libstdc++: Fix test on x86_64 and non-simd targets

* Running a test compiled with AVX512 instructions requires
avx512f_runtime not just avx512f.

* The 'reduce2' test violated an invariant of fixed_size_simd_mask and
thus failed on all targets without 16-Byte vector builtins enabled (in
bits/simd.h).

Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:

	PR libstdc++/115575
	* testsuite/experimental/simd/pr115454_find_last_set.cc: Require
	avx512f_runtime. Don't memcpy fixed_size masks.

(cherry picked from commit 77f321435b4ac37992c2ed6737ca0caa1dd50551)

diff --git a/libstdc++-v3/testsuite/experimental/simd/pr115454_find_last_set.cc b/libstdc++-v3/testsuite/experimental/simd/pr115454_find_last_set.cc
index b47f19d30674fa8a69997ef650e4cfdb9a7b336f..25a713b4e948cb31cfbae865b08871e9ac94f342 100644 (file)
--- a/libstdc++-v3/testsuite/experimental/simd/pr115454_find_last_set.cc
+++ b/libstdc++-v3/testsuite/experimental/simd/pr115454_find_last_set.cc
@@ -1,7 +1,7 @@
 // { dg-options "-std=gnu++17" }
 // { dg-do run { target *-*-* } }
 // { dg-require-effective-target c++17 }
-// { dg-additional-options "-march=x86-64-v4" { target avx512f } }
+// { dg-additional-options "-march=x86-64-v4" { target avx512f_runtime } }
 // { dg-require-cmath "" }
 
 #include <experimental/simd>
@@ -25,7 +25,9 @@ int reduce2()
 {
   using M8 = typename V<short, 8>::mask_type;
   using M4 = typename V<int, 4>::mask_type;
-  if constexpr (sizeof(M8) == sizeof(M4))
+  if constexpr (sizeof(M8) == sizeof(M4)
+                 && !std::is_same_v<M4, stdx::fixed_size_simd_mask<int, 4>>)
+    // fixed_size invariant: padding bits of masks are zero, the memcpy would violate that
     {
       M4 k;
       __builtin_memcpy(&__data(k), &__data(M8(true)), sizeof(M4));