[gcc r11-11431] libstdc++: Avoid ill-formed types on ARM

[Matthias Kretz]

https://gcc.gnu.org/g:fb2f4a191cc74b6ab2899798db8a59a9b2a3f23f

commit r11-11431-gfb2f4a191cc74b6ab2899798db8a59a9b2a3f23f
Author: Matthias Kretz <m.kretz@gsi.de>
Date:   Wed Apr 17 09:11:25 2024 +0200

    libstdc++: Avoid ill-formed types on ARM
    
    This resolves failing tests in check-simd.
    
    Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/114750
            * include/experimental/bits/simd_builtin.h
            (_SimdImplBuiltin::_S_load, _S_store): Fall back to copying
            scalars if the memory type cannot be vectorized for the target.
    
    (cherry picked from commit 0fc7f3c6adc8543f55ec35b309016d9d9c4ddd35)

Diff:
---
 libstdc++-v3/include/experimental/bits/simd_builtin.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/experimental/bits/simd_builtin.h b/libstdc++-v3/include/experimental/bits/simd_builtin.h
index 9c8094d70167..9703012a6d95 100644
--- a/libstdc++-v3/include/experimental/bits/simd_builtin.h
+++ b/libstdc++-v3/include/experimental/bits/simd_builtin.h
@@ -1460,7 +1460,7 @@ template <typename _Abi>
 		   [&](auto __i) constexpr {
 		     return static_cast<_Tp>(__i < _Np ? __mem[__i] : 0);
 		   });
-	else if constexpr (sizeof(_Up) > 8)
+	else if constexpr (sizeof(_Up) > 8 or __vectorized_sizeof<_Up>() <= sizeof(_Up))
 	  return __generate_vector<_Tp, _SimdMember<_Tp>::_S_full_size>(
 		   [&](auto __i) constexpr _GLIBCXX_SIMD_ALWAYS_INLINE_LAMBDA {
 		     return static_cast<_Tp>(__i < _Np ? __mem[__i] : 0);
@@ -1532,7 +1532,7 @@ template <typename _Abi>
 	    for (size_t __i = 0; __i < _Np; ++__i)
 	      __mem[__i] = __v[__i];
 	  }
-	else if constexpr (sizeof(_Up) > 8)
+	else if constexpr (sizeof(_Up) > 8 or __vectorized_sizeof<_Up>() <= sizeof(_Up))
 	  __execute_n_times<_Np>([&](auto __i) constexpr _GLIBCXX_SIMD_ALWAYS_INLINE_LAMBDA {
 	    __mem[__i] = __v[__i];
 	  });