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Diffstat (limited to 'gcc/regmove.c')
| -rw-r--r-- | gcc/regmove.c | 983 |
1 files changed, 0 insertions, 983 deletions
diff --git a/gcc/regmove.c b/gcc/regmove.c deleted file mode 100644 index 639059b3686..00000000000 --- a/gcc/regmove.c +++ /dev/null @@ -1,983 +0,0 @@ -/* Move registers around to reduce number of move instructions needed. - Copyright (C) 1987, 88, 89, 92-5, 1996, 1997 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ - - -/* This module looks for cases where matching constraints would force - an instruction to need a reload, and this reload would be a register - to register move. It then attempts to change the registers used by the - instruction to avoid the move instruction. */ - -#include "config.h" -#ifdef __STDC__ -#include <stdarg.h> -#else -#include <varargs.h> -#endif - -/* Must precede rtl.h for FFS. */ -#include <stdio.h> - -#include "rtl.h" -#include "insn-config.h" -#include "recog.h" -#include "output.h" -#include "reload.h" -#include "regs.h" - -static int stable_but_for_p PROTO((rtx, rtx, rtx)); - -#if defined (HAVE_POST_INCREMENT) || defined (HAVE_POST_DECREMENT) \ - || defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) - -/* INC_INSN is an instruction that adds INCREMENT to REG. - Try to fold INC_INSN as a post/pre in/decrement into INSN. - Iff INC_INSN_SET is nonzero, inc_insn has a destination different from src. - Return nonzero for success. */ -static int -try_auto_increment (insn, inc_insn, inc_insn_set, reg, increment, pre) - rtx reg, insn, inc_insn ,inc_insn_set; - HOST_WIDE_INT increment; - int pre; -{ - enum rtx_code inc_code; - - rtx pset = single_set (insn); - if (pset) - { - /* Can't use the size of SET_SRC, we might have something like - (sign_extend:SI (mem:QI ... */ - rtx use = find_use_as_address (pset, reg, 0); - if (use != 0 && use != (rtx) 1) - { - int size = GET_MODE_SIZE (GET_MODE (use)); - if (0 -#ifdef HAVE_POST_INCREMENT - || (pre == 0 && (inc_code = POST_INC, increment == size)) -#endif -#ifdef HAVE_PRE_INCREMENT - || (pre == 1 && (inc_code = PRE_INC, increment == size)) -#endif -#ifdef HAVE_POST_DECREMENT - || (pre == 0 && (inc_code = POST_DEC, increment == -size)) -#endif -#ifdef HAVE_PRE_DECREMENT - || (pre == 1 && (inc_code = PRE_DEC, increment == -size)) -#endif - ) - { - if (inc_insn_set) - validate_change - (inc_insn, - &SET_SRC (inc_insn_set), - XEXP (SET_SRC (inc_insn_set), 0), 1); - validate_change (insn, &XEXP (use, 0), - gen_rtx (inc_code, - Pmode, - reg), 1); - if (apply_change_group ()) - { - REG_NOTES (insn) - = gen_rtx (EXPR_LIST, REG_INC, - reg, REG_NOTES (insn)); - if (! inc_insn_set) - { - PUT_CODE (inc_insn, NOTE); - NOTE_LINE_NUMBER (inc_insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (inc_insn) = 0; - } - return 1; - } - } - } - } - return 0; -} -#endif /* defined (HAVE_POST_INCREMENT) || defined (HAVE_POST_DECREMENT) */ - -void -regmove_optimize (f, nregs, regmove_dump_file) - rtx f; - int nregs; - FILE *regmove_dump_file; -{ -#ifdef REGISTER_CONSTRAINTS - rtx insn; - int matches[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS]; - int modified[MAX_RECOG_OPERANDS]; - int early_clobber[MAX_RECOG_OPERANDS]; - int commutative; - int pass; - - /* A forward/backward pass. Replace output operands with input operands. */ - - for (pass = 0; pass < 2; pass++) - { - if (regmove_dump_file) - fprintf (regmove_dump_file, "Starting %s pass...\n", - pass ? "backward" : "forward"); - - for (insn = pass ? get_last_insn () : f; insn; - insn = pass ? PREV_INSN (insn) : NEXT_INSN (insn)) - { - if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') - { - int insn_code_number = recog_memoized (insn); - int operand_number, match_number; - - if (insn_code_number < 0) - continue; - - insn_extract (insn); - if (! constrain_operands (insn_code_number, 0)) - continue; - - commutative = -1; - - /* Must initialize this before the loop, because the code for - the commutative case may set matches for operands other than - the current one. */ - bzero (matches, sizeof (matches)); - - for (operand_number = 0; - operand_number < insn_n_operands[insn_code_number]; - operand_number++) - { - int output_operand = 0; - int matching_operand = operand_number; - char *p, c; - int i = 0; - - modified[operand_number] = 0; - early_clobber[operand_number] = 0; - - p = insn_operand_constraint[insn_code_number][operand_number]; - - if (*p == '=') - modified[operand_number] = 2; - else if (*p == '+') - modified[operand_number] = 1; - - for (;*p && i < which_alternative; p++) - if (*p == ',') - i++; - - while ((c = *p++) != '\0' && c != ',') - switch (c) - { - case '=': - break; - case '+': - break; - case '&': - early_clobber[operand_number] = 1; - break; - case '%': - commutative = operand_number; - break; - case '0': case '1': case '2': case '3': case '4': - case '5': case '6': case '7': case '8': case '9': - c -= '0'; - matches[operand_number][c] = 1; - if (commutative >= 0) - { - if (c == commutative || c == commutative + 1) - { - int other = c + (c == commutative ? 1 : -1); - matches[operand_number][other] = 1; - } - if (operand_number == commutative - || operand_number == commutative + 1) - { - int other = (operand_number - + (operand_number == commutative - ? 1 : -1)); - matches[other][c] = 1; - } - } - break; - } - } - - /* Now scan through the operands looking for a source operand - which is supposed to match the destination operand. - Then scan forward for an instruction which uses the dest - operand. - If it dies there, then replace the dest in both operands with - the source operand. */ - - for (operand_number = 0; - operand_number < insn_n_operands[insn_code_number]; - operand_number++) - { - for (match_number = 0; - match_number < insn_n_operands[insn_code_number]; - match_number++) - { - rtx set, p, src, dst, src_subreg; - rtx post_inc = 0, post_inc_set = 0, search_end = 0; - rtx src_note, dst_note; - int success = 0; - int num_calls = 0; - enum rtx_code code = NOTE; - HOST_WIDE_INT insn_const, newconst; - rtx overlap = 0; /* need to move insn ? */ - - /* Nothing to do if the two operands aren't supposed to - match. */ - if (matches[operand_number][match_number] == 0) - continue; - - src = recog_operand[operand_number]; - dst = recog_operand[match_number]; - - if (GET_CODE (src) != REG - || REGNO (src) < FIRST_PSEUDO_REGISTER) - continue; - - src_subreg = src; - if (GET_CODE (dst) == SUBREG - && GET_MODE_SIZE (GET_MODE (dst)) - >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dst)))) - { - src_subreg - = gen_rtx(SUBREG, GET_MODE (SUBREG_REG (dst)), - src, SUBREG_WORD (dst)); - dst = SUBREG_REG (dst); - } - if (GET_CODE (dst) != REG - || REGNO (dst) < FIRST_PSEUDO_REGISTER) - continue; - - /* If the operands already match, then there is nothing - to do. */ - if (operands_match_p (src, dst)) - continue; - - set = single_set (insn); - if (! set) - continue; - - /* operand_number/src must be a read-only operand, and - match_operand/dst must be a write-only operand. */ - if (modified[match_number] != 2) - continue; - - if (early_clobber[match_number] == 1) - continue; - - if (modified[operand_number] != 0) - continue; - - /* Make sure match_operand is the destination. */ - if (recog_operand[match_number] != SET_DEST (set)) - continue; - - src_note = find_reg_note (insn, REG_DEAD, src); - - if (! src_note) - { - /* Look for (set (regX) (op regA constX)) - (set (regY) (op regA constY)) - and change that to - (set (regA) (op regA constX)). - (set (regY) (op regA constY-constX)). - This works for add and shift operations, if - regA is dead after or set by the second insn. */ - - code = GET_CODE (SET_SRC (set)); - if ((code == PLUS || code == LSHIFTRT - || code == ASHIFT || code == ASHIFTRT) - && XEXP (SET_SRC (set), 0) == src - && (GET_CODE (XEXP (SET_SRC (set), 1)) - == CONST_INT)) - insn_const = INTVAL (XEXP (SET_SRC (set), 1)); - else if (! stable_but_for_p (SET_SRC (set), src, dst)) - continue; - else - /* We might find a src_note while scanning. */ - code = NOTE; - } - - if (regmove_dump_file) - fprintf (regmove_dump_file, - "Could fix operand %d of insn %d matching operand %d.\n", - operand_number, INSN_UID (insn), match_number); - - /* ??? If src is set once, and is set equal to a - constant, then do not use it for this optimization, - as this would make it no longer equivalent to a - constant? */ - - /* Scan forward to find the next instruction that - uses the output operand. If the operand dies here, - then replace it in both instructions with - operand_number. */ - - for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) - { - if (GET_CODE (p) == CODE_LABEL - || GET_CODE (p) == JUMP_INSN - || (GET_CODE (p) == NOTE - && ((NOTE_LINE_NUMBER (p) - == NOTE_INSN_LOOP_BEG) - || (NOTE_LINE_NUMBER (p) - == NOTE_INSN_LOOP_END)))) - break; - - if (GET_RTX_CLASS (GET_CODE (p)) != 'i') - continue; - - if (reg_set_p (src, p) || reg_set_p (dst, p) - || (GET_CODE (PATTERN (p)) == USE - && reg_overlap_mentioned_p (src, - XEXP (PATTERN (p), - 0)))) - break; - - /* See if all of DST dies in P. This test is - slightly more conservative than it needs to be. */ - if ((dst_note - = find_regno_note (p, REG_DEAD, REGNO (dst))) - && (GET_MODE (XEXP (dst_note, 0)) - == GET_MODE (dst))) - { - if (! src_note) - { - rtx q; - rtx set2; - - /* If an optimization is done, the value - of SRC while P is executed will be - changed. Check that this is OK. */ - if (reg_overlap_mentioned_p (src, - PATTERN (p))) - break; - for (q = p; q; q = NEXT_INSN (q)) - { - if (GET_CODE (q) == CODE_LABEL - || GET_CODE (q) == JUMP_INSN - || (GET_CODE (q) == NOTE - && ((NOTE_LINE_NUMBER (q) - == NOTE_INSN_LOOP_BEG) - || (NOTE_LINE_NUMBER (q) - == NOTE_INSN_LOOP_END)))) - { - q = 0; - break; - } - if (GET_RTX_CLASS (GET_CODE (q)) != 'i') - continue; - if (reg_overlap_mentioned_p (src, - PATTERN (q)) - || reg_set_p (src, q)) - break; - } - if (q) - set2 = single_set (q); - if (! q || ! set2 - || GET_CODE (SET_SRC (set2)) != code - || XEXP (SET_SRC (set2), 0) != src - || (GET_CODE (XEXP (SET_SRC (set2), 1)) - != CONST_INT) - || (SET_DEST (set2) != src - && !find_reg_note (q, REG_DEAD, src))) - { - /* If this is a PLUS, we can still save - a register by doing - src += insn_const; - P; - src -= insn_const; . - This also gives opportunities for - subsequent optimizations in the - backward pass, so do it there. */ - if (code == PLUS && pass == 1 -#ifdef HAVE_cc0 - /* We man not emit an insn directly - after P if the latter sets CC0. */ - && ! sets_cc0_p (PATTERN (p)) -#endif - ) - - { - search_end = q; - q = insn; - set2 = set; - newconst = -insn_const; - code = MINUS; - } - else - break; - } - else - { - newconst - = (INTVAL (XEXP (SET_SRC (set2), 1)) - - insn_const); - /* Reject out of range shifts. */ - if (code != PLUS - && (newconst < 0 - || (newconst - >= GET_MODE_BITSIZE (GET_MODE (SET_SRC (set2)))))) - break; - if (code == PLUS) - { - post_inc = q; - if (SET_DEST (set2) != src) - post_inc_set = set2; - } - } - /* We use 1 as last argument to - validate_change so that all changes - are accepted or rejected together by - apply_change_group when it is called - by validate_replace_rtx . */ - validate_change (q, &XEXP (SET_SRC (set2), 1), - GEN_INT (newconst), 1); - } - validate_change (insn, - recog_operand_loc[match_number], - src, 1); - if (validate_replace_rtx (dst, src_subreg, p)) - success = 1; - break; - } - - if (reg_overlap_mentioned_p (dst, PATTERN (p))) - break; - if (! src_note - && reg_overlap_mentioned_p (src, PATTERN (p))) - { - /* INSN was already checked to be movable when - we found no REG_DEAD note for src on it. */ - overlap = p; - src_note = find_reg_note (p, REG_DEAD, src); - } - - /* If we have passed a call instruction, and the - pseudo-reg SRC is not already live across a call, - then don't perform the optimization. */ - if (GET_CODE (p) == CALL_INSN) - { - num_calls++; - - if (REG_N_CALLS_CROSSED (REGNO (src)) == 0) - break; - } - } - - if (success) - { - /* Remove the death note for DST from P. */ - remove_note (p, dst_note); - if (code == MINUS) - { - post_inc - = emit_insn_after (copy_rtx (PATTERN (insn)), - p); -#if defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) - if (search_end - && try_auto_increment (search_end, post_inc, - 0, src, newconst, 1)) - post_inc = 0; -#endif - validate_change (insn, &XEXP (SET_SRC (set), 1), - GEN_INT (insn_const), 0); - REG_N_SETS (REGNO (src))++; - } - if (overlap) - { - /* The lifetime of src and dest overlap, - but we can change this by moving insn. */ - rtx pat = PATTERN (insn); - if (src_note) - remove_note (overlap, src_note); -#if defined (HAVE_POST_INCREMENT) || defined (HAVE_POST_DECREMENT) - if (code == PLUS - && try_auto_increment (overlap, insn, 0, - src, insn_const, 0)) - insn = overlap; - else -#endif - { - emit_insn_after_with_line_notes - (pat, PREV_INSN (p), insn); - PUT_CODE (insn, NOTE); - NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (insn) = 0; - /* emit_insn_after_with_line_notes - has no return value, so search - for the new insn. */ - for (insn = p; PATTERN (insn) != pat; ) - insn = PREV_INSN (insn); - } - } - /* Sometimes we'd generate src = const; src += n; - if so, replace the instruction that set src - in the first place. */ - - if (! overlap && (code == PLUS || code == MINUS)) - { - rtx note - = find_reg_note (insn, REG_EQUAL, NULL_RTX); - rtx q, set2; - int num_calls2 = 0; - - if (note && CONSTANT_P (XEXP (note, 0))) - { - for (q = PREV_INSN (insn); q; - q = PREV_INSN(q)) - { - if (GET_CODE (q) == JUMP_INSN) - { - q = 0; - break; - } - if (GET_RTX_CLASS (GET_CODE (q)) != 'i') - continue; - if (reg_set_p (src, q)) - { - set2 = single_set (q); - break; - } - if (reg_overlap_mentioned_p (src, - PATTERN (q))) - { - q = 0; - break; - } - if (GET_CODE (p) == CALL_INSN) - num_calls2++; - } - if (q && set2 && SET_DEST (set2) == src - && CONSTANT_P (SET_SRC (set2)) - && validate_change (insn, &SET_SRC (set), - XEXP (note, 0), 0)) - { - PUT_CODE (q, NOTE); - NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (q) = 0; - REG_N_SETS (REGNO (src))--; - REG_N_CALLS_CROSSED (REGNO (src)) - -= num_calls2; - insn_const = 0; - } - } - } - if (0) ; -#if defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) - else if ((code == PLUS || code == MINUS) - && insn_const - && try_auto_increment (p, insn, 0, - src, insn_const, 1)) - insn = p; -#endif -#if defined (HAVE_POST_INCREMENT) || defined (HAVE_POST_DECREMENT) - else if (post_inc - && try_auto_increment (p, post_inc, - post_inc_set, src, - newconst, 0)) - post_inc = 0; -#endif -#if defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) - /* If post_inc still prevails, try to find an - insn where it can be used as a pre-in/decrement. - If code is MINUS, this was already tried. */ - if (post_inc && code == PLUS - /* Check that newconst is likely to be usable - in a pre-in/decrement before starting the - search. */ - && (0 -#if defined (HAVE_PRE_INCREMENT) - || (newconst > 0 && newconst <= MOVE_MAX) -#endif -#if defined (HAVE_PRE_DECREMENT) - || (newconst < 0 && newconst >= -MOVE_MAX) -#endif - ) && exact_log2 (newconst)) - { - rtx q, inc_dest; - - inc_dest - = post_inc_set ? SET_DEST (post_inc_set) : src; - for (q = post_inc; q = NEXT_INSN (q); ) - { - if (GET_CODE (q) == CODE_LABEL - || GET_CODE (q) == JUMP_INSN - || (GET_CODE (q) == NOTE - && ((NOTE_LINE_NUMBER (q) - == NOTE_INSN_LOOP_BEG) - || (NOTE_LINE_NUMBER (q) - == NOTE_INSN_LOOP_END)))) - break; - if (GET_RTX_CLASS (GET_CODE (q)) != 'i') - continue; - if (src != inc_dest - && (reg_overlap_mentioned_p (src, - PATTERN (q)) - || reg_set_p (src, q))) - break; - if (reg_set_p (inc_dest, q)) - break; - if (reg_overlap_mentioned_p (inc_dest, - PATTERN (q))) - { - try_auto_increment (q, post_inc, - post_inc_set, - inc_dest, - newconst, 1); - break; - } - } - } -#endif /* defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) */ - /* Move the death note for DST to INSN if it is used - there. */ - if (reg_overlap_mentioned_p (dst, PATTERN (insn))) - { - XEXP (dst_note, 1) = REG_NOTES (insn); - REG_NOTES (insn) = dst_note; - } - - if (src_note) - { - /* Move the death note for SRC from INSN to P. */ - if (! overlap) - remove_note (insn, src_note); - XEXP (src_note, 1) = REG_NOTES (p); - REG_NOTES (p) = src_note; - - REG_N_CALLS_CROSSED (REGNO (src)) += num_calls; - } - - REG_N_SETS (REGNO (src))++; - REG_N_SETS (REGNO (dst))--; - - REG_N_CALLS_CROSSED (REGNO (dst)) -= num_calls; - - /* ??? Must adjust reg_live_length, and reg_n_refs for - both registers. Must keep track of loop_depth in - order to get reg_n_refs adjustment correct. */ - - if (regmove_dump_file) - fprintf (regmove_dump_file, - "Fixed operand %d of insn %d matching operand %d.\n", - operand_number, INSN_UID (insn), - match_number); - - goto done_forwards; - } - } - } - done_forwards: - ; - } - } - } - - /* A backward pass. Replace input operands with output operands. */ - - if (regmove_dump_file) - fprintf (regmove_dump_file, "Starting backward pass...\n"); - - for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) - { - if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') - { - int insn_code_number = recog_memoized (insn); - int operand_number, match_number; - - if (insn_code_number < 0) - continue; - - insn_extract (insn); - if (! constrain_operands (insn_code_number, 0)) - continue; - - commutative = -1; - - /* Must initialize this before the loop, because the code for - the commutative case may set matches for operands other than - the current one. */ - bzero (matches, sizeof (matches)); - - for (operand_number = 0; - operand_number < insn_n_operands[insn_code_number]; - operand_number++) - { - int output_operand = 0; - int matching_operand = operand_number; - char *p, c; - int i = 0; - - modified[operand_number] = 0; - early_clobber[operand_number] = 0; - - p = insn_operand_constraint[insn_code_number][operand_number]; - - if (*p == '=') - modified[operand_number] = 2; - else if (*p == '+') - modified[operand_number] = 1; - - for (; *p && i < which_alternative; p++) - if (*p == ',') - i++; - - while ((c = *p++) != '\0' && c != ',') - switch (c) - { - case '=': - break; - case '+': - break; - case '&': - early_clobber[operand_number] = 1; - break; - case '%': - commutative = operand_number; - break; - case '0': case '1': case '2': case '3': case '4': - case '5': case '6': case '7': case '8': case '9': - c -= '0'; - matches[c][operand_number] = 1; - if (commutative >= 0) - { - if (c == commutative || c == commutative + 1) - { - int other = c + (c == commutative ? 1 : -1); - matches[other][operand_number] = 1; - } - if (operand_number == commutative - || operand_number == commutative + 1) - { - int other = (operand_number - + (operand_number == commutative - ? 1 : -1)); - matches[c][other] = 1; - } - } - break; - } - } - - /* Now scan through the operands looking for a destination operand - which is supposed to match a source operand. - Then scan backward for an instruction which sets the source - operand. If safe, then replace the source operand with the - dest operand in both instructions. */ - - for (operand_number = 0; - operand_number < insn_n_operands[insn_code_number]; - operand_number++) - { - for (match_number = 0; - match_number < insn_n_operands[insn_code_number]; - match_number++) - { - rtx set, p, src, dst; - rtx src_note, dst_note; - int success = 0; - int num_calls = 0; - - /* Nothing to do if the two operands aren't supposed to - match. */ - if (matches[operand_number][match_number] == 0) - continue; - - dst = recog_operand[operand_number]; - src = recog_operand[match_number]; - - if (GET_CODE (src) != REG - || REGNO (src) < FIRST_PSEUDO_REGISTER) - continue; - - if (GET_CODE (dst) != REG - || REGNO (dst) < FIRST_PSEUDO_REGISTER) - continue; - - /* If the operands already match, then there is nothing - to do. */ - if (operands_match_p (src, dst)) - continue; - - set = single_set (insn); - if (! set) - continue; - - /* operand_number/dst must be a write-only operand, and - match_operand/src must be a read-only operand. */ - if (modified[match_number] != 0) - continue; - - if (early_clobber[operand_number] == 1) - continue; - - if (modified[operand_number] != 2) - continue; - - /* Make sure operand_number is the destination. */ - if (recog_operand[operand_number] != SET_DEST (set)) - continue; - - if (! (src_note = find_reg_note (insn, REG_DEAD, src))) - continue; - - /* Can not modify an earlier insn to set dst if this insn - uses an old value in the source. */ - if (reg_overlap_mentioned_p (dst, SET_SRC (set))) - continue; - - if (regmove_dump_file) - fprintf (regmove_dump_file, - "Could fix operand %d of insn %d matching operand %d.\n", - operand_number, INSN_UID (insn), match_number); - - /* ??? If src is set once, and is set equal to a constant, - then do not use it for this optimization, as this would - make it no longer equivalent to a constant? */ - - /* Scan backward to find the first instruction that uses - the input operand. If the operand is set here, then - replace it in both instructions with operand_number. */ - - for (p = PREV_INSN (insn); p; p = PREV_INSN (p)) - { - rtx pset; - - if (GET_CODE (p) == CODE_LABEL - || GET_CODE (p) == JUMP_INSN - || (GET_CODE (p) == NOTE - && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG - || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) - break; - - if (GET_RTX_CLASS (GET_CODE (p)) != 'i') - continue; - - /* ??? See if all of SRC is set in P. This test is much - more conservative than it needs to be. */ - pset = single_set (p); - if (pset && SET_DEST (pset) == src) - { - /* We use validate_replace_rtx, in case there - are multiple identical source operands. All of - them have to be changed at the same time. */ - if (validate_replace_rtx (src, dst, insn)) - { - if (validate_change (p, &SET_DEST (pset), - dst, 0)) - success = 1; - else - { - /* Change all source operands back. - This modifies the dst as a side-effect. */ - validate_replace_rtx (dst, src, insn); - /* Now make sure the dst is right. */ - validate_change (insn, - recog_operand_loc[operand_number], - dst, 0); - } - } - break; - } - - if (reg_overlap_mentioned_p (src, PATTERN (p)) - || reg_overlap_mentioned_p (dst, PATTERN (p))) - break; - - /* If we have passed a call instruction, and the - pseudo-reg DST is not already live across a call, - then don't perform the optimization. */ - if (GET_CODE (p) == CALL_INSN) - { - num_calls++; - - if (REG_N_CALLS_CROSSED (REGNO (dst)) == 0) - break; - } - } - - if (success) - { - /* Remove the death note for SRC from INSN. */ - remove_note (insn, src_note); - /* Move the death note for SRC to P if it is used - there. */ - if (reg_overlap_mentioned_p (src, PATTERN (p))) - { - XEXP (src_note, 1) = REG_NOTES (p); - REG_NOTES (p) = src_note; - } - /* If there is a REG_DEAD note for DST on P, then remove - it, because DST is now set there. */ - if (dst_note = find_reg_note (p, REG_DEAD, dst)) - remove_note (p, dst_note); - - REG_N_SETS (REGNO (dst))++; - REG_N_SETS (REGNO (src))--; - - REG_N_CALLS_CROSSED (REGNO (dst)) += num_calls; - REG_N_CALLS_CROSSED (REGNO (src)) -= num_calls; - - /* ??? Must adjust reg_live_length, and reg_n_refs for - both registers. Must keep track of loop_depth in - order to get reg_n_refs adjustment correct. */ - - if (regmove_dump_file) - fprintf (regmove_dump_file, - "Fixed operand %d of insn %d matching operand %d.\n", - operand_number, INSN_UID (insn), match_number); - - goto done_backwards; - } - } - } - done_backwards: - ; - } - } -#endif /* REGISTER_CONSTRAINTS */ -} - -/* return nonzero if X is stable but for mentioning SRC or mentioning / - changing DST . If in doubt, presume it is unstable. */ -static int -stable_but_for_p (x, src, dst) - rtx x, src, dst; -{ - RTX_CODE code = GET_CODE (x); - switch (GET_RTX_CLASS (code)) - { - case '<': case '1': case 'c': case '2': case 'b': case '3': - { - int i; - char *fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - if (fmt[i] == 'e' && ! stable_but_for_p (XEXP (x, i), src, dst)) - return 0; - return 1; - } - case 'o': - if (x == src || x == dst) - return 1; - /* fall through */ - default: - return ! rtx_unstable_p (x); - } -} |