diff options
Diffstat (limited to 'gcc/compare-elim.c')
| -rw-r--r-- | gcc/compare-elim.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/gcc/compare-elim.c b/gcc/compare-elim.c index 5157e76..f11a724 100644 --- a/gcc/compare-elim.c +++ b/gcc/compare-elim.c @@ -563,10 +563,26 @@ try_eliminate_compare (struct comparison *cmp) Validate that PREV_CLOBBER itself does in fact refer to IN_A. Do recall that we've already validated the shape of PREV_CLOBBER. */ x = XVECEXP (PATTERN (insn), 0, 0); - if (!rtx_equal_p (SET_DEST (x), in_a)) + if (rtx_equal_p (SET_DEST (x), in_a)) + cmp_src = SET_SRC (x); + + /* Also check operations with implicit extensions, e.g.: + [(set (reg:DI) + (zero_extend:DI (plus:SI (reg:SI)(reg:SI)))) + (set (reg:CCZ flags) + (compare:CCZ + (plus:SI (reg:SI)(reg:SI)) + (const_int 0)))] */ + else if (REG_P (SET_DEST (x)) + && REG_P (in_a) + && REGNO (SET_DEST (x)) == REGNO (in_a) + && (GET_CODE (SET_SRC (x)) == ZERO_EXTEND + || GET_CODE (SET_SRC (x)) == SIGN_EXTEND) + && GET_MODE (XEXP (SET_SRC (x), 0)) == GET_MODE (in_a)) + cmp_src = XEXP (SET_SRC (x), 0); + else return false; - cmp_src = SET_SRC (x); - + /* Determine if we ought to use a different CC_MODE here. */ flags = maybe_select_cc_mode (cmp, cmp_src, cmp->in_b); if (flags == NULL) |