diff options
| author | Roger Sayle <roger@eyesopen.com> | 2004-03-07 20:13:50 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2004-03-07 20:13:50 +0000 |
| commit | cd2f1c7a623809b0b7e2b224e1240fb74f5f0767 (patch) | |
| tree | 92143fa659d22e48620905f9ea1ee62d1875d469 | |
| parent | 350f4ea897ebddd78030dbb18e4876deac235490 (diff) | |
| download | gcc-cd2f1c7a623809b0b7e2b224e1240fb74f5f0767.zip gcc-cd2f1c7a623809b0b7e2b224e1240fb74f5f0767.tar.gz gcc-cd2f1c7a623809b0b7e2b224e1240fb74f5f0767.tar.bz2 | |
fold-const.c (fold): Fold x | x as x.
* 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.
From-SVN: r79065
| -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; |