diff options
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 64cf992..60c4059 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -11758,12 +11758,10 @@ record_value_for_reg (rtx reg, rtx insn, rtx value) case, we must replace it with (clobber (const_int 0)) to prevent infinite loops. */ rsp = VEC_index (reg_stat_type, reg_stat, regno); - if (value && ! get_last_value_validate (&value, insn, - rsp->last_set_label, 0)) + if (value && !get_last_value_validate (&value, insn, label_tick, 0)) { value = copy_rtx (value); - if (! get_last_value_validate (&value, insn, - rsp->last_set_label, 1)) + if (!get_last_value_validate (&value, insn, label_tick, 1)) value = 0; } @@ -12055,15 +12053,14 @@ check_promoted_subreg (rtx insn, rtx x) } } -/* Utility routine for the following function. Verify that all the registers - mentioned in *LOC are valid when *LOC was part of a value set when - label_tick == TICK. Return 0 if some are not. - - If REPLACE is nonzero, replace the invalid reference with - (clobber (const_int 0)) and return 1. This replacement is useful because - we often can get useful information about the form of a value (e.g., if - it was produced by a shift that always produces -1 or 0) even though - we don't know exactly what registers it was produced from. */ +/* Verify that all the registers and memory references mentioned in *LOC are + still valid. *LOC was part of a value set in INSN when label_tick was + equal to TICK. Return 0 if some are not. If REPLACE is nonzero, replace + the invalid references with (clobber (const_int 0)) and return 1. This + replacement is useful because we often can get useful information about + the form of a value (e.g., if it was produced by a shift that always + produces -1 or 0) even though we don't know exactly what registers it + was produced from. */ static int get_last_value_validate (rtx *loc, rtx insn, int tick, int replace) @@ -12099,11 +12096,12 @@ get_last_value_validate (rtx *loc, rtx insn, int tick, int replace) return 1; } - /* If this is a memory reference, make sure that there were - no stores after it that might have clobbered the value. We don't - have alias info, so we assume any store invalidates it. */ + /* If this is a memory reference, make sure that there were no stores after + it that might have clobbered the value. We don't have alias info, so we + assume any store invalidates it. Moreover, we only have local UIDs, so + we also assume that there were stores in the intervening basic blocks. */ else if (MEM_P (x) && !MEM_READONLY_P (x) - && DF_INSN_LUID (insn) <= mem_last_set) + && (tick != label_tick || DF_INSN_LUID (insn) <= mem_last_set)) { if (replace) *loc = gen_rtx_CLOBBER (GET_MODE (x), const0_rtx); @@ -12213,16 +12211,14 @@ get_last_value (const_rtx x) return 0; /* If the value has all its registers valid, return it. */ - if (get_last_value_validate (&value, rsp->last_set, - rsp->last_set_label, 0)) + if (get_last_value_validate (&value, rsp->last_set, rsp->last_set_label, 0)) return value; /* Otherwise, make a copy and replace any invalid register with (clobber (const_int 0)). If that fails for some reason, return 0. */ value = copy_rtx (value); - if (get_last_value_validate (&value, rsp->last_set, - rsp->last_set_label, 1)) + if (get_last_value_validate (&value, rsp->last_set, rsp->last_set_label, 1)) return value; return 0; |