From: Noah Goldstein <goldstein.w.n@gmail.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: GNU C Library <libc-alpha@sourceware.org>,
"Carlos O'Donell" <carlos@systemhalted.org>
Subject: Re: [PATCH v1] x86: Add support for building {w}memcmp{eq} with explicit ISA level
Date: Wed, 29 Jun 2022 12:27:14 -0700 [thread overview]
Message-ID: <CAFUsyf+vedVfpX9ik2jh5xHRz-6XWQ+gwgA6SuvbfvUrjs-xpg@mail.gmail.com> (raw)
In-Reply-To: <CAMe9rOrWoQGOk=g9pm=kk1iPitO_nzFHk-0ukwVZzRfmsvBzBA@mail.gmail.com>
On Wed, Jun 29, 2022 at 11:52 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Jun 28, 2022 at 8:26 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > 1. Refactor files so that all implementations are in the multiarch
> > directory
> > - Moved the implementation portion of memcmp sse2 from memcmp.S to
> > multiarch/memcmp-sse2.S
> >
> > - The non-multiarch file now only includes one of the
> > implementations in the multiarch directory based on the compiled
> > ISA level (only used for non-multiarch builds. Otherwise we go
> > through the ifunc selector).
> >
> > 2. Add ISA level build guards to different implementations.
> > - I.e memcmp-avx2-movsb.S which is ISA level 3 will only build if
> > compiled ISA level <= 3. Otherwise there is no reason to include
> > it as we will always use one of the ISA level 4
> > implementations (memcmp-evex-movbe.S).
> >
> > 3. Add new multiarch/rtld-{w}memcmp{eq}.S that just include the
> > non-multiarch {w}memcmp{eq}.S which will in turn select the best
> > implementation based on the compiled ISA level.
> >
> > 4. Refactor the ifunc selector and ifunc implementation list to use
> > the ISA level aware wrapper macros that allow functions below the
> > compiled ISA level (with a guranteed replacement) to be skipped.
> >
> > Tested with and without multiarch on x86_64 for ISA levels:
> > {generic, x86-64-v2, x86-64-v3, x86-64-v4}
> >
> > And m32 with and without multiarch.
> > ---
> > sysdeps/x86/cpu-tunables.c | 4 +-
> > sysdeps/x86_64/memcmp-isa-default-impl.h | 28 +
> > sysdeps/x86_64/memcmp.S | 566 +-----------------
> > sysdeps/x86_64/memcmpeq.S | 14 +-
> > sysdeps/x86_64/multiarch/ifunc-impl-list.c | 64 +-
> > sysdeps/x86_64/multiarch/ifunc-memcmp.h | 24 +-
> > sysdeps/x86_64/multiarch/ifunc-memcmpeq.h | 22 +-
> > sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S | 5 +-
> > sysdeps/x86_64/multiarch/memcmp-evex-movbe.S | 5 +-
> > sysdeps/x86_64/multiarch/memcmp-sse2.S | 565 ++++++++++++++++-
> > sysdeps/x86_64/multiarch/memcmpeq-avx2.S | 4 +-
> > sysdeps/x86_64/multiarch/memcmpeq-evex.S | 4 +-
> > sysdeps/x86_64/multiarch/memcmpeq-sse2.S | 8 +-
> > sysdeps/x86_64/multiarch/rtld-memcmp.S | 18 +
> > sysdeps/x86_64/multiarch/rtld-memcmpeq.S | 18 +
> > sysdeps/x86_64/multiarch/rtld-wmemcmp.S | 18 +
> > sysdeps/x86_64/multiarch/wmemcmp-avx2-movbe.S | 6 +-
> > sysdeps/x86_64/multiarch/wmemcmp-evex-movbe.S | 6 +-
> > sysdeps/x86_64/multiarch/wmemcmp-sse2.S | 9 +-
> > sysdeps/x86_64/wmemcmp.S | 12 +-
> > 20 files changed, 762 insertions(+), 638 deletions(-)
> > create mode 100644 sysdeps/x86_64/memcmp-isa-default-impl.h
> > create mode 100644 sysdeps/x86_64/multiarch/rtld-memcmp.S
> > create mode 100644 sysdeps/x86_64/multiarch/rtld-memcmpeq.S
> > create mode 100644 sysdeps/x86_64/multiarch/rtld-wmemcmp.S
> >
> > diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c
> > index 58f7a7f250..8f7c55845d 100644
> > --- a/sysdeps/x86/cpu-tunables.c
> > +++ b/sysdeps/x86/cpu-tunables.c
> > @@ -25,12 +25,12 @@
> > # include <string.h>
> > # include <cpu-features.h>
> > # include <ldsodefs.h>
> > -
>
> Irrelevant change.
>
Sorry that shouldn't have made it in. Will remove for V2.
> > /* We can't use IFUNC memcmp nor strlen in init_cpu_features from libc.a
> > since IFUNC must be set up by init_cpu_features. */
> > # if defined USE_MULTIARCH && !defined SHARED
> > # ifdef __x86_64__
> > -# define DEFAULT_MEMCMP __memcmp_sse2
> > +/* DEFAULT_MEMCMP by sysdeps/x86_64/memcmp-isa-default-impl.h. */
> > +# include <sysdeps/x86_64/memcmp-isa-default-impl.h>
> > # else
> > # define DEFAULT_MEMCMP __memcmp_ia32
> > # endif
> > diff --git a/sysdeps/x86_64/memcmp-isa-default-impl.h b/sysdeps/x86_64/memcmp-isa-default-impl.h
> > new file mode 100644
> > index 0000000000..28bb1eb1be
> > --- /dev/null
> > +++ b/sysdeps/x86_64/memcmp-isa-default-impl.h
> > @@ -0,0 +1,28 @@
> > +/* Set default memcmp impl based on ISA level.
> > + Copyright (C) 2009-2022 Free Software Foundation, Inc.
> Just 2022.
Will fix for V2.
> > + This file is part of the GNU C Library.
> > +
> > + The GNU C Library is free software; you can redistribute it and/or
> > + modify it under the terms of the GNU Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 of the License, or (at your option) any later version.
> > +
> > + The GNU C Library is distributed in the hope that it will be useful,
> > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include <isa-level.h>
> > +#if MINIMUM_X86_ISA_LEVEL == 1 || MINIMUM_X86_ISA_LEVEL == 2
> > +# define DEFAULT_MEMCMP __memcmp_sse2
> > +#elif MINIMUM_X86_ISA_LEVEL == 3
> > +# define DEFAULT_MEMCMP __memcmp_avx2_movbe
> > +#elif MINIMUM_X86_ISA_LEVEL == 4
> > +# define DEFAULT_MEMCMP __memcmp_evex_movbe
> > +#else
> > +# error "Unknown default memcmp implementation"
> > +#endif
> > diff --git a/sysdeps/x86_64/memcmp.S b/sysdeps/x86_64/memcmp.S
> > index 5718a7da86..2623ed62f7 100644
> > --- a/sysdeps/x86_64/memcmp.S
> > +++ b/sysdeps/x86_64/memcmp.S
> > @@ -1,4 +1,4 @@
> > -/* memcmp with SSE2
> > +/* memcmp hook for non-multiarch and RTLD build.
> > Copyright (C) 2009-2022 Free Software Foundation, Inc.
> > This file is part of the GNU C Library.
> >
> > @@ -16,563 +16,13 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#include <sysdep.h>
> > +#define MEMCMP memcmp
> >
> > -#ifdef USE_AS_WMEMCMP
> > -# define PCMPEQ pcmpeqd
> > -# define CHAR_SIZE 4
> > -# define SIZE_OFFSET (0)
> > -#else
> > -# define PCMPEQ pcmpeqb
> > -# define CHAR_SIZE 1
> > -#endif
> > +#define DEFAULT_IMPL_V1 "multiarch/memcmp-sse2.S"
> > +#define DEFAULT_IMPL_V3 "multiarch/memcmp-avx2-movbe.S"
> > +#define DEFAULT_IMPL_V4 "multiarch/memcmp-evex-movbe.S"
> >
> > -#ifdef USE_AS_MEMCMPEQ
> > -# define SIZE_OFFSET (0)
> > -# define CHECK_CMP(x, y) subl x, y
> > -#else
> > -# ifndef SIZE_OFFSET
> > -# define SIZE_OFFSET (CHAR_PER_VEC * 2)
> > -# endif
> > -# define CHECK_CMP(x, y) cmpl x, y
> > -#endif
> > +#include "isa-default-impl.h"
> >
> > -#define VEC_SIZE 16
> > -#define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
> > -
> > -#ifndef MEMCMP
> > -# define MEMCMP memcmp
> > -#endif
> > -
> > - .text
> > -ENTRY(MEMCMP)
> > -# ifdef __ILP32__
> > - /* Clear the upper 32 bits. */
> > - movl %edx, %edx
> > -# endif
> > -#ifdef USE_AS_WMEMCMP
> > - /* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
> > - in ecx for code size. This is preferable to using `incw` as
> > - it avoids partial register stalls on older hardware (pre
> > - SnB). */
> > - movl $0xffff, %ecx
> > -#endif
> > - cmpq $CHAR_PER_VEC, %rdx
> > - ja L(more_1x_vec)
> > -
> > -#ifdef USE_AS_WMEMCMP
> > - /* saves a byte of code keeping the fall through path n = [2, 4]
> > - in the initial cache line. */
> > - decl %edx
> > - jle L(cmp_0_1)
> > -
> > - movq (%rsi), %xmm0
> > - movq (%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - pmovmskb %xmm1, %eax
> > - subl %ecx, %eax
> > - jnz L(ret_nonzero_vec_start_0)
> > -
> > - movq -4(%rsi, %rdx, CHAR_SIZE), %xmm0
> > - movq -4(%rdi, %rdx, CHAR_SIZE), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - pmovmskb %xmm1, %eax
> > - subl %ecx, %eax
> > - jnz L(ret_nonzero_vec_end_0_adj)
> > -#else
> > - cmpl $8, %edx
> > - ja L(cmp_9_16)
> > -
> > - cmpl $4, %edx
> > - jb L(cmp_0_3)
> > -
> > -# ifdef USE_AS_MEMCMPEQ
> > - movl (%rsi), %eax
> > - subl (%rdi), %eax
> > -
> > - movl -4(%rsi, %rdx), %esi
> > - subl -4(%rdi, %rdx), %esi
> > -
> > - orl %esi, %eax
> > - ret
> > -# else
> > - /* Combine comparisons for lo and hi 4-byte comparisons. */
> > - movl -4(%rsi, %rdx), %ecx
> > - movl -4(%rdi, %rdx), %eax
> > - shlq $32, %rcx
> > - shlq $32, %rax
> > - movl (%rsi), %esi
> > - movl (%rdi), %edi
> > - orq %rsi, %rcx
> > - orq %rdi, %rax
> > - /* Only compute proper return if not-equal. */
> > - cmpq %rcx, %rax
> > - jnz L(ret_nonzero)
> > - xorl %eax, %eax
> > - ret
> > -# endif
> > -
> > - .p2align 4,, 10
> > -L(cmp_9_16):
> > -# ifdef USE_AS_MEMCMPEQ
> > - movq (%rsi), %rax
> > - subq (%rdi), %rax
> > -
> > - movq -8(%rsi, %rdx), %rcx
> > - subq -8(%rdi, %rdx), %rcx
> > - orq %rcx, %rax
> > - /* Convert 64 bit -> 32 bit boolean (we should have made the ABI
> > - return long). */
> > - setnz %cl
> > - movzbl %cl, %eax
> > -# else
> > - movq (%rsi), %rcx
> > - movq (%rdi), %rax
> > - /* Only compute proper return if not-equal. */
> > - cmpq %rcx, %rax
> > - jnz L(ret_nonzero)
> > -
> > - movq -8(%rsi, %rdx, CHAR_SIZE), %rcx
> > - movq -8(%rdi, %rdx, CHAR_SIZE), %rax
> > - /* Only compute proper return if not-equal. */
> > - cmpq %rcx, %rax
> > - jnz L(ret_nonzero)
> > - xorl %eax, %eax
> > -# endif
> > -#endif
> > - ret
> > -
> > - .p2align 4,, 8
> > -L(cmp_0_1):
> > - /* Flag set by earlier comparison against 1. */
> > - jne L(cmp_0_0)
> > -#ifdef USE_AS_WMEMCMP
> > - movl (%rdi), %ecx
> > - xorl %edx, %edx
> > - cmpl (%rsi), %ecx
> > - je L(cmp_0_0)
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -#else
> > - movzbl (%rdi), %eax
> > - movzbl (%rsi), %ecx
> > - subl %ecx, %eax
> > -#endif
> > - ret
> > -
> > - /* Fits in aligning bytes. */
> > -L(cmp_0_0):
> > - xorl %eax, %eax
> > - ret
> > -
> > -#ifdef USE_AS_WMEMCMP
> > - .p2align 4
> > -L(ret_nonzero_vec_start_0):
> > - bsfl %eax, %eax
> > - movl (%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > - ret
> > -#else
> > -
> > -# ifndef USE_AS_MEMCMPEQ
> > - .p2align 4,, 14
> > -L(ret_nonzero):
> > - /* Need to bswap to get proper return without branch. */
> > - bswapq %rcx
> > - bswapq %rax
> > - subq %rcx, %rax
> > - sbbl %eax, %eax
> > - orl $1, %eax
> > - ret
> > -# endif
> > -
> > - .p2align 4
> > -L(cmp_0_3):
> > -# ifdef USE_AS_MEMCMPEQ
> > - /* No reason to add to dependency chain on rdx. Saving a the
> > - bytes here doesn't change number of fetch blocks. */
> > - cmpl $1, %edx
> > - jbe L(cmp_0_1)
> > -# else
> > - /* We need the code size to prevent taking an extra fetch block.
> > - */
> > - decl %edx
> > - jle L(cmp_0_1)
> > -# endif
> > - movzwl (%rsi), %ecx
> > - movzwl (%rdi), %eax
> > -
> > -# ifdef USE_AS_MEMCMPEQ
> > - subl %ecx, %eax
> > -
> > - movzbl -1(%rsi, %rdx), %esi
> > - movzbl -1(%rdi, %rdx), %edi
> > - subl %edi, %esi
> > - orl %esi, %eax
> > -# else
> > - bswapl %ecx
> > - bswapl %eax
> > -
> > - /* Implicit right shift by one. We just need to displace the
> > - sign bits. */
> > - shrl %ecx
> > - shrl %eax
> > -
> > - /* Eat a partial register stall here. Saves code stopping
> > - L(cmp_0_3) from bleeding into the next fetch block and saves
> > - an ALU. */
> > - movb (%rsi, %rdx), %cl
> > - movzbl (%rdi, %rdx), %edi
> > - orl %edi, %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -#endif
> > -
> > - .p2align 5
> > -L(more_1x_vec):
> > -#ifndef USE_AS_WMEMCMP
> > - /* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
> > - in ecx for code size. This is preferable to using `incw` as
> > - it avoids partial register stalls on older hardware (pre
> > - SnB). */
> > - movl $0xffff, %ecx
> > -#endif
> > - movups (%rsi), %xmm0
> > - movups (%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - pmovmskb %xmm1, %eax
> > - subl %ecx, %eax
> > - jnz L(ret_nonzero_vec_start_0)
> > -#if SIZE_OFFSET == 0
> > - cmpq $(CHAR_PER_VEC * 2), %rdx
> > -#else
> > - /* Offset rdx. Saves just enough code size to keep the
> > - L(last_2x_vec) case and the non-zero return in a single
> > - cache line. */
> > - subq $(CHAR_PER_VEC * 2), %rdx
> > -#endif
> > - ja L(more_2x_vec)
> > -
> > - movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
> > - movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - pmovmskb %xmm1, %eax
> > - subl %ecx, %eax
> > -#ifndef USE_AS_MEMCMPEQ
> > - /* Don't use `incw ax` as machines this code runs on are liable
> > - to have partial register stall. */
> > - jnz L(ret_nonzero_vec_end_0)
> > -#else
> > - /* Various return targets for memcmpeq. Will always be hot in
> > - Icache and get short encoding. */
> > -L(ret_nonzero_vec_start_1):
> > -L(ret_nonzero_vec_start_0):
> > -L(ret_nonzero_vec_end_0):
> > -#endif
> > - ret
> > -
> > -#ifndef USE_AS_MEMCMPEQ
> > -# ifdef USE_AS_WMEMCMP
> > - .p2align 4
> > -L(ret_nonzero_vec_end_0_adj):
> > - addl $3, %edx
> > -# else
> > - .p2align 4,, 8
> > -# endif
> > -L(ret_nonzero_vec_end_0):
> > - bsfl %eax, %eax
> > -# ifdef USE_AS_WMEMCMP
> > - leal (%rax, %rdx, CHAR_SIZE), %eax
> > - movl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - addl %edx, %eax
> > - movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -# ifndef USE_AS_WMEMCMP
> > - .p2align 4,, 10
> > -L(ret_nonzero_vec_start_0):
> > - bsfl %eax, %eax
> > - movzbl (%rsi, %rax), %ecx
> > - movzbl (%rdi, %rax), %eax
> > - subl %ecx, %eax
> > - ret
> > -# endif
> > -#else
> > -#endif
> > -
> > - .p2align 5
> > -L(more_2x_vec):
> > - movups (VEC_SIZE * 1)(%rsi), %xmm0
> > - movups (VEC_SIZE * 1)(%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - pmovmskb %xmm1, %eax
> > - subl %ecx, %eax
> > - jnz L(ret_nonzero_vec_start_1)
> > -
> > - cmpq $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %rdx
> > - jbe L(last_2x_vec)
> > -
> > - cmpq $(CHAR_PER_VEC * 8 - SIZE_OFFSET), %rdx
> > - ja L(more_8x_vec)
> > -
> > - /* Do comparisons for [65, 96] and [97, 128] 2x VEC at a time.
> > - This can harm performance if non-zero return in [65, 80] or
> > - [97, 112] but helps performance otherwise. Generally zero-
> > - return is hotter. */
> > - movups (VEC_SIZE * 2)(%rsi), %xmm0
> > - movups (VEC_SIZE * 2)(%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - movups (VEC_SIZE * 3)(%rsi), %xmm2
> > - movups (VEC_SIZE * 3)(%rdi), %xmm3
> > - PCMPEQ %xmm2, %xmm3
> > - pand %xmm1, %xmm3
> > -
> > - pmovmskb %xmm3, %eax
> > - CHECK_CMP (%ecx, %eax)
> > - jnz L(ret_nonzero_vec_start_2_3)
> > -
> > - cmpl $(CHAR_PER_VEC * 6 - SIZE_OFFSET), %edx
> > - jbe L(last_2x_vec)
> > -
> > - movups (VEC_SIZE * 4)(%rsi), %xmm0
> > - movups (VEC_SIZE * 4)(%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - movups (VEC_SIZE * 5)(%rsi), %xmm2
> > - movups (VEC_SIZE * 5)(%rdi), %xmm3
> > - PCMPEQ %xmm2, %xmm3
> > - pand %xmm1, %xmm3
> > -
> > - pmovmskb %xmm3, %eax
> > - CHECK_CMP (%ecx, %eax)
> > -#ifdef USE_AS_MEMCMPEQ
> > - jz L(last_2x_vec)
> > - ret
> > -#else
> > - jnz L(ret_nonzero_vec_start_4_5)
> > -#endif
> > - .p2align 4
> > -L(last_2x_vec):
> > - movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
> > - movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm2
> > - movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm3
> > - PCMPEQ %xmm2, %xmm3
> > - pand %xmm1, %xmm3
> > - pmovmskb %xmm3, %eax
> > - subl %ecx, %eax
> > -#ifdef USE_AS_MEMCMPEQ
> > - /* Various return targets for memcmpeq. Will always be hot in
> > - Icache and get short encoding. */
> > -L(ret_nonzero_vec_start_2_3):
> > -L(ret_nonzero_vec_start_4_5):
> > - ret
> > -#else
> > - jnz L(ret_nonzero_vec_end_1)
> > - ret
> > -
> > - .p2align 4,, 8
> > -L(ret_nonzero_vec_end_1):
> > - pmovmskb %xmm1, %ecx
> > - /* High 16 bits of eax guranteed to be all ones. Rotate them in
> > - to we can do `or + not` with just `xor`. */
> > - rorl $16, %eax
> > - xorl %ecx, %eax
> > - /* Partial register stall. */
> > -
> > - bsfl %eax, %eax
> > -# ifdef USE_AS_WMEMCMP
> > - leal (%rax, %rdx, CHAR_SIZE), %eax
> > - movl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - addl %edx, %eax
> > - movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -
> > - .p2align 4
> > -L(ret_nonzero_vec_start_4_5):
> > - pmovmskb %xmm1, %edx
> > - sall $16, %eax
> > - leal 1(%rax, %rdx), %eax
> > - bsfl %eax, %eax
> > -# ifdef USE_AS_WMEMCMP
> > - movl (VEC_SIZE * 4)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * 4)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - movzbl (VEC_SIZE * 4)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * 4)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -
> > - .p2align 4,, 8
> > -L(ret_nonzero_vec_start_1):
> > - bsfl %eax, %eax
> > -# ifdef USE_AS_WMEMCMP
> > - movl (VEC_SIZE * 1)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * 1)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - movzbl (VEC_SIZE * 1)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * 1)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -#endif
> > -
> > - .p2align 4
> > -L(more_8x_vec):
> > - subq %rdi, %rsi
> > - leaq (VEC_SIZE * -6 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %rdx
> > - andq $(VEC_SIZE * -1), %rdi
> > - addq %rdi, %rsi
> > - .p2align 4
> > -L(loop_4x):
> > - movups (VEC_SIZE * 2)(%rsi), %xmm0
> > - movups (VEC_SIZE * 3)(%rsi), %xmm1
> > -
> > - PCMPEQ (VEC_SIZE * 2)(%rdi), %xmm0
> > - PCMPEQ (VEC_SIZE * 3)(%rdi), %xmm1
> > -
> > - movups (VEC_SIZE * 4)(%rsi), %xmm2
> > - movups (VEC_SIZE * 5)(%rsi), %xmm3
> > -
> > - PCMPEQ (VEC_SIZE * 4)(%rdi), %xmm2
> > - PCMPEQ (VEC_SIZE * 5)(%rdi), %xmm3
> > -
> > - pand %xmm0, %xmm1
> > - pand %xmm2, %xmm3
> > - pand %xmm1, %xmm3
> > -
> > - pmovmskb %xmm3, %eax
> > - subl %ecx, %eax
> > - jnz L(ret_nonzero_loop)
> > -
> > - addq $(VEC_SIZE * 4), %rdi
> > - addq $(VEC_SIZE * 4), %rsi
> > - cmpq %rdi, %rdx
> > - ja L(loop_4x)
> > - /* Get remaining length in edx. */
> > - subl %edi, %edx
> > - /* Restore offset so we can reuse L(last_2x_vec). */
> > - addl $(VEC_SIZE * 6 - SIZE_OFFSET), %edx
> > -#ifdef USE_AS_WMEMCMP
> > - shrl $2, %edx
> > -#endif
> > - cmpl $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %edx
> > - jbe L(last_2x_vec)
> > -
> > -
> > - movups (VEC_SIZE * 2)(%rsi), %xmm0
> > - movups (VEC_SIZE * 2)(%rdi), %xmm1
> > - PCMPEQ %xmm0, %xmm1
> > - movups (VEC_SIZE * 3)(%rsi), %xmm2
> > - movups (VEC_SIZE * 3)(%rdi), %xmm3
> > - PCMPEQ %xmm2, %xmm3
> > - pand %xmm1, %xmm3
> > -
> > - pmovmskb %xmm3, %eax
> > - CHECK_CMP (%ecx, %eax)
> > - jz L(last_2x_vec)
> > -#ifdef USE_AS_MEMCMPEQ
> > -L(ret_nonzero_loop):
> > - ret
> > -#else
> > -
> > - .p2align 4
> > -L(ret_nonzero_vec_start_2_3):
> > - pmovmskb %xmm1, %edx
> > - sall $16, %eax
> > - leal 1(%rax, %rdx), %eax
> > -
> > - bsfl %eax, %eax
> > -# ifdef USE_AS_WMEMCMP
> > - movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -
> > - .p2align 4
> > -L(ret_nonzero_loop):
> > - pmovmskb %xmm0, %ecx
> > - pmovmskb %xmm1, %edx
> > - sall $(VEC_SIZE * 1), %edx
> > - leal 1(%rcx, %rdx), %edx
> > - pmovmskb %xmm2, %ecx
> > - /* High 16 bits of eax guranteed to be all ones. Rotate them in
> > - to we can do `or + not` with just `xor`. */
> > - rorl $16, %eax
> > - xorl %ecx, %eax
> > -
> > - salq $32, %rax
> > - orq %rdx, %rax
> > -
> > - bsfq %rax, %rax
> > -# ifdef USE_AS_WMEMCMP
> > - movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
> > - xorl %edx, %edx
> > - cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > - /* NB: no partial register stall here because xorl zero idiom
> > - above. */
> > - setg %dl
> > - leal -1(%rdx, %rdx), %eax
> > -# else
> > - movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > - movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
> > - subl %ecx, %eax
> > -# endif
> > - ret
> > -#endif
> > -END(MEMCMP)
> > -
> > -#ifndef USE_AS_WMEMCMP
> > -# ifdef USE_AS_MEMCMPEQ
> > -libc_hidden_def (MEMCMP)
> > -# else
> > -# undef bcmp
> > -weak_alias (MEMCMP, bcmp)
> > -libc_hidden_builtin_def (MEMCMP)
> > -# endif
> > -#endif
> > +libc_hidden_builtin_def(memcmp)
> > +weak_alias (memcmp, bcmp)
> > diff --git a/sysdeps/x86_64/memcmpeq.S b/sysdeps/x86_64/memcmpeq.S
> > index 80c5e912a6..d1e47e0539 100644
> > --- a/sysdeps/x86_64/memcmpeq.S
> > +++ b/sysdeps/x86_64/memcmpeq.S
> > @@ -1,4 +1,4 @@
> > -/* __memcmpeq optimized with SSE2.
> > +/* __memcmpeq hook for non-multiarch and RTLD build.
> > Copyright (C) 2017-2022 Free Software Foundation, Inc.
> > This file is part of the GNU C Library.
> >
> > @@ -16,6 +16,12 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#define MEMCMP __memcmpeq
> > -#define USE_AS_MEMCMPEQ 1
> > -#include "multiarch/memcmp-sse2.S"
> > +#define MEMCMPEQ __memcmpeq
> > +
> > +#define DEFAULT_IMPL_V1 "multiarch/memcmpeq-sse2.S"
> > +#define DEFAULT_IMPL_V3 "multiarch/memcmpeq-avx2.S"
> > +#define DEFAULT_IMPL_V4 "multiarch/memcmpeq-evex.S"
> > +
> > +#include "isa-default-impl.h"
> > +
> > +libc_hidden_def(__memcmpeq)
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > index a1bff560bc..772b4ace6c 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > @@ -36,21 +36,24 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/memcmpeq.c. */
> > IFUNC_IMPL (i, name, __memcmpeq,
> > - IFUNC_IMPL_ADD (array, i, __memcmpeq,
> > + X86_IFUNC_IMPL_ADD_V4 (array, i, __memcmpeq,
> > + (CPU_FEATURE_USABLE (AVX512VL)
> > + && CPU_FEATURE_USABLE (AVX512BW)
> > + && CPU_FEATURE_USABLE (BMI2)),
> > + __memcmpeq_evex)
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, __memcmpeq,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)),
> > __memcmpeq_avx2)
> > - IFUNC_IMPL_ADD (array, i, __memcmpeq,
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, __memcmpeq,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)
> > && CPU_FEATURE_USABLE (RTM)),
> > __memcmpeq_avx2_rtm)
> > - IFUNC_IMPL_ADD (array, i, __memcmpeq,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)),
> > - __memcmpeq_evex)
> > - IFUNC_IMPL_ADD (array, i, __memcmpeq, 1, __memcmpeq_sse2))
> > + /* Can be lowered to V1 if a V2 implementation is added. */
>
> I don't think we need an SSE4 optimized memcmpeq.
The comment isn't really saying we should add an sse4 implementation. Just
if we do for whatever reason that the V2 guard on the sse2 can be moved down
to V1.
Don't want people to read this and think the reason sse2 is guarded by V2
is because it has some V2 dependency.
>
> > + X86_IFUNC_IMPL_ADD_V2 (array, i, __memcmpeq,
> > + 1,
> > + __memcmpeq_sse2))
>
> Are the changes properly indented?
Just rechecked and I believe so.
>
> > /* Support sysdeps/x86_64/multiarch/memchr.c. */
> > IFUNC_IMPL (i, name, memchr,
> > @@ -78,24 +81,30 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/memcmp.c. */
> > IFUNC_IMPL (i, name, memcmp,
> > - IFUNC_IMPL_ADD (array, i, memcmp,
> > + /* NB: If any of these names change or if any new
> > + implementations are added be sure to update
> > + sysdeps/x86_64/memcmp-isa-default-impl.h. */
> > + X86_IFUNC_IMPL_ADD_V4 (array, i, memcmp,
> > + (CPU_FEATURE_USABLE (AVX512VL)
> > + && CPU_FEATURE_USABLE (AVX512BW)
> > + && CPU_FEATURE_USABLE (BMI2)
> > + && CPU_FEATURE_USABLE (MOVBE)),
> > + __memcmp_evex_movbe)
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, memcmp,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)
> > && CPU_FEATURE_USABLE (MOVBE)),
> > __memcmp_avx2_movbe)
> > - IFUNC_IMPL_ADD (array, i, memcmp,
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, memcmp,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)
> > && CPU_FEATURE_USABLE (MOVBE)
> > && CPU_FEATURE_USABLE (RTM)),
> > __memcmp_avx2_movbe_rtm)
> > - IFUNC_IMPL_ADD (array, i, memcmp,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)
> > - && CPU_FEATURE_USABLE (MOVBE)),
> > - __memcmp_evex_movbe)
> > - IFUNC_IMPL_ADD (array, i, memcmp, 1, __memcmp_sse2))
> > + /* Can be lowered to V1 if a V2 implementation is added. */
> > + X86_IFUNC_IMPL_ADD_V2 (array, i, memcmp,
> > + 1,
> > + __memcmp_sse2))
> >
> > #ifdef SHARED
> > /* Support sysdeps/x86_64/multiarch/memmove_chk.c. */
> > @@ -780,24 +789,27 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> >
> > /* Support sysdeps/x86_64/multiarch/wmemcmp.c. */
> > IFUNC_IMPL (i, name, wmemcmp,
> > - IFUNC_IMPL_ADD (array, i, wmemcmp,
> > + X86_IFUNC_IMPL_ADD_V4 (array, i, wmemcmp,
> > + (CPU_FEATURE_USABLE (AVX512VL)
> > + && CPU_FEATURE_USABLE (AVX512BW)
> > + && CPU_FEATURE_USABLE (BMI2)
> > + && CPU_FEATURE_USABLE (MOVBE)),
> > + __wmemcmp_evex_movbe)
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, wmemcmp,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)
> > && CPU_FEATURE_USABLE (MOVBE)),
> > __wmemcmp_avx2_movbe)
> > - IFUNC_IMPL_ADD (array, i, wmemcmp,
> > + X86_IFUNC_IMPL_ADD_V3 (array, i, wmemcmp,
> > (CPU_FEATURE_USABLE (AVX2)
> > && CPU_FEATURE_USABLE (BMI2)
> > && CPU_FEATURE_USABLE (MOVBE)
> > && CPU_FEATURE_USABLE (RTM)),
> > __wmemcmp_avx2_movbe_rtm)
> > - IFUNC_IMPL_ADD (array, i, wmemcmp,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)
> > - && CPU_FEATURE_USABLE (MOVBE)),
> > - __wmemcmp_evex_movbe)
> > - IFUNC_IMPL_ADD (array, i, wmemcmp, 1, __wmemcmp_sse2))
> > + /* Can be lowered to V1 if a V2 implementation is added. */
> > + X86_IFUNC_IMPL_ADD_V2 (array, i, wmemcmp,
> > + 1,
> > + __wmemcmp_sse2))
> >
> > /* Support sysdeps/x86_64/multiarch/wmemset.c. */
> > IFUNC_IMPL (i, name, wmemset,
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-memcmp.h b/sysdeps/x86_64/multiarch/ifunc-memcmp.h
> > index c743970fe3..27a1459413 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-memcmp.h
> > +++ b/sysdeps/x86_64/multiarch/ifunc-memcmp.h
> > @@ -19,29 +19,33 @@
> >
> > # include <init-arch.h>
> >
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
> > +extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_movbe) attribute_hidden;
> > +
> > extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_movbe) attribute_hidden;
> > extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_movbe_rtm) attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE (evex_movbe) attribute_hidden;
> > +
> > +extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
> >
> > static inline void *
> > IFUNC_SELECTOR (void)
> > {
> > - const struct cpu_features* cpu_features = __get_cpu_features ();
> > + const struct cpu_features *cpu_features = __get_cpu_features ();
> >
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > - && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
> > - && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > - && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
> > + if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
> > + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > + && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
> > + AVX_Fast_Unaligned_Load, ))
> > {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
> > + if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
> > return OPTIMIZE (evex_movbe);
> >
> > if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
> > return OPTIMIZE (avx2_movbe_rtm);
> >
> > - if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
> > + if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
> > + Prefer_No_VZEROUPPER, !))
> > return OPTIMIZE (avx2_movbe);
> > }
> >
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-memcmpeq.h b/sysdeps/x86_64/multiarch/ifunc-memcmpeq.h
> > index aa01d48a47..fbcd2afd99 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-memcmpeq.h
> > +++ b/sysdeps/x86_64/multiarch/ifunc-memcmpeq.h
> > @@ -19,28 +19,32 @@
> >
> > # include <init-arch.h>
> >
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2) attribute_hidden;
> > +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex) attribute_hidden;
> > +
> > extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2) attribute_hidden;
> > extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_rtm) attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex) attribute_hidden;
> > +
> > +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2) attribute_hidden;
> >
> > static inline void *
> > IFUNC_SELECTOR (void)
> > {
> > - const struct cpu_features* cpu_features = __get_cpu_features ();
> > + const struct cpu_features *cpu_features = __get_cpu_features ();
> >
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > - && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > - && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
> > + if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > + && X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
> > + AVX_Fast_Unaligned_Load, ))
> > {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
> > + if (X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > + && X86_ISA_CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))
> > return OPTIMIZE1 (evex);
> >
> > if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
> > return OPTIMIZE1 (avx2_rtm);
> >
> > - if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
> > + if (X86_ISA_CPU_FEATURES_ARCH_P (cpu_features,
> > + Prefer_No_VZEROUPPER, !))
> > return OPTIMIZE1 (avx2);
> > }
> >
> > diff --git a/sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S b/sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S
> > index 210c9925b6..1a40210ff5 100644
> > --- a/sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S
> > +++ b/sysdeps/x86_64/multiarch/memcmp-avx2-movbe.S
> > @@ -16,7 +16,9 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > +#include <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (3)
> >
> > /* memcmp/wmemcmp is implemented as:
> > 1. Use ymm vector compares when possible. The only case where
> > @@ -36,7 +38,6 @@
> > 8. Use 4 vector compares when size is 4 * VEC_SIZE or less.
> > 9. Use 8 vector compares when size is 8 * VEC_SIZE or less. */
> >
> > -
> > # include <sysdep.h>
> >
> > # ifndef MEMCMP
> > diff --git a/sysdeps/x86_64/multiarch/memcmp-evex-movbe.S b/sysdeps/x86_64/multiarch/memcmp-evex-movbe.S
> > index aa03aee5dd..bc017768be 100644
> > --- a/sysdeps/x86_64/multiarch/memcmp-evex-movbe.S
> > +++ b/sysdeps/x86_64/multiarch/memcmp-evex-movbe.S
> > @@ -16,7 +16,10 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > +#include <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (4)
> > +
> >
> > /* memcmp/wmemcmp is implemented as:
> > 1. Use ymm vector compares when possible. The only case where
> > diff --git a/sysdeps/x86_64/multiarch/memcmp-sse2.S b/sysdeps/x86_64/multiarch/memcmp-sse2.S
> > index 4080fc1875..afd450d020 100644
> > --- a/sysdeps/x86_64/multiarch/memcmp-sse2.S
> > +++ b/sysdeps/x86_64/multiarch/memcmp-sse2.S
> > @@ -16,24 +16,565 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > +
> > +#include <isa-level.h>
> > +
> > +/* MINIMUM_X86_ISA_LEVEL <= 2 because there is no V2 implementation
> > + so we need this to build for ISA V2 builds. */
> > +#if ISA_SHOULD_BUILD (2)
> > +
> > +#include <sysdep.h>
> > +
> > # ifndef MEMCMP
> > # define MEMCMP __memcmp_sse2
> > # endif
> >
> > -# ifdef SHARED
> > -# undef libc_hidden_builtin_def
> > -# define libc_hidden_builtin_def(name)
> > +# ifdef USE_AS_WMEMCMP
> > +# define PCMPEQ pcmpeqd
> > +# define CHAR_SIZE 4
> > +# define SIZE_OFFSET (0)
> > +# else
> > +# define PCMPEQ pcmpeqb
> > +# define CHAR_SIZE 1
> > +# endif
> >
> > -# undef libc_hidden_def
> > -# define libc_hidden_def(ignored)
> > +# ifdef USE_AS_MEMCMPEQ
> > +# define SIZE_OFFSET (0)
> > +# define CHECK_CMP(x, y) subl x, y
> > +# else
> > +# ifndef SIZE_OFFSET
> > +# define SIZE_OFFSET (CHAR_PER_VEC * 2)
> > +# endif
> > +# define CHECK_CMP(x, y) cmpl x, y
> > # endif
> >
> > -# undef weak_alias
> > -# define weak_alias(ignored1, ignored2)
> > +# define VEC_SIZE 16
> > +# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
> >
> > -# undef strong_alias
> > -# define strong_alias(ignored1, ignored2)
> > -#endif
> > +# ifndef MEMCMP
> > +# define MEMCMP memcmp
> > +# endif
> > +
> > + .text
> > +ENTRY(MEMCMP)
> > +# ifdef __ILP32__
> > + /* Clear the upper 32 bits. */
> > + movl %edx, %edx
> > +# endif
> > +# ifdef USE_AS_WMEMCMP
> > + /* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
> > + in ecx for code size. This is preferable to using `incw` as
> > + it avoids partial register stalls on older hardware (pre
> > + SnB). */
> > + movl $0xffff, %ecx
> > +# endif
> > + cmpq $CHAR_PER_VEC, %rdx
> > + ja L(more_1x_vec)
> > +
> > +# ifdef USE_AS_WMEMCMP
> > + /* saves a byte of code keeping the fall through path n = [2, 4]
> > + in the initial cache line. */
> > + decl %edx
> > + jle L(cmp_0_1)
> > +
> > + movq (%rsi), %xmm0
> > + movq (%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + pmovmskb %xmm1, %eax
> > + subl %ecx, %eax
> > + jnz L(ret_nonzero_vec_start_0)
> > +
> > + movq -4(%rsi, %rdx, CHAR_SIZE), %xmm0
> > + movq -4(%rdi, %rdx, CHAR_SIZE), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + pmovmskb %xmm1, %eax
> > + subl %ecx, %eax
> > + jnz L(ret_nonzero_vec_end_0_adj)
> > +# else
> > + cmpl $8, %edx
> > + ja L(cmp_9_16)
> > +
> > + cmpl $4, %edx
> > + jb L(cmp_0_3)
> > +
> > +# ifdef USE_AS_MEMCMPEQ
> > + movl (%rsi), %eax
> > + subl (%rdi), %eax
> > +
> > + movl -4(%rsi, %rdx), %esi
> > + subl -4(%rdi, %rdx), %esi
> > +
> > + orl %esi, %eax
> > + ret
> > +# else
> > + /* Combine comparisons for lo and hi 4-byte comparisons. */
> > + movl -4(%rsi, %rdx), %ecx
> > + movl -4(%rdi, %rdx), %eax
> > + shlq $32, %rcx
> > + shlq $32, %rax
> > + movl (%rsi), %esi
> > + movl (%rdi), %edi
> > + orq %rsi, %rcx
> > + orq %rdi, %rax
> > + /* Only compute proper return if not-equal. */
> > + cmpq %rcx, %rax
> > + jnz L(ret_nonzero)
> > + xorl %eax, %eax
> > + ret
> > +# endif
> > +
> > + .p2align 4,, 10
> > +L(cmp_9_16):
> > +# ifdef USE_AS_MEMCMPEQ
> > + movq (%rsi), %rax
> > + subq (%rdi), %rax
> > +
> > + movq -8(%rsi, %rdx), %rcx
> > + subq -8(%rdi, %rdx), %rcx
> > + orq %rcx, %rax
> > + /* Convert 64 bit -> 32 bit boolean (we should have made the ABI
> > + return long). */
> > + setnz %cl
> > + movzbl %cl, %eax
> > +# else
> > + movq (%rsi), %rcx
> > + movq (%rdi), %rax
> > + /* Only compute proper return if not-equal. */
> > + cmpq %rcx, %rax
> > + jnz L(ret_nonzero)
> > +
> > + movq -8(%rsi, %rdx, CHAR_SIZE), %rcx
> > + movq -8(%rdi, %rdx, CHAR_SIZE), %rax
> > + /* Only compute proper return if not-equal. */
> > + cmpq %rcx, %rax
> > + jnz L(ret_nonzero)
> > + xorl %eax, %eax
> > +# endif
> > +# endif
> > + ret
> > +
> > + .p2align 4,, 8
> > +L(cmp_0_1):
> > + /* Flag set by earlier comparison against 1. */
> > + jne L(cmp_0_0)
> > +# ifdef USE_AS_WMEMCMP
> > + movl (%rdi), %ecx
> > + xorl %edx, %edx
> > + cmpl (%rsi), %ecx
> > + je L(cmp_0_0)
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + movzbl (%rdi), %eax
> > + movzbl (%rsi), %ecx
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +
> > + /* Fits in aligning bytes. */
> > +L(cmp_0_0):
> > + xorl %eax, %eax
> > + ret
> > +
> > +# ifdef USE_AS_WMEMCMP
> > + .p2align 4
> > +L(ret_nonzero_vec_start_0):
> > + bsfl %eax, %eax
> > + movl (%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > + ret
> > +# else
> > +
> > +# ifndef USE_AS_MEMCMPEQ
> > + .p2align 4,, 14
> > +L(ret_nonzero):
> > + /* Need to bswap to get proper return without branch. */
> > + bswapq %rcx
> > + bswapq %rax
> > + subq %rcx, %rax
> > + sbbl %eax, %eax
> > + orl $1, %eax
> > + ret
> > +# endif
> > +
> > + .p2align 4
> > +L(cmp_0_3):
> > +# ifdef USE_AS_MEMCMPEQ
> > + /* No reason to add to dependency chain on rdx. Saving a the
> > + bytes here doesn't change number of fetch blocks. */
> > + cmpl $1, %edx
> > + jbe L(cmp_0_1)
> > +# else
> > + /* We need the code size to prevent taking an extra fetch block.
> > + */
> > + decl %edx
> > + jle L(cmp_0_1)
> > +# endif
> > + movzwl (%rsi), %ecx
> > + movzwl (%rdi), %eax
> > +
> > +# ifdef USE_AS_MEMCMPEQ
> > + subl %ecx, %eax
> > +
> > + movzbl -1(%rsi, %rdx), %esi
> > + movzbl -1(%rdi, %rdx), %edi
> > + subl %edi, %esi
> > + orl %esi, %eax
> > +# else
> > + bswapl %ecx
> > + bswapl %eax
> > +
> > + /* Implicit right shift by one. We just need to displace the
> > + sign bits. */
> > + shrl %ecx
> > + shrl %eax
> > +
> > + /* Eat a partial register stall here. Saves code stopping
> > + L(cmp_0_3) from bleeding into the next fetch block and saves
> > + an ALU. */
> > + movb (%rsi, %rdx), %cl
> > + movzbl (%rdi, %rdx), %edi
> > + orl %edi, %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +# endif
> > +
> > + .p2align 5
> > +L(more_1x_vec):
> > +# ifndef USE_AS_WMEMCMP
> > + /* Use 0xffff to test for mismatches on pmovmskb bitmask. Store
> > + in ecx for code size. This is preferable to using `incw` as
> > + it avoids partial register stalls on older hardware (pre
> > + SnB). */
> > + movl $0xffff, %ecx
> > +# endif
> > + movups (%rsi), %xmm0
> > + movups (%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + pmovmskb %xmm1, %eax
> > + subl %ecx, %eax
> > + jnz L(ret_nonzero_vec_start_0)
> > +# if SIZE_OFFSET == 0
> > + cmpq $(CHAR_PER_VEC * 2), %rdx
> > +# else
> > + /* Offset rdx. Saves just enough code size to keep the
> > + L(last_2x_vec) case and the non-zero return in a single
> > + cache line. */
> > + subq $(CHAR_PER_VEC * 2), %rdx
> > +# endif
> > + ja L(more_2x_vec)
> >
> > -#include <sysdeps/x86_64/memcmp.S>
> > + movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
> > + movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + pmovmskb %xmm1, %eax
> > + subl %ecx, %eax
> > +# ifndef USE_AS_MEMCMPEQ
> > + /* Don't use `incw ax` as machines this code runs on are liable
> > + to have partial register stall. */
> > + jnz L(ret_nonzero_vec_end_0)
> > +# else
> > + /* Various return targets for memcmpeq. Will always be hot in
> > + Icache and get short encoding. */
> > +L(ret_nonzero_vec_start_1):
> > +L(ret_nonzero_vec_start_0):
> > +L(ret_nonzero_vec_end_0):
> > +# endif
> > + ret
> > +
> > +# ifndef USE_AS_MEMCMPEQ
> > +# ifdef USE_AS_WMEMCMP
> > + .p2align 4
> > +L(ret_nonzero_vec_end_0_adj):
> > + addl $3, %edx
> > +# else
> > + .p2align 4,, 8
> > +# endif
> > +L(ret_nonzero_vec_end_0):
> > + bsfl %eax, %eax
> > +# ifdef USE_AS_WMEMCMP
> > + leal (%rax, %rdx, CHAR_SIZE), %eax
> > + movl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + addl %edx, %eax
> > + movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +# ifndef USE_AS_WMEMCMP
> > + .p2align 4,, 10
> > +L(ret_nonzero_vec_start_0):
> > + bsfl %eax, %eax
> > + movzbl (%rsi, %rax), %ecx
> > + movzbl (%rdi, %rax), %eax
> > + subl %ecx, %eax
> > + ret
> > +# endif
> > +# else
> > +# endif
> > +
> > + .p2align 5
> > +L(more_2x_vec):
> > + movups (VEC_SIZE * 1)(%rsi), %xmm0
> > + movups (VEC_SIZE * 1)(%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + pmovmskb %xmm1, %eax
> > + subl %ecx, %eax
> > + jnz L(ret_nonzero_vec_start_1)
> > +
> > + cmpq $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %rdx
> > + jbe L(last_2x_vec)
> > +
> > + cmpq $(CHAR_PER_VEC * 8 - SIZE_OFFSET), %rdx
> > + ja L(more_8x_vec)
> > +
> > + /* Do comparisons for [65, 96] and [97, 128] 2x VEC at a time.
> > + This can harm performance if non-zero return in [65, 80] or
> > + [97, 112] but helps performance otherwise. Generally zero-
> > + return is hotter. */
> > + movups (VEC_SIZE * 2)(%rsi), %xmm0
> > + movups (VEC_SIZE * 2)(%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + movups (VEC_SIZE * 3)(%rsi), %xmm2
> > + movups (VEC_SIZE * 3)(%rdi), %xmm3
> > + PCMPEQ %xmm2, %xmm3
> > + pand %xmm1, %xmm3
> > +
> > + pmovmskb %xmm3, %eax
> > + CHECK_CMP (%ecx, %eax)
> > + jnz L(ret_nonzero_vec_start_2_3)
> > +
> > + cmpl $(CHAR_PER_VEC * 6 - SIZE_OFFSET), %edx
> > + jbe L(last_2x_vec)
> > +
> > + movups (VEC_SIZE * 4)(%rsi), %xmm0
> > + movups (VEC_SIZE * 4)(%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + movups (VEC_SIZE * 5)(%rsi), %xmm2
> > + movups (VEC_SIZE * 5)(%rdi), %xmm3
> > + PCMPEQ %xmm2, %xmm3
> > + pand %xmm1, %xmm3
> > +
> > + pmovmskb %xmm3, %eax
> > + CHECK_CMP (%ecx, %eax)
> > +# ifdef USE_AS_MEMCMPEQ
> > + jz L(last_2x_vec)
> > + ret
> > +# else
> > + jnz L(ret_nonzero_vec_start_4_5)
> > +# endif
> > + .p2align 4
> > +L(last_2x_vec):
> > + movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm0
> > + movups (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rsi, %rdx, CHAR_SIZE), %xmm2
> > + movups (VEC_SIZE * -1 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %xmm3
> > + PCMPEQ %xmm2, %xmm3
> > + pand %xmm1, %xmm3
> > + pmovmskb %xmm3, %eax
> > + subl %ecx, %eax
> > +# ifdef USE_AS_MEMCMPEQ
> > + /* Various return targets for memcmpeq. Will always be hot in
> > + Icache and get short encoding. */
> > +L(ret_nonzero_vec_start_2_3):
> > +L(ret_nonzero_vec_start_4_5):
> > + ret
> > +# else
> > + jnz L(ret_nonzero_vec_end_1)
> > + ret
> > +
> > + .p2align 4,, 8
> > +L(ret_nonzero_vec_end_1):
> > + pmovmskb %xmm1, %ecx
> > + /* High 16 bits of eax guranteed to be all ones. Rotate them in
> > + to we can do `or + not` with just `xor`. */
> > + rorl $16, %eax
> > + xorl %ecx, %eax
> > + /* Partial register stall. */
> > +
> > + bsfl %eax, %eax
> > +# ifdef USE_AS_WMEMCMP
> > + leal (%rax, %rdx, CHAR_SIZE), %eax
> > + movl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + addl %edx, %eax
> > + movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * -2 + SIZE_OFFSET)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +
> > + .p2align 4
> > +L(ret_nonzero_vec_start_4_5):
> > + pmovmskb %xmm1, %edx
> > + sall $16, %eax
> > + leal 1(%rax, %rdx), %eax
> > + bsfl %eax, %eax
> > +# ifdef USE_AS_WMEMCMP
> > + movl (VEC_SIZE * 4)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * 4)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + movzbl (VEC_SIZE * 4)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * 4)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +
> > + .p2align 4,, 8
> > +L(ret_nonzero_vec_start_1):
> > + bsfl %eax, %eax
> > +# ifdef USE_AS_WMEMCMP
> > + movl (VEC_SIZE * 1)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * 1)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + movzbl (VEC_SIZE * 1)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * 1)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +# endif
> > +
> > + .p2align 4
> > +L(more_8x_vec):
> > + subq %rdi, %rsi
> > + leaq (VEC_SIZE * -6 + SIZE_OFFSET)(%rdi, %rdx, CHAR_SIZE), %rdx
> > + andq $(VEC_SIZE * -1), %rdi
> > + addq %rdi, %rsi
> > + .p2align 4
> > +L(loop_4x):
> > + movups (VEC_SIZE * 2)(%rsi), %xmm0
> > + movups (VEC_SIZE * 3)(%rsi), %xmm1
> > +
> > + PCMPEQ (VEC_SIZE * 2)(%rdi), %xmm0
> > + PCMPEQ (VEC_SIZE * 3)(%rdi), %xmm1
> > +
> > + movups (VEC_SIZE * 4)(%rsi), %xmm2
> > + movups (VEC_SIZE * 5)(%rsi), %xmm3
> > +
> > + PCMPEQ (VEC_SIZE * 4)(%rdi), %xmm2
> > + PCMPEQ (VEC_SIZE * 5)(%rdi), %xmm3
> > +
> > + pand %xmm0, %xmm1
> > + pand %xmm2, %xmm3
> > + pand %xmm1, %xmm3
> > +
> > + pmovmskb %xmm3, %eax
> > + subl %ecx, %eax
> > + jnz L(ret_nonzero_loop)
> > +
> > + addq $(VEC_SIZE * 4), %rdi
> > + addq $(VEC_SIZE * 4), %rsi
> > + cmpq %rdi, %rdx
> > + ja L(loop_4x)
> > + /* Get remaining length in edx. */
> > + subl %edi, %edx
> > + /* Restore offset so we can reuse L(last_2x_vec). */
> > + addl $(VEC_SIZE * 6 - SIZE_OFFSET), %edx
> > +# ifdef USE_AS_WMEMCMP
> > + shrl $2, %edx
> > +# endif
> > + cmpl $(CHAR_PER_VEC * 4 - SIZE_OFFSET), %edx
> > + jbe L(last_2x_vec)
> > +
> > +
> > + movups (VEC_SIZE * 2)(%rsi), %xmm0
> > + movups (VEC_SIZE * 2)(%rdi), %xmm1
> > + PCMPEQ %xmm0, %xmm1
> > + movups (VEC_SIZE * 3)(%rsi), %xmm2
> > + movups (VEC_SIZE * 3)(%rdi), %xmm3
> > + PCMPEQ %xmm2, %xmm3
> > + pand %xmm1, %xmm3
> > +
> > + pmovmskb %xmm3, %eax
> > + CHECK_CMP (%ecx, %eax)
> > + jz L(last_2x_vec)
> > +# ifdef USE_AS_MEMCMPEQ
> > +L(ret_nonzero_loop):
> > + ret
> > +# else
> > +
> > + .p2align 4
> > +L(ret_nonzero_vec_start_2_3):
> > + pmovmskb %xmm1, %edx
> > + sall $16, %eax
> > + leal 1(%rax, %rdx), %eax
> > +
> > + bsfl %eax, %eax
> > +# ifdef USE_AS_WMEMCMP
> > + movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +
> > + .p2align 4
> > +L(ret_nonzero_loop):
> > + pmovmskb %xmm0, %ecx
> > + pmovmskb %xmm1, %edx
> > + sall $(VEC_SIZE * 1), %edx
> > + leal 1(%rcx, %rdx), %edx
> > + pmovmskb %xmm2, %ecx
> > + /* High 16 bits of eax guranteed to be all ones. Rotate them in
> > + to we can do `or + not` with just `xor`. */
> > + rorl $16, %eax
> > + xorl %ecx, %eax
> > +
> > + salq $32, %rax
> > + orq %rdx, %rax
> > +
> > + bsfq %rax, %rax
> > +# ifdef USE_AS_WMEMCMP
> > + movl (VEC_SIZE * 2)(%rdi, %rax), %ecx
> > + xorl %edx, %edx
> > + cmpl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > + /* NB: no partial register stall here because xorl zero idiom
> > + above. */
> > + setg %dl
> > + leal -1(%rdx, %rdx), %eax
> > +# else
> > + movzbl (VEC_SIZE * 2)(%rsi, %rax), %ecx
> > + movzbl (VEC_SIZE * 2)(%rdi, %rax), %eax
> > + subl %ecx, %eax
> > +# endif
> > + ret
> > +# endif
> > +END(MEMCMP)
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/memcmpeq-avx2.S b/sysdeps/x86_64/multiarch/memcmpeq-avx2.S
> > index 80020c46c4..664b109714 100644
> > --- a/sysdeps/x86_64/multiarch/memcmpeq-avx2.S
> > +++ b/sysdeps/x86_64/multiarch/memcmpeq-avx2.S
> > @@ -16,7 +16,9 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > +#include <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (3)
> >
> > /* __memcmpeq is implemented as:
> > 1. Use ymm vector compares when possible. The only case where
> > diff --git a/sysdeps/x86_64/multiarch/memcmpeq-evex.S b/sysdeps/x86_64/multiarch/memcmpeq-evex.S
> > index 7114547527..41124ef1d3 100644
> > --- a/sysdeps/x86_64/multiarch/memcmpeq-evex.S
> > +++ b/sysdeps/x86_64/multiarch/memcmpeq-evex.S
> > @@ -16,7 +16,9 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > +#include <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (4)
> >
> > /* __memcmpeq is implemented as:
> > 1. Use ymm vector compares when possible. The only case where
> > diff --git a/sysdeps/x86_64/multiarch/memcmpeq-sse2.S b/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > index 9d991e5c74..a412b0b9b7 100644
> > --- a/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > +++ b/sysdeps/x86_64/multiarch/memcmpeq-sse2.S
> > @@ -16,10 +16,10 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#if IS_IN (libc)
> > -# define MEMCMP __memcmpeq_sse2
> > -#else
> > -# define MEMCMP __memcmpeq
> > +#ifndef MEMCMPEQ
> > +# define MEMCMPEQ __memcmpeq_sse2
> > #endif
> > +
> > +#define MEMCMP MEMCMPEQ
> > #define USE_AS_MEMCMPEQ 1
> > #include "memcmp-sse2.S"
> > diff --git a/sysdeps/x86_64/multiarch/rtld-memcmp.S b/sysdeps/x86_64/multiarch/rtld-memcmp.S
> > new file mode 100644
> > index 0000000000..cf710f3530
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/rtld-memcmp.S
> > @@ -0,0 +1,18 @@
> > +/* Copyright (C) 2022 Free Software Foundation, Inc.
> > + This file is part of the GNU C Library.
> > +
> > + The GNU C Library is free software; you can redistribute it and/or
> > + modify it under the terms of the GNU Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 of the License, or (at your option) any later version.
> > +
> > + The GNU C Library is distributed in the hope that it will be useful,
> > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include "../memcmp.S"
> > diff --git a/sysdeps/x86_64/multiarch/rtld-memcmpeq.S b/sysdeps/x86_64/multiarch/rtld-memcmpeq.S
> > new file mode 100644
> > index 0000000000..132300885f
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/rtld-memcmpeq.S
> > @@ -0,0 +1,18 @@
> > +/* Copyright (C) 2022 Free Software Foundation, Inc.
> > + This file is part of the GNU C Library.
> > +
> > + The GNU C Library is free software; you can redistribute it and/or
> > + modify it under the terms of the GNU Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 of the License, or (at your option) any later version.
> > +
> > + The GNU C Library is distributed in the hope that it will be useful,
> > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include "../memcmpeq.S"
> > diff --git a/sysdeps/x86_64/multiarch/rtld-wmemcmp.S b/sysdeps/x86_64/multiarch/rtld-wmemcmp.S
> > new file mode 100644
> > index 0000000000..71a6f0affa
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/rtld-wmemcmp.S
> > @@ -0,0 +1,18 @@
> > +/* Copyright (C) 2022 Free Software Foundation, Inc.
> > + This file is part of the GNU C Library.
> > +
> > + The GNU C Library is free software; you can redistribute it and/or
> > + modify it under the terms of the GNU Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 of the License, or (at your option) any later version.
> > +
> > + The GNU C Library is distributed in the hope that it will be useful,
> > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include "../wmemcmp.S"
> > diff --git a/sysdeps/x86_64/multiarch/wmemcmp-avx2-movbe.S b/sysdeps/x86_64/multiarch/wmemcmp-avx2-movbe.S
> > index bfa1a16a35..9e723f22b2 100644
> > --- a/sysdeps/x86_64/multiarch/wmemcmp-avx2-movbe.S
> > +++ b/sysdeps/x86_64/multiarch/wmemcmp-avx2-movbe.S
> > @@ -1,4 +1,8 @@
> > -#define MEMCMP __wmemcmp_avx2_movbe
> > +#ifndef WMEMCMP
> > +# define WMEMCMP __wmemcmp_avx2_movbe
> > +#endif
> > +
> > +#define MEMCMP WMEMCMP
> > #define USE_AS_WMEMCMP 1
> >
> > #include "memcmp-avx2-movbe.S"
> > diff --git a/sysdeps/x86_64/multiarch/wmemcmp-evex-movbe.S b/sysdeps/x86_64/multiarch/wmemcmp-evex-movbe.S
> > index 4726d74aa1..40dbf0fef9 100644
> > --- a/sysdeps/x86_64/multiarch/wmemcmp-evex-movbe.S
> > +++ b/sysdeps/x86_64/multiarch/wmemcmp-evex-movbe.S
> > @@ -1,4 +1,8 @@
> > -#define MEMCMP __wmemcmp_evex_movbe
> > +#ifndef WMEMCMP
> > +# define WMEMCMP __wmemcmp_evex_movbe
> > +#endif
> > +
> > +#define MEMCMP WMEMCMP
> > #define USE_AS_WMEMCMP 1
> >
> > #include "memcmp-evex-movbe.S"
> > diff --git a/sysdeps/x86_64/multiarch/wmemcmp-sse2.S b/sysdeps/x86_64/multiarch/wmemcmp-sse2.S
> > index f09192ed77..47f600665b 100644
> > --- a/sysdeps/x86_64/multiarch/wmemcmp-sse2.S
> > +++ b/sysdeps/x86_64/multiarch/wmemcmp-sse2.S
> > @@ -16,6 +16,11 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > +#ifndef WMEMCMP
> > +# define WMEMCMP __wmemcmp_sse2
> > +#endif
> > +
> > +#define MEMCMP WMEMCMP
> > #define USE_AS_WMEMCMP 1
> > -#define MEMCMP __wmemcmp_sse2
> > -#include "../memcmp.S"
> > +
> > +#include "memcmp-sse2.S"
> > diff --git a/sysdeps/x86_64/wmemcmp.S b/sysdeps/x86_64/wmemcmp.S
> > index 815b999e4e..cf90a64c95 100644
> > --- a/sysdeps/x86_64/wmemcmp.S
> > +++ b/sysdeps/x86_64/wmemcmp.S
> > @@ -1,4 +1,4 @@
> > -/* wmemcmp optimized with SSE2.
> > +/* wmemcmp hook for non-multiarch and RTLD build.
> > Copyright (C) 2022 Free Software Foundation, Inc.
> > This file is part of the GNU C Library.
> >
> > @@ -16,8 +16,12 @@
> > License along with the GNU C Library; if not, see
> > <https://www.gnu.org/licenses/>. */
> >
> > -#define MEMCMP __wmemcmp
> > -#define USE_AS_WMEMCMP 1
> > -#include "memcmp.S"
> > +#define WMEMCMP __wmemcmp
> > +
> > +#define DEFAULT_IMPL_V1 "multiarch/wmemcmp-sse2.S"
> > +#define DEFAULT_IMPL_V3 "multiarch/wmemcmp-avx2-movbe.S"
> > +#define DEFAULT_IMPL_V4 "multiarch/wmemcmp-evex-movbe.S"
> > +
> > +#include "isa-default-impl.h"
> >
> > weak_alias (__wmemcmp, wmemcmp)
> > --
> > 2.34.1
> >
>
>
> --
> H.J.
next prev parent reply other threads:[~2022-06-29 19:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-28 15:26 [PATCH v1] x86-64: Small improvements to dl-trampoline.S Noah Goldstein
2022-06-28 15:26 ` [PATCH v1] x86: Add support for building strstr with explicit ISA level Noah Goldstein
2022-06-28 18:20 ` H.J. Lu
2022-06-28 18:24 ` Noah Goldstein
2022-06-28 18:34 ` H.J. Lu
2022-06-28 18:38 ` Noah Goldstein
2022-06-28 15:26 ` [PATCH v1] x86: Add support for building {w}memcmp{eq} " Noah Goldstein
2022-06-29 18:52 ` H.J. Lu
2022-06-29 19:27 ` Noah Goldstein [this message]
2022-06-29 19:41 ` H.J. Lu
2022-06-29 19:44 ` Noah Goldstein
2022-06-29 19:48 ` H.J. Lu
2022-06-29 22:09 ` Noah Goldstein
2022-06-29 22:09 ` [PATCH v2] " Noah Goldstein
2022-06-29 22:49 ` H.J. Lu
2022-06-29 23:11 ` Noah Goldstein
2022-06-29 23:11 ` [PATCH v3] " Noah Goldstein
2022-07-01 22:56 ` H.J. Lu
2022-06-28 18:15 ` [PATCH v1] x86-64: Small improvements to dl-trampoline.S H.J. Lu
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