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Diffstat (limited to 'contrib/gcc/local-alloc.c')
| -rw-r--r-- | contrib/gcc/local-alloc.c | 2267 |
1 files changed, 0 insertions, 2267 deletions
diff --git a/contrib/gcc/local-alloc.c b/contrib/gcc/local-alloc.c deleted file mode 100644 index 2fc3aec49770..000000000000 --- a/contrib/gcc/local-alloc.c +++ /dev/null @@ -1,2267 +0,0 @@ -/* Allocate registers within a basic block, for GNU compiler. - Copyright (C) 1987, 88, 91, 93-98, 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. */ - - -/* Allocation of hard register numbers to pseudo registers is done in - two passes. In this pass we consider only regs that are born and - die once within one basic block. We do this one basic block at a - time. Then the next pass allocates the registers that remain. - Two passes are used because this pass uses methods that work only - on linear code, but that do a better job than the general methods - used in global_alloc, and more quickly too. - - The assignments made are recorded in the vector reg_renumber - whose space is allocated here. The rtl code itself is not altered. - - We assign each instruction in the basic block a number - which is its order from the beginning of the block. - Then we can represent the lifetime of a pseudo register with - a pair of numbers, and check for conflicts easily. - We can record the availability of hard registers with a - HARD_REG_SET for each instruction. The HARD_REG_SET - contains 0 or 1 for each hard reg. - - To avoid register shuffling, we tie registers together when one - dies by being copied into another, or dies in an instruction that - does arithmetic to produce another. The tied registers are - allocated as one. Registers with different reg class preferences - can never be tied unless the class preferred by one is a subclass - of the one preferred by the other. - - Tying is represented with "quantity numbers". - A non-tied register is given a new quantity number. - Tied registers have the same quantity number. - - We have provision to exempt registers, even when they are contained - within the block, that can be tied to others that are not contained in it. - This is so that global_alloc could process them both and tie them then. - But this is currently disabled since tying in global_alloc is not - yet implemented. */ - -/* Pseudos allocated here can be reallocated by global.c if the hard register - is used as a spill register. Currently we don't allocate such pseudos - here if their preferred class is likely to be used by spills. */ - -#include "config.h" -#include "system.h" -#include "rtl.h" -#include "flags.h" -#include "basic-block.h" -#include "regs.h" -#include "hard-reg-set.h" -#include "insn-config.h" -#include "insn-attr.h" -#include "recog.h" -#include "output.h" -#include "toplev.h" - -/* Next quantity number available for allocation. */ - -static int next_qty; - -/* In all the following vectors indexed by quantity number. */ - -/* Element Q is the hard reg number chosen for quantity Q, - or -1 if none was found. */ - -static short *qty_phys_reg; - -/* We maintain two hard register sets that indicate suggested hard registers - for each quantity. The first, qty_phys_copy_sugg, contains hard registers - that are tied to the quantity by a simple copy. The second contains all - hard registers that are tied to the quantity via an arithmetic operation. - - The former register set is given priority for allocation. This tends to - eliminate copy insns. */ - -/* Element Q is a set of hard registers that are suggested for quantity Q by - copy insns. */ - -static HARD_REG_SET *qty_phys_copy_sugg; - -/* Element Q is a set of hard registers that are suggested for quantity Q by - arithmetic insns. */ - -static HARD_REG_SET *qty_phys_sugg; - -/* Element Q is the number of suggested registers in qty_phys_copy_sugg. */ - -static short *qty_phys_num_copy_sugg; - -/* Element Q is the number of suggested registers in qty_phys_sugg. */ - -static short *qty_phys_num_sugg; - -/* Element Q is the number of refs to quantity Q. */ - -static int *qty_n_refs; - -/* Element Q is a reg class contained in (smaller than) the - preferred classes of all the pseudo regs that are tied in quantity Q. - This is the preferred class for allocating that quantity. */ - -static enum reg_class *qty_min_class; - -/* Insn number (counting from head of basic block) - where quantity Q was born. -1 if birth has not been recorded. */ - -static int *qty_birth; - -/* Insn number (counting from head of basic block) - where quantity Q died. Due to the way tying is done, - and the fact that we consider in this pass only regs that die but once, - a quantity can die only once. Each quantity's life span - is a set of consecutive insns. -1 if death has not been recorded. */ - -static int *qty_death; - -/* Number of words needed to hold the data in quantity Q. - This depends on its machine mode. It is used for these purposes: - 1. It is used in computing the relative importances of qtys, - which determines the order in which we look for regs for them. - 2. It is used in rules that prevent tying several registers of - different sizes in a way that is geometrically impossible - (see combine_regs). */ - -static int *qty_size; - -/* This holds the mode of the registers that are tied to qty Q, - or VOIDmode if registers with differing modes are tied together. */ - -static enum machine_mode *qty_mode; - -/* Number of times a reg tied to qty Q lives across a CALL_INSN. */ - -static int *qty_n_calls_crossed; - -/* Register class within which we allocate qty Q if we can't get - its preferred class. */ - -static enum reg_class *qty_alternate_class; - -/* Element Q is nonzero if this quantity has been used in a SUBREG - that changes its size. */ - -static char *qty_changes_size; - -/* Element Q is the register number of one pseudo register whose - reg_qty value is Q. This register should be the head of the chain - maintained in reg_next_in_qty. */ - -static int *qty_first_reg; - -/* If (REG N) has been assigned a quantity number, is a register number - of another register assigned the same quantity number, or -1 for the - end of the chain. qty_first_reg point to the head of this chain. */ - -static int *reg_next_in_qty; - -/* reg_qty[N] (where N is a pseudo reg number) is the qty number of that reg - if it is >= 0, - of -1 if this register cannot be allocated by local-alloc, - or -2 if not known yet. - - Note that if we see a use or death of pseudo register N with - reg_qty[N] == -2, register N must be local to the current block. If - it were used in more than one block, we would have reg_qty[N] == -1. - This relies on the fact that if reg_basic_block[N] is >= 0, register N - will not appear in any other block. We save a considerable number of - tests by exploiting this. - - If N is < FIRST_PSEUDO_REGISTER, reg_qty[N] is undefined and should not - be referenced. */ - -static int *reg_qty; - -/* The offset (in words) of register N within its quantity. - This can be nonzero if register N is SImode, and has been tied - to a subreg of a DImode register. */ - -static char *reg_offset; - -/* Vector of substitutions of register numbers, - used to map pseudo regs into hardware regs. - This is set up as a result of register allocation. - Element N is the hard reg assigned to pseudo reg N, - or is -1 if no hard reg was assigned. - If N is a hard reg number, element N is N. */ - -short *reg_renumber; - -/* Set of hard registers live at the current point in the scan - of the instructions in a basic block. */ - -static HARD_REG_SET regs_live; - -/* Each set of hard registers indicates registers live at a particular - point in the basic block. For N even, regs_live_at[N] says which - hard registers are needed *after* insn N/2 (i.e., they may not - conflict with the outputs of insn N/2 or the inputs of insn N/2 + 1. - - If an object is to conflict with the inputs of insn J but not the - outputs of insn J + 1, we say it is born at index J*2 - 1. Similarly, - if it is to conflict with the outputs of insn J but not the inputs of - insn J + 1, it is said to die at index J*2 + 1. */ - -static HARD_REG_SET *regs_live_at; - -/* Communicate local vars `insn_number' and `insn' - from `block_alloc' to `reg_is_set', `wipe_dead_reg', and `alloc_qty'. */ -static int this_insn_number; -static rtx this_insn; - -/* Used to communicate changes made by update_equiv_regs to - memref_referenced_p. reg_equiv_replacement is set for any REG_EQUIV note - found or created, so that we can keep track of what memory accesses might - be created later, e.g. by reload. */ - -static rtx *reg_equiv_replacement; - -/* Used for communication between update_equiv_regs and no_equiv. */ -static rtx *reg_equiv_init_insns; - -/* Nonzero if we recorded an equivalence for a LABEL_REF. */ -static int recorded_label_ref; - -static void alloc_qty PROTO((int, enum machine_mode, int, int)); -static void validate_equiv_mem_from_store PROTO((rtx, rtx)); -static int validate_equiv_mem PROTO((rtx, rtx, rtx)); -static int contains_replace_regs PROTO((rtx, char *)); -static int memref_referenced_p PROTO((rtx, rtx)); -static int memref_used_between_p PROTO((rtx, rtx, rtx)); -static void update_equiv_regs PROTO((void)); -static void no_equiv PROTO((rtx, rtx)); -static void block_alloc PROTO((int)); -static int qty_sugg_compare PROTO((int, int)); -static int qty_sugg_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR)); -static int qty_compare PROTO((int, int)); -static int qty_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR)); -static int combine_regs PROTO((rtx, rtx, int, int, rtx, int)); -static int reg_meets_class_p PROTO((int, enum reg_class)); -static void update_qty_class PROTO((int, int)); -static void reg_is_set PROTO((rtx, rtx)); -static void reg_is_born PROTO((rtx, int)); -static void wipe_dead_reg PROTO((rtx, int)); -static int find_free_reg PROTO((enum reg_class, enum machine_mode, - int, int, int, int, int)); -static void mark_life PROTO((int, enum machine_mode, int)); -static void post_mark_life PROTO((int, enum machine_mode, int, int, int)); -static int no_conflict_p PROTO((rtx, rtx, rtx)); -static int requires_inout PROTO((const char *)); - -/* Allocate a new quantity (new within current basic block) - for register number REGNO which is born at index BIRTH - within the block. MODE and SIZE are info on reg REGNO. */ - -static void -alloc_qty (regno, mode, size, birth) - int regno; - enum machine_mode mode; - int size, birth; -{ - register int qty = next_qty++; - - reg_qty[regno] = qty; - reg_offset[regno] = 0; - reg_next_in_qty[regno] = -1; - - qty_first_reg[qty] = regno; - qty_size[qty] = size; - qty_mode[qty] = mode; - qty_birth[qty] = birth; - qty_n_calls_crossed[qty] = REG_N_CALLS_CROSSED (regno); - qty_min_class[qty] = reg_preferred_class (regno); - qty_alternate_class[qty] = reg_alternate_class (regno); - qty_n_refs[qty] = REG_N_REFS (regno); - qty_changes_size[qty] = REG_CHANGES_SIZE (regno); -} - -/* Main entry point of this file. */ - -int -local_alloc () -{ - register int b, i; - int max_qty; - - /* We need to keep track of whether or not we recorded a LABEL_REF so - that we know if the jump optimizer needs to be rerun. */ - recorded_label_ref = 0; - - /* Leaf functions and non-leaf functions have different needs. - If defined, let the machine say what kind of ordering we - should use. */ -#ifdef ORDER_REGS_FOR_LOCAL_ALLOC - ORDER_REGS_FOR_LOCAL_ALLOC; -#endif - - /* Promote REG_EQUAL notes to REG_EQUIV notes and adjust status of affected - registers. */ - update_equiv_regs (); - - /* This sets the maximum number of quantities we can have. Quantity - numbers start at zero and we can have one for each pseudo. */ - max_qty = (max_regno - FIRST_PSEUDO_REGISTER); - - /* Allocate vectors of temporary data. - See the declarations of these variables, above, - for what they mean. */ - - qty_phys_reg = (short *) alloca (max_qty * sizeof (short)); - qty_phys_copy_sugg - = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET)); - qty_phys_num_copy_sugg = (short *) alloca (max_qty * sizeof (short)); - qty_phys_sugg = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET)); - qty_phys_num_sugg = (short *) alloca (max_qty * sizeof (short)); - qty_birth = (int *) alloca (max_qty * sizeof (int)); - qty_death = (int *) alloca (max_qty * sizeof (int)); - qty_first_reg = (int *) alloca (max_qty * sizeof (int)); - qty_size = (int *) alloca (max_qty * sizeof (int)); - qty_mode - = (enum machine_mode *) alloca (max_qty * sizeof (enum machine_mode)); - qty_n_calls_crossed = (int *) alloca (max_qty * sizeof (int)); - qty_min_class - = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class)); - qty_alternate_class - = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class)); - qty_n_refs = (int *) alloca (max_qty * sizeof (int)); - qty_changes_size = (char *) alloca (max_qty * sizeof (char)); - - reg_qty = (int *) xmalloc (max_regno * sizeof (int)); - reg_offset = (char *) xmalloc (max_regno * sizeof (char)); - reg_next_in_qty = (int *) xmalloc(max_regno * sizeof (int)); - - /* Allocate the reg_renumber array */ - allocate_reg_info (max_regno, FALSE, TRUE); - - /* Determine which pseudo-registers can be allocated by local-alloc. - In general, these are the registers used only in a single block and - which only die once. However, if a register's preferred class has only - a few entries, don't allocate this register here unless it is preferred - or nothing since retry_global_alloc won't be able to move it to - GENERAL_REGS if a reload register of this class is needed. - - We need not be concerned with which block actually uses the register - since we will never see it outside that block. */ - - for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) - { - if (REG_BASIC_BLOCK (i) >= 0 && REG_N_DEATHS (i) == 1 - && (reg_alternate_class (i) == NO_REGS - || ! CLASS_LIKELY_SPILLED_P (reg_preferred_class (i)))) - reg_qty[i] = -2; - else - reg_qty[i] = -1; - } - - /* Force loop below to initialize entire quantity array. */ - next_qty = max_qty; - - /* Allocate each block's local registers, block by block. */ - - for (b = 0; b < n_basic_blocks; b++) - { - /* NEXT_QTY indicates which elements of the `qty_...' - vectors might need to be initialized because they were used - for the previous block; it is set to the entire array before - block 0. Initialize those, with explicit loop if there are few, - else with bzero and bcopy. Do not initialize vectors that are - explicit set by `alloc_qty'. */ - - if (next_qty < 6) - { - for (i = 0; i < next_qty; i++) - { - CLEAR_HARD_REG_SET (qty_phys_copy_sugg[i]); - qty_phys_num_copy_sugg[i] = 0; - CLEAR_HARD_REG_SET (qty_phys_sugg[i]); - qty_phys_num_sugg[i] = 0; - } - } - else - { -#define CLEAR(vector) \ - bzero ((char *) (vector), (sizeof (*(vector))) * next_qty); - - CLEAR (qty_phys_copy_sugg); - CLEAR (qty_phys_num_copy_sugg); - CLEAR (qty_phys_sugg); - CLEAR (qty_phys_num_sugg); - } - - next_qty = 0; - - block_alloc (b); -#ifdef USE_C_ALLOCA - alloca (0); -#endif - } - - free (reg_qty); - free (reg_offset); - free (reg_next_in_qty); - return recorded_label_ref; -} - -/* Depth of loops we are in while in update_equiv_regs. */ -static int loop_depth; - -/* Used for communication between the following two functions: contains - a MEM that we wish to ensure remains unchanged. */ -static rtx equiv_mem; - -/* Set nonzero if EQUIV_MEM is modified. */ -static int equiv_mem_modified; - -/* If EQUIV_MEM is modified by modifying DEST, indicate that it is modified. - Called via note_stores. */ - -static void -validate_equiv_mem_from_store (dest, set) - rtx dest; - rtx set ATTRIBUTE_UNUSED; -{ - if ((GET_CODE (dest) == REG - && reg_overlap_mentioned_p (dest, equiv_mem)) - || (GET_CODE (dest) == MEM - && true_dependence (dest, VOIDmode, equiv_mem, rtx_varies_p))) - equiv_mem_modified = 1; -} - -/* Verify that no store between START and the death of REG invalidates - MEMREF. MEMREF is invalidated by modifying a register used in MEMREF, - by storing into an overlapping memory location, or with a non-const - CALL_INSN. - - Return 1 if MEMREF remains valid. */ - -static int -validate_equiv_mem (start, reg, memref) - rtx start; - rtx reg; - rtx memref; -{ - rtx insn; - rtx note; - - equiv_mem = memref; - equiv_mem_modified = 0; - - /* If the memory reference has side effects or is volatile, it isn't a - valid equivalence. */ - if (side_effects_p (memref)) - return 0; - - for (insn = start; insn && ! equiv_mem_modified; insn = NEXT_INSN (insn)) - { - if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') - continue; - - if (find_reg_note (insn, REG_DEAD, reg)) - return 1; - - if (GET_CODE (insn) == CALL_INSN && ! RTX_UNCHANGING_P (memref) - && ! CONST_CALL_P (insn)) - return 0; - - note_stores (PATTERN (insn), validate_equiv_mem_from_store); - - /* If a register mentioned in MEMREF is modified via an - auto-increment, we lose the equivalence. Do the same if one - dies; although we could extend the life, it doesn't seem worth - the trouble. */ - - for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - if ((REG_NOTE_KIND (note) == REG_INC - || REG_NOTE_KIND (note) == REG_DEAD) - && GET_CODE (XEXP (note, 0)) == REG - && reg_overlap_mentioned_p (XEXP (note, 0), memref)) - return 0; - } - - return 0; -} - -/* TRUE if X uses any registers for which reg_equiv_replace is true. */ - -static int -contains_replace_regs (x, reg_equiv_replace) - rtx x; - char *reg_equiv_replace; -{ - int i, j; - char *fmt; - enum rtx_code code = GET_CODE (x); - - switch (code) - { - case CONST_INT: - case CONST: - case LABEL_REF: - case SYMBOL_REF: - case CONST_DOUBLE: - case PC: - case CC0: - case HIGH: - case LO_SUM: - return 0; - - case REG: - return reg_equiv_replace[REGNO (x)]; - - default: - break; - } - - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - switch (fmt[i]) - { - case 'e': - if (contains_replace_regs (XEXP (x, i), reg_equiv_replace)) - return 1; - break; - case 'E': - for (j = XVECLEN (x, i) - 1; j >= 0; j--) - if (contains_replace_regs (XVECEXP (x, i, j), reg_equiv_replace)) - return 1; - break; - } - - return 0; -} - -/* TRUE if X references a memory location that would be affected by a store - to MEMREF. */ - -static int -memref_referenced_p (memref, x) - rtx x; - rtx memref; -{ - int i, j; - char *fmt; - enum rtx_code code = GET_CODE (x); - - switch (code) - { - case CONST_INT: - case CONST: - case LABEL_REF: - case SYMBOL_REF: - case CONST_DOUBLE: - case PC: - case CC0: - case HIGH: - case LO_SUM: - return 0; - - case REG: - return (reg_equiv_replacement[REGNO (x)] - && memref_referenced_p (memref, - reg_equiv_replacement[REGNO (x)])); - - case MEM: - if (true_dependence (memref, VOIDmode, x, rtx_varies_p)) - return 1; - break; - - case SET: - /* If we are setting a MEM, it doesn't count (its address does), but any - other SET_DEST that has a MEM in it is referencing the MEM. */ - if (GET_CODE (SET_DEST (x)) == MEM) - { - if (memref_referenced_p (memref, XEXP (SET_DEST (x), 0))) - return 1; - } - else if (memref_referenced_p (memref, SET_DEST (x))) - return 1; - - return memref_referenced_p (memref, SET_SRC (x)); - - default: - break; - } - - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - switch (fmt[i]) - { - case 'e': - if (memref_referenced_p (memref, XEXP (x, i))) - return 1; - break; - case 'E': - for (j = XVECLEN (x, i) - 1; j >= 0; j--) - if (memref_referenced_p (memref, XVECEXP (x, i, j))) - return 1; - break; - } - - return 0; -} - -/* TRUE if some insn in the range (START, END] references a memory location - that would be affected by a store to MEMREF. */ - -static int -memref_used_between_p (memref, start, end) - rtx memref; - rtx start; - rtx end; -{ - rtx insn; - - for (insn = NEXT_INSN (start); insn != NEXT_INSN (end); - insn = NEXT_INSN (insn)) - if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' - && memref_referenced_p (memref, PATTERN (insn))) - return 1; - - return 0; -} - -/* Return nonzero if the rtx X is invariant over the current function. */ -int -function_invariant_p (x) - rtx x; -{ - if (CONSTANT_P (x)) - return 1; - if (x == frame_pointer_rtx || x == arg_pointer_rtx) - return 1; - if (GET_CODE (x) == PLUS - && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx) - && CONSTANT_P (XEXP (x, 1))) - return 1; - return 0; -} - -/* Find registers that are equivalent to a single value throughout the - compilation (either because they can be referenced in memory or are set once - from a single constant). Lower their priority for a register. - - If such a register is only referenced once, try substituting its value - into the using insn. If it succeeds, we can eliminate the register - completely. */ - -static void -update_equiv_regs () -{ - /* Set when an attempt should be made to replace a register with the - associated reg_equiv_replacement entry at the end of this function. */ - char *reg_equiv_replace - = (char *) alloca (max_regno * sizeof *reg_equiv_replace); - rtx insn; - int block, depth; - - reg_equiv_init_insns = (rtx *) alloca (max_regno * sizeof (rtx)); - reg_equiv_replacement = (rtx *) alloca (max_regno * sizeof (rtx)); - - bzero ((char *) reg_equiv_init_insns, max_regno * sizeof (rtx)); - bzero ((char *) reg_equiv_replacement, max_regno * sizeof (rtx)); - bzero ((char *) reg_equiv_replace, max_regno * sizeof *reg_equiv_replace); - - init_alias_analysis (); - - loop_depth = 1; - - /* Scan the insns and find which registers have equivalences. Do this - in a separate scan of the insns because (due to -fcse-follow-jumps) - a register can be set below its use. */ - for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - { - rtx note; - rtx set; - rtx dest, src; - int regno; - - if (GET_CODE (insn) == NOTE) - { - if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) - loop_depth++; - else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) - loop_depth--; - } - - if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') - continue; - - for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) - if (REG_NOTE_KIND (note) == REG_INC) - no_equiv (XEXP (note, 0), note); - - set = single_set (insn); - - /* If this insn contains more (or less) than a single SET, - only mark all destinations as having no known equivalence. */ - if (set == 0) - { - note_stores (PATTERN (insn), no_equiv); - continue; - } - else if (GET_CODE (PATTERN (insn)) == PARALLEL) - { - int i; - - for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) - { - rtx part = XVECEXP (PATTERN (insn), 0, i); - if (part != set) - note_stores (part, no_equiv); - } - } - - dest = SET_DEST (set); - src = SET_SRC (set); - - /* If this sets a MEM to the contents of a REG that is only used - in a single basic block, see if the register is always equivalent - to that memory location and if moving the store from INSN to the - insn that set REG is safe. If so, put a REG_EQUIV note on the - initializing insn. - - Don't add a REG_EQUIV note if the insn already has one. The existing - REG_EQUIV is likely more useful than the one we are adding. - - If one of the regs in the address is marked as reg_equiv_replace, - then we can't add this REG_EQUIV note. The reg_equiv_replace - optimization may move the set of this register immediately before - insn, which puts it after reg_equiv_init_insns[regno], and hence - the mention in the REG_EQUIV note would be to an uninitialized - pseudo. */ - /* ????? This test isn't good enough; we might see a MEM with a use of - a pseudo register before we see its setting insn that will cause - reg_equiv_replace for that pseudo to be set. - Equivalences to MEMs should be made in another pass, after the - reg_equiv_replace information has been gathered. */ - - if (GET_CODE (dest) == MEM && GET_CODE (src) == REG - && (regno = REGNO (src)) >= FIRST_PSEUDO_REGISTER - && REG_BASIC_BLOCK (regno) >= 0 - && REG_N_SETS (regno) == 1 - && reg_equiv_init_insns[regno] != 0 - && reg_equiv_init_insns[regno] != const0_rtx - && ! find_reg_note (XEXP (reg_equiv_init_insns[regno], 0), - REG_EQUIV, NULL_RTX) - && ! contains_replace_regs (XEXP (dest, 0), reg_equiv_replace)) - { - rtx init_insn = XEXP (reg_equiv_init_insns[regno], 0); - if (validate_equiv_mem (init_insn, src, dest) - && ! memref_used_between_p (dest, init_insn, insn)) - REG_NOTES (init_insn) - = gen_rtx_EXPR_LIST (REG_EQUIV, dest, REG_NOTES (init_insn)); - } - - /* We only handle the case of a pseudo register being set - once, or always to the same value. */ - /* ??? The mn10200 port breaks if we add equivalences for - values that need an ADDRESS_REGS register and set them equivalent - to a MEM of a pseudo. The actual problem is in the over-conservative - handling of INPADDR_ADDRESS / INPUT_ADDRESS / INPUT triples in - calculate_needs, but we traditionally work around this problem - here by rejecting equivalences when the destination is in a register - that's likely spilled. This is fragile, of course, since the - preferred class of a pseudo depends on all instructions that set - or use it. */ - - if (GET_CODE (dest) != REG - || (regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER - || reg_equiv_init_insns[regno] == const0_rtx - || (CLASS_LIKELY_SPILLED_P (reg_preferred_class (regno)) - && GET_CODE (src) == MEM)) - { - /* This might be seting a SUBREG of a pseudo, a pseudo that is - also set somewhere else to a constant. */ - note_stores (set, no_equiv); - continue; - } - /* Don't handle the equivalence if the source is in a register - class that's likely to be spilled. */ - if (GET_CODE (src) == REG - && REGNO (src) >= FIRST_PSEUDO_REGISTER - && CLASS_LIKELY_SPILLED_P (reg_preferred_class (REGNO (src)))) - { - no_equiv (dest, set); - continue; - } - - note = find_reg_note (insn, REG_EQUAL, NULL_RTX); - - if (REG_N_SETS (regno) != 1 - && (! note - || ! function_invariant_p (XEXP (note, 0)) - || (reg_equiv_replacement[regno] - && ! rtx_equal_p (XEXP (note, 0), - reg_equiv_replacement[regno])))) - { - no_equiv (dest, set); - continue; - } - /* Record this insn as initializing this register. */ - reg_equiv_init_insns[regno] - = gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv_init_insns[regno]); - - /* If this register is known to be equal to a constant, record that - it is always equivalent to the constant. */ - if (note && function_invariant_p (XEXP (note, 0))) - PUT_MODE (note, (enum machine_mode) REG_EQUIV); - - /* If this insn introduces a "constant" register, decrease the priority - of that register. Record this insn if the register is only used once - more and the equivalence value is the same as our source. - - The latter condition is checked for two reasons: First, it is an - indication that it may be more efficient to actually emit the insn - as written (if no registers are available, reload will substitute - the equivalence). Secondly, it avoids problems with any registers - dying in this insn whose death notes would be missed. - - If we don't have a REG_EQUIV note, see if this insn is loading - a register used only in one basic block from a MEM. If so, and the - MEM remains unchanged for the life of the register, add a REG_EQUIV - note. */ - - note = find_reg_note (insn, REG_EQUIV, NULL_RTX); - - if (note == 0 && REG_BASIC_BLOCK (regno) >= 0 - && GET_CODE (SET_SRC (set)) == MEM - && validate_equiv_mem (insn, dest, SET_SRC (set))) - REG_NOTES (insn) = note = gen_rtx_EXPR_LIST (REG_EQUIV, SET_SRC (set), - REG_NOTES (insn)); - - if (note) - { - int regno = REGNO (dest); - - /* Record whether or not we created a REG_EQUIV note for a LABEL_REF. - We might end up substituting the LABEL_REF for uses of the - pseudo here or later. That kind of transformation may turn an - indirect jump into a direct jump, in which case we must rerun the - jump optimizer to ensure that the JUMP_LABEL fields are valid. */ - if (GET_CODE (XEXP (note, 0)) == LABEL_REF - || (GET_CODE (XEXP (note, 0)) == CONST - && GET_CODE (XEXP (XEXP (note, 0), 0)) == PLUS - && (GET_CODE (XEXP (XEXP (XEXP (note, 0), 0), 0)) - == LABEL_REF))) - recorded_label_ref = 1; - - - reg_equiv_replacement[regno] = XEXP (note, 0); - - /* Don't mess with things live during setjmp. */ - if (REG_LIVE_LENGTH (regno) >= 0) - { - /* Note that the statement below does not affect the priority - in local-alloc! */ - REG_LIVE_LENGTH (regno) *= 2; - - - /* If the register is referenced exactly twice, meaning it is - set once and used once, indicate that the reference may be - replaced by the equivalence we computed above. If the - register is only used in one basic block, this can't succeed - or combine would have done it. - - It would be nice to use "loop_depth * 2" in the compare - below. Unfortunately, LOOP_DEPTH need not be constant within - a basic block so this would be too complicated. - - This case normally occurs when a parameter is read from - memory and then used exactly once, not in a loop. */ - - if (REG_N_REFS (regno) == 2 - && REG_BASIC_BLOCK (regno) < 0 - && rtx_equal_p (XEXP (note, 0), SET_SRC (set))) - reg_equiv_replace[regno] = 1; - } - } - } - - /* Now scan all regs killed in an insn to see if any of them are - registers only used that once. If so, see if we can replace the - reference with the equivalent from. If we can, delete the - initializing reference and this register will go away. If we - can't replace the reference, and the instruction is not in a - loop, then move the register initialization just before the use, - so that they are in the same basic block. */ - block = -1; - depth = 0; - for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - { - rtx link; - - /* Keep track of which basic block we are in. */ - if (block + 1 < n_basic_blocks - && BLOCK_HEAD (block + 1) == insn) - ++block; - - if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') - { - if (GET_CODE (insn) == NOTE) - { - if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) - ++depth; - else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) - { - --depth; - if (depth < 0) - abort (); - } - } - - continue; - } - - for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) - { - if (REG_NOTE_KIND (link) == REG_DEAD - /* Make sure this insn still refers to the register. */ - && reg_mentioned_p (XEXP (link, 0), PATTERN (insn))) - { - int regno = REGNO (XEXP (link, 0)); - rtx equiv_insn; - - if (! reg_equiv_replace[regno]) - continue; - - /* reg_equiv_replace[REGNO] gets set only when - REG_N_REFS[REGNO] is 2, i.e. the register is set - once and used once. (If it were only set, but not used, - flow would have deleted the setting insns.) Hence - there can only be one insn in reg_equiv_init_insns. */ - equiv_insn = XEXP (reg_equiv_init_insns[regno], 0); - - if (validate_replace_rtx (regno_reg_rtx[regno], - reg_equiv_replacement[regno], insn)) - { - remove_death (regno, insn); - REG_N_REFS (regno) = 0; - PUT_CODE (equiv_insn, NOTE); - NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (equiv_insn) = 0; - } - /* If we aren't in a loop, and there are no calls in - INSN or in the initialization of the register, then - move the initialization of the register to just - before INSN. Update the flow information. */ - else if (depth == 0 - && GET_CODE (equiv_insn) == INSN - && GET_CODE (insn) == INSN - && REG_BASIC_BLOCK (regno) < 0) - { - int l; - - emit_insn_before (copy_rtx (PATTERN (equiv_insn)), insn); - REG_NOTES (PREV_INSN (insn)) = REG_NOTES (equiv_insn); - - PUT_CODE (equiv_insn, NOTE); - NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (equiv_insn) = 0; - REG_NOTES (equiv_insn) = 0; - - if (block < 0) - REG_BASIC_BLOCK (regno) = 0; - else - REG_BASIC_BLOCK (regno) = block; - REG_N_CALLS_CROSSED (regno) = 0; - REG_LIVE_LENGTH (regno) = 2; - - if (block >= 0 && insn == BLOCK_HEAD (block)) - BLOCK_HEAD (block) = PREV_INSN (insn); - - for (l = 0; l < n_basic_blocks; l++) - CLEAR_REGNO_REG_SET (BASIC_BLOCK (l)->global_live_at_start, - regno); - } - } - } - } -} - -/* Mark REG as having no known equivalence. - Some instructions might have been proceessed before and furnished - with REG_EQUIV notes for this register; these notes will have to be - removed. - STORE is the piece of RTL that does the non-constant / conflicting - assignment - a SET, CLOBBER or REG_INC note. It is currently not used, - but needs to be there because this function is called from note_stores. */ -static void -no_equiv (reg, store) - rtx reg, store ATTRIBUTE_UNUSED; -{ - int regno; - rtx list; - - if (GET_CODE (reg) != REG) - return; - regno = REGNO (reg); - list = reg_equiv_init_insns[regno]; - if (list == const0_rtx) - return; - for (; list; list = XEXP (list, 1)) - { - rtx insn = XEXP (list, 0); - remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX)); - } - reg_equiv_init_insns[regno] = const0_rtx; - reg_equiv_replacement[regno] = NULL_RTX; -} - -/* Allocate hard regs to the pseudo regs used only within block number B. - Only the pseudos that die but once can be handled. */ - -static void -block_alloc (b) - int b; -{ - register int i, q; - register rtx insn; - rtx note; - int insn_number = 0; - int insn_count = 0; - int max_uid = get_max_uid (); - int *qty_order; - int no_conflict_combined_regno = -1; - - /* Count the instructions in the basic block. */ - - insn = BLOCK_END (b); - while (1) - { - if (GET_CODE (insn) != NOTE) - if (++insn_count > max_uid) - abort (); - if (insn == BLOCK_HEAD (b)) - break; - insn = PREV_INSN (insn); - } - - /* +2 to leave room for a post_mark_life at the last insn and for - the birth of a CLOBBER in the first insn. */ - regs_live_at = (HARD_REG_SET *) alloca ((2 * insn_count + 2) - * sizeof (HARD_REG_SET)); - bzero ((char *) regs_live_at, (2 * insn_count + 2) * sizeof (HARD_REG_SET)); - - /* Initialize table of hardware registers currently live. */ - - REG_SET_TO_HARD_REG_SET (regs_live, BASIC_BLOCK (b)->global_live_at_start); - - /* This loop scans the instructions of the basic block - and assigns quantities to registers. - It computes which registers to tie. */ - - insn = BLOCK_HEAD (b); - while (1) - { - register rtx body = PATTERN (insn); - - if (GET_CODE (insn) != NOTE) - insn_number++; - - if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') - { - register rtx link, set; - register int win = 0; - register rtx r0, r1; - int combined_regno = -1; - int i; - - this_insn_number = insn_number; - this_insn = insn; - - extract_insn (insn); - which_alternative = -1; - - /* Is this insn suitable for tying two registers? - If so, try doing that. - Suitable insns are those with at least two operands and where - operand 0 is an output that is a register that is not - earlyclobber. - - We can tie operand 0 with some operand that dies in this insn. - First look for operands that are required to be in the same - register as operand 0. If we find such, only try tying that - operand or one that can be put into that operand if the - operation is commutative. If we don't find an operand - that is required to be in the same register as operand 0, - we can tie with any operand. - - Subregs in place of regs are also ok. - - If tying is done, WIN is set nonzero. */ - - if (1 -#ifdef REGISTER_CONSTRAINTS - && recog_n_operands > 1 - && recog_constraints[0][0] == '=' - && recog_constraints[0][1] != '&' -#else - && GET_CODE (PATTERN (insn)) == SET - && rtx_equal_p (SET_DEST (PATTERN (insn)), recog_operand[0]) -#endif - ) - { -#ifdef REGISTER_CONSTRAINTS - /* If non-negative, is an operand that must match operand 0. */ - int must_match_0 = -1; - /* Counts number of alternatives that require a match with - operand 0. */ - int n_matching_alts = 0; - - for (i = 1; i < recog_n_operands; i++) - { - const char *p = recog_constraints[i]; - int this_match = (requires_inout (p)); - - n_matching_alts += this_match; - if (this_match == recog_n_alternatives) - must_match_0 = i; - } -#endif - - r0 = recog_operand[0]; - for (i = 1; i < recog_n_operands; i++) - { -#ifdef REGISTER_CONSTRAINTS - /* Skip this operand if we found an operand that - must match operand 0 and this operand isn't it - and can't be made to be it by commutativity. */ - - if (must_match_0 >= 0 && i != must_match_0 - && ! (i == must_match_0 + 1 - && recog_constraints[i-1][0] == '%') - && ! (i == must_match_0 - 1 - && recog_constraints[i][0] == '%')) - continue; - - /* Likewise if each alternative has some operand that - must match operand zero. In that case, skip any - operand that doesn't list operand 0 since we know that - the operand always conflicts with operand 0. We - ignore commutatity in this case to keep things simple. */ - if (n_matching_alts == recog_n_alternatives - && 0 == requires_inout (recog_constraints[i])) - continue; -#endif - - r1 = recog_operand[i]; - - /* If the operand is an address, find a register in it. - There may be more than one register, but we only try one - of them. */ - if ( -#ifdef REGISTER_CONSTRAINTS - recog_constraints[i][0] == 'p' -#else - recog_operand_address_p[i] -#endif - ) - while (GET_CODE (r1) == PLUS || GET_CODE (r1) == MULT) - r1 = XEXP (r1, 0); - - if (GET_CODE (r0) == REG || GET_CODE (r0) == SUBREG) - { - /* We have two priorities for hard register preferences. - If we have a move insn or an insn whose first input - can only be in the same register as the output, give - priority to an equivalence found from that insn. */ - int may_save_copy - = ((SET_DEST (body) == r0 && SET_SRC (body) == r1) -#ifdef REGISTER_CONSTRAINTS - || (r1 == recog_operand[i] && must_match_0 >= 0) -#endif - ); - - if (GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG) - win = combine_regs (r1, r0, may_save_copy, - insn_number, insn, 0); - } - if (win) - break; - } - } - - /* Recognize an insn sequence with an ultimate result - which can safely overlap one of the inputs. - The sequence begins with a CLOBBER of its result, - and ends with an insn that copies the result to itself - and has a REG_EQUAL note for an equivalent formula. - That note indicates what the inputs are. - The result and the input can overlap if each insn in - the sequence either doesn't mention the input - or has a REG_NO_CONFLICT note to inhibit the conflict. - - We do the combining test at the CLOBBER so that the - destination register won't have had a quantity number - assigned, since that would prevent combining. */ - - if (GET_CODE (PATTERN (insn)) == CLOBBER - && (r0 = XEXP (PATTERN (insn), 0), - GET_CODE (r0) == REG) - && (link = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0 - && XEXP (link, 0) != 0 - && GET_CODE (XEXP (link, 0)) == INSN - && (set = single_set (XEXP (link, 0))) != 0 - && SET_DEST (set) == r0 && SET_SRC (set) == r0 - && (note = find_reg_note (XEXP (link, 0), REG_EQUAL, - NULL_RTX)) != 0) - { - if (r1 = XEXP (note, 0), GET_CODE (r1) == REG - /* Check that we have such a sequence. */ - && no_conflict_p (insn, r0, r1)) - win = combine_regs (r1, r0, 1, insn_number, insn, 1); - else if (GET_RTX_FORMAT (GET_CODE (XEXP (note, 0)))[0] == 'e' - && (r1 = XEXP (XEXP (note, 0), 0), - GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG) - && no_conflict_p (insn, r0, r1)) - win = combine_regs (r1, r0, 0, insn_number, insn, 1); - - /* Here we care if the operation to be computed is - commutative. */ - else if ((GET_CODE (XEXP (note, 0)) == EQ - || GET_CODE (XEXP (note, 0)) == NE - || GET_RTX_CLASS (GET_CODE (XEXP (note, 0))) == 'c') - && (r1 = XEXP (XEXP (note, 0), 1), - (GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG)) - && no_conflict_p (insn, r0, r1)) - win = combine_regs (r1, r0, 0, insn_number, insn, 1); - - /* If we did combine something, show the register number - in question so that we know to ignore its death. */ - if (win) - no_conflict_combined_regno = REGNO (r1); - } - - /* If registers were just tied, set COMBINED_REGNO - to the number of the register used in this insn - that was tied to the register set in this insn. - This register's qty should not be "killed". */ - - if (win) - { - while (GET_CODE (r1) == SUBREG) - r1 = SUBREG_REG (r1); - combined_regno = REGNO (r1); - } - - /* Mark the death of everything that dies in this instruction, - except for anything that was just combined. */ - - for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) - if (REG_NOTE_KIND (link) == REG_DEAD - && GET_CODE (XEXP (link, 0)) == REG - && combined_regno != REGNO (XEXP (link, 0)) - && (no_conflict_combined_regno != REGNO (XEXP (link, 0)) - || ! find_reg_note (insn, REG_NO_CONFLICT, XEXP (link, 0)))) - wipe_dead_reg (XEXP (link, 0), 0); - - /* Allocate qty numbers for all registers local to this block - that are born (set) in this instruction. - A pseudo that already has a qty is not changed. */ - - note_stores (PATTERN (insn), reg_is_set); - - /* If anything is set in this insn and then unused, mark it as dying - after this insn, so it will conflict with our outputs. This - can't match with something that combined, and it doesn't matter - if it did. Do this after the calls to reg_is_set since these - die after, not during, the current insn. */ - - for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) - if (REG_NOTE_KIND (link) == REG_UNUSED - && GET_CODE (XEXP (link, 0)) == REG) - wipe_dead_reg (XEXP (link, 0), 1); - - /* If this is an insn that has a REG_RETVAL note pointing at a - CLOBBER insn, we have reached the end of a REG_NO_CONFLICT - block, so clear any register number that combined within it. */ - if ((note = find_reg_note (insn, REG_RETVAL, NULL_RTX)) != 0 - && GET_CODE (XEXP (note, 0)) == INSN - && GET_CODE (PATTERN (XEXP (note, 0))) == CLOBBER) - no_conflict_combined_regno = -1; - } - - /* Set the registers live after INSN_NUMBER. Note that we never - record the registers live before the block's first insn, since no - pseudos we care about are live before that insn. */ - - IOR_HARD_REG_SET (regs_live_at[2 * insn_number], regs_live); - IOR_HARD_REG_SET (regs_live_at[2 * insn_number + 1], regs_live); - - if (insn == BLOCK_END (b)) - break; - - insn = NEXT_INSN (insn); - } - - /* Now every register that is local to this basic block - should have been given a quantity, or else -1 meaning ignore it. - Every quantity should have a known birth and death. - - Order the qtys so we assign them registers in order of the - number of suggested registers they need so we allocate those with - the most restrictive needs first. */ - - qty_order = (int *) alloca (next_qty * sizeof (int)); - for (i = 0; i < next_qty; i++) - qty_order[i] = i; - -#define EXCHANGE(I1, I2) \ - { i = qty_order[I1]; qty_order[I1] = qty_order[I2]; qty_order[I2] = i; } - - switch (next_qty) - { - case 3: - /* Make qty_order[2] be the one to allocate last. */ - if (qty_sugg_compare (0, 1) > 0) - EXCHANGE (0, 1); - if (qty_sugg_compare (1, 2) > 0) - EXCHANGE (2, 1); - - /* ... Fall through ... */ - case 2: - /* Put the best one to allocate in qty_order[0]. */ - if (qty_sugg_compare (0, 1) > 0) - EXCHANGE (0, 1); - - /* ... Fall through ... */ - - case 1: - case 0: - /* Nothing to do here. */ - break; - - default: - qsort (qty_order, next_qty, sizeof (int), qty_sugg_compare_1); - } - - /* Try to put each quantity in a suggested physical register, if it has one. - This may cause registers to be allocated that otherwise wouldn't be, but - this seems acceptable in local allocation (unlike global allocation). */ - for (i = 0; i < next_qty; i++) - { - q = qty_order[i]; - if (qty_phys_num_sugg[q] != 0 || qty_phys_num_copy_sugg[q] != 0) - qty_phys_reg[q] = find_free_reg (qty_min_class[q], qty_mode[q], q, - 0, 1, qty_birth[q], qty_death[q]); - else - qty_phys_reg[q] = -1; - } - - /* Order the qtys so we assign them registers in order of - decreasing length of life. Normally call qsort, but if we - have only a very small number of quantities, sort them ourselves. */ - - for (i = 0; i < next_qty; i++) - qty_order[i] = i; - -#define EXCHANGE(I1, I2) \ - { i = qty_order[I1]; qty_order[I1] = qty_order[I2]; qty_order[I2] = i; } - - switch (next_qty) - { - case 3: - /* Make qty_order[2] be the one to allocate last. */ - if (qty_compare (0, 1) > 0) - EXCHANGE (0, 1); - if (qty_compare (1, 2) > 0) - EXCHANGE (2, 1); - - /* ... Fall through ... */ - case 2: - /* Put the best one to allocate in qty_order[0]. */ - if (qty_compare (0, 1) > 0) - EXCHANGE (0, 1); - - /* ... Fall through ... */ - - case 1: - case 0: - /* Nothing to do here. */ - break; - - default: - qsort (qty_order, next_qty, sizeof (int), qty_compare_1); - } - - /* Now for each qty that is not a hardware register, - look for a hardware register to put it in. - First try the register class that is cheapest for this qty, - if there is more than one class. */ - - for (i = 0; i < next_qty; i++) - { - q = qty_order[i]; - if (qty_phys_reg[q] < 0) - { -#ifdef INSN_SCHEDULING - /* These values represent the adjusted lifetime of a qty so - that it conflicts with qtys which appear near the start/end - of this qty's lifetime. - - The purpose behind extending the lifetime of this qty is to - discourage the register allocator from creating false - dependencies. - - The adjustment value is choosen to indicate that this qty - conflicts with all the qtys in the instructions immediately - before and after the lifetime of this qty. - - Experiments have shown that higher values tend to hurt - overall code performance. - - If allocation using the extended lifetime fails we will try - again with the qty's unadjusted lifetime. */ - int fake_birth = MAX (0, qty_birth[q] - 2 + qty_birth[q] % 2); - int fake_death = MIN (insn_number * 2 + 1, - qty_death[q] + 2 - qty_death[q] % 2); -#endif - - if (N_REG_CLASSES > 1) - { -#ifdef INSN_SCHEDULING - /* We try to avoid using hard registers allocated to qtys which - are born immediately after this qty or die immediately before - this qty. - - This optimization is only appropriate when we will run - a scheduling pass after reload and we are not optimizing - for code size. */ - if (flag_schedule_insns_after_reload - && !optimize_size - && !SMALL_REGISTER_CLASSES) - { - - qty_phys_reg[q] = find_free_reg (qty_min_class[q], - qty_mode[q], q, 0, 0, - fake_birth, fake_death); - if (qty_phys_reg[q] >= 0) - continue; - } -#endif - qty_phys_reg[q] = find_free_reg (qty_min_class[q], - qty_mode[q], q, 0, 0, - qty_birth[q], qty_death[q]); - if (qty_phys_reg[q] >= 0) - continue; - } - -#ifdef INSN_SCHEDULING - /* Similarly, avoid false dependencies. */ - if (flag_schedule_insns_after_reload - && !optimize_size - && !SMALL_REGISTER_CLASSES - && qty_alternate_class[q] != NO_REGS) - qty_phys_reg[q] = find_free_reg (qty_alternate_class[q], - qty_mode[q], q, 0, 0, - fake_birth, fake_death); -#endif - if (qty_alternate_class[q] != NO_REGS) - qty_phys_reg[q] = find_free_reg (qty_alternate_class[q], - qty_mode[q], q, 0, 0, - qty_birth[q], qty_death[q]); - } - } - - /* Now propagate the register assignments - to the pseudo regs belonging to the qtys. */ - - for (q = 0; q < next_qty; q++) - if (qty_phys_reg[q] >= 0) - { - for (i = qty_first_reg[q]; i >= 0; i = reg_next_in_qty[i]) - reg_renumber[i] = qty_phys_reg[q] + reg_offset[i]; - } -} - -/* Compare two quantities' priority for getting real registers. - We give shorter-lived quantities higher priority. - Quantities with more references are also preferred, as are quantities that - require multiple registers. This is the identical prioritization as - done by global-alloc. - - We used to give preference to registers with *longer* lives, but using - the same algorithm in both local- and global-alloc can speed up execution - of some programs by as much as a factor of three! */ - -/* Note that the quotient will never be bigger than - the value of floor_log2 times the maximum number of - times a register can occur in one insn (surely less than 100). - Multiplying this by 10000 can't overflow. - QTY_CMP_PRI is also used by qty_sugg_compare. */ - -#define QTY_CMP_PRI(q) \ - ((int) (((double) (floor_log2 (qty_n_refs[q]) * qty_n_refs[q] * qty_size[q]) \ - / (qty_death[q] - qty_birth[q])) * 10000)) - -static int -qty_compare (q1, q2) - int q1, q2; -{ - return QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); -} - -static int -qty_compare_1 (q1p, q2p) - const GENERIC_PTR q1p; - const GENERIC_PTR q2p; -{ - register int q1 = *(int *)q1p, q2 = *(int *)q2p; - register int tem = QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); - - if (tem != 0) - return tem; - - /* If qtys are equally good, sort by qty number, - so that the results of qsort leave nothing to chance. */ - return q1 - q2; -} - -/* Compare two quantities' priority for getting real registers. This version - is called for quantities that have suggested hard registers. First priority - goes to quantities that have copy preferences, then to those that have - normal preferences. Within those groups, quantities with the lower - number of preferences have the highest priority. Of those, we use the same - algorithm as above. */ - -#define QTY_CMP_SUGG(q) \ - (qty_phys_num_copy_sugg[q] \ - ? qty_phys_num_copy_sugg[q] \ - : qty_phys_num_sugg[q] * FIRST_PSEUDO_REGISTER) - -static int -qty_sugg_compare (q1, q2) - int q1, q2; -{ - register int tem = QTY_CMP_SUGG (q1) - QTY_CMP_SUGG (q2); - - if (tem != 0) - return tem; - - return QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); -} - -static int -qty_sugg_compare_1 (q1p, q2p) - const GENERIC_PTR q1p; - const GENERIC_PTR q2p; -{ - register int q1 = *(int *)q1p, q2 = *(int *)q2p; - register int tem = QTY_CMP_SUGG (q1) - QTY_CMP_SUGG (q2); - - if (tem != 0) - return tem; - - tem = QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1); - if (tem != 0) - return tem; - - /* If qtys are equally good, sort by qty number, - so that the results of qsort leave nothing to chance. */ - return q1 - q2; -} - -#undef QTY_CMP_SUGG -#undef QTY_CMP_PRI - -/* Attempt to combine the two registers (rtx's) USEDREG and SETREG. - Returns 1 if have done so, or 0 if cannot. - - Combining registers means marking them as having the same quantity - and adjusting the offsets within the quantity if either of - them is a SUBREG). - - We don't actually combine a hard reg with a pseudo; instead - we just record the hard reg as the suggestion for the pseudo's quantity. - If we really combined them, we could lose if the pseudo lives - across an insn that clobbers the hard reg (eg, movstr). - - ALREADY_DEAD is non-zero if USEDREG is known to be dead even though - there is no REG_DEAD note on INSN. This occurs during the processing - of REG_NO_CONFLICT blocks. - - MAY_SAVE_COPYCOPY is non-zero if this insn is simply copying USEDREG to - SETREG or if the input and output must share a register. - In that case, we record a hard reg suggestion in QTY_PHYS_COPY_SUGG. - - There are elaborate checks for the validity of combining. */ - - -static int -combine_regs (usedreg, setreg, may_save_copy, insn_number, insn, already_dead) - rtx usedreg, setreg; - int may_save_copy; - int insn_number; - rtx insn; - int already_dead; -{ - register int ureg, sreg; - register int offset = 0; - int usize, ssize; - register int sqty; - - /* Determine the numbers and sizes of registers being used. If a subreg - is present that does not change the entire register, don't consider - this a copy insn. */ - - while (GET_CODE (usedreg) == SUBREG) - { - if (GET_MODE_SIZE (GET_MODE (SUBREG_REG (usedreg))) > UNITS_PER_WORD) - may_save_copy = 0; - offset += SUBREG_WORD (usedreg); - usedreg = SUBREG_REG (usedreg); - } - if (GET_CODE (usedreg) != REG) - return 0; - ureg = REGNO (usedreg); - usize = REG_SIZE (usedreg); - - while (GET_CODE (setreg) == SUBREG) - { - if (GET_MODE_SIZE (GET_MODE (SUBREG_REG (setreg))) > UNITS_PER_WORD) - may_save_copy = 0; - offset -= SUBREG_WORD (setreg); - setreg = SUBREG_REG (setreg); - } - if (GET_CODE (setreg) != REG) - return 0; - sreg = REGNO (setreg); - ssize = REG_SIZE (setreg); - - /* If UREG is a pseudo-register that hasn't already been assigned a - quantity number, it means that it is not local to this block or dies - more than once. In either event, we can't do anything with it. */ - if ((ureg >= FIRST_PSEUDO_REGISTER && reg_qty[ureg] < 0) - /* Do not combine registers unless one fits within the other. */ - || (offset > 0 && usize + offset > ssize) - || (offset < 0 && usize + offset < ssize) - /* Do not combine with a smaller already-assigned object - if that smaller object is already combined with something bigger. */ - || (ssize > usize && ureg >= FIRST_PSEUDO_REGISTER - && usize < qty_size[reg_qty[ureg]]) - /* Can't combine if SREG is not a register we can allocate. */ - || (sreg >= FIRST_PSEUDO_REGISTER && reg_qty[sreg] == -1) - /* Don't combine with a pseudo mentioned in a REG_NO_CONFLICT note. - These have already been taken care of. This probably wouldn't - combine anyway, but don't take any chances. */ - || (ureg >= FIRST_PSEUDO_REGISTER - && find_reg_note (insn, REG_NO_CONFLICT, usedreg)) - /* Don't tie something to itself. In most cases it would make no - difference, but it would screw up if the reg being tied to itself - also dies in this insn. */ - || ureg == sreg - /* Don't try to connect two different hardware registers. */ - || (ureg < FIRST_PSEUDO_REGISTER && sreg < FIRST_PSEUDO_REGISTER) - /* Don't use a hard reg that might be spilled. */ - || (ureg < FIRST_PSEUDO_REGISTER - && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (ureg))) - || (sreg < FIRST_PSEUDO_REGISTER - && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (sreg))) - /* Don't connect two different machine modes if they have different - implications as to which registers may be used. */ - || !MODES_TIEABLE_P (GET_MODE (usedreg), GET_MODE (setreg))) - return 0; - - /* Now, if UREG is a hard reg and SREG is a pseudo, record the hard reg in - qty_phys_sugg for the pseudo instead of tying them. - - Return "failure" so that the lifespan of UREG is terminated here; - that way the two lifespans will be disjoint and nothing will prevent - the pseudo reg from being given this hard reg. */ - - if (ureg < FIRST_PSEUDO_REGISTER) - { - /* Allocate a quantity number so we have a place to put our - suggestions. */ - if (reg_qty[sreg] == -2) - reg_is_born (setreg, 2 * insn_number); - - if (reg_qty[sreg] >= 0) - { - if (may_save_copy - && ! TEST_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[sreg]], ureg)) - { - SET_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[sreg]], ureg); - qty_phys_num_copy_sugg[reg_qty[sreg]]++; - } - else if (! TEST_HARD_REG_BIT (qty_phys_sugg[reg_qty[sreg]], ureg)) - { - SET_HARD_REG_BIT (qty_phys_sugg[reg_qty[sreg]], ureg); - qty_phys_num_sugg[reg_qty[sreg]]++; - } - } - return 0; - } - - /* Similarly for SREG a hard register and UREG a pseudo register. */ - - if (sreg < FIRST_PSEUDO_REGISTER) - { - if (may_save_copy - && ! TEST_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[ureg]], sreg)) - { - SET_HARD_REG_BIT (qty_phys_copy_sugg[reg_qty[ureg]], sreg); - qty_phys_num_copy_sugg[reg_qty[ureg]]++; - } - else if (! TEST_HARD_REG_BIT (qty_phys_sugg[reg_qty[ureg]], sreg)) - { - SET_HARD_REG_BIT (qty_phys_sugg[reg_qty[ureg]], sreg); - qty_phys_num_sugg[reg_qty[ureg]]++; - } - return 0; - } - - /* At this point we know that SREG and UREG are both pseudos. - Do nothing if SREG already has a quantity or is a register that we - don't allocate. */ - if (reg_qty[sreg] >= -1 - /* If we are not going to let any regs live across calls, - don't tie a call-crossing reg to a non-call-crossing reg. */ - || (current_function_has_nonlocal_label - && ((REG_N_CALLS_CROSSED (ureg) > 0) - != (REG_N_CALLS_CROSSED (sreg) > 0)))) - return 0; - - /* We don't already know about SREG, so tie it to UREG - if this is the last use of UREG, provided the classes they want - are compatible. */ - - if ((already_dead || find_regno_note (insn, REG_DEAD, ureg)) - && reg_meets_class_p (sreg, qty_min_class[reg_qty[ureg]])) - { - /* Add SREG to UREG's quantity. */ - sqty = reg_qty[ureg]; - reg_qty[sreg] = sqty; - reg_offset[sreg] = reg_offset[ureg] + offset; - reg_next_in_qty[sreg] = qty_first_reg[sqty]; - qty_first_reg[sqty] = sreg; - - /* If SREG's reg class is smaller, set qty_min_class[SQTY]. */ - update_qty_class (sqty, sreg); - - /* Update info about quantity SQTY. */ - qty_n_calls_crossed[sqty] += REG_N_CALLS_CROSSED (sreg); - qty_n_refs[sqty] += REG_N_REFS (sreg); - if (usize < ssize) - { - register int i; - - for (i = qty_first_reg[sqty]; i >= 0; i = reg_next_in_qty[i]) - reg_offset[i] -= offset; - - qty_size[sqty] = ssize; - qty_mode[sqty] = GET_MODE (setreg); - } - } - else - return 0; - - return 1; -} - -/* Return 1 if the preferred class of REG allows it to be tied - to a quantity or register whose class is CLASS. - True if REG's reg class either contains or is contained in CLASS. */ - -static int -reg_meets_class_p (reg, class) - int reg; - enum reg_class class; -{ - register enum reg_class rclass = reg_preferred_class (reg); - return (reg_class_subset_p (rclass, class) - || reg_class_subset_p (class, rclass)); -} - -/* Update the class of QTY assuming that REG is being tied to it. */ - -static void -update_qty_class (qty, reg) - int qty; - int reg; -{ - enum reg_class rclass = reg_preferred_class (reg); - if (reg_class_subset_p (rclass, qty_min_class[qty])) - qty_min_class[qty] = rclass; - - rclass = reg_alternate_class (reg); - if (reg_class_subset_p (rclass, qty_alternate_class[qty])) - qty_alternate_class[qty] = rclass; - - if (REG_CHANGES_SIZE (reg)) - qty_changes_size[qty] = 1; -} - -/* Handle something which alters the value of an rtx REG. - - REG is whatever is set or clobbered. SETTER is the rtx that - is modifying the register. - - If it is not really a register, we do nothing. - The file-global variables `this_insn' and `this_insn_number' - carry info from `block_alloc'. */ - -static void -reg_is_set (reg, setter) - rtx reg; - rtx setter; -{ - /* Note that note_stores will only pass us a SUBREG if it is a SUBREG of - a hard register. These may actually not exist any more. */ - - if (GET_CODE (reg) != SUBREG - && GET_CODE (reg) != REG) - return; - - /* Mark this register as being born. If it is used in a CLOBBER, mark - it as being born halfway between the previous insn and this insn so that - it conflicts with our inputs but not the outputs of the previous insn. */ - - reg_is_born (reg, 2 * this_insn_number - (GET_CODE (setter) == CLOBBER)); -} - -/* Handle beginning of the life of register REG. - BIRTH is the index at which this is happening. */ - -static void -reg_is_born (reg, birth) - rtx reg; - int birth; -{ - register int regno; - - if (GET_CODE (reg) == SUBREG) - regno = REGNO (SUBREG_REG (reg)) + SUBREG_WORD (reg); - else - regno = REGNO (reg); - - if (regno < FIRST_PSEUDO_REGISTER) - { - mark_life (regno, GET_MODE (reg), 1); - - /* If the register was to have been born earlier that the present - insn, mark it as live where it is actually born. */ - if (birth < 2 * this_insn_number) - post_mark_life (regno, GET_MODE (reg), 1, birth, 2 * this_insn_number); - } - else - { - if (reg_qty[regno] == -2) - alloc_qty (regno, GET_MODE (reg), PSEUDO_REGNO_SIZE (regno), birth); - - /* If this register has a quantity number, show that it isn't dead. */ - if (reg_qty[regno] >= 0) - qty_death[reg_qty[regno]] = -1; - } -} - -/* Record the death of REG in the current insn. If OUTPUT_P is non-zero, - REG is an output that is dying (i.e., it is never used), otherwise it - is an input (the normal case). - If OUTPUT_P is 1, then we extend the life past the end of this insn. */ - -static void -wipe_dead_reg (reg, output_p) - register rtx reg; - int output_p; -{ - register int regno = REGNO (reg); - - /* If this insn has multiple results, - and the dead reg is used in one of the results, - extend its life to after this insn, - so it won't get allocated together with any other result of this insn. - - It is unsafe to use !single_set here since it will ignore an unused - output. Just because an output is unused does not mean the compiler - can assume the side effect will not occur. Consider if REG appears - in the address of an output and we reload the output. If we allocate - REG to the same hard register as an unused output we could set the hard - register before the output reload insn. */ - if (GET_CODE (PATTERN (this_insn)) == PARALLEL - && multiple_sets (this_insn)) - { - int i; - for (i = XVECLEN (PATTERN (this_insn), 0) - 1; i >= 0; i--) - { - rtx set = XVECEXP (PATTERN (this_insn), 0, i); - if (GET_CODE (set) == SET - && GET_CODE (SET_DEST (set)) != REG - && !rtx_equal_p (reg, SET_DEST (set)) - && reg_overlap_mentioned_p (reg, SET_DEST (set))) - output_p = 1; - } - } - - /* If this register is used in an auto-increment address, then extend its - life to after this insn, so that it won't get allocated together with - the result of this insn. */ - if (! output_p && find_regno_note (this_insn, REG_INC, regno)) - output_p = 1; - - if (regno < FIRST_PSEUDO_REGISTER) - { - mark_life (regno, GET_MODE (reg), 0); - - /* If a hard register is dying as an output, mark it as in use at - the beginning of this insn (the above statement would cause this - not to happen). */ - if (output_p) - post_mark_life (regno, GET_MODE (reg), 1, - 2 * this_insn_number, 2 * this_insn_number+ 1); - } - - else if (reg_qty[regno] >= 0) - qty_death[reg_qty[regno]] = 2 * this_insn_number + output_p; -} - -/* Find a block of SIZE words of hard regs in reg_class CLASS - that can hold something of machine-mode MODE - (but actually we test only the first of the block for holding MODE) - and still free between insn BORN_INDEX and insn DEAD_INDEX, - and return the number of the first of them. - Return -1 if such a block cannot be found. - If QTY crosses calls, insist on a register preserved by calls, - unless ACCEPT_CALL_CLOBBERED is nonzero. - - If JUST_TRY_SUGGESTED is non-zero, only try to see if the suggested - register is available. If not, return -1. */ - -static int -find_free_reg (class, mode, qty, accept_call_clobbered, just_try_suggested, - born_index, dead_index) - enum reg_class class; - enum machine_mode mode; - int qty; - int accept_call_clobbered; - int just_try_suggested; - int born_index, dead_index; -{ - register int i, ins; -#ifdef HARD_REG_SET - register /* Declare it register if it's a scalar. */ -#endif - HARD_REG_SET used, first_used; -#ifdef ELIMINABLE_REGS - static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; -#endif - - /* Validate our parameters. */ - if (born_index < 0 || born_index > dead_index) - abort (); - - /* Don't let a pseudo live in a reg across a function call - if we might get a nonlocal goto. */ - if (current_function_has_nonlocal_label - && qty_n_calls_crossed[qty] > 0) - return -1; - - if (accept_call_clobbered) - COPY_HARD_REG_SET (used, call_fixed_reg_set); - else if (qty_n_calls_crossed[qty] == 0) - COPY_HARD_REG_SET (used, fixed_reg_set); - else - COPY_HARD_REG_SET (used, call_used_reg_set); - - if (accept_call_clobbered) - IOR_HARD_REG_SET (used, losing_caller_save_reg_set); - - for (ins = born_index; ins < dead_index; ins++) - IOR_HARD_REG_SET (used, regs_live_at[ins]); - - IOR_COMPL_HARD_REG_SET (used, reg_class_contents[(int) class]); - - /* Don't use the frame pointer reg in local-alloc even if - we may omit the frame pointer, because if we do that and then we - need a frame pointer, reload won't know how to move the pseudo - to another hard reg. It can move only regs made by global-alloc. - - This is true of any register that can be eliminated. */ -#ifdef ELIMINABLE_REGS - for (i = 0; i < (int)(sizeof eliminables / sizeof eliminables[0]); i++) - SET_HARD_REG_BIT (used, eliminables[i].from); -#if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM - /* If FRAME_POINTER_REGNUM is not a real register, then protect the one - that it might be eliminated into. */ - SET_HARD_REG_BIT (used, HARD_FRAME_POINTER_REGNUM); -#endif -#else - SET_HARD_REG_BIT (used, FRAME_POINTER_REGNUM); -#endif - -#ifdef CLASS_CANNOT_CHANGE_SIZE - if (qty_changes_size[qty]) - IOR_HARD_REG_SET (used, - reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE]); -#endif - - /* Normally, the registers that can be used for the first register in - a multi-register quantity are the same as those that can be used for - subsequent registers. However, if just trying suggested registers, - restrict our consideration to them. If there are copy-suggested - register, try them. Otherwise, try the arithmetic-suggested - registers. */ - COPY_HARD_REG_SET (first_used, used); - - if (just_try_suggested) - { - if (qty_phys_num_copy_sugg[qty] != 0) - IOR_COMPL_HARD_REG_SET (first_used, qty_phys_copy_sugg[qty]); - else - IOR_COMPL_HARD_REG_SET (first_used, qty_phys_sugg[qty]); - } - - /* If all registers are excluded, we can't do anything. */ - GO_IF_HARD_REG_SUBSET (reg_class_contents[(int) ALL_REGS], first_used, fail); - - /* If at least one would be suitable, test each hard reg. */ - - for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) - { -#ifdef REG_ALLOC_ORDER - int regno = reg_alloc_order[i]; -#else - int regno = i; -#endif - if (! TEST_HARD_REG_BIT (first_used, regno) - && HARD_REGNO_MODE_OK (regno, mode) - && (qty_n_calls_crossed[qty] == 0 - || accept_call_clobbered - || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))) - { - register int j; - register int size1 = HARD_REGNO_NREGS (regno, mode); - for (j = 1; j < size1 && ! TEST_HARD_REG_BIT (used, regno + j); j++); - if (j == size1) - { - /* Mark that this register is in use between its birth and death - insns. */ - post_mark_life (regno, mode, 1, born_index, dead_index); - return regno; - } -#ifndef REG_ALLOC_ORDER - i += j; /* Skip starting points we know will lose */ -#endif - } - } - - fail: - - /* If we are just trying suggested register, we have just tried copy- - suggested registers, and there are arithmetic-suggested registers, - try them. */ - - /* If it would be profitable to allocate a call-clobbered register - and save and restore it around calls, do that. */ - if (just_try_suggested && qty_phys_num_copy_sugg[qty] != 0 - && qty_phys_num_sugg[qty] != 0) - { - /* Don't try the copy-suggested regs again. */ - qty_phys_num_copy_sugg[qty] = 0; - return find_free_reg (class, mode, qty, accept_call_clobbered, 1, - born_index, dead_index); - } - - /* We need not check to see if the current function has nonlocal - labels because we don't put any pseudos that are live over calls in - registers in that case. */ - - if (! accept_call_clobbered - && flag_caller_saves - && ! just_try_suggested - && qty_n_calls_crossed[qty] != 0 - && CALLER_SAVE_PROFITABLE (qty_n_refs[qty], qty_n_calls_crossed[qty])) - { - i = find_free_reg (class, mode, qty, 1, 0, born_index, dead_index); - if (i >= 0) - caller_save_needed = 1; - return i; - } - return -1; -} - -/* Mark that REGNO with machine-mode MODE is live starting from the current - insn (if LIFE is non-zero) or dead starting at the current insn (if LIFE - is zero). */ - -static void -mark_life (regno, mode, life) - register int regno; - enum machine_mode mode; - int life; -{ - register int j = HARD_REGNO_NREGS (regno, mode); - if (life) - while (--j >= 0) - SET_HARD_REG_BIT (regs_live, regno + j); - else - while (--j >= 0) - CLEAR_HARD_REG_BIT (regs_live, regno + j); -} - -/* Mark register number REGNO (with machine-mode MODE) as live (if LIFE - is non-zero) or dead (if LIFE is zero) from insn number BIRTH (inclusive) - to insn number DEATH (exclusive). */ - -static void -post_mark_life (regno, mode, life, birth, death) - int regno; - enum machine_mode mode; - int life, birth, death; -{ - register int j = HARD_REGNO_NREGS (regno, mode); -#ifdef HARD_REG_SET - register /* Declare it register if it's a scalar. */ -#endif - HARD_REG_SET this_reg; - - CLEAR_HARD_REG_SET (this_reg); - while (--j >= 0) - SET_HARD_REG_BIT (this_reg, regno + j); - - if (life) - while (birth < death) - { - IOR_HARD_REG_SET (regs_live_at[birth], this_reg); - birth++; - } - else - while (birth < death) - { - AND_COMPL_HARD_REG_SET (regs_live_at[birth], this_reg); - birth++; - } -} - -/* INSN is the CLOBBER insn that starts a REG_NO_NOCONFLICT block, R0 - is the register being clobbered, and R1 is a register being used in - the equivalent expression. - - If R1 dies in the block and has a REG_NO_CONFLICT note on every insn - in which it is used, return 1. - - Otherwise, return 0. */ - -static int -no_conflict_p (insn, r0, r1) - rtx insn, r0, r1; -{ - int ok = 0; - rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); - rtx p, last; - - /* If R1 is a hard register, return 0 since we handle this case - when we scan the insns that actually use it. */ - - if (note == 0 - || (GET_CODE (r1) == REG && REGNO (r1) < FIRST_PSEUDO_REGISTER) - || (GET_CODE (r1) == SUBREG && GET_CODE (SUBREG_REG (r1)) == REG - && REGNO (SUBREG_REG (r1)) < FIRST_PSEUDO_REGISTER)) - return 0; - - last = XEXP (note, 0); - - for (p = NEXT_INSN (insn); p && p != last; p = NEXT_INSN (p)) - if (GET_RTX_CLASS (GET_CODE (p)) == 'i') - { - if (find_reg_note (p, REG_DEAD, r1)) - ok = 1; - - /* There must be a REG_NO_CONFLICT note on every insn, otherwise - some earlier optimization pass has inserted instructions into - the sequence, and it is not safe to perform this optimization. - Note that emit_no_conflict_block always ensures that this is - true when these sequences are created. */ - if (! find_reg_note (p, REG_NO_CONFLICT, r1)) - return 0; - } - - return ok; -} - -#ifdef REGISTER_CONSTRAINTS - -/* Return the number of alternatives for which the constraint string P - indicates that the operand must be equal to operand 0 and that no register - is acceptable. */ - -static int -requires_inout (p) - const char *p; -{ - char c; - int found_zero = 0; - int reg_allowed = 0; - int num_matching_alts = 0; - - while ((c = *p++)) - switch (c) - { - case '=': case '+': case '?': - case '#': case '&': case '!': - case '*': case '%': - case '1': case '2': case '3': case '4': - case 'm': case '<': case '>': case 'V': case 'o': - 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': -#ifdef EXTRA_CONSTRAINT - case 'Q': case 'R': case 'S': case 'T': case 'U': -#endif - case 'X': - /* These don't say anything we care about. */ - break; - - case ',': - if (found_zero && ! reg_allowed) - num_matching_alts++; - - found_zero = reg_allowed = 0; - break; - - case '0': - found_zero = 1; - break; - - case 'p': - case 'g': case 'r': - default: - reg_allowed = 1; - break; - } - - if (found_zero && ! reg_allowed) - num_matching_alts++; - - return num_matching_alts; -} -#endif /* REGISTER_CONSTRAINTS */ - -void -dump_local_alloc (file) - FILE *file; -{ - register int i; - for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) - if (reg_renumber[i] != -1) - fprintf (file, ";; Register %d in %d.\n", i, reg_renumber[i]); -} |