diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/combine.c | 16 |
2 files changed, 20 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index efe5aa1..a6fa3dd 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2011-03-22 Eric Botcazou <ebotcazou@adacore.com> + + * combine.c (simplify_set): Try harder to find the best CC mode when + simplifying a nested COMPARE on the RHS. + 2011-03-22 Joseph Myers <joseph@codesourcery.com> * config/alpha/gnu.h: Remove. diff --git a/gcc/combine.c b/gcc/combine.c index fe3302a..60bd9ee 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); |