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| author | Kai Tietz <ktietz@redhat.com> | 2011-06-20 13:49:27 +0200 |
|---|---|---|
| committer | Kai Tietz <ktietz@gcc.gnu.org> | 2011-06-20 13:49:27 +0200 |
| commit | a95015b6cd1d68d540e1805686d534e88ec6bfbd (patch) | |
| tree | dd4bcae7ea7637ba444dd69516cc7a1ce4f2d852 /gcc/fold-const.c | |
| parent | 6f17ef336c92537292114eb6675360f264575099 (diff) | |
| download | gcc-a95015b6cd1d68d540e1805686d534e88ec6bfbd.zip gcc-a95015b6cd1d68d540e1805686d534e88ec6bfbd.tar.gz gcc-a95015b6cd1d68d540e1805686d534e88ec6bfbd.tar.bz2 | |
ChangeLog gcc/
2011-06-20 Kai Tietz <ktietz@redhat.com>
* fold-const.c (fold_binary_loc): Add missing
folding for truth-not operations in combination
with binary and.
ChangeLog gcc/testsuite/
2011-06-20 Kai Tietz <ktietz@redhat.com>
* gcc.dg/binop-notand1.c: New test.
* gcc.dg/binop-notand2.c: New test.
* gcc.dg/binop-notand3.c: New test.
* gcc.dg/binop-notand4.c: New test.
* gcc.dg/binop-notand5.c: New test.
* gcc.dg/binop-notand6.c: New test.
From-SVN: r175206
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 c39d33e..e48aae9 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10866,13 +10866,19 @@ fold_binary_loc (location_t loc, if (operand_equal_p (arg0, arg1, 0)) return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0)); - /* ~X & X is always zero. */ - if (TREE_CODE (arg0) == BIT_NOT_EXPR + /* ~X & X, (X == 0) & X, and !X & X are always zero. */ + if ((TREE_CODE (arg0) == BIT_NOT_EXPR + || TREE_CODE (arg0) == TRUTH_NOT_EXPR + || (TREE_CODE (arg0) == EQ_EXPR + && integer_zerop (TREE_OPERAND (arg0, 1)))) && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)) return omit_one_operand_loc (loc, type, integer_zero_node, arg1); - /* X & ~X is always zero. */ - if (TREE_CODE (arg1) == BIT_NOT_EXPR + /* X & ~X , X & (X == 0), and X & !X are always zero. */ + if ((TREE_CODE (arg1) == BIT_NOT_EXPR + || TREE_CODE (arg1) == TRUTH_NOT_EXPR + || (TREE_CODE (arg1) == EQ_EXPR + && integer_zerop (TREE_OPERAND (arg1, 1)))) && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)) return omit_one_operand_loc (loc, type, integer_zero_node, arg0); @@ -10933,6 +10939,14 @@ fold_binary_loc (location_t loc, build_int_cst (TREE_TYPE (tem), 1)), build_int_cst (TREE_TYPE (tem), 0)); } + /* Fold !X & 1 as X == 0. */ + if (TREE_CODE (arg0) == TRUTH_NOT_EXPR + && integer_onep (arg1)) + { + tem = TREE_OPERAND (arg0, 0); + return fold_build2_loc (loc, EQ_EXPR, type, tem, + build_int_cst (TREE_TYPE (tem), 0)); + } /* Fold (X ^ Y) & Y as ~X & Y. */ if (TREE_CODE (arg0) == BIT_XOR_EXPR |