For sources which can't use any vector instructions, <x86intrin.h> and
<immintrin.h> cannot be included for compiler intrinsics:
$ echo "#include <x86intrin.h>" | gcc -S -O2 -mno-sse -mno-mmx -x c -
In file included from /usr/include/stdlib.h:1013,
from /usr/lib/gcc/x86_64-redhat-linux/10/include/mm_malloc.h:27,
from /usr/lib/gcc/x86_64-redhat-linux/10/include/xmmintrin.h:34,
from /usr/lib/gcc/x86_64-redhat-linux/10/include/immintrin.h:29,
from /usr/lib/gcc/x86_64-redhat-linux/10/include/x86intrin.h:32,
from <stdin>:1:
/usr/include/bits/stdlib-float.h: In function ‘atof’:
/usr/include/bits/stdlib-float.h:26:1: error: SSE register return with SSE disabled
26 | {
| ^
$
libgcc/config/i386/shadow-stack-unwind.h has a workaround:
/* NB: We need _get_ssp and _inc_ssp from <cetintrin.h>. But we can't
include <x86intrin.h> which ends up including <mm_malloc.h>, which
includes <stdlib.h> and <errno.h> unconditionally. But we can't
include any libc system headers unconditionally from libgcc. Avoid
including <mm_malloc.h> here by defining _IMMINTRIN_H_INCLUDED. */
#define _IMMINTRIN_H_INCLUDED
#include <cetintrin.h>
#undef _IMMINTRIN_H_INCLUDED
Add a standalone intrinsic header file, <x86gprintrin.h>, to provide
integer only intrinsics. All integer only intrinsics are placed in
<x86gprintrin.h>. <x86intrin.h> and <immintrin.h> simply include
<x86gprintrin.h>.
* gcc.target/i386/avx-1.c (__builtin_ia32_lwpval32): New to
support <lwpintrin.h> included in <x86gprintrin.h>.
(__builtin_ia32_lwpval64): Likewise.
(__builtin_ia32_lwpins32): Likewise.
(__builtin_ia32_lwpins64): Likewise.
(__builtin_ia32_bextri_u32): New to support <tbmintrin.h>
included in <x86gprintrin.h>.
(__builtin_ia32_bextri_u64): Likewise.
* gcc.target/i386/x86gprintrin-1.c: New test.
* gcc.target/i386/x86gprintrin-2.c: Likewise.
* gcc.target/i386/x86gprintrin-3.c: Likewise.
* gcc.target/i386/x86gprintrin-4.c: Likewise.
* gcc.target/i386/x86gprintrin-4a.c: Likewise.
* gcc.target/i386/x86gprintrin-5.c: Likewise.
* gcc.target/i386/x86gprintrin-5a.c: Likewise.
* gcc.target/i386/x86gprintrin-5b.c: Likewise.
* gcc.target/i386/x86gprintrin-6.c: Likewise.
libgcc/
PR target/97148
* config/i386/shadow-stack-unwind.h: Include <x86gprintrin.h>
instead of <cetintrin.h>.