diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/fold-const.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2094b29..b0c115e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2004-03-07 Roger Sayle <roger@eyesopen.com> + * fold-const.c (fold) <IOR_EXPR>: Fold x | x as x. + <XOR_EXPR>: Fold x ^ x as zero. + <AND_EXPR>: Fold x & x as x. + +2004-03-07 Roger Sayle <roger@eyesopen.com> + * fold-const.c (fold) <EQ_EXPR>: Rewrite optimization to transform "foo++ == const" into "++foo == const+incr". diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 042cd9e..bbef4e6 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -6605,6 +6605,8 @@ fold (tree expr) return omit_one_operand (type, arg1, arg0); if (integer_zerop (arg1)) return non_lvalue (fold_convert (type, arg0)); + if (operand_equal_p (arg0, arg1, 0)) + return non_lvalue (fold_convert (type, arg0)); t1 = distribute_bit_expr (code, type, arg0, arg1); if (t1 != NULL_TREE) return t1; @@ -6633,6 +6635,8 @@ fold (tree expr) return non_lvalue (fold_convert (type, arg0)); if (integer_all_onesp (arg1)) return fold (build1 (BIT_NOT_EXPR, type, arg0)); + if (operand_equal_p (arg0, arg1, 0)) + return omit_one_operand (type, integer_zero_node, arg0); /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing with a constant, and the two constants have no bits in common, @@ -6659,6 +6663,8 @@ fold (tree expr) return non_lvalue (fold_convert (type, arg0)); if (integer_zerop (arg1)) return omit_one_operand (type, arg1, arg0); + if (operand_equal_p (arg0, arg1, 0)) + return non_lvalue (fold_convert (type, arg0)); t1 = distribute_bit_expr (code, type, arg0, arg1); if (t1 != NULL_TREE) return t1; |