Hi!
The following testcase is optimized with char/unsigned char/signed char,
but not with std::byte. The following patch fixes that. Didn't use
INTEGRAL_TYPE_P because bswapping bools is just too weird.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for GCC11 (or is
it simple enough that we want it in GCC10 already)?
2020-03-31 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/94403
* gimple-ssa-store-merging.c (verify_symbolic_number_p): Allow also
ENUMERAL_TYPE lhs_type.
* g++.dg/tree-ssa/pr94403.C: New test.
--- gcc/gimple-ssa-store-merging.c.jj 2020-03-20 09:33:03.602112329 +0100
+++ gcc/gimple-ssa-store-merging.c 2020-03-30 18:30:31.723341519 +0200
@@ -315,7 +315,8 @@ verify_symbolic_number_p (struct symboli
lhs_type = gimple_expr_type (stmt);
- if (TREE_CODE (lhs_type) != INTEGER_TYPE)
+ if (TREE_CODE (lhs_type) != INTEGER_TYPE
+ && TREE_CODE (lhs_type) != ENUMERAL_TYPE)
return false;
if (TYPE_PRECISION (lhs_type) != TYPE_PRECISION (n->type))
--- gcc/testsuite/g++.dg/tree-ssa/pr94403.C.jj 2020-03-30 18:42:28.563719010
+0200
+++ gcc/testsuite/g++.dg/tree-ssa/pr94403.C 2020-03-30 18:51:21.135828389
+0200
@@ -0,0 +1,37 @@
+// PR tree-optimization/94403
+// Only test on some 64-bit targets which do have bswap{si,di}2 patterns and
+// are either big or little endian (not pdp endian).
+// { dg-do compile { target { lp64 && { i?86-*-* x86_64-*-* powerpc*-*-*
aarch64*-*-* } } } }
+// { dg-require-effective-target store_merge }
+// { dg-options "-O2 -fdump-tree-store-merging -std=c++17" }
+
+namespace std {
+ template <typename T>
+ void swap (T& t1, T& t2) { T tmp (t1); t1 = t2; t2 = tmp; }
+ enum class byte : unsigned char {};
+}
+
+unsigned
+bswap32 (unsigned int x)
+{
+ unsigned int y = x;
+ std::byte *bytes = reinterpret_cast<std::byte*> (&y);
+ std::swap (bytes[0], bytes[3]);
+ std::swap (bytes[1], bytes[2]);
+ return y;
+}
+
+unsigned long long
+bswap64 (unsigned long long x)
+{
+ unsigned long long y = x;
+ std::byte *bytes = reinterpret_cast<std::byte*> (&y);
+ std::swap (bytes[0], bytes[7]);
+ std::swap (bytes[1], bytes[6]);
+ std::swap (bytes[2], bytes[5]);
+ std::swap (bytes[3], bytes[4]);
+ return y;
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_bswap64" 1 "store-merging" } }
*/
+/* { dg-final { scan-tree-dump-times "__builtin_bswap32" 1 "store-merging" } }
*/
Jakub
