From a575c519169184bef374009c8ed6e805ebac609a Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <oliva@adacore.com>
Date: Tue, 28 Apr 2026 22:31:27 -0300
Subject: [PATCH] libstdc++: simd: map 64-bit long double to double on sse
 [PR124657]

When long double is as wide as double on x86 (-mlong-double-64), make
the __intrinsic_type a vector of double.


for  libstdc++-v3/ChangeLog

	PR libstdc++/124657
	* include/experimental/bits/simd.h (__intrinsic_type::type):
	Map long double to double.
---
 libstdc++-v3/include/experimental/bits/simd.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/include/experimental/bits/simd.h
index b96818af6e6..8c30c8af268 100644
--- a/libstdc++-v3/include/experimental/bits/simd.h
+++ b/libstdc++-v3/include/experimental/bits/simd.h
@@ -2477,7 +2477,8 @@ template <typename _Tp, size_t _Bytes>
     static constexpr size_t _S_VBytes = _Bytes <= 16 ? 16 : _Bytes <= 32 ? 32 : 64;
 
     using type [[__gnu__::__vector_size__(_S_VBytes)]]
-      = conditional_t<is_integral_v<_Tp>, long long int, _Tp>;
+      = conditional_t<is_integral_v<_Tp>, long long int,
+		      conditional_t<is_same_v<_Tp, long double>, double, _Tp> >;
   };
 #endif // _GLIBCXX_SIMD_HAVE_SSE