Re: [PATCH] libstdc++: Skip integer division optimization for Clang

2023-03-21 Thread Jonathan Wakely via Gcc-patches
On Tue, 21 Mar 2023 at 17:06, Matthias Kretz via Libstdc++ <
libstd...@gcc.gnu.org> wrote:

> Tested on x86_64-pc-linux-gnu.
>
> - 8< ---
>
> 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 
>
> 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__.


OK


[PATCH] libstdc++: Skip integer division optimization for Clang

2023-03-21 Thread Matthias Kretz via Gcc-patches
Tested on x86_64-pc-linux-gnu.

- 8< ---

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 

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__.
---
 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(-)


--
──
 Dr. Matthias Kretz   https://mattkretz.github.io
 GSI Helmholtz Centre for Heavy Ion Research   https://gsi.de
 stdₓ::simd
──diff --git a/libstdc++-v3/include/experimental/bits/simd_detail.h b/libstdc++-v3/include/experimental/bits/simd_detail.h
index 49b94decf0a..1fb77866bb2 100644
--- a/libstdc++-v3/include/experimental/bits/simd_detail.h
+++ b/libstdc++-v3/include/experimental/bits/simd_detail.h
@@ -320,7 +320,9 @@ namespace experimental
 #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 7b8f1c664b3..28ba344c2b2 100644
--- a/libstdc++-v3/include/experimental/bits/simd_x86.h
+++ b/libstdc++-v3/include/experimental/bits/simd_x86.h
@@ -1469,7 +1469,7 @@ _CsrGuard()
 		[&__xf, &__yf](auto __i) _GLIBCXX_SIMD_ALWAYS_INLINE_LAMBDA
 		  -> _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
@@ -1524,7 +1524,7 @@ _CsrGuard()
 	  */
 	return _Base::_S_divides(__x, __y);
   }
-  #endif // _GLIBCXX_SIMD_WORKAROUND_PR90993
+#endif // _GLIBCXX_SIMD_WORKAROUND_PR90993
 
 // }}}
 // _S_modulus {{{