[gcc r12-9305] libstdc++: Skip integer division optimization for Clang

[Matthias Kretz <mkretz@gcc.gnu.org>]

https://gcc.gnu.org/g:8d91c9dd93861c8ede2e150c60a64c591efa6e25

commit r12-9305-g8d91c9dd93861c8ede2e150c60a64c591efa6e25
Author: Matthias Kretz <m.kretz@gsi.de>
Date:   Tue Mar 21 14:20:52 2023 +0100

    libstdc++: Skip integer division optimization for Clang
    
    Clang ICEs on _SimdImplX86::_S_divides. The function is only working
    around a missed optimization and not necessary for correctness.
    Therefore, don't use it for Clang.
    
    Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
    
    libstdc++-v3/ChangeLog:
    
            * include/experimental/bits/simd_detail.h: Don't define
            _GLIBCXX_SIMD_WORKAROUND_PR90993 for Clang.
            * include/experimental/bits/simd_x86.h (_S_divides): Remove
            check for __clang__.
    
    (cherry picked from commit 403e48ef441b0502af46ad3598f699f4a1611791)

Diff:
---
 libstdc++-v3/include/experimental/bits/simd_detail.h | 2 ++
 libstdc++-v3/include/experimental/bits/simd_x86.h    | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/experimental/bits/simd_detail.h b/libstdc++-v3/include/experimental/bits/simd_detail.h
index 9135d3e75d3..de8d018c515 100644
--- a/libstdc++-v3/include/experimental/bits/simd_detail.h
+++ b/libstdc++-v3/include/experimental/bits/simd_detail.h
@@ -316,7 +316,9 @@
 #endif
 
 // integer division not optimized
+#ifndef __clang__
 #define _GLIBCXX_SIMD_WORKAROUND_PR90993 1
+#endif
 
 // very bad codegen for extraction and concatenation of 128/256 "subregisters"
 // with sizeof(element type) < 8: https://godbolt.org/g/mqUsgM
diff --git a/libstdc++-v3/include/experimental/bits/simd_x86.h b/libstdc++-v3/include/experimental/bits/simd_x86.h
index b9af1ce538c..53e886c5136 100644
--- a/libstdc++-v3/include/experimental/bits/simd_x86.h
+++ b/libstdc++-v3/include/experimental/bits/simd_x86.h
@@ -1422,7 +1422,7 @@ template <typename _Abi, typename>
 		},
 		[&__xf,
 		 &__yf](auto __i) -> _SimdWrapper<_Float, __n_intermediate> {
-#if !defined __clang__ && __GCC_IEC_559 == 0
+#if __GCC_IEC_559 == 0
 		  // If -freciprocal-math is active, using the `/` operator is
 		  // incorrect because it may be translated to an imprecise
 		  // multiplication with reciprocal. We need to use inline
@@ -1477,7 +1477,7 @@ template <typename _Abi, typename>
 	  */
 	return _Base::_S_divides(__x, __y);
       }
-  #endif // _GLIBCXX_SIMD_WORKAROUND_PR90993
+#endif // _GLIBCXX_SIMD_WORKAROUND_PR90993
 
     // }}}
     // _S_modulus {{{