Index: cprop.c =================================================================== --- cprop.c (revision 221523) +++ cprop.c (working copy) @@ -285,6 +285,15 @@ cprop_constant_p (const_rtx x) return CONSTANT_P (x) && (GET_CODE (x) != CONST || shared_const_p (x)); } +/* Determine whether the rtx X should be treated as a register that can + be propagated. Any pseudo-register is fine. */ + +static bool +cprop_reg_p (const_rtx x) +{ + return REG_P (x) && !HARD_REGISTER_P (x); +} + /* Scan SET present in INSN and add an entry to the hash TABLE. IMPLICIT is true if it's an implicit set, false otherwise. */ @@ -295,8 +304,7 @@ hash_scan_set (rtx set, rtx_insn *insn, struct has rtx src = SET_SRC (set); rtx dest = SET_DEST (set); - if (REG_P (dest) - && ! HARD_REGISTER_P (dest) + if (cprop_reg_p (dest) && reg_available_p (dest, insn) && can_copy_p (GET_MODE (dest))) { @@ -321,9 +329,8 @@ hash_scan_set (rtx set, rtx_insn *insn, struct has src = XEXP (note, 0), set = gen_rtx_SET (VOIDmode, dest, src); /* Record sets for constant/copy propagation. */ - if ((REG_P (src) + if ((cprop_reg_p (src) && src != dest - && ! HARD_REGISTER_P (src) && reg_available_p (src, insn)) || cprop_constant_p (src)) insert_set_in_table (dest, src, insn, table, implicit); @@ -821,15 +828,15 @@ try_replace_reg (rtx from, rtx to, rtx_insn *insn) return success; } -/* Find a set of REGNOs that are available on entry to INSN's block. Return - NULL no such set is found. */ +/* Find a set of REGNOs that are available on entry to INSN's block. If found, + SET_RET[0] will be assigned a set with a register source and SET_RET[1] a + set with a constant source. If not found the corresponding entry is set to + NULL. */ -static struct cprop_expr * -find_avail_set (int regno, rtx_insn *insn) +static void +find_avail_set (int regno, rtx_insn *insn, struct cprop_expr *set_ret[2]) { - /* SET1 contains the last set found that can be returned to the caller for - use in a substitution. */ - struct cprop_expr *set1 = 0; + set_ret[0] = set_ret[1] = NULL; /* Loops are not possible here. To get a loop we would need two sets available at the start of the block containing INSN. i.e. we would @@ -869,8 +876,10 @@ try_replace_reg (rtx from, rtx to, rtx_insn *insn) If the source operand changed, we may still use it for the next iteration of this loop, but we may not use it for substitutions. */ - if (cprop_constant_p (src) || reg_not_set_p (src, insn)) - set1 = set; + if (cprop_constant_p (src)) + set_ret[1] = set; + else if (reg_not_set_p (src, insn)) + set_ret[0] = set; /* If the source of the set is anything except a register, then we have reached the end of the copy chain. */ @@ -881,10 +890,6 @@ try_replace_reg (rtx from, rtx to, rtx_insn *insn) and see if we have an available copy into SRC. */ regno = REGNO (src); } - - /* SET1 holds the last set that was available and anticipatable at - INSN. */ - return set1; } /* Subroutine of cprop_insn that tries to propagate constants into @@ -1050,7 +1055,8 @@ cprop_insn (rtx_insn *insn) int changed = 0, changed_this_round; rtx note; -retry: + do + { changed_this_round = 0; reg_use_count = 0; note_uses (&PATTERN (insn), find_used_regs, NULL); @@ -1064,8 +1070,8 @@ cprop_insn (rtx_insn *insn) { rtx reg_used = reg_use_table[i]; unsigned int regno = REGNO (reg_used); - rtx src; - struct cprop_expr *set; + rtx src_cst = NULL, src_reg = NULL; + struct cprop_expr *set[2]; /* If the register has already been set in this block, there's nothing we can do. */ @@ -1074,17 +1080,16 @@ cprop_insn (rtx_insn *insn) /* Find an assignment that sets reg_used and is available at the start of the block. */ - set = find_avail_set (regno, insn); - if (! set) - continue; + find_avail_set (regno, insn, set); + if (set[0]) + src_reg = set[0]->src; + if (set[1]) + src_cst = set[1]->src; - src = set->src; - /* Constant propagation. */ - if (cprop_constant_p (src)) + if (src_cst && cprop_constant_p (src_cst) + && constprop_register (reg_used, src_cst, insn)) { - if (constprop_register (reg_used, src, insn)) - { changed_this_round = changed = 1; global_const_prop_count++; if (dump_file != NULL) @@ -1093,19 +1098,17 @@ cprop_insn (rtx_insn *insn) "GLOBAL CONST-PROP: Replacing reg %d in ", regno); fprintf (dump_file, "insn %d with constant ", INSN_UID (insn)); - print_rtl (dump_file, src); + print_rtl (dump_file, src_cst); fprintf (dump_file, "\n"); } if (insn->deleted ()) return 1; } - } - else if (REG_P (src) - && REGNO (src) >= FIRST_PSEUDO_REGISTER - && REGNO (src) != regno) + /* Copy propagation. */ + else if (src_reg && cprop_reg_p (src_reg) + && REGNO (src_reg) != regno + && try_replace_reg (reg_used, src_reg, insn)) { - if (try_replace_reg (reg_used, src, insn)) - { changed_this_round = changed = 1; global_copy_prop_count++; if (dump_file != NULL) @@ -1113,7 +1116,7 @@ cprop_insn (rtx_insn *insn) fprintf (dump_file, "GLOBAL COPY-PROP: Replacing reg %d in insn %d", regno, INSN_UID (insn)); - fprintf (dump_file, " with reg %d\n", REGNO (src)); + fprintf (dump_file, " with reg %d\n", REGNO (src_reg)); } /* The original insn setting reg_used may or may not now be @@ -1123,12 +1126,10 @@ cprop_insn (rtx_insn *insn) and made things worse. */ } } - + } /* If try_replace_reg simplified the insn, the regs found by find_used_regs may not be valid anymore. Start over. */ - if (changed_this_round) - goto retry; - } + while (changed_this_round); if (changed && DEBUG_INSN_P (insn)) return 0; @@ -1191,7 +1192,7 @@ do_local_cprop (rtx x, rtx_insn *insn) /* Rule out USE instructions and ASM statements as we don't want to change the hard registers mentioned. */ if (REG_P (x) - && (REGNO (x) >= FIRST_PSEUDO_REGISTER + && (cprop_reg_p (x) || (GET_CODE (PATTERN (insn)) != USE && asm_noperands (PATTERN (insn)) < 0))) { @@ -1207,7 +1208,7 @@ do_local_cprop (rtx x, rtx_insn *insn) if (cprop_constant_p (this_rtx)) newcnst = this_rtx; - if (REG_P (this_rtx) && REGNO (this_rtx) >= FIRST_PSEUDO_REGISTER + if (cprop_reg_p (this_rtx) /* Don't copy propagate if it has attached REG_EQUIV note. At this point this only function parameters should have REG_EQUIV notes and if the argument slot is used somewhere @@ -1328,9 +1329,8 @@ implicit_set_cond_p (const_rtx cond) if (GET_CODE (cond) != EQ && GET_CODE (cond) != NE) return false; - /* The first operand of COND must be a pseudo-reg. */ - if (! REG_P (XEXP (cond, 0)) - || HARD_REGISTER_P (XEXP (cond, 0))) + /* The first operand of COND must be a register we can propagate. */ + if (cprop_reg_p (XEXP (cond, 0))) return false; /* The second operand of COND must be a suitable constant. */