diff --git a/gcc/match.pd b/gcc/match.pd index f08ab674a7064ddb41e73e42c9428ef2bd0c2ca1..e731bdba171e82dfdba3938ea51db5024b225a76 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3993,6 +3993,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (single_use (@2)) (cmp @0 @1))))) +/* Simplify (x < 0) ^ (y < 0) to (x ^ y) < 0 and + (x >= 0) ^ (y >= 0) to (x ^ y) < 0. */ +(for cmp (lt ge) + (simplify + (bit_xor (cmp:s @0 integer_zerop) (cmp:s @1 integer_zerop)) + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && !TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (TREE_TYPE (@0), TREE_TYPE (@1))) + (lt (bit_xor @0 @1) { build_zero_cst (TREE_TYPE (@0)); })))) +/* Simplify (x < 0) ^ (y >= 0) to (x ^ y) >= 0 and + (x >= 0) ^ (y < 0) to (x ^ y) >= 0. */ +(simplify + (bit_xor:c (lt:s @0 integer_zerop) (ge:s @1 integer_zerop)) + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && !TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (TREE_TYPE (@0), TREE_TYPE (@1))) + (ge (bit_xor @0 @1) { build_zero_cst (TREE_TYPE (@0)); }))) + /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the signed arithmetic case. That form is created by the compiler often enough for folding it to be of value. One example is in diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr96681.c b/gcc/testsuite/gcc.dg/tree-ssa/pr96681.c new file mode 100644 index 0000000000000000000000000000000000000000..6d72a1a3d7d83483f1761558952a3e58d434f9c6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr96681.c @@ -0,0 +1,35 @@ +/* PR tree-optimization/96681 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump-times " \\^ " 5 "optimized" } } */ +/* { dg-final { scan-tree-dump-times " (?:<|>=) 0" 5 "optimized" } } */ + +int +foo (int x, int y) +{ + return (x < 0) ^ (y < 0); +} + +int +bar (int x, int y) +{ + return (x > -1) ^ (y > -1); +} + +int +baz (int x, int y) +{ + return (x ^ y) < 0; +} + +int +qux (int x, int y) +{ + return (x ^ y) >= 0; +} + +int +corge (int x, int y) +{ + return (x >= 0) ^ (y < 0); +}