diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index ab653ea..9f5c097 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -7843,10 +7843,13 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0) return fold_build1_loc (loc, code, type, TREE_OPERAND (op0, 0)); /* If we have a sign-extension of a zero-extended value, we can - replace that by a single zero-extension. */ + replace that by a single zero-extension. Likewise if the + final conversion does not change precision we can drop the + intermediate conversion. */ if (inside_int && inter_int && final_int - && inside_prec < inter_prec && inter_prec < final_prec - && inside_unsignedp && !inter_unsignedp) + && ((inside_prec < inter_prec && inter_prec < final_prec + && inside_unsignedp && !inter_unsignedp) + || final_prec == inter_prec)) return fold_build1_loc (loc, code, type, TREE_OPERAND (op0, 0)); /* Two conversions in a row are not needed unless: @@ -10335,10 +10338,21 @@ fold_binary_loc (location_t loc, if (TREE_CODE (tmp0) == NEGATE_EXPR) tmp0 = TREE_OPERAND (tmp0, 0); + if (CONVERT_EXPR_P (tmp0) + && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (tmp0, 0))) + && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (tmp0, 0))) + <= TYPE_PRECISION (type))) + tmp0 = TREE_OPERAND (tmp0, 0); if (TREE_CODE (tmp1) == NEGATE_EXPR) tmp1 = TREE_OPERAND (tmp1, 0); + if (CONVERT_EXPR_P (tmp1) + && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (tmp1, 0))) + && (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (tmp1, 0))) + <= TYPE_PRECISION (type))) + tmp1 = TREE_OPERAND (tmp1, 0); /* The only case we can still associate with two variables - is if they are the same, modulo negation. */ + is if they are the same, modulo negation and bit-pattern + preserving conversions. */ if (!operand_equal_p (tmp0, tmp1, 0)) ok = false; } |