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| author | Eric Botcazou <ebotcazou@adacore.com> | 2011-03-22 20:04:58 +0000 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@gcc.gnu.org> | 2011-03-22 20:04:58 +0000 |
| commit | e8b97ccd59010685e183b437b1f192e01e2809ad (patch) | |
| tree | d4c27b860570439ad5f74e0502248939bc81a27e /gcc/combine.c | |
| parent | 56f8587a5bdc641ab06e81d8dbdb4a441431344a (diff) | |
| download | gcc-e8b97ccd59010685e183b437b1f192e01e2809ad.tar.gz | |
combine.c (simplify_set): Try harder to find the best CC mode when simplifying a nested COMPARE on the RHS.
* combine.c (simplify_set): Try harder to find the best CC mode when
simplifying a nested COMPARE on the RHS.
From-SVN: r171304
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index fe3302a492d..60bd9eedd55 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -6240,10 +6240,18 @@ simplify_set (rtx x) enum rtx_code new_code; rtx op0, op1, tmp; int other_changed = 0; + rtx inner_compare = NULL_RTX; enum machine_mode compare_mode = GET_MODE (dest); if (GET_CODE (src) == COMPARE) - op0 = XEXP (src, 0), op1 = XEXP (src, 1); + { + op0 = XEXP (src, 0), op1 = XEXP (src, 1); + if (GET_CODE (op0) == COMPARE && op1 == const0_rtx) + { + inner_compare = op0; + op0 = XEXP (inner_compare, 0), op1 = XEXP (inner_compare, 1); + } + } else op0 = src, op1 = CONST0_RTX (GET_MODE (src)); @@ -6285,6 +6293,12 @@ simplify_set (rtx x) need to use a different CC mode here. */ if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC) compare_mode = GET_MODE (op0); + else if (inner_compare + && GET_MODE_CLASS (GET_MODE (inner_compare)) == MODE_CC + && new_code == old_code + && op0 == XEXP (inner_compare, 0) + && op1 == XEXP (inner_compare, 1)) + compare_mode = GET_MODE (inner_compare); else compare_mode = SELECT_CC_MODE (new_code, op0, op1); |