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-rw-r--r--contrib/gcc/stupid.c770
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diff --git a/contrib/gcc/stupid.c b/contrib/gcc/stupid.c
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-/* Dummy data flow analysis for GNU compiler in nonoptimizing mode.
- Copyright (C) 1987, 91, 94-96, 1998 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 performs stupid register allocation, which is used
- when cc1 gets the -noreg switch (which is when cc does not get -O).
-
- Stupid register allocation goes in place of the flow_analysis,
- local_alloc and global_alloc passes. combine_instructions cannot
- be done with stupid allocation because the data flow info that it needs
- is not computed here.
-
- In stupid allocation, the only user-defined variables that can
- go in registers are those declared "register". They are assumed
- to have a life span equal to their scope. Other user variables
- are given stack slots in the rtl-generation pass and are not
- represented as pseudo regs. A compiler-generated temporary
- is assumed to live from its first mention to its last mention.
-
- Since each pseudo-reg's life span is just an interval, it can be
- represented as a pair of numbers, each of which identifies an insn by
- its position in the function (number of insns before it). The first
- thing done for stupid allocation is to compute such a number for each
- insn. It is called the suid. Then the life-interval of each
- pseudo reg is computed. Then the pseudo regs are ordered by priority
- and assigned hard regs in priority order. */
-
-#include "config.h"
-#include "system.h"
-
-#include "rtl.h"
-#include "hard-reg-set.h"
-#include "basic-block.h"
-#include "regs.h"
-#include "insn-config.h"
-#include "reload.h"
-#include "flags.h"
-#include "toplev.h"
-
-/* Vector mapping INSN_UIDs to suids.
- The suids are like uids but increase monotonically always.
- We use them to see whether a subroutine call came
- between a variable's birth and its death. */
-
-static int *uid_suid;
-
-/* Get the suid of an insn. */
-
-#define INSN_SUID(INSN) (uid_suid[INSN_UID (INSN)])
-
-/* Record the suid of the last CALL_INSN
- so we can tell whether a pseudo reg crosses any calls. */
-
-static int last_call_suid;
-
-/* Record the suid of the last NOTE_INSN_SETJMP
- so we can tell whether a pseudo reg crosses any setjmp. */
-
-static int last_setjmp_suid;
-
-/* Element N is suid of insn where life span of pseudo reg N ends.
- Element is 0 if register N has not been seen yet on backward scan. */
-
-static int *reg_where_dead;
-
-/* Likewise, but point to the insn_chain structure of the insn at which
- the reg dies. */
-static struct insn_chain **reg_where_dead_chain;
-
-/* Element N is suid of insn where life span of pseudo reg N begins. */
-static int *reg_where_born_exact;
-
-/* Element N is 1 if the birth of pseudo reg N is due to a CLOBBER,
- 0 otherwise. */
-static int *reg_where_born_clobber;
-
-/* Return the suid of the insn where the register is born, or the suid
- of the insn before if the birth is due to a CLOBBER. */
-#define REG_WHERE_BORN(N) \
- (reg_where_born_exact[(N)] - reg_where_born_clobber[(N)])
-
-/* Numbers of pseudo-regs to be allocated, highest priority first. */
-
-static int *reg_order;
-
-/* Indexed by reg number (hard or pseudo), nonzero if register is live
- at the current point in the instruction stream. */
-
-static char *regs_live;
-
-/* Indexed by reg number, nonzero if reg was used in a SUBREG that changes
- its size. */
-
-static char *regs_change_size;
-
-/* Indexed by reg number, nonzero if reg crosses a setjmp. */
-
-static char *regs_crosses_setjmp;
-
-/* Indexed by insn's suid, the set of hard regs live after that insn. */
-
-static HARD_REG_SET *after_insn_hard_regs;
-
-/* Record that hard reg REGNO is live after insn INSN. */
-
-#define MARK_LIVE_AFTER(INSN,REGNO) \
- SET_HARD_REG_BIT (after_insn_hard_regs[INSN_SUID (INSN)], (REGNO))
-
-static int stupid_reg_compare PROTO((const GENERIC_PTR,const GENERIC_PTR));
-static int stupid_find_reg PROTO((int, enum reg_class, enum machine_mode,
- int, int, int));
-static void stupid_mark_refs PROTO((rtx, struct insn_chain *));
-static void find_clobbered_regs PROTO((rtx, rtx));
-
-/* For communication between stupid_life_analysis and find_clobbered_regs. */
-static struct insn_chain *current_chain;
-
-/* This function, called via note_stores, marks any hard registers that are
- clobbered in an insn as being live in the live_after and live_before fields
- of the appropriate insn_chain structure. */
-
-static void
-find_clobbered_regs (reg, setter)
- rtx reg, setter;
-{
- int regno, nregs;
- if (setter == 0 || GET_CODE (setter) != CLOBBER)
- return;
-
- if (GET_CODE (reg) == SUBREG)
- reg = SUBREG_REG (reg);
-
- if (GET_CODE (reg) != REG)
- return;
- regno = REGNO (reg);
- if (regno >= FIRST_PSEUDO_REGISTER)
- return;
-
- if (GET_MODE (reg) == VOIDmode)
- abort ();
- else
- nregs = HARD_REGNO_NREGS (regno, GET_MODE (reg));
- while (nregs-- > 0)
- {
- SET_REGNO_REG_SET (current_chain->live_after, regno);
- SET_REGNO_REG_SET (current_chain->live_before, regno++);
- }
-}
-
-/* Stupid life analysis is for the case where only variables declared
- `register' go in registers. For this case, we mark all
- pseudo-registers that belong to register variables as
- dying in the last instruction of the function, and all other
- pseudo registers as dying in the last place they are referenced.
- Hard registers are marked as dying in the last reference before
- the end or before each store into them. */
-
-void
-stupid_life_analysis (f, nregs, file)
- rtx f;
- int nregs;
- FILE *file;
-{
- register int i;
- register rtx last, insn;
- int max_uid, max_suid;
-
- current_function_has_computed_jump = 0;
-
- bzero (regs_ever_live, sizeof regs_ever_live);
-
- regs_live = (char *) xmalloc (nregs);
-
- /* First find the last real insn, and count the number of insns,
- and assign insns their suids. */
-
- for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
- if (INSN_UID (insn) > i)
- i = INSN_UID (insn);
-
- max_uid = i + 1;
- uid_suid = (int *) xmalloc ((i + 1) * sizeof (int));
-
- /* Compute the mapping from uids to suids.
- Suids are numbers assigned to insns, like uids,
- except that suids increase monotonically through the code. */
-
- last = 0; /* In case of empty function body */
- for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
- {
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
- last = insn;
-
- INSN_SUID (insn) = ++i;
- }
-
- last_call_suid = i + 1;
- last_setjmp_suid = i + 1;
- max_suid = i + 1;
-
- max_regno = nregs;
-
- /* Allocate tables to record info about regs. */
-
- reg_where_dead = (int *) xmalloc (nregs * sizeof (int));
- bzero ((char *) reg_where_dead, nregs * sizeof (int));
-
- reg_where_born_exact = (int *) xmalloc (nregs * sizeof (int));
- bzero ((char *) reg_where_born_exact, nregs * sizeof (int));
-
- reg_where_born_clobber = (int *) xmalloc (nregs * sizeof (int));
- bzero ((char *) reg_where_born_clobber, nregs * sizeof (int));
-
- reg_where_dead_chain = (struct insn_chain **) xmalloc (nregs * sizeof (struct insn_chain *));
- bzero ((char *) reg_where_dead_chain, nregs * sizeof (struct insn_chain *));
-
- reg_order = (int *) xmalloc (nregs * sizeof (int));
- bzero ((char *) reg_order, nregs * sizeof (int));
-
- regs_change_size = (char *) xmalloc (nregs * sizeof (char));
- bzero ((char *) regs_change_size, nregs * sizeof (char));
-
- regs_crosses_setjmp = (char *) xmalloc (nregs * sizeof (char));
- bzero ((char *) regs_crosses_setjmp, nregs * sizeof (char));
-
- /* Allocate the reg_renumber array */
- allocate_reg_info (max_regno, FALSE, TRUE);
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- reg_renumber[i] = i;
-
- after_insn_hard_regs
- = (HARD_REG_SET *) xmalloc (max_suid * sizeof (HARD_REG_SET));
-
- bzero ((char *) after_insn_hard_regs, max_suid * sizeof (HARD_REG_SET));
-
- /* Allocate and zero out many data structures
- that will record the data from lifetime analysis. */
-
- allocate_reg_life_data ();
- allocate_bb_life_data ();
-
- for (i = 0; i < max_regno; i++)
- REG_N_DEATHS (i) = 1;
-
- bzero (regs_live, nregs);
-
- /* Find where each pseudo register is born and dies,
- by scanning all insns from the end to the start
- and noting all mentions of the registers.
-
- Also find where each hard register is live
- and record that info in after_insn_hard_regs.
- regs_live[I] is 1 if hard reg I is live
- at the current point in the scan.
-
- Build reload_insn_chain while we're walking the insns. */
-
- reload_insn_chain = 0;
- for (insn = last; insn; insn = PREV_INSN (insn))
- {
- register HARD_REG_SET *p = after_insn_hard_regs + INSN_SUID (insn);
- struct insn_chain *chain;
-
- /* Copy the info in regs_live into the element of after_insn_hard_regs
- for the current position in the rtl code. */
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regs_live[i])
- SET_HARD_REG_BIT (*p, i);
-
- if (GET_CODE (insn) != NOTE && GET_CODE (insn) != BARRIER)
- {
- chain = new_insn_chain ();
- if (reload_insn_chain)
- reload_insn_chain->prev = chain;
- chain->next = reload_insn_chain;
- chain->prev = 0;
- reload_insn_chain = chain;
- chain->block = 0;
- chain->insn = insn;
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regs_live[i])
- SET_REGNO_REG_SET (chain->live_before, i);
- }
-
- /* Update which hard regs are currently live
- and also the birth and death suids of pseudo regs
- based on the pattern of this insn. */
-
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
- stupid_mark_refs (PATTERN (insn), chain);
-
- if (GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP)
- last_setjmp_suid = INSN_SUID (insn);
-
- /* Mark all call-clobbered regs as dead after each call insn so that
- a pseudo whose life span includes this insn will not go in one of
- them. If the function contains a non-local goto, mark all hard
- registers dead (except for stack related bits).
-
- Then mark those regs as all dead for the continuing scan
- of the insns before the call. */
-
- if (GET_CODE (insn) == CALL_INSN)
- {
- last_call_suid = INSN_SUID (insn);
-
- if (current_function_has_nonlocal_label)
- {
- IOR_COMPL_HARD_REG_SET (after_insn_hard_regs[last_call_suid],
- fixed_reg_set);
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (! fixed_regs[i])
- regs_live[i] = 0;
- }
- else
- {
- IOR_HARD_REG_SET (after_insn_hard_regs[last_call_suid],
- call_used_reg_set);
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (call_used_regs[i])
- regs_live[i] = 0;
- }
-
- /* It is important that this be done after processing the insn's
- pattern because we want the function result register to still
- be live if it's also used to pass arguments. */
- stupid_mark_refs (CALL_INSN_FUNCTION_USAGE (insn), chain);
- }
-
- if (GET_CODE (insn) != NOTE && GET_CODE (insn) != BARRIER)
- {
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regs_live[i])
- SET_REGNO_REG_SET (chain->live_after, i);
-
- /* The regs_live array doesn't say anything about hard registers
- clobbered by this insn. So we need an extra pass over the
- pattern. */
- current_chain = chain;
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
- note_stores (PATTERN (insn), find_clobbered_regs);
- }
-
- if (GET_CODE (insn) == JUMP_INSN && computed_jump_p (insn))
- current_function_has_computed_jump = 1;
- }
-
- /* Now decide the order in which to allocate the pseudo registers. */
-
- for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
- reg_order[i] = i;
-
- qsort (&reg_order[LAST_VIRTUAL_REGISTER + 1],
- max_regno - LAST_VIRTUAL_REGISTER - 1, sizeof (int),
- stupid_reg_compare);
-
- /* Now, in that order, try to find hard registers for those pseudo regs. */
-
- for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
- {
- register int r = reg_order[i];
-
- /* Some regnos disappear from the rtl. Ignore them to avoid crash.
- Also don't allocate registers that cross a setjmp, or live across
- a call if this function receives a nonlocal goto.
- Also ignore registers we didn't see during the scan. */
- if (regno_reg_rtx[r] == 0 || regs_crosses_setjmp[r]
- || (reg_where_born_exact[r] == 0 && reg_where_dead[r] == 0)
- || (REG_N_CALLS_CROSSED (r) > 0
- && current_function_has_nonlocal_label))
- continue;
-
- /* Now find the best hard-register class for this pseudo register */
- if (N_REG_CLASSES > 1)
- reg_renumber[r] = stupid_find_reg (REG_N_CALLS_CROSSED (r),
- reg_preferred_class (r),
- PSEUDO_REGNO_MODE (r),
- REG_WHERE_BORN (r),
- reg_where_dead[r],
- regs_change_size[r]);
-
- /* If no reg available in that class, try alternate class. */
- if (reg_renumber[r] == -1 && reg_alternate_class (r) != NO_REGS)
- reg_renumber[r] = stupid_find_reg (REG_N_CALLS_CROSSED (r),
- reg_alternate_class (r),
- PSEUDO_REGNO_MODE (r),
- REG_WHERE_BORN (r),
- reg_where_dead[r],
- regs_change_size[r]);
- }
-
- /* Fill in the pseudo reg life information into the insn chain. */
- for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
- {
- struct insn_chain *chain;
- int regno;
-
- regno = reg_renumber[i];
- if (regno < 0)
- continue;
-
- chain = reg_where_dead_chain[i];
- if (reg_where_dead[i] > INSN_SUID (chain->insn))
- SET_REGNO_REG_SET (chain->live_after, i);
-
- while (INSN_SUID (chain->insn) > reg_where_born_exact[i])
- {
- SET_REGNO_REG_SET (chain->live_before, i);
- chain = chain->prev;
- if (!chain)
- break;
- SET_REGNO_REG_SET (chain->live_after, i);
- }
-
- if (INSN_SUID (chain->insn) == reg_where_born_exact[i]
- && reg_where_born_clobber[i])
- SET_REGNO_REG_SET (chain->live_before, i);
- }
-
- if (file)
- dump_flow_info (file);
-
- free (regs_live);
- free (uid_suid);
- free (reg_where_dead);
- free (reg_where_born_exact);
- free (reg_where_born_clobber);
- free (reg_where_dead_chain);
- free (reg_order);
- free (regs_change_size);
- free (regs_crosses_setjmp);
- free (after_insn_hard_regs);
-}
-
-/* Comparison function for qsort.
- Returns -1 (1) if register *R1P is higher priority than *R2P. */
-
-static int
-stupid_reg_compare (r1p, r2p)
- const GENERIC_PTR r1p;
- const GENERIC_PTR r2p;
-{
- register int r1 = *(int *)r1p, r2 = *(int *)r2p;
- register int len1 = reg_where_dead[r1] - REG_WHERE_BORN (r1);
- register int len2 = reg_where_dead[r2] - REG_WHERE_BORN (r2);
- int tem;
-
- tem = len2 - len1;
- if (tem != 0)
- return tem;
-
- tem = REG_N_REFS (r1) - REG_N_REFS (r2);
- if (tem != 0)
- return tem;
-
- /* If regs are equally good, sort by regno,
- so that the results of qsort leave nothing to chance. */
- return r1 - r2;
-}
-
-/* Find a block of SIZE words of hard registers in reg_class CLASS
- that can hold a value of machine-mode MODE
- (but actually we test only the first of the block for holding MODE)
- currently free from after insn whose suid is BORN_INSN
- through the insn whose suid is DEAD_INSN,
- and return the number of the first of them.
- Return -1 if such a block cannot be found.
-
- If CALL_PRESERVED is nonzero, insist on registers preserved
- over subroutine calls, and return -1 if cannot find such.
-
- If CHANGES_SIZE is nonzero, it means this register was used as the
- operand of a SUBREG that changes its size. */
-
-static int
-stupid_find_reg (call_preserved, class, mode,
- born_insn, dead_insn, changes_size)
- int call_preserved;
- enum reg_class class;
- enum machine_mode mode;
- int born_insn, dead_insn;
- int changes_size ATTRIBUTE_UNUSED;
-{
- register int i, ins;
-#ifdef HARD_REG_SET
- register /* Declare them register if they are scalars. */
-#endif
- HARD_REG_SET used, this_reg;
-#ifdef ELIMINABLE_REGS
- static struct {int from, to; } eliminables[] = ELIMINABLE_REGS;
-#endif
-
- /* If this register's life is more than 5,000 insns, we probably
- can't allocate it, so don't waste the time trying. This avoids
- quadratic behavior on programs that have regularly-occurring
- SAVE_EXPRs. */
- if (dead_insn > born_insn + 5000)
- return -1;
-
- COPY_HARD_REG_SET (used,
- call_preserved ? call_used_reg_set : fixed_reg_set);
-
-#ifdef ELIMINABLE_REGS
- for (i = 0; i < (int)(sizeof eliminables / sizeof eliminables[0]); i++)
- SET_HARD_REG_BIT (used, eliminables[i].from);
-#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
- SET_HARD_REG_BIT (used, HARD_FRAME_POINTER_REGNUM);
-#endif
-#else
- SET_HARD_REG_BIT (used, FRAME_POINTER_REGNUM);
-#endif
-
- for (ins = born_insn; ins < dead_insn; ins++)
- IOR_HARD_REG_SET (used, after_insn_hard_regs[ins]);
-
-#ifdef STACK_REGS
- if (current_function_has_computed_jump)
- for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
- SET_HARD_REG_BIT (used, i);
-#endif
-
- IOR_COMPL_HARD_REG_SET (used, reg_class_contents[(int) class]);
-
-#ifdef CLASS_CANNOT_CHANGE_SIZE
- if (changes_size)
- IOR_HARD_REG_SET (used,
- reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE]);
-#endif
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- {
-#ifdef REG_ALLOC_ORDER
- int regno = reg_alloc_order[i];
-#else
- int regno = i;
-#endif
-
- /* If a register has screwy overlap problems,
- don't use it at all if not optimizing.
- Actually this is only for the 387 stack register,
- and it's because subsequent code won't work. */
-#ifdef OVERLAPPING_REGNO_P
- if (OVERLAPPING_REGNO_P (regno))
- continue;
-#endif
-
- if (! TEST_HARD_REG_BIT (used, regno)
- && HARD_REGNO_MODE_OK (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)
- {
- CLEAR_HARD_REG_SET (this_reg);
- while (--j >= 0)
- SET_HARD_REG_BIT (this_reg, regno + j);
- for (ins = born_insn; ins < dead_insn; ins++)
- {
- IOR_HARD_REG_SET (after_insn_hard_regs[ins], this_reg);
- }
- return regno;
- }
-#ifndef REG_ALLOC_ORDER
- i += j; /* Skip starting points we know will lose */
-#endif
- }
- }
-
- return -1;
-}
-
-/* Walk X, noting all assignments and references to registers
- and recording what they imply about life spans.
- INSN is the current insn, supplied so we can find its suid. */
-
-static void
-stupid_mark_refs (x, chain)
- rtx x;
- struct insn_chain *chain;
-{
- register RTX_CODE code;
- register char *fmt;
- register int regno, i;
- rtx insn = chain->insn;
-
- if (x == 0)
- return;
-
- code = GET_CODE (x);
-
- if (code == SET || code == CLOBBER)
- {
- if (SET_DEST (x) != 0
- && (GET_CODE (SET_DEST (x)) == REG
- || (GET_CODE (SET_DEST (x)) == SUBREG
- && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG
- && (REGNO (SUBREG_REG (SET_DEST (x)))
- >= FIRST_PSEUDO_REGISTER))))
- {
- /* Register is being assigned. */
- /* If setting a SUBREG, we treat the entire reg as being set. */
- if (GET_CODE (SET_DEST (x)) == SUBREG)
- regno = REGNO (SUBREG_REG (SET_DEST (x)));
- else
- regno = REGNO (SET_DEST (x));
-
- /* For hard regs, update the where-live info. */
- if (regno < FIRST_PSEUDO_REGISTER)
- {
- register int j
- = HARD_REGNO_NREGS (regno, GET_MODE (SET_DEST (x)));
-
- while (--j >= 0)
- {
- regs_ever_live[regno+j] = 1;
- regs_live[regno+j] = 0;
-
- /* The following line is for unused outputs;
- they do get stored even though never used again. */
- MARK_LIVE_AFTER (insn, regno+j);
-
- /* When a hard reg is clobbered, mark it in use
- just before this insn, so it is live all through. */
- if (code == CLOBBER && INSN_SUID (insn) > 0)
- SET_HARD_REG_BIT (after_insn_hard_regs[INSN_SUID (insn) - 1],
- regno+j);
- }
- }
- /* For pseudo regs, record where born, where dead, number of
- times used, and whether live across a call. */
- else
- {
- /* Update the life-interval bounds of this pseudo reg. */
-
- /* When a pseudo-reg is CLOBBERed, it is born just before
- the clobbering insn. When setting, just after. */
- int where_born = INSN_SUID (insn) - (code == CLOBBER);
-
- reg_where_born_exact[regno] = INSN_SUID (insn);
- reg_where_born_clobber[regno] = (code == CLOBBER);
-
- if (reg_where_dead_chain[regno] == 0)
- reg_where_dead_chain[regno] = chain;
-
- /* The reg must live at least one insn even
- in it is never again used--because it has to go
- in SOME hard reg. Mark it as dying after the current
- insn so that it will conflict with any other outputs of
- this insn. */
- if (reg_where_dead[regno] < where_born + 2)
- {
- reg_where_dead[regno] = where_born + 2;
- regs_live[regno] = 1;
- }
-
- /* Count the refs of this reg. */
- REG_N_REFS (regno)++;
-
- if (last_call_suid < reg_where_dead[regno])
- REG_N_CALLS_CROSSED (regno) += 1;
-
- if (last_setjmp_suid < reg_where_dead[regno])
- regs_crosses_setjmp[regno] = 1;
-
- /* If this register is clobbered or it is only used in
- this insn and is only set, mark it unused. We have
- to do this even when not optimizing so that MD patterns
- which count on this behavior (e.g., it not causing an
- output reload on an insn setting CC) will operate
- correctly. */
- if (GET_CODE (SET_DEST (x)) == REG
- && (code == CLOBBER
- || (REGNO_FIRST_UID (regno) == INSN_UID (insn)
- && REGNO_LAST_UID (regno) == INSN_UID (insn)
- && ! reg_mentioned_p (SET_DEST (x),
- SET_SRC (x)))))
- REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_UNUSED,
- SET_DEST (x),
- REG_NOTES (insn));
- }
- }
-
- /* Record references from the value being set,
- or from addresses in the place being set if that's not a reg.
- If setting a SUBREG, we treat the entire reg as *used*. */
- if (code == SET)
- {
- stupid_mark_refs (SET_SRC (x), chain);
- if (GET_CODE (SET_DEST (x)) != REG)
- stupid_mark_refs (SET_DEST (x), chain);
- }
- return;
- }
-
- else if (code == SUBREG
- && GET_CODE (SUBREG_REG (x)) == REG
- && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER
- && (GET_MODE_SIZE (GET_MODE (x))
- != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
- && (INTEGRAL_MODE_P (GET_MODE (x))
- || INTEGRAL_MODE_P (GET_MODE (SUBREG_REG (x)))))
- regs_change_size[REGNO (SUBREG_REG (x))] = 1;
-
- /* Register value being used, not set. */
-
- else if (code == REG)
- {
- regno = REGNO (x);
- if (regno < FIRST_PSEUDO_REGISTER)
- {
- /* Hard reg: mark it live for continuing scan of previous insns. */
- register int j = HARD_REGNO_NREGS (regno, GET_MODE (x));
- while (--j >= 0)
- {
- regs_ever_live[regno+j] = 1;
- regs_live[regno+j] = 1;
- }
- }
- else
- {
- /* Pseudo reg: record first use, last use and number of uses. */
-
- reg_where_born_exact[regno] = INSN_SUID (insn);
- reg_where_born_clobber[regno] = 0;
- REG_N_REFS (regno)++;
- if (regs_live[regno] == 0)
- {
- regs_live[regno] = 1;
- reg_where_dead[regno] = INSN_SUID (insn);
- reg_where_dead_chain[regno] = chain;
- }
- }
- return;
- }
-
- /* Recursive scan of all other rtx's. */
-
- fmt = GET_RTX_FORMAT (code);
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e')
- stupid_mark_refs (XEXP (x, i), chain);
- if (fmt[i] == 'E')
- {
- register int j;
- for (j = XVECLEN (x, i) - 1; j >= 0; j--)
- stupid_mark_refs (XVECEXP (x, i, j), chain);
- }
- }
-}