diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/match.pd | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c | 28 |
2 files changed, 38 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 758322d..7f76925 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -865,6 +865,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) { tree utype = unsigned_type_for (type); } (convert (rshift (lshift (convert:utype @0) @2) @3)))))) +/* Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit. */ +(simplify + (lshift (convert (lt @0 integer_zerop@1)) INTEGER_CST@2) + (if (TYPE_SIGN (TREE_TYPE (@0)) == SIGNED + && wi::eq_p (wi::to_wide (@2), TYPE_PRECISION (TREE_TYPE (@0)) - 1)) + (with { wide_int wone = wi::one (TYPE_PRECISION (type)); } + (bit_and (convert @0) + { wide_int_to_tree (type, + wi::lshift (wone, wi::to_wide (@2))); })))) + /* Fold (-x >> C) into -(x > 0) where C = precision(type) - 1. */ (for cst (INTEGER_CST VECTOR_CST) (simplify diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c new file mode 100644 index 0000000..f086f07 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c @@ -0,0 +1,28 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* PR tree-optimization/103218 */ + +/* These first two are removed during forwprop1 */ +signed char f(signed char a) +{ + signed char t = a < 0; + int tt = (unsigned char)(t << 7); + return tt; +} +signed char f0(signed char a) +{ + unsigned char t = a < 0; + int tt = (unsigned char)(t << 7); + return tt; +} + +/* This one is removed during phiopt. */ +signed char f1(signed char a) +{ + if (a < 0) + return 1u<<7; + return 0; +} + +/* These three examples should remove "a < 0" by optimized. */ +/* { dg-final { scan-tree-dump-times "< 0" 0 "optimized"} } */ |