add_case_node (value1, value2, label, duplicate); -} - -/* Do the actual insertion of a case label for pushcase and pushcase_range - into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid - slowdown for large switch statements. */ - -static int -add_case_node (low, high, label, duplicate) - tree low, high; - tree label; - tree *duplicate; -{ - struct case_node *p, **q, *r; - - q = &case_stack->data.case_stmt.case_list; - p = *q; - - while ((r = *q)) - { - p = r; - - /* Keep going past elements distinctly greater than HIGH. */ - if (tree_int_cst_lt (high, p->low)) - q = &p->left; - - /* or distinctly less than LOW. */ - else if (tree_int_cst_lt (p->high, low)) - q = &p->right; - - else - { - /* We have an overlap; this is an error. */ - *duplicate = p->code_label; - return 2; - } - } - - /* Add this label to the chain, and succeed. - Copy LOW, HIGH so they are on temporary rather than momentary - obstack and will thus survive till the end of the case statement. */ - - r = (struct case_node *) oballoc (sizeof (struct case_node)); - r->low = copy_node (low); - - /* If the bounds are equal, turn this into the one-value case. */ - - if (tree_int_cst_equal (low, high)) - r->high = r->low; - else - { - r->high = copy_node (high); - case_stack->data.case_stmt.num_ranges++; - } - - r->code_label = label; - expand_label (label); - - *q = r; - r->parent = p; - r->left = 0; - r->right = 0; - r->balance = 0; - - while (p) - { - struct case_node *s; - - if (r == p->left) - { - int b; - - if (! (b = p->balance)) - /* Growth propagation from left side. */ - p->balance = -1; - else if (b < 0) - { - if (r->balance < 0) - { - /* R-Rotation */ - if ((p->left = s = r->right)) - s->parent = p; - - r->right = p; - p->balance = 0; - r->balance = 0; - s = p->parent; - p->parent = r; - - if ((r->parent = s)) - { - if (s->left == p) - s->left = r; - else - s->right = r; - } - else - case_stack->data.case_stmt.case_list = r; - } - else - /* r->balance == +1 */ - { - /* LR-Rotation */ - - int b2; - struct case_node *t = r->right; - - if ((p->left = s = t->right)) - s->parent = p; - - t->right = p; - if ((r->right = s = t->left)) - s->parent = r; - - t->left = r; - b = t->balance; - b2 = b < 0; - p->balance = b2; - b2 = -b2 - b; - r->balance = b2; - t->balance = 0; - s = p->parent; - p->parent = t; - r->parent = t; - - if ((t->parent = s)) - { - if (s->left == p) - s->left = t; - else - s->right = t; - } - else - case_stack->data.case_stmt.case_list = t; - } - break; - } - - else - { - /* p->balance == +1; growth of left side balances the node. */ - p->balance = 0; - break; - } - } - else - /* r == p->right */ - { - int b; - - if (! (b = p->balance)) - /* Growth propagation from right side. */ - p->balance++; - else if (b > 0) - { - if (r->balance > 0) - { - /* L-Rotation */ - - if ((p->right = s = r->left)) - s->parent = p; - - r->left = p; - p->balance = 0; - r->balance = 0; - s = p->parent; - p->parent = r; - if ((r->parent = s)) - { - if (s->left == p) - s->left = r; - else - s->right = r; - } - - else - case_stack->data.case_stmt.case_list = r; - } - - else - /* r->balance == -1 */ - { - /* RL-Rotation */ - int b2; - struct case_node *t = r->left; - - if ((p->right = s = t->left)) - s->parent = p; - - t->left = p; - - if ((r->left = s = t->right)) - s->parent = r; - - t->right = r; - b = t->balance; - b2 = b < 0; - r->balance = b2; - b2 = -b2 - b; - p->balance = b2; - t->balance = 0; - s = p->parent; - p->parent = t; - r->parent = t; - - if ((t->parent = s)) - { - if (s->left == p) - s->left = t; - else - s->right = t; - } - - else - case_stack->data.case_stmt.case_list = t; - } - break; - } - else - { - /* p->balance == -1; growth of right side balances the node. */ - p->balance = 0; - break; - } - } - - r = p; - p = p->parent; - } - - return 0; -} - - -/* Returns the number of possible values of TYPE. - Returns -1 if the number is unknown or variable. - Returns -2 if the number does not fit in a HOST_WIDE_INT. - Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values - do not increase monotonically (there may be duplicates); - to 1 if the values increase monotonically, but not always by 1; - otherwise sets it to 0. */ - -HOST_WIDE_INT -all_cases_count (type, spareness) - tree type; - int *spareness; -{ - HOST_WIDE_INT count; - *spareness = 0; - - switch (TREE_CODE (type)) - { - tree t; - case BOOLEAN_TYPE: - count = 2; - break; - case CHAR_TYPE: - count = 1 << BITS_PER_UNIT; - break; - default: - case INTEGER_TYPE: - if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST - || TYPE_MAX_VALUE (type) == NULL - || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST) - return -1; - else - { - /* count - = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type)) - - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1 - but with overflow checking. */ - tree mint = TYPE_MIN_VALUE (type); - tree maxt = TYPE_MAX_VALUE (type); - HOST_WIDE_INT lo, hi; - neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint), - &lo, &hi); - add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt), - lo, hi, &lo, &hi); - add_double (lo, hi, 1, 0, &lo, &hi); - if (hi != 0 || lo < 0) - return -2; - count = lo; - } - break; - case ENUMERAL_TYPE: - count = 0; - for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t)) - { - if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST - || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST - || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count - != TREE_INT_CST_LOW (TREE_VALUE (t))) - *spareness = 1; - count++; - } - if (*spareness == 1) - { - tree prev = TREE_VALUE (TYPE_VALUES (type)); - for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; ) - { - if (! tree_int_cst_lt (prev, TREE_VALUE (t))) - { - *spareness = 2; - break; - } - prev = TREE_VALUE (t); - } - - } - } - return count; -} - - -#define BITARRAY_TEST(ARRAY, INDEX) \ - ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\ - & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))) -#define BITARRAY_SET(ARRAY, INDEX) \ - ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\ - |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)) - -/* Set the elements of the bitstring CASES_SEEN (which has length COUNT), - with the case values we have seen, assuming the case expression - has the given TYPE. - SPARSENESS is as determined by all_cases_count. - - The time needed is proportional to COUNT, unless - SPARSENESS is 2, in which case quadratic time is needed. */ - -void -mark_seen_cases (type, cases_seen, count, sparseness) - tree type; - unsigned char *cases_seen; - long count; - int sparseness; -{ - tree next_node_to_try = NULL_TREE; - long next_node_offset = 0; - - register struct case_node *n, *root = case_stack->data.case_stmt.case_list; - tree val = make_node (INTEGER_CST); - TREE_TYPE (val) = type; - if (! root) - ; /* Do nothing */ - else if (sparseness == 2) - { - tree t; - HOST_WIDE_INT xlo; - - /* This less efficient loop is only needed to handle - duplicate case values (multiple enum constants - with the same value). */ - TREE_TYPE (val) = TREE_TYPE (root->low); - for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE; - t = TREE_CHAIN (t), xlo++) - { - TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t)); - TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t)); - n = root; - do - { - /* Keep going past elements distinctly greater than VAL. */ - if (tree_int_cst_lt (val, n->low)) - n = n->left; - - /* or distinctly less than VAL. */ - else if (tree_int_cst_lt (n->high, val)) - n = n->right; - - else - { - /* We have found a matching range. */ - BITARRAY_SET (cases_seen, xlo); - break; - } - } - while (n); - } - } - else - { - if (root->left) - case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0); - for (n = root; n; n = n->right) - { - TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low); - TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low); - while ( ! tree_int_cst_lt (n->high, val)) - { - /* Calculate (into xlo) the "offset" of the integer (val). - The element with lowest value has offset 0, the next smallest - element has offset 1, etc. */ - - HOST_WIDE_INT xlo, xhi; - tree t; - if (sparseness && TYPE_VALUES (type) != NULL_TREE) - { - /* The TYPE_VALUES will be in increasing order, so - starting searching where we last ended. */ - t = next_node_to_try; - xlo = next_node_offset; - xhi = 0; - for (;;) - { - if (t == NULL_TREE) - { - t = TYPE_VALUES (type); - xlo = 0; - } - if (tree_int_cst_equal (val, TREE_VALUE (t))) - { - next_node_to_try = TREE_CHAIN (t); - next_node_offset = xlo + 1; - break; - } - xlo++; - t = TREE_CHAIN (t); - if (t == next_node_to_try) - { - xlo = -1; - break; - } - } - } - else - { - t = TYPE_MIN_VALUE (type); - if (t) - neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), - &xlo, &xhi); - else - xlo = xhi = 0; - add_double (xlo, xhi, - TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val), - &xlo, &xhi); - } - - if (xhi == 0 && xlo >= 0 && xlo < count) - BITARRAY_SET (cases_seen, xlo); - add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val), - 1, 0, - &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val)); - } - } - } -} - -/* Called when the index of a switch statement is an enumerated type - and there is no default label. - - Checks that all enumeration literals are covered by the case - expressions of a switch. Also, warn if there are any extra - switch cases that are *not* elements of the enumerated type. - - If all enumeration literals were covered by the case expressions, - turn one of the expressions into the default expression since it should - not be possible to fall through such a switch. */ - -void -check_for_full_enumeration_handling (type) - tree type; -{ - register struct case_node *n; - register tree chain; -#if 0 /* variable used by 'if 0'ed code below. */ - register struct case_node **l; - int all_values = 1; -#endif - - /* True iff the selector type is a numbered set mode. */ - int sparseness = 0; - - /* The number of possible selector values. */ - HOST_WIDE_INT size; - - /* For each possible selector value. a one iff it has been matched - by a case value alternative. */ - unsigned char *cases_seen; - - /* The allocated size of cases_seen, in chars. */ - long bytes_needed; - - if (! warn_switch) - return; - - size = all_cases_count (type, &sparseness); - bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR; - - if (size > 0 && size < 600000 - /* We deliberately use malloc here - not xmalloc. */ - && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL) - { - long i; - tree v = TYPE_VALUES (type); - bzero (cases_seen, bytes_needed); - - /* The time complexity of this code is normally O(N), where - N being the number of members in the enumerated type. - However, if type is a ENUMERAL_TYPE whose values do not - increase monotonically, O(N*log(N)) time may be needed. */ - - mark_seen_cases (type, cases_seen, size, sparseness); - - for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v)) - { - if (BITARRAY_TEST(cases_seen, i) == 0) - warning ("enumeration value `%s' not handled in switch", - IDENTIFIER_POINTER (TREE_PURPOSE (v))); - } - - free (cases_seen); - } - - /* Now we go the other way around; we warn if there are case - expressions that don't correspond to enumerators. This can - occur since C and C++ don't enforce type-checking of - assignments to enumeration variables. */ - - if (case_stack->data.case_stmt.case_list - && case_stack->data.case_stmt.case_list->left) - case_stack->data.case_stmt.case_list - = case_tree2list (case_stack->data.case_stmt.case_list, 0); - if (warn_switch) - for (n = case_stack->data.case_stmt.case_list; n; n = n->right) - { - for (chain = TYPE_VALUES (type); - chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain)); - chain = TREE_CHAIN (chain)) - ; - - if (!chain) - { - if (TYPE_NAME (type) == 0) - warning ("case value `%ld' not in enumerated type", - (long) TREE_INT_CST_LOW (n->low)); - else - warning ("case value `%ld' not in enumerated type `%s'", - (long) TREE_INT_CST_LOW (n->low), - IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) - == IDENTIFIER_NODE) - ? TYPE_NAME (type) - : DECL_NAME (TYPE_NAME (type)))); - } - if (!tree_int_cst_equal (n->low, n->high)) - { - for (chain = TYPE_VALUES (type); - chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain)); - chain = TREE_CHAIN (chain)) - ; - - if (!chain) - { - if (TYPE_NAME (type) == 0) - warning ("case value `%ld' not in enumerated type", - (long) TREE_INT_CST_LOW (n->high)); - else - warning ("case value `%ld' not in enumerated type `%s'", - (long) TREE_INT_CST_LOW (n->high), - IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type)) - == IDENTIFIER_NODE) - ? TYPE_NAME (type) - : DECL_NAME (TYPE_NAME (type)))); - } - } - } - -#if 0 - /* ??? This optimization is disabled because it causes valid programs to - fail. ANSI C does not guarantee that an expression with enum type - will have a value that is the same as one of the enumeration literals. */ - - /* If all values were found as case labels, make one of them the default - label. Thus, this switch will never fall through. We arbitrarily pick - the last one to make the default since this is likely the most - efficient choice. */ - - if (all_values) - { - for (l = &case_stack->data.case_stmt.case_list; - (*l)->right != 0; - l = &(*l)->right) - ; - - case_stack->data.case_stmt.default_label = (*l)->code_label; - *l = 0; - } -#endif /* 0 */ -} - - -/* Terminate a case (Pascal) or switch (C) statement - in which ORIG_INDEX is the expression to be tested. - Generate the code to test it and jump to the right place. */ - -void -expand_end_case (orig_index) - tree orig_index; -{ - tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval; - rtx default_label = 0; - register struct case_node *n; - unsigned int count; - rtx index; - rtx table_label; - int ncases; - rtx *labelvec; - register int i; - rtx before_case; - register struct nesting *thiscase = case_stack; - tree index_expr, index_type; - int unsignedp; - - table_label = gen_label_rtx (); - index_expr = thiscase->data.case_stmt.index_expr; - index_type = TREE_TYPE (index_expr); - unsignedp = TREE_UNSIGNED (index_type); - - do_pending_stack_adjust (); - - /* This might get an spurious warning in the presence of a syntax error; - it could be fixed by moving the call to check_seenlabel after the - check for error_mark_node, and copying the code of check_seenlabel that - deals with case_stack->data.case_stmt.line_number_status / - restore_line_number_status in front of the call to end_cleanup_deferral; - However, this might miss some useful warnings in the presence of - non-syntax errors. */ - check_seenlabel (); - - /* An ERROR_MARK occurs for various reasons including invalid data type. */ - if (index_type != error_mark_node) - { - /* If switch expression was an enumerated type, check that all - enumeration literals are covered by the cases. - No sense trying this if there's a default case, however. */ - - if (!thiscase->data.case_stmt.default_label - && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE - && TREE_CODE (index_expr) != INTEGER_CST) - check_for_full_enumeration_handling (TREE_TYPE (orig_index)); - - /* If we don't have a default-label, create one here, - after the body of the switch. */ - if (thiscase->data.case_stmt.default_label == 0) - { - thiscase->data.case_stmt.default_label - = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - expand_label (thiscase->data.case_stmt.default_label); - } - default_label = label_rtx (thiscase->data.case_stmt.default_label); - - before_case = get_last_insn (); - - if (thiscase->data.case_stmt.case_list - && thiscase->data.case_stmt.case_list->left) - thiscase->data.case_stmt.case_list - = case_tree2list(thiscase->data.case_stmt.case_list, 0); - - /* Simplify the case-list before we count it. */ - group_case_nodes (thiscase->data.case_stmt.case_list); - - /* Get upper and lower bounds of case values. - Also convert all the case values to the index expr's data type. */ - - count = 0; - for (n = thiscase->data.case_stmt.case_list; n; n = n->right) - { - /* Check low and high label values are integers. */ - if (TREE_CODE (n->low) != INTEGER_CST) - abort (); - if (TREE_CODE (n->high) != INTEGER_CST) - abort (); - - n->low = convert (index_type, n->low); - n->high = convert (index_type, n->high); - - /* Count the elements and track the largest and smallest - of them (treating them as signed even if they are not). */ - if (count++ == 0) - { - minval = n->low; - maxval = n->high; - } - else - { - if (INT_CST_LT (n->low, minval)) - minval = n->low; - if (INT_CST_LT (maxval, n->high)) - maxval = n->high; - } - /* A range counts double, since it requires two compares. */ - if (! tree_int_cst_equal (n->low, n->high)) - count++; - } - - orig_minval = minval; - - /* Compute span of values. */ - if (count != 0) - range = fold (build (MINUS_EXPR, index_type, maxval, minval)); - - end_cleanup_deferral (); - - if (count == 0) - { - expand_expr (index_expr, const0_rtx, VOIDmode, 0); - emit_queue (); - emit_jump (default_label); - } - - /* If range of values is much bigger than number of values, - make a sequence of conditional branches instead of a dispatch. - If the switch-index is a constant, do it this way - because we can optimize it. */ - -#ifndef CASE_VALUES_THRESHOLD -#ifdef HAVE_casesi -#define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5) -#else - /* If machine does not have a case insn that compares the - bounds, this means extra overhead for dispatch tables - which raises the threshold for using them. */ -#define CASE_VALUES_THRESHOLD 5 -#endif /* HAVE_casesi */ -#endif /* CASE_VALUES_THRESHOLD */ - - else if (TREE_INT_CST_HIGH (range) != 0 - || count < (unsigned int) CASE_VALUES_THRESHOLD - || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range)) - > 10 * count) -#ifndef ASM_OUTPUT_ADDR_DIFF_ELT - || flag_pic -#endif - || TREE_CODE (index_expr) == INTEGER_CST - /* These will reduce to a constant. */ - || (TREE_CODE (index_expr) == CALL_EXPR - && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL - && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE) - || (TREE_CODE (index_expr) == COMPOUND_EXPR - && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST)) - { - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - - /* If the index is a short or char that we do not have - an insn to handle comparisons directly, convert it to - a full integer now, rather than letting each comparison - generate the conversion. */ - - if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT - && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code - == CODE_FOR_nothing)) - { - enum machine_mode wider_mode; - for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; - wider_mode = GET_MODE_WIDER_MODE (wider_mode)) - if (cmp_optab->handlers[(int) wider_mode].insn_code - != CODE_FOR_nothing) - { - index = convert_to_mode (wider_mode, index, unsignedp); - break; - } - } - - emit_queue (); - do_pending_stack_adjust (); - - index = protect_from_queue (index, 0); - if (GET_CODE (index) == MEM) - index = copy_to_reg (index); - if (GET_CODE (index) == CONST_INT - || TREE_CODE (index_expr) == INTEGER_CST) - { - /* Make a tree node with the proper constant value - if we don't already have one. */ - if (TREE_CODE (index_expr) != INTEGER_CST) - { - index_expr - = build_int_2 (INTVAL (index), - unsignedp || INTVAL (index) >= 0 ? 0 : -1); - index_expr = convert (index_type, index_expr); - } - - /* For constant index expressions we need only - issue a unconditional branch to the appropriate - target code. The job of removing any unreachable - code is left to the optimisation phase if the - "-O" option is specified. */ - for (n = thiscase->data.case_stmt.case_list; n; n = n->right) - if (! tree_int_cst_lt (index_expr, n->low) - && ! tree_int_cst_lt (n->high, index_expr)) - break; - - if (n) - emit_jump (label_rtx (n->code_label)); - else - emit_jump (default_label); - } - else - { - /* If the index expression is not constant we generate - a binary decision tree to select the appropriate - target code. This is done as follows: - - The list of cases is rearranged into a binary tree, - nearly optimal assuming equal probability for each case. - - The tree is transformed into RTL, eliminating - redundant test conditions at the same time. - - If program flow could reach the end of the - decision tree an unconditional jump to the - default code is emitted. */ - - use_cost_table - = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE - && estimate_case_costs (thiscase->data.case_stmt.case_list)); - balance_case_nodes (&thiscase->data.case_stmt.case_list, - NULL_PTR); - emit_case_nodes (index, thiscase->data.case_stmt.case_list, - default_label, index_type); - emit_jump_if_reachable (default_label); - } - } - else - { - int win = 0; -#ifdef HAVE_casesi - if (HAVE_casesi) - { - enum machine_mode index_mode = SImode; - int index_bits = GET_MODE_BITSIZE (index_mode); - rtx op1, op2; - enum machine_mode op_mode; - - /* Convert the index to SImode. */ - if (GET_MODE_BITSIZE (TYPE_MODE (index_type)) - > GET_MODE_BITSIZE (index_mode)) - { - enum machine_mode omode = TYPE_MODE (index_type); - rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0); - - /* We must handle the endpoints in the original mode. */ - index_expr = build (MINUS_EXPR, index_type, - index_expr, minval); - minval = integer_zero_node; - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX, - omode, 1, 0, default_label); - /* Now we can safely truncate. */ - index = convert_to_mode (index_mode, index, 0); - } - else - { - if (TYPE_MODE (index_type) != index_mode) - { - index_expr = convert (type_for_size (index_bits, 0), - index_expr); - index_type = TREE_TYPE (index_expr); - } - - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - } - emit_queue (); - index = protect_from_queue (index, 0); - do_pending_stack_adjust (); - - op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0]; - if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0]) - (index, op_mode)) - index = copy_to_mode_reg (op_mode, index); - - op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0); - - op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1]; - if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1]) - (op1, op_mode)) - op1 = copy_to_mode_reg (op_mode, op1); - - op2 = expand_expr (range, NULL_RTX, VOIDmode, 0); - - op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2]; - if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2]) - (op2, op_mode)) - op2 = copy_to_mode_reg (op_mode, op2); - - emit_jump_insn (gen_casesi (index, op1, op2, - table_label, default_label)); - win = 1; - } -#endif -#ifdef HAVE_tablejump - if (! win && HAVE_tablejump) - { - index_expr = convert (thiscase->data.case_stmt.nominal_type, - fold (build (MINUS_EXPR, index_type, - index_expr, minval))); - index_type = TREE_TYPE (index_expr); - index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); - emit_queue (); - index = protect_from_queue (index, 0); - do_pending_stack_adjust (); - - do_tablejump (index, TYPE_MODE (index_type), - expand_expr (range, NULL_RTX, VOIDmode, 0), - table_label, default_label); - win = 1; - } -#endif - if (! win) - abort (); - - /* Get table of labels to jump to, in order of case index. */ - - ncases = TREE_INT_CST_LOW (range) + 1; - labelvec = (rtx *) alloca (ncases * sizeof (rtx)); - bzero ((char *) labelvec, ncases * sizeof (rtx)); - - for (n = thiscase->data.case_stmt.case_list; n; n = n->right) - { - register HOST_WIDE_INT i - = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval); - - while (1) - { - labelvec[i] - = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); - if (i + TREE_INT_CST_LOW (orig_minval) - == TREE_INT_CST_LOW (n->high)) - break; - i++; - } - } - - /* Fill in the gaps with the default. */ - for (i = 0; i < ncases; i++) - if (labelvec[i] == 0) - labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); - - /* Output the table */ - emit_label (table_label); - - if (CASE_VECTOR_PC_RELATIVE || flag_pic) - emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, - gen_rtx_LABEL_REF (Pmode, table_label), - gen_rtvec_v (ncases, labelvec), - const0_rtx, const0_rtx, 0)); - else - emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, - gen_rtvec_v (ncases, labelvec))); - - /* If the case insn drops through the table, - after the table we must jump to the default-label. - Otherwise record no drop-through after the table. */ -#ifdef CASE_DROPS_THROUGH - emit_jump (default_label); -#else - emit_barrier (); -#endif - } - - before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ()); - reorder_insns (before_case, get_last_insn (), - thiscase->data.case_stmt.start); - } - else - end_cleanup_deferral (); - - if (thiscase->exit_label) - emit_label (thiscase->exit_label); - - POPSTACK (case_stack); - - free_temp_slots (); -} - -/* Convert the tree NODE into a list linked by the right field, with the left - field zeroed. RIGHT is used for recursion; it is a list to be placed - rightmost in the resulting list. */ - -static struct case_node * -case_tree2list (node, right) - struct case_node *node, *right; -{ - struct case_node *left; - - if (node->right) - right = case_tree2list (node->right, right); - - node->right = right; - if ((left = node->left)) - { - node->left = 0; - return case_tree2list (left, node); - } - - return node; -} - -/* Generate code to jump to LABEL if OP1 and OP2 are equal. */ - -static void -do_jump_if_equal (op1, op2, label, unsignedp) - rtx op1, op2, label; - int unsignedp; -{ - if (GET_CODE (op1) == CONST_INT - && GET_CODE (op2) == CONST_INT) - { - if (INTVAL (op1) == INTVAL (op2)) - emit_jump (label); - } - else - { - enum machine_mode mode = GET_MODE (op1); - if (mode == VOIDmode) - mode = GET_MODE (op2); - emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp, - 0, label); - } -} - -/* Not all case values are encountered equally. This function - uses a heuristic to weight case labels, in cases where that - looks like a reasonable thing to do. - - Right now, all we try to guess is text, and we establish the - following weights: - - chars above space: 16 - digits: 16 - default: 12 - space, punct: 8 - tab: 4 - newline: 2 - other "\" chars: 1 - remaining chars: 0 - - If we find any cases in the switch that are not either -1 or in the range - of valid ASCII characters, or are control characters other than those - commonly used with "\", don't treat this switch scanning text. - - Return 1 if these nodes are suitable for cost estimation, otherwise - return 0. */ - -static int -estimate_case_costs (node) - case_node_ptr node; -{ - tree min_ascii = build_int_2 (-1, -1); - tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0)); - case_node_ptr n; - int i; - - /* If we haven't already made the cost table, make it now. Note that the - lower bound of the table is -1, not zero. */ - - if (cost_table == NULL) - { - cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1; - bzero ((char *) (cost_table - 1), 129 * sizeof (short)); - - for (i = 0; i < 128; i++) - { - if (ISALNUM (i)) - cost_table[i] = 16; - else if (ISPUNCT (i)) - cost_table[i] = 8; - else if (ISCNTRL (i)) - cost_table[i] = -1; - } - - cost_table[' '] = 8; - cost_table['\t'] = 4; - cost_table['\0'] = 4; - cost_table['\n'] = 2; - cost_table['\f'] = 1; - cost_table['\v'] = 1; - cost_table['\b'] = 1; - } - - /* See if all the case expressions look like text. It is text if the - constant is >= -1 and the highest constant is <= 127. Do all comparisons - as signed arithmetic since we don't want to ever access cost_table with a - value less than -1. Also check that none of the constants in a range - are strange control characters. */ - - for (n = node; n; n = n->right) - { - if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) - return 0; - - for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++) - if (cost_table[i] < 0) - return 0; - } - - /* All interesting values are within the range of interesting - ASCII characters. */ - return 1; -} - -/* Scan an ordered list of case nodes - combining those with consecutive values or ranges. - - Eg. three separate entries 1: 2: 3: become one entry 1..3: */ - -static void -group_case_nodes (head) - case_node_ptr head; -{ - case_node_ptr node = head; - - while (node) - { - rtx lb = next_real_insn (label_rtx (node->code_label)); - rtx lb2; - case_node_ptr np = node; - - /* Try to group the successors of NODE with NODE. */ - while (((np = np->right) != 0) - /* Do they jump to the same place? */ - && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb - || (lb != 0 && lb2 != 0 - && simplejump_p (lb) - && simplejump_p (lb2) - && rtx_equal_p (SET_SRC (PATTERN (lb)), - SET_SRC (PATTERN (lb2))))) - /* Are their ranges consecutive? */ - && tree_int_cst_equal (np->low, - fold (build (PLUS_EXPR, - TREE_TYPE (node->high), - node->high, - integer_one_node))) - /* An overflow is not consecutive. */ - && tree_int_cst_lt (node->high, - fold (build (PLUS_EXPR, - TREE_TYPE (node->high), - node->high, - integer_one_node)))) - { - node->high = np->high; - } - /* NP is the first node after NODE which can't be grouped with it. - Delete the nodes in between, and move on to that node. */ - node->right = np; - node = np; - } -} - -/* Take an ordered list of case nodes - and transform them into a near optimal binary tree, - on the assumption that any target code selection value is as - likely as any other. - - The transformation is performed by splitting the ordered - list into two equal sections plus a pivot. The parts are - then attached to the pivot as left and right branches. Each - branch is then transformed recursively. */ - -static void -balance_case_nodes (head, parent) - case_node_ptr *head; - case_node_ptr parent; -{ - register case_node_ptr np; - - np = *head; - if (np) - { - int cost = 0; - int i = 0; - int ranges = 0; - register case_node_ptr *npp; - case_node_ptr left; - - /* Count the number of entries on branch. Also count the ranges. */ - - while (np) - { - if (!tree_int_cst_equal (np->low, np->high)) - { - ranges++; - if (use_cost_table) - cost += cost_table[TREE_INT_CST_LOW (np->high)]; - } - - if (use_cost_table) - cost += cost_table[TREE_INT_CST_LOW (np->low)]; - - i++; - np = np->right; - } - - if (i > 2) - { - /* Split this list if it is long enough for that to help. */ - npp = head; - left = *npp; - if (use_cost_table) - { - /* Find the place in the list that bisects the list's total cost, - Here I gets half the total cost. */ - int n_moved = 0; - i = (cost + 1) / 2; - while (1) - { - /* Skip nodes while their cost does not reach that amount. */ - if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) - i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)]; - i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)]; - if (i <= 0) - break; - npp = &(*npp)->right; - n_moved += 1; - } - if (n_moved == 0) - { - /* Leave this branch lopsided, but optimize left-hand - side and fill in `parent' fields for right-hand side. */ - np = *head; - np->parent = parent; - balance_case_nodes (&np->left, np); - for (; np->right; np = np->right) - np->right->parent = np; - return; - } - } - /* If there are just three nodes, split at the middle one. */ - else if (i == 3) - npp = &(*npp)->right; - else - { - /* Find the place in the list that bisects the list's total cost, - where ranges count as 2. - Here I gets half the total cost. */ - i = (i + ranges + 1) / 2; - while (1) - { - /* Skip nodes while their cost does not reach that amount. */ - if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) - i--; - i--; - if (i <= 0) - break; - npp = &(*npp)->right; - } - } - *head = np = *npp; - *npp = 0; - np->parent = parent; - np->left = left; - - /* Optimize each of the two split parts. */ - balance_case_nodes (&np->left, np); - balance_case_nodes (&np->right, np); - } - else - { - /* Else leave this branch as one level, - but fill in `parent' fields. */ - np = *head; - np->parent = parent; - for (; np->right; np = np->right) - np->right->parent = np; - } - } -} - -/* Search the parent sections of the case node tree - to see if a test for the lower bound of NODE would be redundant. - INDEX_TYPE is the type of the index expression. - - The instructions to generate the case decision tree are - output in the same order as nodes are processed so it is - known that if a parent node checks the range of the current - node minus one that the current node is bounded at its lower - span. Thus the test would be redundant. */ - -static int -node_has_low_bound (node, index_type) - case_node_ptr node; - tree index_type; -{ - tree low_minus_one; - case_node_ptr pnode; - - /* If the lower bound of this node is the lowest value in the index type, - we need not test it. */ - - if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) - return 1; - - /* If this node has a left branch, the value at the left must be less - than that at this node, so it cannot be bounded at the bottom and - we need not bother testing any further. */ - - if (node->left) - return 0; - - low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low), - node->low, integer_one_node)); - - /* If the subtraction above overflowed, we can't verify anything. - Otherwise, look for a parent that tests our value - 1. */ - - if (! tree_int_cst_lt (low_minus_one, node->low)) - return 0; - - for (pnode = node->parent; pnode; pnode = pnode->parent) - if (tree_int_cst_equal (low_minus_one, pnode->high)) - return 1; - - return 0; -} - -/* Search the parent sections of the case node tree - to see if a test for the upper bound of NODE would be redundant. - INDEX_TYPE is the type of the index expression. - - The instructions to generate the case decision tree are - output in the same order as nodes are processed so it is - known that if a parent node checks the range of the current - node plus one that the current node is bounded at its upper - span. Thus the test would be redundant. */ - -static int -node_has_high_bound (node, index_type) - case_node_ptr node; - tree index_type; -{ - tree high_plus_one; - case_node_ptr pnode; - - /* If there is no upper bound, obviously no test is needed. */ - - if (TYPE_MAX_VALUE (index_type) == NULL) - return 1; - - /* If the upper bound of this node is the highest value in the type - of the index expression, we need not test against it. */ - - if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) - return 1; - - /* If this node has a right branch, the value at the right must be greater - than that at this node, so it cannot be bounded at the top and - we need not bother testing any further. */ - - if (node->right) - return 0; - - high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high), - node->high, integer_one_node)); - - /* If the addition above overflowed, we can't verify anything. - Otherwise, look for a parent that tests our value + 1. */ - - if (! tree_int_cst_lt (node->high, high_plus_one)) - return 0; - - for (pnode = node->parent; pnode; pnode = pnode->parent) - if (tree_int_cst_equal (high_plus_one, pnode->low)) - return 1; - - return 0; -} - -/* Search the parent sections of the - case node tree to see if both tests for the upper and lower - bounds of NODE would be redundant. */ - -static int -node_is_bounded (node, index_type) - case_node_ptr node; - tree index_type; -{ - return (node_has_low_bound (node, index_type) - && node_has_high_bound (node, index_type)); -} - -/* Emit an unconditional jump to LABEL unless it would be dead code. */ - -static void -emit_jump_if_reachable (label) - rtx label; -{ - if (GET_CODE (get_last_insn ()) != BARRIER) - emit_jump (label); -} - -/* Emit step-by-step code to select a case for the value of INDEX. - The thus generated decision tree follows the form of the - case-node binary tree NODE, whose nodes represent test conditions. - INDEX_TYPE is the type of the index of the switch. - - Care is taken to prune redundant tests from the decision tree - by detecting any boundary conditions already checked by - emitted rtx. (See node_has_high_bound, node_has_low_bound - and node_is_bounded, above.) - - Where the test conditions can be shown to be redundant we emit - an unconditional jump to the target code. As a further - optimization, the subordinates of a tree node are examined to - check for bounded nodes. In this case conditional and/or - unconditional jumps as a result of the boundary check for the - current node are arranged to target the subordinates associated - code for out of bound conditions on the current node. - - We can assume that when control reaches the code generated here, - the index value has already been compared with the parents - of this node, and determined to be on the same side of each parent - as this node is. Thus, if this node tests for the value 51, - and a parent tested for 52, we don't need to consider - the possibility of a value greater than 51. If another parent - tests for the value 50, then this node need not test anything. */ - -static void -emit_case_nodes (index, node, default_label, index_type) - rtx index; - case_node_ptr node; - rtx default_label; - tree index_type; -{ - /* If INDEX has an unsigned type, we must make unsigned branches. */ - int unsignedp = TREE_UNSIGNED (index_type); - typedef rtx rtx_fn (); - enum machine_mode mode = GET_MODE (index); - - /* See if our parents have already tested everything for us. - If they have, emit an unconditional jump for this node. */ - if (node_is_bounded (node, index_type)) - emit_jump (label_rtx (node->code_label)); - - else if (tree_int_cst_equal (node->low, node->high)) - { - /* Node is single valued. First see if the index expression matches - this node and then check our children, if any. */ - - do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0), - label_rtx (node->code_label), unsignedp); - - if (node->right != 0 && node->left != 0) - { - /* This node has children on both sides. - Dispatch to one side or the other - by comparing the index value with this node's value. - If one subtree is bounded, check that one first, - so we can avoid real branches in the tree. */ - - if (node_is_bounded (node->right, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->right->code_label)); - emit_case_nodes (index, node->left, default_label, index_type); - } - - else if (node_is_bounded (node->left, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->left->code_label)); - emit_case_nodes (index, node->right, default_label, index_type); - } - - else - { - /* Neither node is bounded. First distinguish the two sides; - then emit the code for one side at a time. */ - - tree test_label - = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - - /* See if the value is on the right. */ - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - label_rtx (test_label)); - - /* Value must be on the left. - Handle the left-hand subtree. */ - emit_case_nodes (index, node->left, default_label, index_type); - /* If left-hand subtree does nothing, - go to default. */ - emit_jump_if_reachable (default_label); - - /* Code branches here for the right-hand subtree. */ - expand_label (test_label); - emit_case_nodes (index, node->right, default_label, index_type); - } - } - - else if (node->right != 0 && node->left == 0) - { - /* Here we have a right child but no left so we issue conditional - branch to default and process the right child. - - Omit the conditional branch to default if we it avoid only one - right child; it costs too much space to save so little time. */ - - if (node->right->right || node->right->left - || !tree_int_cst_equal (node->right->low, node->right->high)) - { - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, - NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - emit_case_nodes (index, node->right, default_label, index_type); - } - else - /* We cannot process node->right normally - since we haven't ruled out the numbers less than - this node's value. So handle node->right explicitly. */ - do_jump_if_equal (index, - expand_expr (node->right->low, NULL_RTX, - VOIDmode, 0), - label_rtx (node->right->code_label), unsignedp); - } - - else if (node->right == 0 && node->left != 0) - { - /* Just one subtree, on the left. */ - -#if 0 /* The following code and comment were formerly part - of the condition here, but they didn't work - and I don't understand what the idea was. -- rms. */ - /* If our "most probable entry" is less probable - than the default label, emit a jump to - the default label using condition codes - already lying around. With no right branch, - a branch-greater-than will get us to the default - label correctly. */ - if (use_cost_table - && cost_table[TREE_INT_CST_LOW (node->high)] < 12) - ; -#endif /* 0 */ - if (node->left->left || node->left->right - || !tree_int_cst_equal (node->left->low, node->left->high)) - { - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, - NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - emit_case_nodes (index, node->left, default_label, index_type); - } - else - /* We cannot process node->left normally - since we haven't ruled out the numbers less than - this node's value. So handle node->left explicitly. */ - do_jump_if_equal (index, - expand_expr (node->left->low, NULL_RTX, - VOIDmode, 0), - label_rtx (node->left->code_label), unsignedp); - } - } - else - { - /* Node is a range. These cases are very similar to those for a single - value, except that we do not start by testing whether this node - is the one to branch to. */ - - if (node->right != 0 && node->left != 0) - { - /* Node has subtrees on both sides. - If the right-hand subtree is bounded, - test for it first, since we can go straight there. - Otherwise, we need to make a branch in the control structure, - then handle the two subtrees. */ - tree test_label = 0; - - - if (node_is_bounded (node->right, index_type)) - /* Right hand node is fully bounded so we can eliminate any - testing and branch directly to the target code. */ - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->right->code_label)); - else - { - /* Right hand node requires testing. - Branch to a label where we will handle it later. */ - - test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - label_rtx (test_label)); - } - - /* Value belongs to this node or to the left-hand subtree. */ - - emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - GE, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->code_label)); - - /* Handle the left-hand subtree. */ - emit_case_nodes (index, node->left, default_label, index_type); - - /* If right node had to be handled later, do that now. */ - - if (test_label) - { - /* If the left-hand subtree fell through, - don't let it fall into the right-hand subtree. */ - emit_jump_if_reachable (default_label); - - expand_label (test_label); - emit_case_nodes (index, node->right, default_label, index_type); - } - } - - else if (node->right != 0 && node->left == 0) - { - /* Deal with values to the left of this node, - if they are possible. */ - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - /* Value belongs to this node or to the right-hand subtree. */ - - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - LE, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->code_label)); - - emit_case_nodes (index, node->right, default_label, index_type); - } - - else if (node->right == 0 && node->left != 0) - { - /* Deal with values to the right of this node, - if they are possible. */ - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - /* Value belongs to this node or to the left-hand subtree. */ - - emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - GE, NULL_RTX, mode, unsignedp, 0, - label_rtx (node->code_label)); - - emit_case_nodes (index, node->left, default_label, index_type); - } - - else - { - /* Node has no children so we check low and high bounds to remove - redundant tests. Only one of the bounds can exist, - since otherwise this node is bounded--a case tested already. */ - - if (!node_has_high_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX, - VOIDmode, 0), - GT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - if (!node_has_low_bound (node, index_type)) - { - emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX, - VOIDmode, 0), - LT, NULL_RTX, mode, unsignedp, 0, - default_label); - } - - emit_jump (label_rtx (node->code_label)); - } - } -} - -/* These routines are used by the loop unrolling code. They copy BLOCK trees - so that the debugging info will be correct for the unrolled loop. */ - -/* Indexed by block number, contains a pointer to the N'th block node. - - Allocated by the call to identify_blocks, then released after the call - to reorder_blocks in the function unroll_block_trees. */ - -static tree *block_vector; - -void -find_loop_tree_blocks () -{ - tree block = DECL_INITIAL (current_function_decl); - - block_vector = identify_blocks (block, get_insns ()); -} - -void -unroll_block_trees () -{ - tree block = DECL_INITIAL (current_function_decl); - - reorder_blocks (block_vector, block, get_insns ()); - - /* Release any memory allocated by identify_blocks. */ - if (block_vector) - free (block_vector); -} |