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From: Alexandre Oliva <>
Cc: David Edelsohn <>,
	Segher Boessenkool <>
Subject: [PATCH] libstdc++: ppc: conditionalize vsx-only simd intrinsics
Date: Thu, 28 Apr 2022 03:09:54 -0300	[thread overview]
Message-ID: <> (raw)

libstdc++'s bits/simd.h section for PPC (Altivec) defines various
intrinsic vector types that are only available along with VSX: 64-bit
long double, double, (un)signed long long, and 64-bit (un)signed long.

experimental/simd/standard_abi_usable{,_2}.cc tests error out reporting
the unmet requirements when the target cpu doesn't enable VSX.  Make the
reported instrinsic types conditional on VSX so that <experimental/simd>
can be used on ppc variants that do not have VSX support.

Regstrapped on powerpc64el-linux-gnu.  Ok to install?

This is also relevant for gcc-11.  Tested with
x86_64-linux-gnu-x-ppc64-vx7r2.  Ok for gcc-11?

for  libstdc++-v3/ChangeLog

	* include/experimental/bits/simd.h [__ALTIVEC__]: Require VSX
	for double, long long, and 64-bit long and 64-bit long double
	intrinsic types.
 libstdc++-v3/include/experimental/bits/simd.h |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/include/experimental/bits/simd.h
index 82e9841195e1d..66c07127ec435 100644
--- a/libstdc++-v3/include/experimental/bits/simd.h
+++ b/libstdc++-v3/include/experimental/bits/simd.h
@@ -2430,17 +2430,23 @@ template <typename _Tp>
   template <>                                                                  \
     struct __intrinsic_type_impl<_Tp> { using type = __vector _Tp; }
+# ifdef __VSX__
+# endif
 _GLIBCXX_SIMD_PPC_INTRIN(unsigned char);
 _GLIBCXX_SIMD_PPC_INTRIN(signed short);
 _GLIBCXX_SIMD_PPC_INTRIN(unsigned short);
 _GLIBCXX_SIMD_PPC_INTRIN(unsigned int);
+# if defined __VSX__ || __LONG_WIDTH__ == 32
 _GLIBCXX_SIMD_PPC_INTRIN(unsigned long);
+# endif
+# ifdef __VSX__
 _GLIBCXX_SIMD_PPC_INTRIN(signed long long);
 _GLIBCXX_SIMD_PPC_INTRIN(unsigned long long);
+# endif
 template <typename _Tp, size_t _Bytes>
@@ -2452,8 +2458,9 @@ template <typename _Tp, size_t _Bytes>
     static_assert(!(_S_is_ldouble && sizeof(long double) > sizeof(double)),
 		  "no __intrinsic_type support for long double on PPC");
 #ifndef __VSX__
-    static_assert(!is_same_v<_Tp, double>,
-		  "no __intrinsic_type support for double on PPC w/o VSX");
+    static_assert(!(is_same_v<_Tp, double>
+		    || (_S_is_ldouble && sizeof(long double) == sizeof(double))),
+		  "no __intrinsic_type support for [long] double on PPC w/o VSX");
     using type =
       typename __intrinsic_type_impl<

Alexandre Oliva, happy hacker      
   Free Software Activist                       GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts.  Ask me about <>

             reply	other threads:[~2022-04-28  6:10 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-28  6:09 Alexandre Oliva [this message]
2022-04-28 13:03 ` Segher Boessenkool
2022-04-29  1:53   ` Alexandre Oliva
2022-04-29 18:44     ` Matthias Kretz
2022-05-02 21:36     ` Segher Boessenkool
2022-05-03  2:00       ` [PATCH v2] " Alexandre Oliva
2022-05-06 16:14         ` Segher Boessenkool
2022-05-06 17:05           ` Jonathan Wakely
2022-05-06 18:24             ` [PATCH v3] " Alexandre Oliva
2022-04-28 13:56 ` [PATCH] " Matthias Kretz
2022-04-28 16:06   ` Segher Boessenkool

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