diff options
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 91dfddb..b2f8429 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1209,6 +1209,35 @@ along with GCC; see the file COPYING3. If not see (if (tem && !TREE_OVERFLOW (tem)) (scmp @0 { tem; })))))) + +/* Equality compare simplifications from fold_binary */ +(for cmp (eq ne) + + /* If we have (A | C) == D where C & ~D != 0, convert this into 0. + Similarly for NE_EXPR. */ + (simplify + (cmp (convert?@3 (bit_ior @0 INTEGER_CST@1)) INTEGER_CST@2) + (if (tree_nop_conversion_p (TREE_TYPE (@3), TREE_TYPE (@0)) + && wi::bit_and_not (@1, @2) != 0) + { constant_boolean_node (cmp == NE_EXPR, type); })) + + /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */ + (simplify + (cmp (bit_xor @0 @1) integer_zerop) + (cmp @0 @1)) + + /* (X ^ Y) == Y becomes X == 0. + Likewise (X ^ Y) == X becomes Y == 0. */ + (simplify + (cmp (bit_xor:c @0 @1) @0) + (cmp @1 { build_zero_cst (TREE_TYPE (@1)); })) + + /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */ + (simplify + (cmp (convert?@3 (bit_xor @0 INTEGER_CST@1)) INTEGER_CST@2) + (if (tree_nop_conversion_p (TREE_TYPE (@3), TREE_TYPE (@0))) + (cmp @0 (bit_xor @1 (convert @2)))))) + /* Simplification of math builtins. */ (define_operator_list LOG BUILT_IN_LOGF BUILT_IN_LOG BUILT_IN_LOGL) |