diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 4774661..7cf132b 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -7926,6 +7926,26 @@ fold_unary (enum tree_code code, tree type, tree op0) return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem)); } + /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the + type of X and Y (integer types only). */ + if (INTEGRAL_TYPE_P (type) + && TREE_CODE (op0) == MULT_EXPR + && INTEGRAL_TYPE_P (TREE_TYPE (op0)) + && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0))) + { + /* Be careful not to introduce new overflows. */ + tree mult_type; + if (TYPE_OVERFLOW_WRAPS (type)) + mult_type = type; + else + mult_type = unsigned_type_for (type); + + tem = fold_build2 (MULT_EXPR, mult_type, + fold_convert (mult_type, TREE_OPERAND (op0, 0)), + fold_convert (mult_type, TREE_OPERAND (op0, 1))); + return fold_convert (type, tem); + } + tem = fold_convert_const (code, type, op0); return tem ? tem : NULL_TREE; |