From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 5C6383851C00; Tue, 28 Apr 2020 19:50:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5C6383851C00 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1588103421; bh=f4iF/6UMDh3mypl2VKFQ8ZhGLWRKBO3WxGBXjhP7qQ8=; h=From:To:Subject:Date:From; b=EqH9bHN9npL6Kor4dGPzUi6F11+qMwKmKyCROK4R0133IxGKj7NxSZZuaT9H9DE+1 lCM7PUvK8uazghTGR1zJ5xU5JDUu10Pcvyme3ya4AcZIJnox3b6cIsWYS2WWjPs0sH OWpxQQ1OMLFfr5CQVN9hZjZ6A/Bj5XIk5DR/8UYw= From: "gcc at kheafield dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/94832] New: AVX512 scatter/gather macros lack parentheses when unoptimized Date: Tue, 28 Apr 2020 19:50:21 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 9.3.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: gcc at kheafield dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Apr 2020 19:50:21 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94832 Bug ID: 94832 Summary: AVX512 scatter/gather macros lack parentheses when unoptimized Product: gcc Version: 9.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: gcc at kheafield dot com Target Milestone: --- This code behaves differently and produces a warning about void * arithmetic when compiled without optimization: #include void Fail(int *data) { _mm512_mask_i32scatter_epi32(data - 1, 0xffff, _mm512_set1_epi32(1), _mm512_set1_epi32(1), 1); } Warning and writes are based at (void*)data - 1: g++ -mavx512bw example.cc -c -o example.o In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/include/immintrin.h:55, from example.cc:1: example.cc: In function =E2=80=98void Foo(int*)=E2=80=99: example.cc:4:37: warning: pointer of type =E2=80=98void *=E2=80=99 used in = arithmetic [-Wpointer-arith] 4 | _mm512_mask_i32scatter_epi32(data - 1, 0xffff, _mm512_set1_epi32(= 1), _mm512_set1_epi32(1), 1); | ^ No warning and writes are based at (void*)(data - 1), the expected behavior: g++ -mavx512bw example.cc -O3 -c -o example.o # No output. If we look at avx512fintrin.h, it becomes clear why: #ifdef __OPTIMIZE__ /* ... */ extern __inline void __attribute__ ((__gnu_inline__, __always_inline__, __artificial__)) _mm512_mask_i32scatter_epi32 (void *__addr, __mmask16 __mask, __m512i __index, __m512i __v1, int __scale) { __builtin_ia32_scattersiv16si (__addr, __mask, (__v16si) __index, (__v16si) __v1, __scale); } /* ... */ #else /* ... */ #define _mm512_mask_i32scatter_epi32(ADDR, MASK, INDEX, V1, SCALE) \ __builtin_ia32_scattersiv16si ((void *)ADDR, (__mmask16)MASK, \ (__v16si)(__m512i)INDEX, \ (__v16si)(__m512i)V1, (int)SCALE) /* ... */ #endif When compiled without optimization, the header uses a macro. And data - 1 = is mapping to (void*)data - 1, producing a warning about type =E2=80=98void *= =E2=80=99 used in arithmetic as well as a different address calculation.=20=20 Tested on two gcc versions.=20=20 Using built-in specs. COLLECT_GCC=3Dgcc COLLECT_LTO_WRAPPER=3D/usr/libexec/gcc/x86_64-pc-linux-gnu/9.3.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-9.3.0/work/gcc-9.3.0/config= ure --host=3Dx86_64-pc-linux-gnu --build=3Dx86_64-pc-linux-gnu --prefix=3D/usr --bindir=3D/usr/x86_64-pc-linux-gnu/gcc-bin/9.3.0 --includedir=3D/usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/include --datadir=3D/usr/share/gcc-data/x86_64-pc-linux-gnu/9.3.0 --mandir=3D/usr/share/gcc-data/x86_64-pc-linux-gnu/9.3.0/man --infodir=3D/usr/share/gcc-data/x86_64-pc-linux-gnu/9.3.0/info --with-gxx-include-dir=3D/usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/include/g++= -v9 --with-python-dir=3D/share/gcc-data/x86_64-pc-linux-gnu/9.3.0/python --enable-languages=3Dc,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=3Drelease --with-bugurl=3Dhttps://bugs.gentoo.org/ --with-pkgversion=3D'Gentoo 9.3.0 p2' --disable-esp --enable-libstdcxx-time --enable-shared --enable-threads=3Dposix --enable-__cxa_atexit --enable-clocale=3Dgnu --enable-multilib --with-multilib-list=3Dm32,m64 --disable-altivec --disable-fixed-point --enable-targets=3Dall --enable-lib= gomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --enable-vtable-verify --enable-lto --without-isl --enable-default-pie --enable-default-ssp Thread model: posix gcc version 9.3.0 (Gentoo 9.3.0 p2)=20 Using built-in specs. COLLECT_GCC=3Dg++ COLLECT_LTO_WRAPPER=3D/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper OFFLOAD_TARGET_NAMES=3Dnvptx-none OFFLOAD_TARGET_DEFAULT=3D1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion=3D'Ubuntu 8.4.0-1ubuntu1~18.04' --with-bugurl=3Dfile:///usr/share/doc/gcc-8/README.Bu= gs --enable-languages=3Dc,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=3D/u= sr --with-gcc-major-version-only --program-suffix=3D-8 --program-prefix=3Dx86_64-linux-gnu- --enable-shared --enable-linker-build-= id --libexecdir=3D/usr/lib --without-included-gettext --enable-threads=3Dposix --libdir=3D/usr/lib --enable-nls --enable-clocale=3Dgnu --enable-libstdcxx-= debug --enable-libstdcxx-time=3Dyes --with-default-libstdcxx-abi=3Dnew --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib=3Dauto --enable-objc-gc=3Dauto --enable-multiarch --disable-werror --with-arch-32=3Di686 --with-abi=3Dm64 --with-multilib-list=3Dm32,m64,mx32 --enable-multilib --with-tune=3Dgeneric --enable-offload-targets=3Dnvptx-none --without-cuda-driver --enable-checking=3Drelease --build=3Dx86_64-linux-gnu --host=3Dx86_64-linu= x-gnu --target=3Dx86_64-linux-gnu Thread model: posix gcc version 8.4.0 (Ubuntu 8.4.0-1ubuntu1~18.04)=