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| author | Kai Tietz <ktietz@redhat.com> | 2011-04-20 18:16:28 +0200 |
|---|---|---|
| committer | Kai Tietz <ktietz@gcc.gnu.org> | 2011-04-20 18:16:28 +0200 |
| commit | 583722ee5836f737b0a05f915d6d4ffc095565f9 (patch) | |
| tree | 946228850bcada56ffd10a40a2a1dfe0ba959199 /gcc/fold-const.c | |
| parent | 422c0989b5a4470dabec04c3795eafec7015c2ff (diff) | |
| download | gcc-583722ee5836f737b0a05f915d6d4ffc095565f9.zip gcc-583722ee5836f737b0a05f915d6d4ffc095565f9.tar.gz gcc-583722ee5836f737b0a05f915d6d4ffc095565f9.tar.bz2 | |
ChangeLog gcc/
2011-04-20 Kai Tietz <ktietz@redhat.com>
* fold-const.c (fold_binary_loc): Add handling for
(X & ~Y) | (~X & Y) and (X && !Y) | (!X && Y) optimization
to (X ^ Y).
ChangeLog gcc/testsuite
2011-04-20 Kai Tietz <ktietz@redhat.com>
* gcc.dg/binio-xor1.c: New test.
* gcc.dg/binio-xor2.c: New test.
* gcc.dg/binio-xor3.c: New test.
* gcc.dg/binio-xor4.c: New test.
* gcc.dg/binio-xor5.c: New test.
From-SVN: r172776
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 8d543c4..c4bf088 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10660,6 +10660,28 @@ fold_binary_loc (location_t loc, && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0))) return omit_one_operand_loc (loc, type, arg0, TREE_OPERAND (arg1, 0)); + /* (X & ~Y) | (~X & Y) is X ^ Y */ + if (TREE_CODE (arg0) == BIT_AND_EXPR + && TREE_CODE (arg1) == BIT_AND_EXPR) + { + tree a0, a1, l0, l1, n0, n1; + + a0 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0)); + a1 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1)); + + l0 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0)); + l1 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1)); + + n0 = fold_build1_loc (loc, BIT_NOT_EXPR, type, l0); + n1 = fold_build1_loc (loc, BIT_NOT_EXPR, type, l1); + + if ((operand_equal_p (n0, a0, 0) + && operand_equal_p (n1, a1, 0)) + || (operand_equal_p (n0, a1, 0) + && operand_equal_p (n1, a0, 0))) + return fold_build2_loc (loc, BIT_XOR_EXPR, type, l0, n1); + } + t1 = distribute_bit_expr (loc, code, type, arg0, arg1); if (t1 != NULL_TREE) return t1; @@ -12039,6 +12061,27 @@ fold_binary_loc (location_t loc, && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)) return omit_one_operand_loc (loc, type, integer_one_node, arg0); + /* (X && !Y) || (!X && Y) is X ^ Y */ + if (TREE_CODE (arg0) == TRUTH_AND_EXPR + && TREE_CODE (arg1) == TRUTH_AND_EXPR) + { + tree a0, a1, l0, l1, n0, n1; + + a0 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0)); + a1 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1)); + + l0 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0)); + l1 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1)); + + n0 = fold_build1_loc (loc, TRUTH_NOT_EXPR, type, l0); + n1 = fold_build1_loc (loc, TRUTH_NOT_EXPR, type, l1); + + if ((operand_equal_p (n0, a0, 0) + && operand_equal_p (n1, a1, 0)) + || (operand_equal_p (n0, a1, 0) + && operand_equal_p (n1, a0, 0))) + return fold_build2_loc (loc, TRUTH_XOR_EXPR, type, l0, n1); + } goto truth_andor; case TRUTH_XOR_EXPR: |