diff options
| -rw-r--r-- | gcc/match.pd | 8 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/pr96930.C | 10 |
2 files changed, 16 insertions, 2 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 56fb583..c286a54 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -321,7 +321,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (unsigned long long) (1 << 31) is -2147483648ULL, not 2147483648ULL, so it is valid only if A >> 31 is zero. */ (simplify - (trunc_div @0 (convert? (lshift integer_onep@1 @2))) + (trunc_div (convert?@0 @3) (convert2? (lshift integer_onep@1 @2))) (if ((TYPE_UNSIGNED (type) || tree_expr_nonnegative_p (@0)) && (!VECTOR_TYPE_P (type) || target_supports_op_p (type, RSHIFT_EXPR, optab_vector) @@ -336,7 +336,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) & wi::mask (element_precision (TREE_TYPE (@1)) - 1, true, element_precision (type))) == 0))))) - (rshift @0 @2))) + (if (!VECTOR_TYPE_P (type) + && useless_type_conversion_p (TREE_TYPE (@3), TREE_TYPE (@1)) + && element_precision (TREE_TYPE (@3)) < element_precision (type)) + (convert (rshift @3 @2)) + (rshift @0 @2)))) /* Preserve explicit divisions by 0: the C++ front-end wants to detect undefined behavior in constexpr evaluation, and assuming that the division diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr96930.C b/gcc/testsuite/g++.dg/tree-ssa/pr96930.C new file mode 100644 index 0000000..3d4d098 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/pr96930.C @@ -0,0 +1,10 @@ +// PR tree-optimization/96930 +// { dg-do compile } +// { dg-options "-O2 -fdump-tree-optimized" } +// { dg-final { scan-tree-dump " = a_\[0-9]\\\(D\\\) >> b_\[0-9]\\\(D\\\);" "optimized" } } + +unsigned +foo (unsigned a, unsigned b) +{ + return a / (unsigned long long) (1U << b); +} |