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From: Jakub Jelinek <jakub@redhat.com>
To: Uros Bizjak <ubizjak@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: [PATCH] x86: Avoid -Wuninitialized warnings on _mm*_undefined_* in C++ [PR105593]
Date: Fri, 13 Jan 2023 01:36:05 +0100	[thread overview]
Message-ID: <Y8CndZxq5djLlAB/@tucnak> (raw)

Hi!

In https://gcc.gnu.org/pipermail/gcc-patches/2023-January/609844.html
I've posted a patch to allow ignoring -Winit-self using GCC diagnostic
pragmas, such that one can mark self-initialization as intentional
disabling of -Wuninitialized warnings.

The following incremental patch uses that in the x86 intrinsic
headers.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk
if the above mentioned patch is approved/committed?

2023-01-13  Jakub Jelinek  <jakub@redhat.com>

	PR c++/105593
gcc/
	* config/i386/xmmintrin.h (_mm_undefined_ps): Temporarily
	disable -Winit-self using pragma GCC diagnostic ignored.
	* config/i386/emmintrin.h (_mm_undefined_pd, _mm_undefined_si128):
	Likewise.
	* config/i386/avxintrin.h (_mm256_undefined_pd, _mm256_undefined_ps,
	_mm256_undefined_si256): Likewise.
	* config/i386/avx512fintrin.h (_mm512_undefined_pd,
	_mm512_undefined_ps, _mm512_undefined_epi32): Likewise.
	* config/i386/avx512fp16intrin.h (_mm_undefined_ph,
	_mm256_undefined_ph, _mm512_undefined_ph): Likewise.
gcc/testsuite/
	* g++.target/i386/pr105593.C: New test.

--- gcc/config/i386/xmmintrin.h.jj	2022-11-07 10:30:42.741629972 +0100
+++ gcc/config/i386/xmmintrin.h	2023-01-12 15:33:21.685483809 +0100
@@ -112,7 +112,10 @@ typedef float __v4sf __attribute__ ((__v
 extern __inline __m128 __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm_undefined_ps (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m128 __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
--- gcc/config/i386/emmintrin.h.jj	2022-03-14 14:48:04.299055735 +0100
+++ gcc/config/i386/emmintrin.h	2023-01-12 15:33:04.148735997 +0100
@@ -99,7 +99,10 @@ _mm_setr_pd (double __W, double __X)
 extern __inline __m128d __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm_undefined_pd (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m128d __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
@@ -785,7 +788,10 @@ _mm_move_epi64 (__m128i __A)
 extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm_undefined_si128 (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m128i __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
--- gcc/config/i386/avxintrin.h.jj	2022-01-11 23:11:21.763298965 +0100
+++ gcc/config/i386/avxintrin.h	2023-01-12 15:34:15.395711408 +0100
@@ -1207,21 +1207,30 @@ _mm256_movemask_ps (__m256 __A)
 extern __inline __m256d __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm256_undefined_pd (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m256d __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
 extern __inline __m256 __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm256_undefined_ps (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m256 __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
 extern __inline __m256i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm256_undefined_si256 (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m256i __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
--- gcc/config/i386/avx512fintrin.h.jj	2022-04-25 13:54:38.277309716 +0200
+++ gcc/config/i386/avx512fintrin.h	2023-01-12 15:35:09.868928035 +0100
@@ -185,7 +185,10 @@ extern __inline __m512
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm512_undefined_ps (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m512 __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
@@ -195,7 +198,10 @@ extern __inline __m512d
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm512_undefined_pd (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m512d __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
@@ -203,7 +209,10 @@ extern __inline __m512i
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm512_undefined_epi32 (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m512i __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
--- gcc/config/i386/avx512fp16intrin.h.jj	2022-11-21 10:28:24.284544313 +0100
+++ gcc/config/i386/avx512fp16intrin.h	2023-01-12 15:35:41.070479329 +0100
@@ -204,7 +204,10 @@ extern __inline __m128h
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm_undefined_ph (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m128h __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
@@ -212,7 +215,10 @@ extern __inline __m256h
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm256_undefined_ph (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m256h __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
@@ -220,7 +226,10 @@ extern __inline __m512h
 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
 _mm512_undefined_ph (void)
 {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-self"
   __m512h __Y = __Y;
+#pragma GCC diagnostic pop
   return __Y;
 }
 
--- gcc/testsuite/g++.target/i386/pr105593.C.jj	2023-01-12 15:58:59.668363504 +0100
+++ gcc/testsuite/g++.target/i386/pr105593.C	2023-01-12 16:01:17.785377769 +0100
@@ -0,0 +1,20 @@
+// PR c++/105593
+// { dg-do compile { target c++14 } }
+// { dg-options "-mavx512fp16 -W -Wall -O2" }
+
+#include <x86intrin.h>
+
+auto f1 () { return _mm_undefined_pd (); }
+auto f2 () { return _mm_undefined_ps (); }
+auto f3 () { return _mm_undefined_si128 (); }
+auto f4 () { return _mm_undefined_ph (); }
+auto f5 () { return _mm256_undefined_pd (); }
+auto f6 () { return _mm256_undefined_ps (); }
+auto f7 () { return _mm256_undefined_si256 (); }
+auto f8 () { return _mm256_undefined_ph (); }
+auto f9 () { return _mm512_undefined_pd (); }
+auto f10 () { return _mm512_undefined_ps (); }
+auto f11 () { return _mm512_undefined_epi32 (); }
+auto f12 () { return _mm512_undefined_ph (); }
+
+// { dg-bogus "is used uninitialized" "" { target *-*-* } 0 }

	Jakub


             reply	other threads:[~2023-01-13  0:36 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-13  0:36 Jakub Jelinek [this message]
2023-01-13  6:58 ` Uros Bizjak

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