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 <ja...@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
