| /* Move registers around to reduce number of move instructions needed. |
| Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc. |
| |
| This file is part of GNU CC. |
| |
| GNU CC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU CC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU CC; see the file COPYING. If not, write to |
| the Free Software Foundation, 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 |
| |
| /* stdio.h must precede rtl.h for FFS. */ |
| #include "system.h" |
| |
| #include "rtl.h" |
| #include "insn-config.h" |
| #include "recog.h" |
| #include "output.h" |
| #include "reload.h" |
| #include "regs.h" |
| #include "hard-reg-set.h" |
| #include "flags.h" |
| #include "expr.h" |
| #include "insn-flags.h" |
| #include "basic-block.h" |
| #include "toplev.h" |
| |
| static int optimize_reg_copy_1 PROTO((rtx, rtx, rtx)); |
| static void optimize_reg_copy_2 PROTO((rtx, rtx, rtx)); |
| static void optimize_reg_copy_3 PROTO((rtx, rtx, rtx)); |
| static rtx gen_add3_insn PROTO((rtx, rtx, rtx)); |
| static void copy_src_to_dest PROTO((rtx, rtx, rtx, int)); |
| static int *regmove_bb_head; |
| |
| struct match { |
| int with[MAX_RECOG_OPERANDS]; |
| enum { READ, WRITE, READWRITE } use[MAX_RECOG_OPERANDS]; |
| int commutative[MAX_RECOG_OPERANDS]; |
| int early_clobber[MAX_RECOG_OPERANDS]; |
| }; |
| |
| #ifdef AUTO_INC_DEC |
| static int try_auto_increment PROTO((rtx, rtx, rtx, rtx, HOST_WIDE_INT, int)); |
| #endif |
| static int find_matches PROTO((rtx, struct match *)); |
| static int fixup_match_1 PROTO((rtx, rtx, rtx, rtx, rtx, int, int, int, FILE *)) |
| ; |
| static int reg_is_remote_constant_p PROTO((rtx, rtx, rtx)); |
| static int stable_but_for_p PROTO((rtx, rtx, rtx)); |
| static int loop_depth; |
| |
| /* Generate and return an insn body to add r1 and c, |
| storing the result in r0. */ |
| static rtx |
| gen_add3_insn (r0, r1, c) |
| rtx r0, r1, c; |
| { |
| int icode = (int) add_optab->handlers[(int) GET_MODE (r0)].insn_code; |
| |
| if (icode == CODE_FOR_nothing |
| || ! (*insn_operand_predicate[icode][0]) (r0, insn_operand_mode[icode][0]) |
| || ! (*insn_operand_predicate[icode][1]) (r1, insn_operand_mode[icode][1]) |
| || ! (*insn_operand_predicate[icode][2]) (c, insn_operand_mode[icode][2])) |
| return NULL_RTX; |
| |
| return (GEN_FCN (icode) (r0, r1, c)); |
| } |
| |
| #ifdef AUTO_INC_DEC |
| |
| /* 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_fmt_e (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 /* AUTO_INC_DEC */ |
| |
| static int *regno_src_regno; |
| |
| /* Indicate how good a choice REG (which appears as a source) is to replace |
| a destination register with. The higher the returned value, the better |
| the choice. The main objective is to avoid using a register that is |
| a candidate for tying to a hard register, since the output might in |
| turn be a candidate to be tied to a different hard register. */ |
| int |
| replacement_quality(reg) |
| rtx reg; |
| { |
| int src_regno; |
| |
| /* Bad if this isn't a register at all. */ |
| if (GET_CODE (reg) != REG) |
| return 0; |
| |
| /* If this register is not meant to get a hard register, |
| it is a poor choice. */ |
| if (REG_LIVE_LENGTH (REGNO (reg)) < 0) |
| return 0; |
| |
| src_regno = regno_src_regno[REGNO (reg)]; |
| |
| /* If it was not copied from another register, it is fine. */ |
| if (src_regno < 0) |
| return 3; |
| |
| /* Copied from a hard register? */ |
| if (src_regno < FIRST_PSEUDO_REGISTER) |
| return 1; |
| |
| /* Copied from a pseudo register - not as bad as from a hard register, |
| yet still cumbersome, since the register live length will be lengthened |
| when the registers get tied. */ |
| return 2; |
| } |
| |
| /* INSN is a copy from SRC to DEST, both registers, and SRC does not die |
| in INSN. |
| |
| Search forward to see if SRC dies before either it or DEST is modified, |
| but don't scan past the end of a basic block. If so, we can replace SRC |
| with DEST and let SRC die in INSN. |
| |
| This will reduce the number of registers live in that range and may enable |
| DEST to be tied to SRC, thus often saving one register in addition to a |
| register-register copy. */ |
| |
| static int |
| optimize_reg_copy_1 (insn, dest, src) |
| rtx insn; |
| rtx dest; |
| rtx src; |
| { |
| rtx p, q; |
| rtx note; |
| rtx dest_death = 0; |
| int sregno = REGNO (src); |
| int dregno = REGNO (dest); |
| |
| /* We don't want to mess with hard regs if register classes are small. */ |
| if (sregno == dregno |
| || (SMALL_REGISTER_CLASSES |
| && (sregno < FIRST_PSEUDO_REGISTER |
| || dregno < FIRST_PSEUDO_REGISTER)) |
| /* We don't see all updates to SP if they are in an auto-inc memory |
| reference, so we must disallow this optimization on them. */ |
| || sregno == STACK_POINTER_REGNUM || dregno == STACK_POINTER_REGNUM) |
| return 0; |
| |
| 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; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it is inside |
| an EH region. There is no easy way to tell, so we just always break |
| when we see a CALL_INSN if flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| break; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| |
| if (reg_set_p (src, p) || reg_set_p (dest, p) |
| /* Don't change a USE of a register. */ |
| || (GET_CODE (PATTERN (p)) == USE |
| && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0)))) |
| break; |
| |
| /* See if all of SRC dies in P. This test is slightly more |
| conservative than it needs to be. */ |
| if ((note = find_regno_note (p, REG_DEAD, sregno)) != 0 |
| && GET_MODE (XEXP (note, 0)) == GET_MODE (src)) |
| { |
| int failed = 0; |
| int d_length = 0; |
| int s_length = 0; |
| int d_n_calls = 0; |
| int s_n_calls = 0; |
| |
| /* We can do the optimization. Scan forward from INSN again, |
| replacing regs as we go. Set FAILED if a replacement can't |
| be done. In that case, we can't move the death note for SRC. |
| This should be rare. */ |
| |
| /* Set to stop at next insn. */ |
| for (q = next_real_insn (insn); |
| q != next_real_insn (p); |
| q = next_real_insn (q)) |
| { |
| if (reg_overlap_mentioned_p (src, PATTERN (q))) |
| { |
| /* If SRC is a hard register, we might miss some |
| overlapping registers with validate_replace_rtx, |
| so we would have to undo it. We can't if DEST is |
| present in the insn, so fail in that combination |
| of cases. */ |
| if (sregno < FIRST_PSEUDO_REGISTER |
| && reg_mentioned_p (dest, PATTERN (q))) |
| failed = 1; |
| |
| /* Replace all uses and make sure that the register |
| isn't still present. */ |
| else if (validate_replace_rtx (src, dest, q) |
| && (sregno >= FIRST_PSEUDO_REGISTER |
| || ! reg_overlap_mentioned_p (src, |
| PATTERN (q)))) |
| { |
| /* We assume that a register is used exactly once per |
| insn in the REG_N_REFS updates below. If this is not |
| correct, no great harm is done. |
| |
| Since we do not know if we will change the lifetime of |
| SREGNO or DREGNO, we must not update REG_LIVE_LENGTH |
| or REG_N_CALLS_CROSSED at this time. */ |
| if (sregno >= FIRST_PSEUDO_REGISTER) |
| REG_N_REFS (sregno) -= loop_depth; |
| |
| if (dregno >= FIRST_PSEUDO_REGISTER) |
| REG_N_REFS (dregno) += loop_depth; |
| } |
| else |
| { |
| validate_replace_rtx (dest, src, q); |
| failed = 1; |
| } |
| } |
| |
| /* For SREGNO, count the total number of insns scanned. |
| For DREGNO, count the total number of insns scanned after |
| passing the death note for DREGNO. */ |
| s_length++; |
| if (dest_death) |
| d_length++; |
| |
| /* If the insn in which SRC dies is a CALL_INSN, don't count it |
| as a call that has been crossed. Otherwise, count it. */ |
| if (q != p && GET_CODE (q) == CALL_INSN) |
| { |
| /* Similarly, total calls for SREGNO, total calls beyond |
| the death note for DREGNO. */ |
| s_n_calls++; |
| if (dest_death) |
| d_n_calls++; |
| } |
| |
| /* If DEST dies here, remove the death note and save it for |
| later. Make sure ALL of DEST dies here; again, this is |
| overly conservative. */ |
| if (dest_death == 0 |
| && (dest_death = find_regno_note (q, REG_DEAD, dregno)) != 0) |
| { |
| if (GET_MODE (XEXP (dest_death, 0)) != GET_MODE (dest)) |
| failed = 1, dest_death = 0; |
| else |
| remove_note (q, dest_death); |
| } |
| } |
| |
| if (! failed) |
| { |
| /* These counters need to be updated if and only if we are |
| going to move the REG_DEAD note. */ |
| if (sregno >= FIRST_PSEUDO_REGISTER) |
| { |
| if (REG_LIVE_LENGTH (sregno) >= 0) |
| { |
| REG_LIVE_LENGTH (sregno) -= s_length; |
| /* REG_LIVE_LENGTH is only an approximation after |
| combine if sched is not run, so make sure that we |
| still have a reasonable value. */ |
| if (REG_LIVE_LENGTH (sregno) < 2) |
| REG_LIVE_LENGTH (sregno) = 2; |
| } |
| |
| REG_N_CALLS_CROSSED (sregno) -= s_n_calls; |
| } |
| |
| /* Move death note of SRC from P to INSN. */ |
| remove_note (p, note); |
| XEXP (note, 1) = REG_NOTES (insn); |
| REG_NOTES (insn) = note; |
| } |
| |
| /* Put death note of DEST on P if we saw it die. */ |
| if (dest_death) |
| { |
| XEXP (dest_death, 1) = REG_NOTES (p); |
| REG_NOTES (p) = dest_death; |
| |
| if (dregno >= FIRST_PSEUDO_REGISTER) |
| { |
| /* If and only if we are moving the death note for DREGNO, |
| then we need to update its counters. */ |
| if (REG_LIVE_LENGTH (dregno) >= 0) |
| REG_LIVE_LENGTH (dregno) += d_length; |
| REG_N_CALLS_CROSSED (dregno) += d_n_calls; |
| } |
| } |
| |
| return ! failed; |
| } |
| |
| /* If SRC is a hard register which is set or killed in some other |
| way, we can't do this optimization. */ |
| else if (sregno < FIRST_PSEUDO_REGISTER |
| && dead_or_set_p (p, src)) |
| break; |
| } |
| return 0; |
| } |
| |
| /* INSN is a copy of SRC to DEST, in which SRC dies. See if we now have |
| a sequence of insns that modify DEST followed by an insn that sets |
| SRC to DEST in which DEST dies, with no prior modification of DEST. |
| (There is no need to check if the insns in between actually modify |
| DEST. We should not have cases where DEST is not modified, but |
| the optimization is safe if no such modification is detected.) |
| In that case, we can replace all uses of DEST, starting with INSN and |
| ending with the set of SRC to DEST, with SRC. We do not do this |
| optimization if a CALL_INSN is crossed unless SRC already crosses a |
| call or if DEST dies before the copy back to SRC. |
| |
| It is assumed that DEST and SRC are pseudos; it is too complicated to do |
| this for hard registers since the substitutions we may make might fail. */ |
| |
| static void |
| optimize_reg_copy_2 (insn, dest, src) |
| rtx insn; |
| rtx dest; |
| rtx src; |
| { |
| rtx p, q; |
| rtx set; |
| int sregno = REGNO (src); |
| int dregno = REGNO (dest); |
| |
| 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; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it is inside |
| an EH region. There is no easy way to tell, so we just always break |
| when we see a CALL_INSN if flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| break; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| |
| set = single_set (p); |
| if (set && SET_SRC (set) == dest && SET_DEST (set) == src |
| && find_reg_note (p, REG_DEAD, dest)) |
| { |
| /* We can do the optimization. Scan forward from INSN again, |
| replacing regs as we go. */ |
| |
| /* Set to stop at next insn. */ |
| for (q = insn; q != NEXT_INSN (p); q = NEXT_INSN (q)) |
| if (GET_RTX_CLASS (GET_CODE (q)) == 'i') |
| { |
| if (reg_mentioned_p (dest, PATTERN (q))) |
| { |
| PATTERN (q) = replace_rtx (PATTERN (q), dest, src); |
| |
| /* We assume that a register is used exactly once per |
| insn in the updates below. If this is not correct, |
| no great harm is done. */ |
| REG_N_REFS (dregno) -= loop_depth; |
| REG_N_REFS (sregno) += loop_depth; |
| } |
| |
| |
| if (GET_CODE (q) == CALL_INSN) |
| { |
| REG_N_CALLS_CROSSED (dregno)--; |
| REG_N_CALLS_CROSSED (sregno)++; |
| } |
| } |
| |
| remove_note (p, find_reg_note (p, REG_DEAD, dest)); |
| REG_N_DEATHS (dregno)--; |
| remove_note (insn, find_reg_note (insn, REG_DEAD, src)); |
| REG_N_DEATHS (sregno)--; |
| return; |
| } |
| |
| if (reg_set_p (src, p) |
| || find_reg_note (p, REG_DEAD, dest) |
| || (GET_CODE (p) == CALL_INSN && REG_N_CALLS_CROSSED (sregno) == 0)) |
| break; |
| } |
| } |
| /* INSN is a ZERO_EXTEND or SIGN_EXTEND of SRC to DEST. |
| Look if SRC dies there, and if it is only set once, by loading |
| it from memory. If so, try to encorporate the zero/sign extension |
| into the memory read, change SRC to the mode of DEST, and alter |
| the remaining accesses to use the appropriate SUBREG. This allows |
| SRC and DEST to be tied later. */ |
| static void |
| optimize_reg_copy_3 (insn, dest, src) |
| rtx insn; |
| rtx dest; |
| rtx src; |
| { |
| rtx src_reg = XEXP (src, 0); |
| int src_no = REGNO (src_reg); |
| int dst_no = REGNO (dest); |
| rtx p, set, subreg; |
| enum machine_mode old_mode; |
| |
| /* This code has been disabled on the egcs-1.1 release branch due to |
| a potentially serious bug. |
| |
| In a nutshell, if we perform a series of substitutions, then have a |
| later substitution fail we will not be able to undo the previous |
| substitutions, leaving bogus RTL. |
| |
| A fix for this can be found in the mainline sources, but it did not |
| seem worth the trouble and potential problems to migrate the real |
| fix to the egcs-1.1 branch. */ |
| return; |
| |
| if (src_no < FIRST_PSEUDO_REGISTER |
| || dst_no < FIRST_PSEUDO_REGISTER |
| || ! find_reg_note (insn, REG_DEAD, src_reg) |
| || REG_N_SETS (src_no) != 1) |
| return; |
| for (p = PREV_INSN (insn); ! reg_set_p (src_reg, p); p = PREV_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))) |
| return; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it is inside |
| an EH region. There is no easy way to tell, so we just always break |
| when we see a CALL_INSN if flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| return; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| } |
| if (! (set = single_set (p)) |
| || GET_CODE (SET_SRC (set)) != MEM |
| || SET_DEST (set) != src_reg) |
| return; |
| old_mode = GET_MODE (src_reg); |
| PUT_MODE (src_reg, GET_MODE (src)); |
| XEXP (src, 0) = SET_SRC (set); |
| if (! validate_change (p, &SET_SRC (set), src, 0)) |
| { |
| PUT_MODE (src_reg, old_mode); |
| XEXP (src, 0) = src_reg; |
| return; |
| } |
| subreg = gen_rtx_SUBREG (old_mode, src_reg, 0); |
| while (p = NEXT_INSN (p), p != insn) |
| { |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| validate_replace_rtx (src_reg, subreg, p); |
| } |
| validate_replace_rtx (src, src_reg, insn); |
| } |
| |
| |
| /* If we were not able to update the users of src to use dest directly, try |
| instead moving the value to dest directly before the operation. */ |
| |
| static void |
| copy_src_to_dest (insn, src, dest, loop_depth) |
| rtx insn; |
| rtx src; |
| rtx dest; |
| int loop_depth; |
| { |
| rtx seq; |
| rtx link; |
| rtx next; |
| rtx set; |
| rtx move_insn; |
| rtx *p_insn_notes; |
| rtx *p_move_notes; |
| int src_regno; |
| int dest_regno; |
| int bb; |
| int insn_uid; |
| int move_uid; |
| |
| /* A REG_LIVE_LENGTH of -1 indicates the register is equivalent to a constant |
| or memory location and is used infrequently; a REG_LIVE_LENGTH of -2 is |
| parameter when there is no frame pointer that is not allocated a register. |
| For now, we just reject them, rather than incrementing the live length. */ |
| |
| if (GET_CODE (src) == REG |
| && REG_LIVE_LENGTH (REGNO (src)) > 0 |
| && GET_CODE (dest) == REG |
| && REG_LIVE_LENGTH (REGNO (dest)) > 0 |
| && (set = single_set (insn)) != NULL_RTX |
| && !reg_mentioned_p (dest, SET_SRC (set)) |
| && validate_replace_rtx (src, dest, insn)) |
| { |
| /* Generate the src->dest move. */ |
| start_sequence (); |
| emit_move_insn (dest, src); |
| seq = gen_sequence (); |
| end_sequence (); |
| emit_insn_before (seq, insn); |
| move_insn = PREV_INSN (insn); |
| p_move_notes = ®_NOTES (move_insn); |
| p_insn_notes = ®_NOTES (insn); |
| |
| /* Move any notes mentioning src to the move instruction */ |
| for (link = REG_NOTES (insn); link != NULL_RTX; link = next) |
| { |
| next = XEXP (link, 1); |
| if (XEXP (link, 0) == src) |
| { |
| *p_move_notes = link; |
| p_move_notes = &XEXP (link, 1); |
| } |
| else |
| { |
| *p_insn_notes = link; |
| p_insn_notes = &XEXP (link, 1); |
| } |
| } |
| |
| *p_move_notes = NULL_RTX; |
| *p_insn_notes = NULL_RTX; |
| |
| /* Is the insn the head of a basic block? If so extend it */ |
| insn_uid = INSN_UID (insn); |
| move_uid = INSN_UID (move_insn); |
| bb = regmove_bb_head[insn_uid]; |
| if (bb >= 0) |
| { |
| basic_block_head[bb] = move_insn; |
| regmove_bb_head[insn_uid] = -1; |
| } |
| |
| /* Update the various register tables. */ |
| dest_regno = REGNO (dest); |
| REG_N_SETS (dest_regno) += loop_depth; |
| REG_N_REFS (dest_regno) += loop_depth; |
| REG_LIVE_LENGTH (dest_regno)++; |
| if (REGNO_FIRST_UID (dest_regno) == insn_uid) |
| REGNO_FIRST_UID (dest_regno) = move_uid; |
| |
| src_regno = REGNO (src); |
| if (! find_reg_note (move_insn, REG_DEAD, src)) |
| REG_LIVE_LENGTH (src_regno)++; |
| |
| if (REGNO_FIRST_UID (src_regno) == insn_uid) |
| REGNO_FIRST_UID (src_regno) = move_uid; |
| |
| if (REGNO_LAST_UID (src_regno) == insn_uid) |
| REGNO_LAST_UID (src_regno) = move_uid; |
| |
| if (REGNO_LAST_NOTE_UID (src_regno) == insn_uid) |
| REGNO_LAST_NOTE_UID (src_regno) = move_uid; |
| } |
| } |
| |
| |
| /* Return whether REG is set in only one location, and is set to a |
| constant, but is set in a different basic block from INSN (an |
| instructions which uses REG). In this case REG is equivalent to a |
| constant, and we don't want to break that equivalence, because that |
| may increase register pressure and make reload harder. If REG is |
| set in the same basic block as INSN, we don't worry about it, |
| because we'll probably need a register anyhow (??? but what if REG |
| is used in a different basic block as well as this one?). FIRST is |
| the first insn in the function. */ |
| |
| static int |
| reg_is_remote_constant_p (reg, insn, first) |
| rtx reg; |
| rtx insn; |
| rtx first; |
| { |
| register rtx p; |
| |
| if (REG_N_SETS (REGNO (reg)) != 1) |
| return 0; |
| |
| /* Look for the set. */ |
| for (p = LOG_LINKS (insn); p; p = XEXP (p, 1)) |
| { |
| rtx s; |
| |
| if (REG_NOTE_KIND (p) != 0) |
| continue; |
| s = single_set (XEXP (p, 0)); |
| if (s != 0 |
| && GET_CODE (SET_DEST (s)) == REG |
| && REGNO (SET_DEST (s)) == REGNO (reg)) |
| { |
| /* The register is set in the same basic block. */ |
| return 0; |
| } |
| } |
| |
| for (p = first; p && p != insn; p = NEXT_INSN (p)) |
| { |
| rtx s; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| s = single_set (p); |
| if (s != 0 |
| && GET_CODE (SET_DEST (s)) == REG |
| && REGNO (SET_DEST (s)) == REGNO (reg)) |
| { |
| /* This is the instruction which sets REG. If there is a |
| REG_EQUAL note, then REG is equivalent to a constant. */ |
| if (find_reg_note (p, REG_EQUAL, NULL_RTX)) |
| return 1; |
| return 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* INSN is adding a CONST_INT to a REG. We search backwards looking for |
| another add immediate instruction with the same source and dest registers, |
| and if we find one, we change INSN to an increment, and return 1. If |
| no changes are made, we return 0. |
| |
| This changes |
| (set (reg100) (plus reg1 offset1)) |
| ... |
| (set (reg100) (plus reg1 offset2)) |
| to |
| (set (reg100) (plus reg1 offset1)) |
| ... |
| (set (reg100) (plus reg100 offset2-offset1)) */ |
| |
| /* ??? What does this comment mean? */ |
| /* cse disrupts preincrement / postdecrement squences when it finds a |
| hard register as ultimate source, like the frame pointer. */ |
| |
| int |
| fixup_match_2 (insn, dst, src, offset, regmove_dump_file) |
| rtx insn, dst, src, offset; |
| FILE *regmove_dump_file; |
| { |
| rtx p, dst_death = 0; |
| int length, num_calls = 0; |
| |
| /* If SRC dies in INSN, we'd have to move the death note. This is |
| considered to be very unlikely, so we just skip the optimization |
| in this case. */ |
| if (find_regno_note (insn, REG_DEAD, REGNO (src))) |
| return 0; |
| |
| /* Scan backward to find the first instruction that sets DST. */ |
| |
| for (length = 0, 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; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it is inside |
| an EH region. There is no easy way to tell, so we just always break |
| when we see a CALL_INSN if flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| break; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| |
| if (find_regno_note (p, REG_DEAD, REGNO (dst))) |
| dst_death = p; |
| if (! dst_death) |
| length++; |
| |
| pset = single_set (p); |
| if (pset && SET_DEST (pset) == dst |
| && GET_CODE (SET_SRC (pset)) == PLUS |
| && XEXP (SET_SRC (pset), 0) == src |
| && GET_CODE (XEXP (SET_SRC (pset), 1)) == CONST_INT) |
| { |
| HOST_WIDE_INT newconst |
| = INTVAL (offset) - INTVAL (XEXP (SET_SRC (pset), 1)); |
| rtx add = gen_add3_insn (dst, dst, GEN_INT (newconst)); |
| |
| if (add && validate_change (insn, &PATTERN (insn), add, 0)) |
| { |
| /* Remove the death note for DST from DST_DEATH. */ |
| if (dst_death) |
| { |
| remove_death (REGNO (dst), dst_death); |
| REG_LIVE_LENGTH (REGNO (dst)) += length; |
| REG_N_CALLS_CROSSED (REGNO (dst)) += num_calls; |
| } |
| |
| REG_N_REFS (REGNO (dst)) += loop_depth; |
| REG_N_REFS (REGNO (src)) -= loop_depth; |
| |
| if (regmove_dump_file) |
| fprintf (regmove_dump_file, |
| "Fixed operand of insn %d.\n", |
| INSN_UID (insn)); |
| |
| #ifdef AUTO_INC_DEC |
| for (p = PREV_INSN (insn); p; p = PREV_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_overlap_mentioned_p (dst, PATTERN (p))) |
| { |
| if (try_auto_increment (p, insn, 0, dst, newconst, 0)) |
| return 1; |
| break; |
| } |
| } |
| 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_overlap_mentioned_p (dst, PATTERN (p))) |
| { |
| try_auto_increment (p, insn, 0, dst, newconst, 1); |
| break; |
| } |
| } |
| #endif |
| return 1; |
| } |
| } |
| |
| if (reg_set_p (dst, PATTERN (p))) |
| break; |
| |
| /* 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. */ |
| /* reg_set_p is overly conservative for CALL_INSNS, thinks that all |
| hard regs are clobbered. Thus, we only use it for src for |
| non-call insns. */ |
| if (GET_CODE (p) == CALL_INSN) |
| { |
| if (! dst_death) |
| num_calls++; |
| |
| if (REG_N_CALLS_CROSSED (REGNO (src)) == 0) |
| break; |
| |
| if (call_used_regs [REGNO (dst)] |
| || find_reg_fusage (p, CLOBBER, dst)) |
| break; |
| } |
| else if (reg_set_p (src, PATTERN (p))) |
| break; |
| } |
| |
| return 0; |
| } |
| |
| void |
| regmove_optimize (f, nregs, regmove_dump_file) |
| rtx f; |
| int nregs; |
| FILE *regmove_dump_file; |
| { |
| rtx insn; |
| struct match match; |
| int pass; |
| int maxregnum = max_reg_num (), i; |
| rtx copy_src, copy_dst; |
| |
| regno_src_regno = (int *)alloca (sizeof *regno_src_regno * maxregnum); |
| for (i = maxregnum; --i >= 0; ) regno_src_regno[i] = -1; |
| |
| regmove_bb_head = (int *)alloca (sizeof (int) * (get_max_uid () + 1)); |
| for (i = get_max_uid (); i >= 0; i--) regmove_bb_head[i] = -1; |
| for (i = 0; i < n_basic_blocks; i++) |
| regmove_bb_head[INSN_UID (basic_block_head[i])] = i; |
| |
| /* A forward/backward pass. Replace output operands with input operands. */ |
| |
| loop_depth = 1; |
| |
| for (pass = 0; pass <= 2; pass++) |
| { |
| if (! flag_regmove && pass >= flag_expensive_optimizations) |
| return; |
| |
| 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)) |
| { |
| rtx set; |
| int insn_code_number; |
| int operand_number, match_number; |
| |
| 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--; |
| } |
| |
| set = single_set (insn); |
| if (! set) |
| continue; |
| |
| if (flag_expensive_optimizations && ! pass |
| && (GET_CODE (SET_SRC (set)) == SIGN_EXTEND |
| || GET_CODE (SET_SRC (set)) == ZERO_EXTEND) |
| && GET_CODE (XEXP (SET_SRC (set), 0)) == REG |
| && GET_CODE (SET_DEST(set)) == REG) |
| optimize_reg_copy_3 (insn, SET_DEST (set), SET_SRC (set)); |
| |
| if (flag_expensive_optimizations && ! pass |
| && GET_CODE (SET_SRC (set)) == REG |
| && GET_CODE (SET_DEST(set)) == REG) |
| { |
| /* If this is a register-register copy where SRC is not dead, |
| see if we can optimize it. If this optimization succeeds, |
| it will become a copy where SRC is dead. */ |
| if ((find_reg_note (insn, REG_DEAD, SET_SRC (set)) |
| || optimize_reg_copy_1 (insn, SET_DEST (set), SET_SRC (set))) |
| && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) |
| { |
| /* Similarly for a pseudo-pseudo copy when SRC is dead. */ |
| if (REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER) |
| optimize_reg_copy_2 (insn, SET_DEST (set), SET_SRC (set)); |
| if (regno_src_regno[REGNO (SET_DEST (set))] < 0 |
| && SET_SRC (set) != SET_DEST (set)) |
| { |
| int srcregno = REGNO (SET_SRC(set)); |
| if (regno_src_regno[srcregno] >= 0) |
| srcregno = regno_src_regno[srcregno]; |
| regno_src_regno[REGNO (SET_DEST (set))] = srcregno; |
| } |
| } |
| } |
| #ifdef REGISTER_CONSTRAINTS |
| insn_code_number |
| = find_matches (insn, &match); |
| |
| if (insn_code_number < 0) |
| continue; |
| |
| /* 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++) |
| { |
| rtx src, dst, src_subreg; |
| enum reg_class src_class, dst_class; |
| |
| match_number = match.with[operand_number]; |
| |
| /* Nothing to do if the two operands aren't supposed to match. */ |
| if (match_number < 0) |
| continue; |
| |
| src = recog_operand[operand_number]; |
| dst = recog_operand[match_number]; |
| |
| if (GET_CODE (src) != REG) |
| 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 (REGNO (src) < FIRST_PSEUDO_REGISTER) |
| { |
| if (match.commutative[operand_number] < operand_number) |
| regno_src_regno[REGNO (dst)] = REGNO (src); |
| continue; |
| } |
| |
| if (REG_LIVE_LENGTH (REGNO (src)) < 0) |
| continue; |
| |
| /* operand_number/src must be a read-only operand, and |
| match_operand/dst must be a write-only operand. */ |
| if (match.use[operand_number] != READ |
| || match.use[match_number] != WRITE) |
| continue; |
| |
| if (match.early_clobber[match_number] |
| && count_occurrences (PATTERN (insn), src) > 1) |
| continue; |
| |
| /* Make sure match_operand is the destination. */ |
| if (recog_operand[match_number] != SET_DEST (set)) |
| continue; |
| |
| /* If the operands already match, then there is nothing to do. */ |
| /* But in the commutative case, we might find a better match. */ |
| if (operands_match_p (src, dst) |
| || (match.commutative[operand_number] >= 0 |
| && operands_match_p (recog_operand[match.commutative |
| [operand_number]], dst) |
| && (replacement_quality (recog_operand[match.commutative |
| [operand_number]]) |
| >= replacement_quality (src)))) |
| continue; |
| |
| src_class = reg_preferred_class (REGNO (src)); |
| dst_class = reg_preferred_class (REGNO (dst)); |
| if (src_class != dst_class |
| && (! reg_class_subset_p (src_class, dst_class) |
| || CLASS_LIKELY_SPILLED_P (src_class)) |
| && (! reg_class_subset_p (dst_class, src_class) |
| || CLASS_LIKELY_SPILLED_P (dst_class))) |
| continue; |
| |
| if (fixup_match_1 (insn, set, src, src_subreg, dst, pass, |
| operand_number, match_number, |
| regmove_dump_file)) |
| break; |
| } |
| } |
| } |
| |
| /* A backward pass. Replace input operands with output operands. */ |
| |
| if (regmove_dump_file) |
| fprintf (regmove_dump_file, "Starting backward pass...\n"); |
| |
| loop_depth = 1; |
| |
| for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) |
| { |
| if (GET_CODE (insn) == NOTE) |
| { |
| if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
| loop_depth++; |
| else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) |
| loop_depth--; |
| } |
| if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
| { |
| int insn_code_number = find_matches (insn, &match); |
| int operand_number, match_number; |
| int success = 0; |
| |
| if (insn_code_number < 0) |
| continue; |
| |
| /* 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. */ |
| |
| copy_src = NULL_RTX; |
| copy_dst = NULL_RTX; |
| for (operand_number = 0; |
| operand_number < insn_n_operands[insn_code_number]; |
| operand_number++) |
| { |
| rtx set, p, src, dst; |
| rtx src_note, dst_note; |
| int num_calls = 0; |
| enum reg_class src_class, dst_class; |
| int length; |
| |
| match_number = match.with[operand_number]; |
| |
| /* Nothing to do if the two operands aren't supposed to match. */ |
| if (match_number < 0) |
| continue; |
| |
| dst = recog_operand[match_number]; |
| src = recog_operand[operand_number]; |
| |
| if (GET_CODE (src) != REG) |
| continue; |
| |
| if (GET_CODE (dst) != REG |
| || REGNO (dst) < FIRST_PSEUDO_REGISTER |
| || REG_LIVE_LENGTH (REGNO (dst)) < 0) |
| continue; |
| |
| /* If the operands already match, then there is nothing to do. */ |
| if (operands_match_p (src, dst) |
| || (match.commutative[operand_number] >= 0 |
| && operands_match_p (recog_operand[match.commutative[operand_number]], dst))) |
| continue; |
| |
| set = single_set (insn); |
| if (! set) |
| continue; |
| |
| /* match_number/dst must be a write-only operand, and |
| operand_operand/src must be a read-only operand. */ |
| if (match.use[operand_number] != READ |
| || match.use[match_number] != WRITE) |
| continue; |
| |
| if (match.early_clobber[match_number] |
| && count_occurrences (PATTERN (insn), src) > 1) |
| continue; |
| |
| /* Make sure match_number is the destination. */ |
| if (recog_operand[match_number] != SET_DEST (set)) |
| continue; |
| |
| if (REGNO (src) < FIRST_PSEUDO_REGISTER) |
| { |
| if (GET_CODE (SET_SRC (set)) == PLUS |
| && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT |
| && XEXP (SET_SRC (set), 0) == src |
| && fixup_match_2 (insn, dst, src, |
| XEXP (SET_SRC (set), 1), |
| regmove_dump_file)) |
| break; |
| continue; |
| } |
| src_class = reg_preferred_class (REGNO (src)); |
| dst_class = reg_preferred_class (REGNO (dst)); |
| if (src_class != dst_class |
| && (! reg_class_subset_p (src_class, dst_class) |
| || CLASS_LIKELY_SPILLED_P (src_class)) |
| && (! reg_class_subset_p (dst_class, src_class) |
| || CLASS_LIKELY_SPILLED_P (dst_class))) |
| { |
| if (!copy_src) |
| { |
| copy_src = src; |
| copy_dst = dst; |
| } |
| 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))) |
| { |
| if (!copy_src) |
| { |
| copy_src = src; |
| copy_dst = dst; |
| } |
| continue; |
| } |
| |
| if (! (src_note = find_reg_note (insn, REG_DEAD, src))) |
| { |
| if (!copy_src) |
| { |
| copy_src = src; |
| copy_dst = dst; |
| } |
| continue; |
| } |
| |
| |
| /* If src is set once in a different basic block, |
| 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. */ |
| |
| if (reg_is_remote_constant_p (src, insn, f)) |
| { |
| if (!copy_src) |
| { |
| copy_src = src; |
| copy_dst = dst; |
| } |
| 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); |
| |
| /* 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 match_number. */ |
| |
| for (length = 0, 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; |
| |
| /* ??? We can't scan past the end of a basic block without |
| updating the register lifetime info |
| (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if |
| it is inside an EH region. There is no easy way to tell, |
| so we just always break when we see a CALL_INSN if |
| flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| break; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| |
| length++; |
| |
| /* ??? 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[match_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) |
| { |
| int dstno, srcno; |
| |
| /* 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); |
| |
| dstno = REGNO (dst); |
| srcno = REGNO (src); |
| |
| REG_N_SETS (dstno)++; |
| REG_N_SETS (srcno)--; |
| |
| REG_N_CALLS_CROSSED (dstno) += num_calls; |
| REG_N_CALLS_CROSSED (srcno) -= num_calls; |
| |
| REG_LIVE_LENGTH (dstno) += length; |
| if (REG_LIVE_LENGTH (srcno) >= 0) |
| { |
| REG_LIVE_LENGTH (srcno) -= length; |
| /* REG_LIVE_LENGTH is only an approximation after |
| combine if sched is not run, so make sure that we |
| still have a reasonable value. */ |
| if (REG_LIVE_LENGTH (srcno) < 2) |
| REG_LIVE_LENGTH (srcno) = 2; |
| } |
| |
| /* We assume that a register is used exactly once per |
| insn in the updates above. If this is not correct, |
| no great harm is done. */ |
| |
| REG_N_REFS (dstno) += 2 * loop_depth; |
| REG_N_REFS (srcno) -= 2 * loop_depth; |
| |
| /* If that was the only time src was set, |
| and src was not live at the start of the |
| function, we know that we have no more |
| references to src; clear REG_N_REFS so it |
| won't make reload do any work. */ |
| if (REG_N_SETS (REGNO (src)) == 0 |
| && ! regno_uninitialized (REGNO (src))) |
| REG_N_REFS (REGNO (src)) = 0; |
| |
| 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); |
| |
| break; |
| } |
| } |
| |
| /* If we weren't able to replace any of the alternatives, try an |
| alternative appoach of copying the source to the destination. */ |
| if (!success && copy_src != NULL_RTX) |
| copy_src_to_dest (insn, copy_src, copy_dst, loop_depth); |
| |
| } |
| } |
| #endif /* REGISTER_CONSTRAINTS */ |
| } |
| |
| /* Returns the INSN_CODE for INSN if its pattern has matching constraints for |
| any operand. Returns -1 if INSN can't be recognized, or if the alternative |
| can't be determined. |
| |
| Initialize the info in MATCHP based on the constraints. */ |
| |
| static int |
| find_matches (insn, matchp) |
| rtx insn; |
| struct match *matchp; |
| { |
| int likely_spilled[MAX_RECOG_OPERANDS]; |
| int operand_number; |
| int insn_code_number = recog_memoized (insn); |
| int any_matches = 0; |
| |
| if (insn_code_number < 0) |
| return -1; |
| |
| insn_extract (insn); |
| if (! constrain_operands (insn_code_number, 0)) |
| return -1; |
| |
| /* Must initialize this before main loop, because the code for |
| the commutative case may set matches for operands other than |
| the current one. */ |
| for (operand_number = insn_n_operands[insn_code_number]; |
| --operand_number >= 0; ) |
| matchp->with[operand_number] = matchp->commutative[operand_number] = -1; |
| |
| for (operand_number = 0; operand_number < insn_n_operands[insn_code_number]; |
| operand_number++) |
| { |
| char *p, c; |
| int i = 0; |
| |
| p = insn_operand_constraint[insn_code_number][operand_number]; |
| |
| likely_spilled[operand_number] = 0; |
| matchp->use[operand_number] = READ; |
| matchp->early_clobber[operand_number] = 0; |
| if (*p == '=') |
| matchp->use[operand_number] = WRITE; |
| else if (*p == '+') |
| matchp->use[operand_number] = READWRITE; |
| |
| for (;*p && i < which_alternative; p++) |
| if (*p == ',') |
| i++; |
| |
| while ((c = *p++) != '\0' && c != ',') |
| switch (c) |
| { |
| case '=': |
| break; |
| case '+': |
| break; |
| case '&': |
| matchp->early_clobber[operand_number] = 1; |
| break; |
| case '%': |
| matchp->commutative[operand_number] = operand_number + 1; |
| matchp->commutative[operand_number + 1] = 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'; |
| if (c < operand_number && likely_spilled[(unsigned char) c]) |
| break; |
| matchp->with[operand_number] = c; |
| any_matches = 1; |
| if (matchp->commutative[operand_number] >= 0) |
| matchp->with[matchp->commutative[operand_number]] = c; |
| break; |
| case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'h': |
| case 'j': case 'k': case 'l': case 'p': case 'q': case 't': case 'u': |
| case 'v': case 'w': case 'x': case 'y': case 'z': case 'A': case 'B': |
| case 'C': case 'D': case 'W': case 'Y': case 'Z': |
| if (CLASS_LIKELY_SPILLED_P (REG_CLASS_FROM_LETTER (c))) |
| likely_spilled[operand_number] = 1; |
| break; |
| } |
| } |
| return any_matches ? insn_code_number : -1; |
| } |
| |
| /* Try to replace output operand DST in SET, with input operand SRC. SET is |
| the only set in INSN. INSN has just been recgnized and constrained. |
| SRC is operand number OPERAND_NUMBER in INSN. |
| DST is operand number MATCH_NUMBER in INSN. |
| If BACKWARD is nonzero, we have been called in a backward pass. |
| Return nonzero for success. */ |
| static int |
| fixup_match_1 (insn, set, src, src_subreg, dst, backward, operand_number, |
| match_number, regmove_dump_file) |
| rtx insn, set, src, src_subreg, dst; |
| int backward, operand_number, match_number; |
| FILE *regmove_dump_file; |
| { |
| rtx p; |
| rtx post_inc = 0, post_inc_set = 0, search_end = 0; |
| int success = 0; |
| int num_calls = 0, s_num_calls = 0; |
| enum rtx_code code = NOTE; |
| HOST_WIDE_INT insn_const, newconst; |
| rtx overlap = 0; /* need to move insn ? */ |
| rtx src_note = find_reg_note (insn, REG_DEAD, src), dst_note; |
| int length, s_length, true_loop_depth; |
| |
| 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)) |
| return 0; |
| 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 equivalent to a constant set in a different basic block, |
| then do not use it for this optimization. We want the equivalence |
| so that if we have to reload this register, we can reload the |
| constant, rather than extending the lifespan of the register. */ |
| if (reg_is_remote_constant_p (src, insn, get_insns ())) |
| return 0; |
| |
| /* 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 (length = s_length = 0, 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; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it is |
| inside an EH region. There is no easy way to tell, so we just |
| always break when we see a CALL_INSN if flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (p) == CALL_INSN) |
| break; |
| |
| if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
| continue; |
| |
| length++; |
| if (src_note) |
| s_length++; |
| |
| 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; |
| } |
| |
| /* ??? We can't scan past the end of a basic block without |
| updating the register lifetime info |
| (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if |
| it is inside an EH region. There is no easy way to tell, |
| so we just always break when we see a CALL_INSN if |
| flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
| { |
| 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 && backward |
| #ifdef HAVE_cc0 |
| /* We may 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) |
| { |
| if (REG_N_CALLS_CROSSED (REGNO (src)) == 0) |
| break; |
| |
| num_calls++; |
| |
| if (src_note) |
| s_num_calls++; |
| |
| } |
| } |
| |
| if (! success) |
| return 0; |
| |
| true_loop_depth = backward ? 2 - loop_depth : loop_depth; |
| |
| /* 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))++; |
| REG_N_REFS (REGNO (src)) += true_loop_depth; |
| REG_LIVE_LENGTH (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 |
| { |
| rtx notes = REG_NOTES (insn); |
| |
| 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); |
| |
| REG_NOTES (insn) = notes; |
| } |
| } |
| /* 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, s_length2 = 0; |
| |
| if (note && CONSTANT_P (XEXP (note, 0))) |
| { |
| for (q = PREV_INSN (insn); q; q = PREV_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; |
| } |
| |
| /* ??? We can't scan past the end of a basic block without |
| updating the register lifetime info |
| (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if |
| it is inside an EH region. There is no easy way to tell, |
| so we just always break when we see a CALL_INSN if |
| flag_exceptions is nonzero. */ |
| if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
| { |
| q = 0; |
| break; |
| } |
| |
| if (GET_RTX_CLASS (GET_CODE (q)) != 'i') |
| continue; |
| s_length2++; |
| 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; |
| REG_N_REFS (REGNO (src)) -= true_loop_depth; |
| REG_LIVE_LENGTH (REGNO (src)) -= s_length2; |
| insn_const = 0; |
| } |
| } |
| } |
| |
| /* Don't remove this seemingly useless if, it is needed to pair with the |
| else in the next two conditionally included code blocks. */ |
| 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; |
| |
| /* ??? We can't scan past the end of a basic block without updating |
| the register lifetime info (REG_DEAD/basic_block_live_at_start). |
| A CALL_INSN might be the last insn of a basic block, if it |
| is inside an EH region. There is no easy way to tell so we |
| just always break when we see a CALL_INSN if flag_exceptions |
| is nonzero. */ |
| if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
| 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)) += s_num_calls; |
| } |
| |
| REG_N_SETS (REGNO (src))++; |
| REG_N_SETS (REGNO (dst))--; |
| |
| REG_N_CALLS_CROSSED (REGNO (dst)) -= num_calls; |
| |
| REG_LIVE_LENGTH (REGNO (src)) += s_length; |
| if (REG_LIVE_LENGTH (REGNO (dst)) >= 0) |
| { |
| REG_LIVE_LENGTH (REGNO (dst)) -= length; |
| /* REG_LIVE_LENGTH is only an approximation after |
| combine if sched is not run, so make sure that we |
| still have a reasonable value. */ |
| if (REG_LIVE_LENGTH (REGNO (dst)) < 2) |
| REG_LIVE_LENGTH (REGNO (dst)) = 2; |
| } |
| |
| /* We assume that a register is used exactly once per |
| insn in the updates above. If this is not correct, |
| no great harm is done. */ |
| |
| REG_N_REFS (REGNO (src)) += 2 * true_loop_depth; |
| REG_N_REFS (REGNO (dst)) -= 2 * true_loop_depth; |
| |
| /* If that was the only time dst was set, |
| and dst was not live at the start of the |
| function, we know that we have no more |
| references to dst; clear REG_N_REFS so it |
| won't make reload do any work. */ |
| if (REG_N_SETS (REGNO (dst)) == 0 |
| && ! regno_uninitialized (REGNO (dst))) |
| REG_N_REFS (REGNO (dst)) = 0; |
| |
| 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); |
| return 1; |
| } |
| |
| |
| /* 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); |
| } |
| } |
| |
| /* Test if regmove seems profitable for this target. Regmove is useful only |
| if some common patterns are two address, i.e. require matching constraints, |
| so we check that condition here. */ |
| |
| int |
| regmove_profitable_p () |
| { |
| #ifdef REGISTER_CONSTRAINTS |
| struct match match; |
| enum machine_mode mode; |
| optab tstoptab = add_optab; |
| do /* check add_optab and ashl_optab */ |
| for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; |
| mode = GET_MODE_WIDER_MODE (mode)) |
| { |
| int icode = (int) tstoptab->handlers[(int) mode].insn_code; |
| rtx reg0, reg1, reg2, pat; |
| int i; |
| |
| if (GET_MODE_BITSIZE (mode) < 32 || icode == CODE_FOR_nothing) |
| continue; |
| for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
| if (TEST_HARD_REG_BIT (reg_class_contents[GENERAL_REGS], i)) |
| break; |
| if (i + 2 >= FIRST_PSEUDO_REGISTER) |
| break; |
| reg0 = gen_rtx_REG (insn_operand_mode[icode][0], i); |
| reg1 = gen_rtx_REG (insn_operand_mode[icode][1], i + 1); |
| reg2 = gen_rtx_REG (insn_operand_mode[icode][2], i + 2); |
| if (! (*insn_operand_predicate[icode][0]) (reg0, VOIDmode) |
| || ! (*insn_operand_predicate[icode][1]) (reg1, VOIDmode) |
| || ! (*insn_operand_predicate[icode][2]) (reg2, VOIDmode)) |
| break; |
| pat = GEN_FCN (icode) (reg0, reg1, reg2); |
| if (! pat) |
| continue; |
| if (GET_CODE (pat) == SEQUENCE) |
| pat = XVECEXP (pat, 0, XVECLEN (pat, 0) - 1); |
| else |
| pat = make_insn_raw (pat); |
| if (! single_set (pat) |
| || GET_CODE (SET_SRC (single_set (pat))) != tstoptab->code) |
| /* Unexpected complexity; don't need to handle this unless |
| we find a machine where this occurs and regmove should |
| be enabled. */ |
| break; |
| if (find_matches (pat, &match) >= 0) |
| return 1; |
| break; |
| } |
| while (tstoptab != ashl_optab && (tstoptab = ashl_optab, 1)); |
| #endif /* REGISTER_CONSTRAINTS */ |
| return 0; |
| } |