diff options
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/match.pd | 9 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr94783.c | 12 |
4 files changed, 28 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5bad3ff..75b0ed1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,9 @@ 2020-05-08 Jakub Jelinek <jakub@redhat.com> + PR tree-optimization/94783 + * match.pd ((X + (X >> (prec - 1))) ^ (X >> (prec - 1)) to abs (X)): + New simplification. + PR tree-optimization/94956 * match.pd (FFS): Optimize __builtin_ffs* of non-zero argument into __builtin_ctz* + 1 if direct IFN_CTZ is supported. diff --git a/gcc/match.pd b/gcc/match.pd index 892df1e..e8c53e3 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -120,6 +120,15 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); } (convert (absu:utype @0))))) +#if GIMPLE +/* Optimize (X + (X >> (prec - 1))) ^ (X >> (prec - 1)) into abs (X). */ +(simplify + (bit_xor:c (plus:c @0 (rshift@2 @0 INTEGER_CST@1)) @2) + (if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && !TYPE_UNSIGNED (TREE_TYPE (@0)) + && wi::to_widest (@1) == element_precision (TREE_TYPE (@0)) - 1) + (abs @0))) +#endif /* Simplifications of operations with one constant operand and simplifications to constants or single values. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e8c54c7..174198f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,8 @@ 2020-05-08 Jakub Jelinek <jakub@redhat.com> + PR tree-optimization/94783 + * gcc.dg/tree-ssa/pr94783.c: New test. + PR tree-optimization/94956 * gcc.target/i386/pr94956.c: New test. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr94783.c b/gcc/testsuite/gcc.dg/tree-ssa/pr94783.c new file mode 100644 index 0000000..c52f657 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr94783.c @@ -0,0 +1,12 @@ +/* PR tree-optimization/94783 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump "ABS_EXPR" "optimized" } } */ +/* { dg-final { scan-tree-dump-not " >> 31" "optimized" } } */ + +int +foo (int v) +{ + int mask = v >> (__SIZEOF_INT__ * __CHAR_BIT__ - 1); + return (v + mask) ^ mask; +} |