diff options
Diffstat (limited to 'gcc/simplify-rtx.cc')
| -rw-r--r-- | gcc/simplify-rtx.cc | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index c478bd0..fe007bc 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -2655,6 +2655,9 @@ simplify_context::simplify_logical_relational_operation (rtx_code code, enum rtx_code code0 = GET_CODE (op0); enum rtx_code code1 = GET_CODE (op1); + machine_mode cmp_mode = GET_MODE (XEXP (op0, 0)); + if (cmp_mode == VOIDmode) + cmp_mode = GET_MODE (XEXP (op0, 1)); /* Assume at first that the comparisons are on integers, and that the operands are therefore ordered. */ @@ -2672,8 +2675,10 @@ simplify_context::simplify_logical_relational_operation (rtx_code code, } else { - /* See whether the operands might be unordered. */ - if (HONOR_NANS (GET_MODE (XEXP (op0, 0)))) + /* See whether the operands might be unordered. Assume that all + results are possible for CC modes, and punt later if we don't get an + always-true or always-false answer. */ + if (GET_MODE_CLASS (cmp_mode) == MODE_CC || HONOR_NANS (cmp_mode)) all = 15; mask0 = comparison_to_mask (code0) & all; mask1 = comparison_to_mask (code1) & all; @@ -2702,6 +2707,9 @@ simplify_context::simplify_logical_relational_operation (rtx_code code, code = mask_to_unsigned_comparison (mask); else { + if (GET_MODE_CLASS (cmp_mode) == MODE_CC) + return 0; + code = mask_to_comparison (mask); /* LTGT and NE are arithmetically equivalent for ordered operands, with NE being the canonical choice. */ |