diff options
Diffstat (limited to 'contrib/gcc/combine.c')
| -rw-r--r-- | contrib/gcc/combine.c | 51 |
1 files changed, 2 insertions, 49 deletions
diff --git a/contrib/gcc/combine.c b/contrib/gcc/combine.c index 0b64a86..57b2e86 100644 --- a/contrib/gcc/combine.c +++ b/contrib/gcc/combine.c @@ -10834,56 +10834,9 @@ get_last_value (x) return 0; /* If the value was set in a later insn than the ones we are processing, - we can't use it even if the register was only set once, but make a quick - check to see if the previous insn set it to something. This is commonly - the case when the same pseudo is used by repeated insns. - - This does not work if there exists an instruction which is temporarily - not on the insn chain. */ - + we can't use it even if the register was only set once. */ if (INSN_CUID (reg_last_set[regno]) >= subst_low_cuid) - { - rtx insn, set; - - /* We can not do anything useful in this case, because there is - an instruction which is not on the insn chain. */ - if (subst_prev_insn) - return 0; - - /* Skip over USE insns. They are not useful here, and they may have - been made by combine, in which case they do not have a INSN_CUID - value. We can't use prev_real_insn, because that would incorrectly - take us backwards across labels. Skip over BARRIERs also, since - they could have been made by combine. If we see one, we must be - optimizing dead code, so it doesn't matter what we do. */ - for (insn = prev_nonnote_insn (subst_insn); - insn && ((GET_CODE (insn) == INSN - && GET_CODE (PATTERN (insn)) == USE) - || GET_CODE (insn) == BARRIER - || INSN_CUID (insn) >= subst_low_cuid); - insn = prev_nonnote_insn (insn)) - ; - - if (insn - && (set = single_set (insn)) != 0 - && rtx_equal_p (SET_DEST (set), x)) - { - value = SET_SRC (set); - - /* Make sure that VALUE doesn't reference X. Replace any - explicit references with a CLOBBER. If there are any remaining - references (rare), don't use the value. */ - - if (reg_mentioned_p (x, value)) - value = replace_rtx (copy_rtx (value), x, - gen_rtx_CLOBBER (GET_MODE (x), const0_rtx)); - - if (reg_overlap_mentioned_p (x, value)) - return 0; - } - else - return 0; - } + return 0; /* If the value has all its registers valid, return it. */ if (get_last_value_validate (&value, reg_last_set[regno], |
