[PATCH v2 2/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions

Noah Goldstein goldstein.w.n@gmail.com
Fri Nov 4 20:20:32 GMT 2022


On Fri, Nov 4, 2022 at 9:34 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Fri, Nov 4, 2022 at 1:20 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > Optimizations are:
> >     1. Use more overlapping stores to avoid branches.
> >     2. Reduce how unrolled the aligning copies are (this is more of a
> >        code-size save, its a negative for some sizes in terms of
> >        perf).
> >     3. Improve the loop a bit (similiar to what we do in strlen with
> >        2x vpminu + kortest instead of 3x vpminu + kmov + test).
> >     4. For st{r|p}n{cat|cpy} re-order the branches to minimize the
> >        number that are taken.
> >
> > Performance Changes:
> >
> >     Times are from N = 10 runs of the benchmark suite and are
> >     reported as geometric mean of all ratios of
> >     New Implementation / Old Implementation.
> >
> >     stpcpy-evex      -> 0.922
> >     strcat-evex      -> 0.985
> >     strcpy-evex      -> 0.880
> >
> >     strncpy-evex     -> 0.831
> >     stpncpy-evex     -> 0.780
> >
> >     strncat-evex     -> 0.958
> >
> > Code Size Changes:
> >     function         -> Bytes New / Bytes Old -> Ratio
> >
> >     strcat-evex      -> 819  / 1874 -> 0.437
> >     strcpy-evex      -> 700  / 1074 -> 0.652
> >     stpcpy-evex      -> 735  / 1094 -> 0.672
> >
> >     strncpy-evex     -> 1397 / 2611 -> 0.535
> >     stpncpy-evex     -> 1489 / 2691 -> 0.553
> >
> >     strncat-evex     -> 1184 / 2832 -> 0.418
> >
> > Notes:
> >     1. Because of the significant difference between the
> >        implementations they are split into three files.
> >
> >            strcpy-evex.S    -> strcpy, stpcpy, strcat
> >            strncpy-evex.S   -> strncpy
> >            strncat-evex.S    > strncat
> >
> >        I couldn't find a way to merge them without making the
> >        ifdefs incredibly difficult to follow.
> >
> >     2. All implementations can be made evex512 by including
> >        "x86-evex512-vecs.h" at the top.
> >
> >     3. All implementations have an optional define:
> >         `USE_EVEX_MASKED_STORE`
> >        Setting to one uses evex-masked stores for handling short
> >        strings.  This saves code size and branches.  It's disabled
> >        for all implementations are the moment as there are some
> >        serious drawbacks to masked stores in certain cases, but
> >        that may be fixed on future architectures.
> >
> > Full check passes on x86-64 and build succeeds for all ISA levels w/
> > and w/o multiarch.
> > ---
> >  sysdeps/x86_64/multiarch/stpncpy-evex.S       |    5 +-
> >  sysdeps/x86_64/multiarch/strcat-evex.S        |  291 +---
> >  sysdeps/x86_64/multiarch/strcat-strlen-evex.S |   85 ++
> >  sysdeps/x86_64/multiarch/strcpy-evex.S        | 1282 ++++++-----------
> >  sysdeps/x86_64/multiarch/strncat-evex.S       |  525 ++++++-
> >  sysdeps/x86_64/multiarch/strncpy-evex.S       |  995 ++++++++++++-
> >  .../multiarch/strncpy-or-cat-overflow-def.h   |   65 +
> >  7 files changed, 2075 insertions(+), 1173 deletions(-)
> >  create mode 100644 sysdeps/x86_64/multiarch/strcat-strlen-evex.S
> >  create mode 100644 sysdeps/x86_64/multiarch/strncpy-or-cat-overflow-def.h
> >
> > diff --git a/sysdeps/x86_64/multiarch/stpncpy-evex.S b/sysdeps/x86_64/multiarch/stpncpy-evex.S
> > index 99ea76a372..3693491baa 100644
> > --- a/sysdeps/x86_64/multiarch/stpncpy-evex.S
> > +++ b/sysdeps/x86_64/multiarch/stpncpy-evex.S
> > @@ -3,6 +3,5 @@
> >  #endif
> >
> >  #define USE_AS_STPCPY
> > -#define USE_AS_STRNCPY
> > -#define STRCPY STPNCPY
> > -#include "strcpy-evex.S"
> > +#define STRNCPY        STPNCPY
> > +#include "strncpy-evex.S"
> > diff --git a/sysdeps/x86_64/multiarch/strcat-evex.S b/sysdeps/x86_64/multiarch/strcat-evex.S
> > index 0e2df947e9..b4207b7889 100644
> > --- a/sysdeps/x86_64/multiarch/strcat-evex.S
> > +++ b/sysdeps/x86_64/multiarch/strcat-evex.S
> > @@ -1,286 +1,7 @@
> > -/* strcat with 256-bit EVEX instructions.
> > -   Copyright (C) 2021-2022 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 <isa-level.h>
> > -
> > -#if ISA_SHOULD_BUILD (4)
> > -
> > -
> > -# include <sysdep.h>
> > -
> > -# ifndef STRCAT
> > -#  define STRCAT  __strcat_evex
> > -# endif
> > -
> > -# define VMOVU         vmovdqu64
> > -# define VMOVA         vmovdqa64
> > -
> > -/* zero register */
> > -# define XMMZERO       xmm16
> > -# define YMMZERO       ymm16
> > -# define YMM0          ymm17
> > -# define YMM1          ymm18
> > -
> > -# define USE_AS_STRCAT
> > -
> > -/* Number of bytes in a vector register */
> > -# define VEC_SIZE      32
> > -
> > -       .section .text.evex,"ax",@progbits
> > -ENTRY (STRCAT)
> > -       mov     %rdi, %r9
> > -# ifdef USE_AS_STRNCAT
> > -       mov     %rdx, %r8
> > -# endif
> > -
> > -       xor     %eax, %eax
> > -       mov     %edi, %ecx
> > -       and     $((VEC_SIZE * 4) - 1), %ecx
> > -       vpxorq  %XMMZERO, %XMMZERO, %XMMZERO
> > -       cmp     $(VEC_SIZE * 3), %ecx
> > -       ja      L(fourth_vector_boundary)
> > -       vpcmpb  $0, (%rdi), %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_first_vector)
> > -       mov     %rdi, %rax
> > -       and     $-VEC_SIZE, %rax
> > -       jmp     L(align_vec_size_start)
> > -L(fourth_vector_boundary):
> > -       mov     %rdi, %rax
> > -       and     $-VEC_SIZE, %rax
> > -       vpcmpb  $0, (%rax), %YMMZERO, %k0
> > -       mov     $-1, %r10d
> > -       sub     %rax, %rcx
> > -       shl     %cl, %r10d
> > -       kmovd   %k0, %edx
> > -       and     %r10d, %edx
> > -       jnz     L(exit)
> > -
> > -L(align_vec_size_start):
> > -       vpcmpb  $0, VEC_SIZE(%rax), %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_second_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 2)(%rax), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_third_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 3)(%rax), %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fourth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 4)(%rax), %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fifth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 5)(%rax), %YMMZERO, %k4
> > -       add     $(VEC_SIZE * 4), %rax
> > -       kmovd   %k4, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_second_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 2)(%rax), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_third_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 3)(%rax), %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fourth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 4)(%rax), %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fifth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 5)(%rax), %YMMZERO, %k4
> > -       kmovd   %k4, %edx
> > -       add     $(VEC_SIZE * 4), %rax
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_second_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 2)(%rax), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_third_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 3)(%rax), %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fourth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 4)(%rax), %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fifth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 5)(%rax), %YMMZERO, %k4
> > -       add     $(VEC_SIZE * 4), %rax
> > -       kmovd   %k4, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_second_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 2)(%rax), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_third_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 3)(%rax), %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fourth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 4)(%rax), %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fifth_vector)
> > -
> > -       test    $((VEC_SIZE * 4) - 1), %rax
> > -       jz      L(align_four_vec_loop)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 5)(%rax), %YMMZERO, %k4
> > -       add     $(VEC_SIZE * 5), %rax
> > -       kmovd   %k4, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit)
> > -
> > -       test    $((VEC_SIZE * 4) - 1), %rax
> > -       jz      L(align_four_vec_loop)
> > -
> > -       vpcmpb  $0, VEC_SIZE(%rax), %YMMZERO, %k0
> > -       add     $VEC_SIZE, %rax
> > -       kmovd   %k0, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit)
> > -
> > -       test    $((VEC_SIZE * 4) - 1), %rax
> > -       jz      L(align_four_vec_loop)
> > -
> > -       vpcmpb  $0, VEC_SIZE(%rax), %YMMZERO, %k0
> > -       add     $VEC_SIZE, %rax
> > -       kmovd   %k0, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit)
> > -
> > -       test    $((VEC_SIZE * 4) - 1), %rax
> > -       jz      L(align_four_vec_loop)
> > -
> > -       vpcmpb  $0, VEC_SIZE(%rax), %YMMZERO, %k1
> > -       add     $VEC_SIZE, %rax
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit)
> > -
> > -       add     $VEC_SIZE, %rax
> > -
> > -       .p2align 4
> > -L(align_four_vec_loop):
> > -       VMOVA   (%rax), %YMM0
> > -       VMOVA   (VEC_SIZE * 2)(%rax), %YMM1
> > -       vpminub VEC_SIZE(%rax), %YMM0, %YMM0
> > -       vpminub (VEC_SIZE * 3)(%rax), %YMM1, %YMM1
> > -       vpminub %YMM0, %YMM1, %YMM0
> > -       /* If K0 != 0, there is a null byte.  */
> > -       vpcmpb  $0, %YMM0, %YMMZERO, %k0
> > -       add     $(VEC_SIZE * 4), %rax
> > -       ktestd  %k0, %k0
> > -       jz      L(align_four_vec_loop)
> > -
> > -       vpcmpb  $0, -(VEC_SIZE * 4)(%rax), %YMMZERO, %k0
> > -       sub     $(VEC_SIZE * 5), %rax
> > -       kmovd   %k0, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_second_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 2)(%rax), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_third_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 3)(%rax), %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       test    %edx, %edx
> > -       jnz     L(exit_null_on_fourth_vector)
> > -
> > -       vpcmpb  $0, (VEC_SIZE * 4)(%rax), %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       sub     %rdi, %rax
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       add     $(VEC_SIZE * 4), %rax
> > -       jmp     L(StartStrcpyPart)
> > -
> > -       .p2align 4
> > -L(exit):
> > -       sub     %rdi, %rax
> > -L(exit_null_on_first_vector):
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       jmp     L(StartStrcpyPart)
> > -
> > -       .p2align 4
> > -L(exit_null_on_second_vector):
> > -       sub     %rdi, %rax
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       add     $VEC_SIZE, %rax
> > -       jmp     L(StartStrcpyPart)
> > -
> > -       .p2align 4
> > -L(exit_null_on_third_vector):
> > -       sub     %rdi, %rax
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       add     $(VEC_SIZE * 2), %rax
> > -       jmp     L(StartStrcpyPart)
> > -
> > -       .p2align 4
> > -L(exit_null_on_fourth_vector):
> > -       sub     %rdi, %rax
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       add     $(VEC_SIZE * 3), %rax
> > -       jmp     L(StartStrcpyPart)
> > -
> > -       .p2align 4
> > -L(exit_null_on_fifth_vector):
> > -       sub     %rdi, %rax
> > -       bsf     %rdx, %rdx
> > -       add     %rdx, %rax
> > -       add     $(VEC_SIZE * 4), %rax
> > -
> > -       .p2align 4
> > -L(StartStrcpyPart):
> > -       lea     (%r9, %rax), %rdi
> > -       mov     %rsi, %rcx
> > -       mov     %r9, %rax      /* save result */
> > -
> > -# ifdef USE_AS_STRNCAT
> > -       test    %r8, %r8
> > -       jz      L(ExitZero)
> > -#  define USE_AS_STRNCPY
> > -# endif
> > -
> > -# include "strcpy-evex.S"
> > +#ifndef STRCAT
> > +# define STRCAT        __strcat_evex
> >  #endif
> > +
> > +#define USE_AS_STRCAT
> > +#define STRCPY STRCAT
> > +#include "strcpy-evex.S"
> > diff --git a/sysdeps/x86_64/multiarch/strcat-strlen-evex.S b/sysdeps/x86_64/multiarch/strcat-strlen-evex.S
> > new file mode 100644
> > index 0000000000..9bc777c339
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/strcat-strlen-evex.S
>
> Copyright notice is missing.

Fixed in V3.
>
> > @@ -0,0 +1,85 @@
> > +    /* Simple strlen implementation that ends at L(strcat_strlen_done).  */
> > +       vpxorq  %VZERO_128, %VZERO_128, %VZERO_128
> > +       movq    %rdi, %r8
> > +       andq    $(VEC_SIZE * -1), %r8
> > +       VPCMPEQ (%r8), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +#ifdef USE_AS_WCSCPY
> > +       subl    %r8d, %edi
> > +       shrl    $2, %edi
> > +#endif
> > +       shrx    %VRDI, %VRCX, %VRCX
> > +#ifdef USE_AS_WCSCPY
> > +       movq    %rax, %rdi
> > +#endif
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v0)
> > +
> > +
> > +       VPCMPEQ VEC_SIZE(%r8), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +       leaq    (VEC_SIZE)(%r8), %rdi
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v0)
> > +
> > +       VPCMPEQ (VEC_SIZE * 2)(%r8), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v1)
> > +
> > +       VPCMPEQ (VEC_SIZE * 3)(%r8), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v2)
> > +
> > +       VPCMPEQ (VEC_SIZE * 4)(%r8), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v3)
> > +
> > +       andq    $-(VEC_SIZE * 4), %rdi
> > +       .p2align 4,, 8
> > +L(loop_2x_vec):
> > +       VMOVA   (VEC_SIZE * 4)(%rdi), %VMM(0)
> > +       VPMIN   (VEC_SIZE * 5)(%rdi), %VMM(0), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 6)(%rdi), %VMM(2)
> > +       VPMIN   (VEC_SIZE * 7)(%rdi), %VMM(2), %VMM(3)
> > +       VPTESTN %VMM(1), %VMM(1), %k1
> > +       VPTESTN %VMM(3), %VMM(3), %k3
> > +       subq    $(VEC_SIZE * -4), %rdi
> > +       KORTEST %k1, %k3
> > +       jz      L(loop_2x_vec)
> > +
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v0)
> > +
> > +       KMOV    %k1, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v1)
> > +
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(bsf_and_done_v2)
> > +
> > +       KMOV    %k3, %VRCX
> > +L(bsf_and_done_v3):
> > +       addq    $VEC_SIZE, %rdi
> > +L(bsf_and_done_v2):
> > +       bsf     %VRCX, %VRCX
> > +       leaq    (VEC_SIZE * 2)(%rdi, %rcx, CHAR_SIZE), %rdi
> > +       jmp     L(strcat_strlen_done)
> > +
> > +       .p2align 4,, 4
> > +L(bsf_and_done_v1):
> > +       addq    $VEC_SIZE, %rdi
> > +L(bsf_and_done_v0):
> > +       bsf     %VRCX, %VRCX
> > +#ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rdi
> > +#else
> > +       addq    %rcx, %rdi
> > +#endif
> > +L(strcat_strlen_done):
> > diff --git a/sysdeps/x86_64/multiarch/strcpy-evex.S b/sysdeps/x86_64/multiarch/strcpy-evex.S
> > index 82e45ac675..1ba0195ed2 100644
> > --- a/sysdeps/x86_64/multiarch/strcpy-evex.S
> > +++ b/sysdeps/x86_64/multiarch/strcpy-evex.S
> > @@ -1,4 +1,4 @@
> > -/* strcpy with 256-bit EVEX instructions.
> > +/* {wcs|wcp|str|stp}cpy with 256/512-bit EVEX instructions.
> >     Copyright (C) 2021-2022 Free Software Foundation, Inc.
> >     This file is part of the GNU C Library.
> >
> > @@ -17,990 +17,526 @@
> >     <https://www.gnu.org/licenses/>.  */
> >
> >  #include <isa-level.h>
> > -
> >  #if ISA_SHOULD_BUILD (4)
> >
> >
> > -# ifndef USE_AS_STRCAT
> > -#  include <sysdep.h>
> > +       /* Use evex-masked stores for small sizes. Turned off at the
> > +          moment.  */
> > +# define USE_EVEX_MASKED_STORE 0
> > +       /* Use movsb in page cross case to save code size.  */
> > +# define USE_MOVSB_IN_PAGE_CROSS       1
> >
> > -#  ifndef STRCPY
> > -#   define STRCPY  __strcpy_evex
> > -#  endif
> > +# include <sysdep.h>
> >
> > +# ifndef VEC_SIZE
> > +#  include "x86-evex256-vecs.h"
> >  # endif
> >
> > -# define VMOVU         vmovdqu64
> > -# define VMOVA         vmovdqa64
> > -
> > -/* Number of bytes in a vector register */
> > -# ifndef VEC_SIZE
> > -#  define VEC_SIZE     32
> > +# ifndef STRCPY
> > +#  define STRCPY       __strcpy_evex
> >  # endif
> >
> > -# define XMM2          xmm18
> > -# define XMM3          xmm19
> >
> > -# define YMM2          ymm18
> > -# define YMM3          ymm19
> > -# define YMM4          ymm20
> > -# define YMM5          ymm21
> > -# define YMM6          ymm22
> > -# define YMM7          ymm23
> > +# ifdef USE_AS_WCSCPY
> > +#  define VMOVU_MASK   vmovdqu32
> > +#  define VPMIN        vpminud
> > +#  define VPTESTN      vptestnmd
> > +#  define VPTEST       vptestmd
> > +#  define VPCMPEQ      vpcmpeqd
> > +#  define CHAR_SIZE    4
> >
> > -# ifndef USE_AS_STRCAT
> > +#  define REP_MOVS     rep movsd
> >
> > -/* zero register */
> > -#  define XMMZERO      xmm16
> > -#  define YMMZERO      ymm16
> > -#  define YMM1         ymm17
> > -
> > -       .section .text.evex,"ax",@progbits
> > -ENTRY (STRCPY)
> > -#  ifdef USE_AS_STRNCPY
> > -       mov     %RDX_LP, %R8_LP
> > -       test    %R8_LP, %R8_LP
> > -       jz      L(ExitZero)
> > -#  endif
> > -       mov     %rsi, %rcx
> > -#  ifndef USE_AS_STPCPY
> > -       mov     %rdi, %rax      /* save result */
> > -#  endif
> > +#  define USE_WIDE_CHAR
> > +# else
> > +#  define VMOVU_MASK   vmovdqu8
> > +#  define VPMIN        vpminub
> > +#  define VPTESTN      vptestnmb
> > +#  define VPTEST       vptestmb
> > +#  define VPCMPEQ      vpcmpeqb
> > +#  define CHAR_SIZE    1
> >
> > -       vpxorq  %XMMZERO, %XMMZERO, %XMMZERO
> > +#  define REP_MOVS     rep movsb
> >  # endif
> >
> > -       and     $((VEC_SIZE * 4) - 1), %ecx
> > -       cmp     $(VEC_SIZE * 2), %ecx
> > -       jbe     L(SourceStringAlignmentLessTwoVecSize)
> > -
> > -       and     $-VEC_SIZE, %rsi
> > -       and     $(VEC_SIZE - 1), %ecx
> > -
> > -       vpcmpb  $0, (%rsi), %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       shr     %cl, %rdx
> > +# include "reg-macros.h"
> >
> > -# ifdef USE_AS_STRNCPY
> > -#  if defined USE_AS_STPCPY || defined USE_AS_STRCAT
> > -       mov     $VEC_SIZE, %r10
> > -       sub     %rcx, %r10
> > -       cmp     %r10, %r8
> > -#  else
> > -       mov     $(VEC_SIZE + 1), %r10
> > -       sub     %rcx, %r10
> > -       cmp     %r10, %r8
> > -#  endif
> > -       jbe     L(CopyVecSizeTailCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -       jnz     L(CopyVecSizeTail)
> > -
> > -       vpcmpb  $0, VEC_SIZE(%rsi), %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> >
> > -# ifdef USE_AS_STRNCPY
> > -       add     $VEC_SIZE, %r10
> > -       cmp     %r10, %r8
> > -       jbe     L(CopyTwoVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -       jnz     L(CopyTwoVecSize)
> > -
> > -       VMOVU   (%rsi, %rcx), %YMM2   /* copy VEC_SIZE bytes */
> > -       VMOVU   %YMM2, (%rdi)
> > -
> > -/* If source address alignment != destination address alignment */
> > -       .p2align 4
> > -L(UnalignVecSizeBoth):
> > -       sub     %rcx, %rdi
> > -# ifdef USE_AS_STRNCPY
> > -       add     %rcx, %r8
> > -       sbb     %rcx, %rcx
> > -       or      %rcx, %r8
> > -# endif
> > -       mov     $VEC_SIZE, %rcx
> > -       VMOVA   (%rsi, %rcx), %YMM2
> > -       VMOVU   %YMM2, (%rdi, %rcx)
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM2
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $(VEC_SIZE * 3), %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec2)
> > +# ifdef USE_AS_STPCPY
> > +#  define END_REG      rax
> >  # else
> > -       jnz     L(CopyVecSize)
> > +#  define END_REG      rdi, %rdx, CHAR_SIZE
> >  # endif
> >
> > -       VMOVU   %YMM2, (%rdi, %rcx)
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM3
> > -       vpcmpb  $0, %YMM3, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec3)
> > +# ifdef USE_AS_STRCAT
> > +#  define PAGE_ALIGN_REG       edx
> > +#  define PAGE_ALIGN_REG_64    rdx
> >  # else
> > -       jnz     L(CopyVecSize)
> > +#  define PAGE_ALIGN_REG       eax
> > +#  define PAGE_ALIGN_REG_64    rax
> >  # endif
> >
> > -       VMOVU   %YMM3, (%rdi, %rcx)
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM4
> > -       vpcmpb  $0, %YMM4, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec4)
> > -# else
> > -       jnz     L(CopyVecSize)
> > -# endif
> > +# define VZERO VMM(7)
> > +# define VZERO_128     VMM_128(7)
> >
> > -       VMOVU   %YMM4, (%rdi, %rcx)
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM2
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec2)
> > -# else
> > -       jnz     L(CopyVecSize)
> > -# endif
> >
> > -       VMOVU   %YMM2, (%rdi, %rcx)
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM2
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec2)
> > -# else
> > -       jnz     L(CopyVecSize)
> > -# endif
> > +# define PAGE_SIZE     4096
> > +# define CHAR_PER_VEC  (VEC_SIZE / CHAR_SIZE)
> >
> > -       VMOVA   VEC_SIZE(%rsi, %rcx), %YMM3
> > -       VMOVU   %YMM2, (%rdi, %rcx)
> > -       vpcmpb  $0, %YMM3, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > -       add     $VEC_SIZE, %rcx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec3)
> > -# else
> > -       jnz     L(CopyVecSize)
> > -# endif
> >
> > -       VMOVU   %YMM3, (%rdi, %rcx)
> > -       mov     %rsi, %rdx
> > -       lea     VEC_SIZE(%rsi, %rcx), %rsi
> > -       and     $-(VEC_SIZE * 4), %rsi
> > -       sub     %rsi, %rdx
> > -       sub     %rdx, %rdi
> > -# ifdef USE_AS_STRNCPY
> > -       lea     (VEC_SIZE * 8)(%r8, %rdx), %r8
> > -# endif
> > -L(UnalignedFourVecSizeLoop):
> > -       VMOVA   (%rsi), %YMM4
> > -       VMOVA   VEC_SIZE(%rsi), %YMM5
> > -       VMOVA   (VEC_SIZE * 2)(%rsi), %YMM6
> > -       VMOVA   (VEC_SIZE * 3)(%rsi), %YMM7
> > -       vpminub %YMM5, %YMM4, %YMM2
> > -       vpminub %YMM7, %YMM6, %YMM3
> > -       vpminub %YMM2, %YMM3, %YMM2
> > -       /* If K7 != 0, there is a null byte.  */
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k7
> > -       kmovd   %k7, %edx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $(VEC_SIZE * 4), %r8
> > -       jbe     L(UnalignedLeaveCase2OrCase3)
> > +       .section SECTION(.text), "ax", @progbits
> > +ENTRY(STRCPY)
> > +# ifdef USE_AS_STRCAT
> > +       movq    %rdi, %rax
> > +#  include "strcat-strlen-evex.S"
> >  # endif
> > -       test    %edx, %edx
> > -       jnz     L(UnalignedFourVecSizeLeave)
> > -
> > -L(UnalignedFourVecSizeLoop_start):
> > -       add     $(VEC_SIZE * 4), %rdi
> > -       add     $(VEC_SIZE * 4), %rsi
> > -       VMOVU   %YMM4, -(VEC_SIZE * 4)(%rdi)
> > -       VMOVA   (%rsi), %YMM4
> > -       VMOVU   %YMM5, -(VEC_SIZE * 3)(%rdi)
> > -       VMOVA   VEC_SIZE(%rsi), %YMM5
> > -       vpminub %YMM5, %YMM4, %YMM2
> > -       VMOVU   %YMM6, -(VEC_SIZE * 2)(%rdi)
> > -       VMOVA   (VEC_SIZE * 2)(%rsi), %YMM6
> > -       VMOVU   %YMM7, -VEC_SIZE(%rdi)
> > -       VMOVA   (VEC_SIZE * 3)(%rsi), %YMM7
> > -       vpminub %YMM7, %YMM6, %YMM3
> > -       vpminub %YMM2, %YMM3, %YMM2
> > -       /* If K7 != 0, there is a null byte.  */
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k7
> > -       kmovd   %k7, %edx
> > -# ifdef USE_AS_STRNCPY
> > -       sub     $(VEC_SIZE * 4), %r8
> > -       jbe     L(UnalignedLeaveCase2OrCase3)
> > +
> > +       movl    %esi, %PAGE_ALIGN_REG
> > +       andl    $(PAGE_SIZE - 1), %PAGE_ALIGN_REG
> > +       cmpl    $(PAGE_SIZE - VEC_SIZE), %PAGE_ALIGN_REG
> > +       ja      L(page_cross)
> > +L(page_cross_continue):
> > +       VMOVU   (%rsi), %VMM(0)
> > +# if !defined USE_AS_STPCPY && !defined USE_AS_STRCAT
> > +       movq    %rdi, %rax
> >  # endif
> > -       test    %edx, %edx
> > -       jz      L(UnalignedFourVecSizeLoop_start)
> >
> > -L(UnalignedFourVecSizeLeave):
> > -       vpcmpb  $0, %YMM4, %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       test    %edx, %edx
> > -       jnz     L(CopyVecSizeUnaligned_0)
> >
> > -       vpcmpb  $0, %YMM5, %YMMZERO, %k2
> > -       kmovd   %k2, %ecx
> > -       test    %ecx, %ecx
> > -       jnz     L(CopyVecSizeUnaligned_16)
> > +       /* Two short string implementations. One with traditional
> > +          branching approach and one with masked instructions (which
> > +          have potential for dramatically bad perf if dst splits a
> > +          page and is not in the TLB).  */
> > +# if USE_EVEX_MASKED_STORE
> > +       VPTEST  %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +#  ifdef USE_AS_WCSCPY
> > +       subl    $((1 << CHAR_PER_VEC)- 1), %VRCX
> > +#  else
> > +       inc     %VRCX
> > +#  endif
> > +       jz      L(more_1x_vec)
> > +       KMOV    %VRCX, %k1
> > +       KXOR    %k0, %k1, %k1
> >
> > -       vpcmpb  $0, %YMM6, %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       test    %edx, %edx
> > -       jnz     L(CopyVecSizeUnaligned_32)
> > -
> > -       vpcmpb  $0, %YMM7, %YMMZERO, %k4
> > -       kmovd   %k4, %ecx
> > -       bsf     %ecx, %edx
> > -       VMOVU   %YMM4, (%rdi)
> > -       VMOVU   %YMM5, VEC_SIZE(%rdi)
> > -       VMOVU   %YMM6, (VEC_SIZE * 2)(%rdi)
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -# ifdef USE_AS_STPCPY
> > -       lea     (VEC_SIZE * 3)(%rdi, %rdx), %rax
> > -# endif
> > -       VMOVU   %YMM7, (VEC_SIZE * 3)(%rdi)
> > -       add     $(VEC_SIZE - 1), %r8
> > -       sub     %rdx, %r8
> > -       lea     ((VEC_SIZE * 3) + 1)(%rdi, %rdx), %rdi
> > -       jmp     L(StrncpyFillTailWithZero)
> > -# else
> > -       add     $(VEC_SIZE * 3), %rsi
> > -       add     $(VEC_SIZE * 3), %rdi
> > -       jmp     L(CopyVecSizeExit)
> > -# endif
> > +       VMOVU_MASK %VMM(0), (%rdi){%k1}
> >
> > -/* If source address alignment == destination address alignment */
> > +#  ifdef USE_AS_STPCPY
> > +       bsf     %VRCX, %VRCX
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rax
> > +#  endif
> > +       ret
> >
> > -L(SourceStringAlignmentLessTwoVecSize):
> > -       VMOVU   (%rsi), %YMM3
> > -       VMOVU   VEC_SIZE(%rsi), %YMM2
> > -       vpcmpb  $0, %YMM3, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> > +# else
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jz      L(more_1x_vec)
> >
> > -# ifdef USE_AS_STRNCPY
> > -#  if defined USE_AS_STPCPY || defined USE_AS_STRCAT
> > -       cmp     $VEC_SIZE, %r8
> > +       xorl    %edx, %edx
> > +       bsf     %VRCX, %VRDX
> > +#  ifdef USE_AS_STPCPY
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#  endif
> > +
> > +       /* Use mask bits in rcx to detect which copy we need. If the low
> > +          mask is zero then there must be a bit set in the upper half.
> > +          I.e if rcx != 0 and ecx == 0, then match must be upper 32
> > +          bits so we use L(copy_32_63).  */
> > +#  if VEC_SIZE == 64
> > +#   ifdef USE_AS_WCSCPY
> > +       testb   %cl, %cl
> > +#   else
> > +       testl   %ecx, %ecx
> > +#   endif
> > +       jz      L(copy_32_63)
> > +#  endif
> > +
> > +#  ifdef USE_AS_WCSCPY
> > +       testb   $0xf, %cl
> >  #  else
> > -       cmp     $(VEC_SIZE + 1), %r8
> > +       testw   %cx, %cx
> >  #  endif
> > -       jbe     L(CopyVecSizeTail1Case2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -       jnz     L(CopyVecSizeTail1)
> > +       jz      L(copy_16_31)
> >
> > -       VMOVU   %YMM3, (%rdi)
> > -       vpcmpb  $0, %YMM2, %YMMZERO, %k0
> > -       kmovd   %k0, %edx
> >
> > -# ifdef USE_AS_STRNCPY
> > -#  if defined USE_AS_STPCPY || defined USE_AS_STRCAT
> > -       cmp     $(VEC_SIZE * 2), %r8
> > +#  ifdef USE_AS_WCSCPY
> > +       testb   $0x3, %cl
> >  #  else
> > -       cmp     $((VEC_SIZE * 2) + 1), %r8
> > +       testb   %cl, %cl
> >  #  endif
> > -       jbe     L(CopyTwoVecSize1Case2OrCase3)
> > -# endif
> > -       test    %edx, %edx
> > -       jnz     L(CopyTwoVecSize1)
> > -
> > -       and     $-VEC_SIZE, %rsi
> > -       and     $(VEC_SIZE - 1), %ecx
> > -       jmp     L(UnalignVecSizeBoth)
> > +       jz      L(copy_8_15)
> >
> > -/*------End of main part with loops---------------------*/
> >
> > -/* Case1 */
> > +#  ifdef USE_AS_WCSCPY
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       /* No need to copy, we know its zero.  */
> > +       movl    $0, (%END_REG)
> >
> > -# if (!defined USE_AS_STRNCPY) || (defined USE_AS_STRCAT)
> > -       .p2align 4
> > -L(CopyVecSize):
> > -       add     %rcx, %rdi
> > -# endif
> > -L(CopyVecSizeTail):
> > -       add     %rcx, %rsi
> > -L(CopyVecSizeTail1):
> > -       bsf     %edx, %edx
> > -L(CopyVecSizeExit):
> > -       cmp     $32, %edx
> > -       jae     L(Exit32_63)
> > -       cmp     $16, %edx
> > -       jae     L(Exit16_31)
> > -       cmp     $8, %edx
> > -       jae     L(Exit8_15)
> > -       cmp     $4, %edx
> > -       jae     L(Exit4_7)
> > -       cmp     $3, %edx
> > -       je      L(Exit3)
> > -       cmp     $1, %edx
> > -       ja      L(Exit2)
> > -       je      L(Exit1)
> > -       movb    $0, (%rdi)
> > -# ifdef USE_AS_STPCPY
> > -       lea     (%rdi), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     $1, %r8
> > -       lea     1(%rdi), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > -# endif
> >         ret
> > +#  else
> >
> > -       .p2align 4
> > -L(CopyTwoVecSize1):
> > -       add     $VEC_SIZE, %rsi
> > -       add     $VEC_SIZE, %rdi
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     $VEC_SIZE, %r8
> > -# endif
> > -       jmp     L(CopyVecSizeTail1)
> > -
> > -       .p2align 4
> > -L(CopyTwoVecSize):
> > -       bsf     %edx, %edx
> > -       add     %rcx, %rsi
> > -       add     $VEC_SIZE, %edx
> > -       sub     %ecx, %edx
> > -       jmp     L(CopyVecSizeExit)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeUnaligned_0):
> > -       bsf     %edx, %edx
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -# ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > -# endif
> > -       VMOVU   %YMM4, (%rdi)
> > -       add     $((VEC_SIZE * 4) - 1), %r8
> > -       sub     %rdx, %r8
> > -       lea     1(%rdi, %rdx), %rdi
> > -       jmp     L(StrncpyFillTailWithZero)
> > -# else
> > -       jmp     L(CopyVecSizeExit)
> > -# endif
> > +       testb   $0x7, %cl
> > +       jz      L(copy_4_7)
> >
> > -       .p2align 4
> > -L(CopyVecSizeUnaligned_16):
> > -       bsf     %ecx, %edx
> > -       VMOVU   %YMM4, (%rdi)
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -# ifdef USE_AS_STPCPY
> > -       lea     VEC_SIZE(%rdi, %rdx), %rax
> > -# endif
> > -       VMOVU   %YMM5, VEC_SIZE(%rdi)
> > -       add     $((VEC_SIZE * 3) - 1), %r8
> > -       sub     %rdx, %r8
> > -       lea     (VEC_SIZE + 1)(%rdi, %rdx), %rdi
> > -       jmp     L(StrncpyFillTailWithZero)
> > -# else
> > -       add     $VEC_SIZE, %rsi
> > -       add     $VEC_SIZE, %rdi
> > -       jmp     L(CopyVecSizeExit)
> > -# endif
> >
> > -       .p2align 4
> > -L(CopyVecSizeUnaligned_32):
> > -       bsf     %edx, %edx
> > -       VMOVU   %YMM4, (%rdi)
> > -       VMOVU   %YMM5, VEC_SIZE(%rdi)
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -# ifdef USE_AS_STPCPY
> > -       lea     (VEC_SIZE * 2)(%rdi, %rdx), %rax
> > -# endif
> > -       VMOVU   %YMM6, (VEC_SIZE * 2)(%rdi)
> > -       add     $((VEC_SIZE * 2) - 1), %r8
> > -       sub     %rdx, %r8
> > -       lea     ((VEC_SIZE * 2) + 1)(%rdi, %rdx), %rdi
> > -       jmp     L(StrncpyFillTailWithZero)
> > -# else
> > -       add     $(VEC_SIZE * 2), %rsi
> > -       add     $(VEC_SIZE * 2), %rdi
> > -       jmp     L(CopyVecSizeExit)
> > -# endif
> > +       test    %edx, %edx
> > +       jz      L(set_null_term)
> >
> > -# ifdef USE_AS_STRNCPY
> > -#  ifndef USE_AS_STRCAT
> > -       .p2align 4
> > -L(CopyVecSizeUnalignedVec6):
> > -       VMOVU   %YMM6, (%rdi, %rcx)
> > -       jmp     L(CopyVecSizeVecExit)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeUnalignedVec5):
> > -       VMOVU   %YMM5, (%rdi, %rcx)
> > -       jmp     L(CopyVecSizeVecExit)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeUnalignedVec4):
> > -       VMOVU   %YMM4, (%rdi, %rcx)
> > -       jmp     L(CopyVecSizeVecExit)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeUnalignedVec3):
> > -       VMOVU   %YMM3, (%rdi, %rcx)
> > -       jmp     L(CopyVecSizeVecExit)
> > +       /* NB: make this `vmovw` if support for AVX512-FP16 is added.
> > +        */
> > +       vmovd   %VMM_128(0), %esi
> > +       movw    %si, (%rdi)
> > +
> > +       .p2align 4,, 1
> > +L(set_null_term):
> > +       /* No need to copy, we know its zero.  */
> > +       movb    $0, (%END_REG)
> > +       ret
> >  #  endif
> >
> > -/* Case2 */
> > -
> > -       .p2align 4
> > -L(CopyVecSizeCase2):
> > -       add     $VEC_SIZE, %r8
> > -       add     %rcx, %rdi
> > -       add     %rcx, %rsi
> > -       bsf     %edx, %edx
> > -       cmp     %r8d, %edx
> > -       jb      L(CopyVecSizeExit)
> > -       jmp     L(StrncpyExit)
> > -
> > -       .p2align 4
> > -L(CopyTwoVecSizeCase2):
> > -       add     %rcx, %rsi
> > -       bsf     %edx, %edx
> > -       add     $VEC_SIZE, %edx
> > -       sub     %ecx, %edx
> > -       cmp     %r8d, %edx
> > -       jb      L(CopyVecSizeExit)
> > -       jmp     L(StrncpyExit)
> > -
> > -L(CopyVecSizeTailCase2):
> > -       add     %rcx, %rsi
> > -       bsf     %edx, %edx
> > -       cmp     %r8d, %edx
> > -       jb      L(CopyVecSizeExit)
> > -       jmp     L(StrncpyExit)
> > -
> > -L(CopyVecSizeTail1Case2):
> > -       bsf     %edx, %edx
> > -       cmp     %r8d, %edx
> > -       jb      L(CopyVecSizeExit)
> > -       jmp     L(StrncpyExit)
> > -
> > -/* Case2 or Case3,  Case3 */
> > -
> > -       .p2align 4
> > -L(CopyVecSizeCase2OrCase3):
> > -       test    %rdx, %rdx
> > -       jnz     L(CopyVecSizeCase2)
> > -L(CopyVecSizeCase3):
> > -       add     $VEC_SIZE, %r8
> > -       add     %rcx, %rdi
> > -       add     %rcx, %rsi
> > -       jmp     L(StrncpyExit)
> > -
> > -       .p2align 4
> > -L(CopyTwoVecSizeCase2OrCase3):
> > -       test    %rdx, %rdx
> > -       jnz     L(CopyTwoVecSizeCase2)
> > -       add     %rcx, %rsi
> > -       jmp     L(StrncpyExit)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeTailCase2OrCase3):
> > -       test    %rdx, %rdx
> > -       jnz     L(CopyVecSizeTailCase2)
> > -       add     %rcx, %rsi
> > -       jmp     L(StrncpyExit)
> > -
> > -       .p2align 4
> > -L(CopyTwoVecSize1Case2OrCase3):
> > -       add     $VEC_SIZE, %rdi
> > -       add     $VEC_SIZE, %rsi
> > -       sub     $VEC_SIZE, %r8
> > -L(CopyVecSizeTail1Case2OrCase3):
> > -       test    %rdx, %rdx
> > -       jnz     L(CopyVecSizeTail1Case2)
> > -       jmp     L(StrncpyExit)
> > +#  if VEC_SIZE == 64
> > +       .p2align 4,, 6
> > +L(copy_32_63):
> > +       VMOVU   -(32 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1)
> > +       VMOVU   %VMM_256(0), (%rdi)
> > +       VMOVU   %VMM_256(1), -(32 - CHAR_SIZE)(%END_REG)
> > +       ret
> > +#  endif
> > +
> > +
> > +       .p2align 4,, 6
> > +L(copy_16_31):
> > +       /* Use xmm1 explicitly here as it won't require a `vzeroupper`
> > +          and will save code size.  */
> > +       vmovdqu -(16 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %xmm1
> > +       VMOVU   %VMM_128(0), (%rdi)
> > +       vmovdqu %xmm1, -(16 - CHAR_SIZE)(%END_REG)
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(copy_8_15):
> > +#  ifdef USE_AS_WCSCPY
> > +       movl    -(8 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %ecx
> > +#  else
> > +       movq    -(8 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %rcx
> > +#  endif
> > +       vmovq   %VMM_128(0), (%rdi)
> > +       movq    %rcx, -(8 - CHAR_SIZE)(%END_REG)
> > +       ret
> >  # endif
> >
> > -/*------------End labels regarding with copying 1-VEC_SIZE bytes--and 1-(VEC_SIZE*2) bytes----*/
> >
> > -       .p2align 4
> > -L(Exit1):
> > -       movzwl  (%rsi), %edx
> > -       mov     %dx, (%rdi)
> > -# ifdef USE_AS_STPCPY
> > -       lea     1(%rdi), %rax
> > +# ifndef USE_AS_WCSCPY
> > +       .p2align 4,, 12
> > +L(copy_4_7):
> > +       movl    -(4 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %ecx
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       movl    %ecx, -(4 - CHAR_SIZE)(%END_REG)
> > +       ret
> >  # endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     $2, %r8
> > -       lea     2(%rdi), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +
> > +
> > +       .p2align 4,, 8
> > +L(more_1x_vec):
> > +# if defined USE_AS_STPCPY || defined USE_AS_STRCAT
> > +       VMOVU   %VMM(0), (%rdi)
> >  # endif
> > -       ret
> > +       subq    %rsi, %rdi
> > +       andq    $-(VEC_SIZE), %rsi
> > +       addq    %rsi, %rdi
> > +       VMOVA   (VEC_SIZE * 1)(%rsi), %VMM(1)
> >
> > -       .p2align 4
> > -L(Exit2):
> > -       movzwl  (%rsi), %ecx
> > -       mov     %cx, (%rdi)
> > -       movb    $0, 2(%rdi)
> > +       /* Ideally we store after moves to minimize impact of potential
> > +          false-dependencies.  */
> > +# if !defined USE_AS_STPCPY && !defined USE_AS_STRCAT
> > +       VMOVU   %VMM(0), (%rax)
> > +# endif
> > +
> > +       VPTESTN %VMM(1), %VMM(1), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x1)
> > +
> > +       VMOVA   (VEC_SIZE * 2)(%rsi), %VMM(2)
> > +       VMOVU   %VMM(1), VEC_SIZE(%rdi)
> > +
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x2)
> > +
> > +       VMOVA   (VEC_SIZE * 3)(%rsi), %VMM(3)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 2)(%rdi)
> > +
> > +       VPTESTN %VMM(3), %VMM(3), %k0
> > +       KMOV    %k0, %VRDX
> > +       test    %VRDX, %VRDX
> > +       jnz     L(ret_vec_x3)
> > +
> > +       VMOVA   (VEC_SIZE * 4)(%rsi), %VMM(4)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       VPTESTN %VMM(4), %VMM(4), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x4)
> > +
> > +       VMOVU   %VMM(4), (VEC_SIZE * 4)(%rdi)
> > +
> > +
> > +       /* Align for 4x loop.  */
> > +       subq    %rsi, %rdi
> > +
> > +       /* + VEC_SIZE * 5 because we never added the original VEC_SIZE
> > +          we covered before aligning.  */
> > +       subq    $-(VEC_SIZE * 5), %rsi
> > +       andq    $-(VEC_SIZE * 4), %rsi
> > +
> > +
> > +       /* Load first half of the loop before entry.  */
> > +       VMOVA   (VEC_SIZE * 0 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(3)
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +       KORTEST %k2, %k4
> > +       jnz     L(loop_4x_done)
> > +
> > +       .p2align 4,, 11
> > +L(loop_4x_vec):
> > +
> > +       VMOVU   %VMM(0), (VEC_SIZE * 0 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 2 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3 + 0)(%rdi, %rsi)
> > +
> > +       subq    $(VEC_SIZE * -4), %rsi
> > +
> > +       VMOVA   (VEC_SIZE * 0 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(3)
> > +
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +       KORTEST %k2, %k4
> > +       jz      L(loop_4x_vec)
> > +
> > +L(loop_4x_done):
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +       /* Restore rdi (%rdi).  */
> > +       addq    %rsi, %rdi
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x0_end)
> > +       VMOVU   %VMM(0), (VEC_SIZE * 0 + 0)(%rdi)
> > +
> > +       KMOV    %k2, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x1)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1 + 0)(%rdi)
> > +
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x2)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 2 + 0)(%rdi)
> > +       /* Place L(ret_vec_x4) here to save code size.  We get a
> > +          meaningfuly benefit doing this for stpcpy.  */
> > +       KMOV    %k4, %VRDX
> > +L(ret_vec_x3):
> > +       bsf     %VRDX, %VRDX
> > +       VMOVU   ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 3 + 0)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> >  # ifdef USE_AS_STPCPY
> > -       lea     2(%rdi), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     $3, %r8
> > -       lea     3(%rdi), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +       leaq    (VEC_SIZE * 3 + 0)(%rdi, %rdx, CHAR_SIZE), %rax
> >  # endif
> > +L(return_end):
> >         ret
> >
> > -       .p2align 4
> > -L(Exit3):
> > -       mov     (%rsi), %edx
> > -       mov     %edx, (%rdi)
> > +       .p2align 4,, 6
> > +L(ret_vec_x0_end):
> > +       bsf     %VRCX, %VRCX
> >  # ifdef USE_AS_STPCPY
> > -       lea     3(%rdi), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     $4, %r8
> > -       lea     4(%rdi), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rax
> >  # endif
> > +       inc     %VRCX
> > +       VMOVU   (-(VEC_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), (-(VEC_SIZE))(%rdi, %rcx, CHAR_SIZE)
> >         ret
> >
> > -       .p2align 4
> > -L(Exit4_7):
> > -       mov     (%rsi), %ecx
> > -       mov     %ecx, (%rdi)
> > -       mov     -3(%rsi, %rdx), %ecx
> > -       mov     %ecx, -3(%rdi, %rdx)
> > +       .p2align 4,, 8
> > +L(ret_vec_x1):
> > +       bsf     %VRCX, %VRCX
> > +       VMOVU   (VEC_SIZE -(VEC_SIZE - CHAR_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), (VEC_SIZE -(VEC_SIZE - CHAR_SIZE))(%rdi, %rcx, CHAR_SIZE)
> >  # ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     %rdx, %r8
> > -       sub     $1, %r8
> > -       lea     1(%rdi, %rdx), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +       leaq    VEC_SIZE(%rdi, %rcx, CHAR_SIZE), %rax
> >  # endif
> >         ret
> >
> > -       .p2align 4
> > -L(Exit8_15):
> > -       mov     (%rsi), %rcx
> > -       mov     -7(%rsi, %rdx), %r9
> > -       mov     %rcx, (%rdi)
> > -       mov     %r9, -7(%rdi, %rdx)
> > +       .p2align 4,, 4
> > +L(ret_vec_x2):
> > +       bsf     %VRCX, %VRCX
> > +       VMOVU   ((VEC_SIZE * 2)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 2)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rcx, CHAR_SIZE)
> >  # ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     %rdx, %r8
> > -       sub     $1, %r8
> > -       lea     1(%rdi, %rdx), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +       leaq    (VEC_SIZE * 2)(%rdi, %rcx, CHAR_SIZE), %rax
> >  # endif
> >         ret
> >
> > -       .p2align 4
> > -L(Exit16_31):
> > -       VMOVU   (%rsi), %XMM2
> > -       VMOVU   -15(%rsi, %rdx), %XMM3
> > -       VMOVU   %XMM2, (%rdi)
> > -       VMOVU   %XMM3, -15(%rdi, %rdx)
> > +       /* ret_vec_x3 reuses return code after the loop.  */
> > +       .p2align 4,, 6
> > +L(ret_vec_x4):
> > +       bsf     %VRCX, %VRCX
> > +       VMOVU   ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rcx, CHAR_SIZE)
> >  # ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > -# endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub %rdx, %r8
> > -       sub $1, %r8
> > -       lea 1(%rdi, %rdx), %rdi
> > -       jnz L(StrncpyFillTailWithZero)
> > +       leaq    (VEC_SIZE * 4)(%rdi, %rcx, CHAR_SIZE), %rax
> >  # endif
> >         ret
> >
> > -       .p2align 4
> > -L(Exit32_63):
> > -       VMOVU   (%rsi), %YMM2
> > -       VMOVU   -31(%rsi, %rdx), %YMM3
> > -       VMOVU   %YMM2, (%rdi)
> > -       VMOVU   %YMM3, -31(%rdi, %rdx)
> > -# ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > +
> > +       .p2align 4,, 4
> > +L(page_cross):
> > +# ifndef USE_AS_STRCAT
> > +       vpxorq  %VZERO_128, %VZERO_128, %VZERO_128
> >  # endif
> > -# if defined USE_AS_STRNCPY && !defined USE_AS_STRCAT
> > -       sub     %rdx, %r8
> > -       sub     $1, %r8
> > -       lea     1(%rdi, %rdx), %rdi
> > -       jnz     L(StrncpyFillTailWithZero)
> > +       movq    %rsi, %rcx
> > +       andq    $(VEC_SIZE * -1), %rcx
> > +
> > +       VPCMPEQ (%rcx), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +# ifdef USE_AS_WCSCPY
> > +       andl    $(VEC_SIZE - 1), %PAGE_ALIGN_REG
> > +       shrl    $2, %PAGE_ALIGN_REG
> >  # endif
> > -       ret
> > +       shrx    %VGPR(PAGE_ALIGN_REG_64), %VRCX, %VRCX
> >
> > -# ifdef USE_AS_STRNCPY
> > +# if USE_MOVSB_IN_PAGE_CROSS
> > +       /* Optimizing more aggressively for space as this is very cold
> > +          code. This saves 2x cache lines.  */
> >
> > -       .p2align 4
> > -L(StrncpyExit1):
> > -       movzbl  (%rsi), %edx
> > -       mov     %dl, (%rdi)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     1(%rdi), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, 1(%rdi)
> > +       /* This adds once to the later result which will get correct
> > +          copy bounds. NB: this can never zero-out a non-zero RCX as
> > +          to be in the page cross case rsi cannot be aligned and we
> > +          already right-shift rcx by the misalignment.  */
> > +       shl     %VRCX
> > +       jz      L(page_cross_continue)
> > +#  if !defined USE_AS_STPCPY && !defined USE_AS_STRCAT
> > +       movq    %rdi, %rax
> >  #  endif
> > -       ret
> > +       bsf     %VRCX, %VRCX
> > +       REP_MOVS
> >
> > -       .p2align 4
> > -L(StrncpyExit2):
> > -       movzwl  (%rsi), %edx
> > -       mov     %dx, (%rdi)
> >  #  ifdef USE_AS_STPCPY
> > -       lea     2(%rdi), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, 2(%rdi)
> > +       leaq    -CHAR_SIZE(%rdi), %rax
> >  #  endif
> >         ret
> >
> > -       .p2align 4
> > -L(StrncpyExit3_4):
> > -       movzwl  (%rsi), %ecx
> > -       movzwl  -2(%rsi, %r8), %edx
> > -       mov     %cx, (%rdi)
> > -       mov     %dx, -2(%rdi, %r8)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %r8), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi, %r8)
> > -#  endif
> > -       ret
> >
> > -       .p2align 4
> > -L(StrncpyExit5_8):
> > -       mov     (%rsi), %ecx
> > -       mov     -4(%rsi, %r8), %edx
> > -       mov     %ecx, (%rdi)
> > -       mov     %edx, -4(%rdi, %r8)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %r8), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi, %r8)
> > -#  endif
> > -       ret
> > +# else
> > +       /* Check if we found zero-char before end of page.  */
> > +       test    %VRCX, %VRCX
> > +       jz      L(page_cross_continue)
> >
> > -       .p2align 4
> > -L(StrncpyExit9_16):
> > -       mov     (%rsi), %rcx
> > -       mov     -8(%rsi, %r8), %rdx
> > -       mov     %rcx, (%rdi)
> > -       mov     %rdx, -8(%rdi, %r8)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %r8), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi, %r8)
> > -#  endif
> > -       ret
> > +       /* Traditional copy case, essentially same as used in non-page-
> > +          cross case but since we can't reuse VMM(0) we need twice as
> > +          many loads from rsi.  */
> >
> > -       .p2align 4
> > -L(StrncpyExit17_32):
> > -       VMOVU   (%rsi), %XMM2
> > -       VMOVU   -16(%rsi, %r8), %XMM3
> > -       VMOVU   %XMM2, (%rdi)
> > -       VMOVU   %XMM3, -16(%rdi, %r8)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %r8), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi, %r8)
> > +#  ifndef USE_AS_STRCAT
> > +       xorl    %edx, %edx
> >  #  endif
> > -       ret
> > -
> > -       .p2align 4
> > -L(StrncpyExit33_64):
> > -       /*  0/32, 31/16 */
> > -       VMOVU   (%rsi), %YMM2
> > -       VMOVU   -VEC_SIZE(%rsi, %r8), %YMM3
> > -       VMOVU   %YMM2, (%rdi)
> > -       VMOVU   %YMM3, -VEC_SIZE(%rdi, %r8)
> > +       /* Dependency on rdi must already have been satisfied.  */
> > +       bsf     %VRCX, %VRDX
> >  #  ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %r8), %rax
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#  elif !defined USE_AS_STRCAT
> > +       movq    %rdi, %rax
> >  #  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi, %r8)
> > -#  endif
> > -       ret
> >
> > -       .p2align 4
> > -L(StrncpyExit65):
> > -       /* 0/32, 32/32, 64/1 */
> > -       VMOVU   (%rsi), %YMM2
> > -       VMOVU   32(%rsi), %YMM3
> > -       mov     64(%rsi), %cl
> > -       VMOVU   %YMM2, (%rdi)
> > -       VMOVU   %YMM3, 32(%rdi)
> > -       mov     %cl, 64(%rdi)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     65(%rdi), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, 65(%rdi)
> > +#  if VEC_SIZE == 64
> > +#   ifdef USE_AS_WCSCPY
> > +       testb   %cl, %cl
> > +#   else
> > +       test    %ecx, %ecx
> > +#   endif
> > +       jz      L(page_cross_copy_32_63)
> >  #  endif
> > -       ret
> > -
> > -#  ifndef USE_AS_STRCAT
> >
> > -       .p2align 4
> > -L(Fill1):
> > -       mov     %dl, (%rdi)
> > -       ret
> > +#  ifdef USE_AS_WCSCPY
> > +       testb   $0xf, %cl
> > +#  else
> > +       testw   %cx, %cx
> > +#  endif
> > +       jz      L(page_cross_copy_16_31)
> >
> > -       .p2align 4
> > -L(Fill2):
> > -       mov     %dx, (%rdi)
> > -       ret
> > +#  ifdef USE_AS_WCSCPY
> > +       testb   $0x3, %cl
> > +#  else
> > +       testb   %cl, %cl
> > +#  endif
> > +       jz      L(page_cross_copy_8_15)
> >
> > -       .p2align 4
> > -L(Fill3_4):
> > -       mov     %dx, (%rdi)
> > -       mov     %dx, -2(%rdi, %r8)
> > +#  ifdef USE_AS_WCSCPY
> > +       movl    (%rsi), %esi
> > +       movl    %esi, (%rdi)
> > +       movl    $0, (%END_REG)
> >         ret
> > +#  else
> >
> > -       .p2align 4
> > -L(Fill5_8):
> > -       mov     %edx, (%rdi)
> > -       mov     %edx, -4(%rdi, %r8)
> > -       ret
> > +       testb   $0x7, %cl
> > +       jz      L(page_cross_copy_4_7)
> >
> > -       .p2align 4
> > -L(Fill9_16):
> > -       mov     %rdx, (%rdi)
> > -       mov     %rdx, -8(%rdi, %r8)
> > +       test    %edx, %edx
> > +       jz      L(page_cross_set_null_term)
> > +       movzwl  (%rsi), %ecx
> > +       movw    %cx, (%rdi)
> > +L(page_cross_set_null_term):
> > +       movb    $0, (%END_REG)
> >         ret
> >
> > -       .p2align 4
> > -L(Fill17_32):
> > -       VMOVU   %XMMZERO, (%rdi)
> > -       VMOVU   %XMMZERO, -16(%rdi, %r8)
> > -       ret
> >
> > -       .p2align 4
> > -L(CopyVecSizeUnalignedVec2):
> > -       VMOVU   %YMM2, (%rdi, %rcx)
> > -
> > -       .p2align 4
> > -L(CopyVecSizeVecExit):
> > -       bsf     %edx, %edx
> > -       add     $(VEC_SIZE - 1), %r8
> > -       add     %rcx, %rdi
> > -#   ifdef USE_AS_STPCPY
> > -       lea     (%rdi, %rdx), %rax
> > -#   endif
> > -       sub     %rdx, %r8
> > -       lea     1(%rdi, %rdx), %rdi
> > -
> > -       .p2align 4
> > -L(StrncpyFillTailWithZero):
> > -       xor     %edx, %edx
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(StrncpyFillExit)
> > -
> > -       VMOVU   %YMMZERO, (%rdi)
> > -       add     $VEC_SIZE, %rdi
> > -
> > -       mov     %rdi, %rsi
> > -       and     $(VEC_SIZE - 1), %esi
> > -       sub     %rsi, %rdi
> > -       add     %rsi, %r8
> > -       sub     $(VEC_SIZE * 4), %r8
> > -       jb      L(StrncpyFillLessFourVecSize)
> > -
> > -L(StrncpyFillLoopVmovdqa):
> > -       VMOVA   %YMMZERO, (%rdi)
> > -       VMOVA   %YMMZERO, VEC_SIZE(%rdi)
> > -       VMOVA   %YMMZERO, (VEC_SIZE * 2)(%rdi)
> > -       VMOVA   %YMMZERO, (VEC_SIZE * 3)(%rdi)
> > -       add     $(VEC_SIZE * 4), %rdi
> > -       sub     $(VEC_SIZE * 4), %r8
> > -       jae     L(StrncpyFillLoopVmovdqa)
> > -
> > -L(StrncpyFillLessFourVecSize):
> > -       add     $(VEC_SIZE * 2), %r8
> > -       jl      L(StrncpyFillLessTwoVecSize)
> > -       VMOVA   %YMMZERO, (%rdi)
> > -       VMOVA   %YMMZERO, VEC_SIZE(%rdi)
> > -       add     $(VEC_SIZE * 2), %rdi
> > -       sub     $VEC_SIZE, %r8
> > -       jl      L(StrncpyFillExit)
> > -       VMOVA   %YMMZERO, (%rdi)
> > -       add     $VEC_SIZE, %rdi
> > -       jmp     L(Fill)
> > -
> > -       .p2align 4
> > -L(StrncpyFillLessTwoVecSize):
> > -       add     $VEC_SIZE, %r8
> > -       jl      L(StrncpyFillExit)
> > -       VMOVA   %YMMZERO, (%rdi)
> > -       add     $VEC_SIZE, %rdi
> > -       jmp     L(Fill)
> > -
> > -       .p2align 4
> > -L(StrncpyFillExit):
> > -       add     $VEC_SIZE, %r8
> > -L(Fill):
> > -       cmp     $17, %r8d
> > -       jae     L(Fill17_32)
> > -       cmp     $9, %r8d
> > -       jae     L(Fill9_16)
> > -       cmp     $5, %r8d
> > -       jae     L(Fill5_8)
> > -       cmp     $3, %r8d
> > -       jae     L(Fill3_4)
> > -       cmp     $1, %r8d
> > -       ja      L(Fill2)
> > -       je      L(Fill1)
> > +       .p2align 4,, 4
> > +L(page_cross_copy_4_7):
> > +       movl    (%rsi), %ecx
> > +       movl    -(4 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %esi
> > +       movl    %ecx, (%rdi)
> > +       movl    %esi, -(4 - CHAR_SIZE)(%END_REG)
> >         ret
> > -
> > -/* end of ifndef USE_AS_STRCAT */
> >  #  endif
> >
> > -       .p2align 4
> > -L(UnalignedLeaveCase2OrCase3):
> > -       test    %rdx, %rdx
> > -       jnz     L(UnalignedFourVecSizeLeaveCase2)
> > -L(UnalignedFourVecSizeLeaveCase3):
> > -       lea     (VEC_SIZE * 4)(%r8), %rcx
> > -       and     $-VEC_SIZE, %rcx
> > -       add     $(VEC_SIZE * 3), %r8
> > -       jl      L(CopyVecSizeCase3)
> > -       VMOVU   %YMM4, (%rdi)
> > -       sub     $VEC_SIZE, %r8
> > -       jb      L(CopyVecSizeCase3)
> > -       VMOVU   %YMM5, VEC_SIZE(%rdi)
> > -       sub     $VEC_SIZE, %r8
> > -       jb      L(CopyVecSizeCase3)
> > -       VMOVU   %YMM6, (VEC_SIZE * 2)(%rdi)
> > -       sub     $VEC_SIZE, %r8
> > -       jb      L(CopyVecSizeCase3)
> > -       VMOVU   %YMM7, (VEC_SIZE * 3)(%rdi)
> > -#  ifdef USE_AS_STPCPY
> > -       lea     (VEC_SIZE * 4)(%rdi), %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (VEC_SIZE * 4)(%rdi)
> > -#  endif
> > +#  if VEC_SIZE == 64
> > +       .p2align 4,, 4
> > +L(page_cross_copy_32_63):
> > +       VMOVU   (%rsi), %VMM_256(0)
> > +       VMOVU   -(32 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1)
> > +       VMOVU   %VMM_256(0), (%rdi)
> > +       VMOVU   %VMM_256(1), -(32 - CHAR_SIZE)(%END_REG)
> >         ret
> > -
> > -       .p2align 4
> > -L(UnalignedFourVecSizeLeaveCase2):
> > -       xor     %ecx, %ecx
> > -       vpcmpb  $0, %YMM4, %YMMZERO, %k1
> > -       kmovd   %k1, %edx
> > -       add     $(VEC_SIZE * 3), %r8
> > -       jle     L(CopyVecSizeCase2OrCase3)
> > -       test    %edx, %edx
> > -#  ifndef USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec4)
> > -#  else
> > -       jnz     L(CopyVecSize)
> > -#  endif
> > -       vpcmpb  $0, %YMM5, %YMMZERO, %k2
> > -       kmovd   %k2, %edx
> > -       VMOVU   %YMM4, (%rdi)
> > -       add     $VEC_SIZE, %rcx
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -       test    %edx, %edx
> > -#  ifndef USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec5)
> > -#  else
> > -       jnz     L(CopyVecSize)
> >  #  endif
> >
> > -       vpcmpb  $0, %YMM6, %YMMZERO, %k3
> > -       kmovd   %k3, %edx
> > -       VMOVU   %YMM5, VEC_SIZE(%rdi)
> > -       add     $VEC_SIZE, %rcx
> > -       sub     $VEC_SIZE, %r8
> > -       jbe     L(CopyVecSizeCase2OrCase3)
> > -       test    %edx, %edx
> > -#  ifndef USE_AS_STRCAT
> > -       jnz     L(CopyVecSizeUnalignedVec6)
> > -#  else
> > -       jnz     L(CopyVecSize)
> > -#  endif
> > -
> > -       vpcmpb  $0, %YMM7, %YMMZERO, %k4
> > -       kmovd   %k4, %edx
> > -       VMOVU   %YMM6, (VEC_SIZE * 2)(%rdi)
> > -       lea     VEC_SIZE(%rdi, %rcx), %rdi
> > -       lea     VEC_SIZE(%rsi, %rcx), %rsi
> > -       bsf     %edx, %edx
> > -       cmp     %r8d, %edx
> > -       jb      L(CopyVecSizeExit)
> > -L(StrncpyExit):
> > -       cmp     $65, %r8d
> > -       je      L(StrncpyExit65)
> > -       cmp     $33, %r8d
> > -       jae     L(StrncpyExit33_64)
> > -       cmp     $17, %r8d
> > -       jae     L(StrncpyExit17_32)
> > -       cmp     $9, %r8d
> > -       jae     L(StrncpyExit9_16)
> > -       cmp     $5, %r8d
> > -       jae     L(StrncpyExit5_8)
> > -       cmp     $3, %r8d
> > -       jae     L(StrncpyExit3_4)
> > -       cmp     $1, %r8d
> > -       ja      L(StrncpyExit2)
> > -       je      L(StrncpyExit1)
> > -#  ifdef USE_AS_STPCPY
> > -       mov     %rdi, %rax
> > -#  endif
> > -#  ifdef USE_AS_STRCAT
> > -       movb    $0, (%rdi)
> > -#  endif
> > +       .p2align 4,, 4
> > +L(page_cross_copy_16_31):
> > +       vmovdqu (%rsi), %xmm0
> > +       vmovdqu -(16 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %xmm1
> > +       vmovdqu %xmm0, (%rdi)
> > +       vmovdqu %xmm1, -(16 - CHAR_SIZE)(%END_REG)
> >         ret
> >
> > -       .p2align 4
> > -L(ExitZero):
> > -#  ifndef USE_AS_STRCAT
> > -       mov     %rdi, %rax
> > -#  endif
> > +       .p2align 4,, 4
> > +L(page_cross_copy_8_15):
> > +       movq    (%rsi), %rcx
> > +       movq    -(8 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %rsi
> > +       movq    %rcx, (%rdi)
> > +       movq    %rsi, -(8 - CHAR_SIZE)(%END_REG)
> >         ret
> > -
> > -# endif
> > -
> > -# ifndef USE_AS_STRCAT
> > -END (STRCPY)
> > -# else
> > -END (STRCAT)
> >  # endif
> > +END(STRCPY)
> >  #endif
> > diff --git a/sysdeps/x86_64/multiarch/strncat-evex.S b/sysdeps/x86_64/multiarch/strncat-evex.S
> > index 203a19bf21..d648ba5cfe 100644
> > --- a/sysdeps/x86_64/multiarch/strncat-evex.S
> > +++ b/sysdeps/x86_64/multiarch/strncat-evex.S
> > @@ -1,7 +1,520 @@
> > -#ifndef STRNCAT
> > -# define STRNCAT       __strncat_evex
> > -#endif
> > +/* {wcs|str}ncat  with 256/512-bit EVEX.
> > +   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 <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (4)
> > +
> > +       /* Use evex-masked stores for small sizes. Turned off at the
> > +          moment.  */
> > +# define USE_EVEX_MASKED_STORE 0
> > +
> > +# include <sysdep.h>
> > +
> > +# ifndef VEC_SIZE
> > +#  include "x86-evex256-vecs.h"
> > +# endif
> > +
> > +# ifndef STRNCAT
> > +#  define STRNCAT      __strncat_evex
> > +# endif
> > +
> > +
> > +# ifdef USE_AS_WCSCPY
> > +#  define movNULL      movl
> > +#  define VMOVU_MASK   vmovdqu32
> > +#  define VPMIN        vpminud
> > +#  define VPTESTN      vptestnmd
> > +#  define VPTEST       vptestmd
> > +#  define VPCMPEQ      vpcmpeqd
> > +#  define CHAR_SIZE    4
> > +
> > +#  define REP_MOVS     rep movsd
> > +
> > +#  define VMASK_REG    VR10
> > +#  define FIND_FIRST_ONE(src, dst)     movl $CHAR_PER_VEC, %dst; bsf %src, %dst
> > +
> > +#  define USE_WIDE_CHAR
> > +# else
> > +#  define movNULL      movb
> > +#  define VMOVU_MASK   vmovdqu8
> > +#  define VPMIN        vpminub
> > +#  define VPTESTN      vptestnmb
> > +#  define VPTEST       vptestmb
> > +#  define VPCMPEQ      vpcmpeqb
> > +#  define CHAR_SIZE    1
> > +
> > +#  define REP_MOVS     rep movsb
> > +
> > +#  define VMASK_REG    VRCX
> > +#  define FIND_FIRST_ONE(src, dst)     tzcnt %src, %dst
> > +
> > +# endif
> > +
> > +# include "strncpy-or-cat-overflow-def.h"
> > +
> > +# include "reg-macros.h"
> > +
> > +
> > +# define VZERO VMM(7)
> > +# define VZERO_128     VMM_128(7)
> > +
> > +# define PAGE_SIZE     4096
> > +# define CHAR_PER_VEC  (VEC_SIZE / CHAR_SIZE)
> > +
> > +       .section SECTION(.text), "ax", @progbits
> > +ENTRY(STRNCAT)
> > +       movq    %rdi, %rax
> > +
> > +       /* NB: It's safe to filter out zero-length strings WITHOUT
> > +          setting null-term. Destination MUST be a null-terminated
> > +          string so essentially the work is already done.  */
> > +# ifdef USE_AS_WCSCPY
> > +       leaq    -1(%rdx), %rcx
> > +       shrq    $56, %rcx
> > +       jnz     L(zero_len)
> > +# else
> > +       test    %rdx, %rdx
> > +       jle     L(zero_len)
> > +# endif
> > +
> > +# include "strcat-strlen-evex.S"
> > +
> > +       movl    %esi, %ecx
> > +       andl    $(PAGE_SIZE - 1), %ecx
> > +       cmpl    $(PAGE_SIZE - VEC_SIZE), %ecx
> > +       ja      L(page_cross)
> > +L(page_cross_continue):
> > +       VMOVU   (%rsi), %VMM(0)
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +
> > +       /* If USE_EVEX_MASK_STORE is enabled then we just handle length
> > +          <= CHAR_PER_VEC with masked instructions (which have
> > +          potential for dramatically bad perf if dst splits a page and
> > +          is not in the TLB).  */
> > +# if USE_EVEX_MASKED_STORE
> > +       KMOV    %k0, %VRCX
> > +       FIND_FIRST_ONE (VRCX, VR8)
> > +       cmpq    %r8, %rdx
> > +       jbe     L(less_1x_vec)
> > +
> > +       test    %VRCX, %VRCX
> > +       jz      L(more_1x_vec)
> > +
> > +       blsmsk  %VRCX, %VRCX
> > +       KMOV    %VRCX, %k1
> > +       VMOVU_MASK %VMM(0), (%rdi){%k1}
> > +       ret
> > +
> > +L(less_1x_vec):
> > +       mov     $-1, %VRCX
> > +       bzhi    %VRDX, %VRCX, %VRCX
> > +       KMOV    %VRCX, %k1
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       VMOVU_MASK %VMM(0), (%rdi){%k1}
> > +
> > +       ret
> > +# else
> > +       KMOV    %k0, %VMASK_REG
> > +       /* tzcnt for strncat and `movl $CHAR_PER_VEC, %VRCX; bsf
> > +          %VMASK_REG, %VRCX` for wcsncat.  */
> > +       FIND_FIRST_ONE (VMASK_REG, VRCX)
> > +       cmpq    %rcx, %rdx
> > +       jbe     L(less_1x_vec)
> > +
> > +       /* If there were no zero-CHARs (rcx was zero before
> > +          FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC.  */
> > +       cmpl    $CHAR_PER_VEC, %ecx
> > +       je      L(more_1x_vec)
> > +
> > +       movl    %ecx, %edx
> > +
> > +L(less_1x_vec):
> > +#  if VEC_SIZE == 64
> > +       cmpl    $(32 / CHAR_SIZE), %edx
> > +       jae     L(copy_32_63)
> > +#  endif
> > +
> > +       cmpl    $(16 / CHAR_SIZE), %edx
> > +       jae     L(copy_16_31)
> > +
> > +
> > +       cmpl    $(8 / CHAR_SIZE), %edx
> > +       jae     L(copy_8_15)
> > +
> > +#  ifdef USE_AS_WCSCPY
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +#  else
> > +
> > +       cmpl    $4, %edx
> > +       jae     L(copy_4_7)
> > +
> > +       movzbl  (%rsi), %ecx
> > +       cmpl    $1, %edx
> > +       jbe     L(set_null_term)
> > +
> > +       movzwl  1(%rsi), %esi
> > +       movw    %si, 1(%rdi)
> > +
> > +       .p2align 4,, 1
> > +L(set_null_term):
> > +       movb    %cl, (%rdi)
> > +       movNULL $0, (%rdi, %rdx)
> > +       ret
> > +#  endif
> > +
> > +#  if VEC_SIZE == 64
> > +       .p2align 4,, 6
> > +L(copy_32_63):
> > +       VMOVU   -(32)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1)
> > +       VMOVU   %VMM_256(0), (%rdi)
> > +       VMOVU   %VMM_256(1), -(32)(%rdi, %rdx, CHAR_SIZE)
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +#  endif
> > +       .p2align 4,, 6
> > +L(copy_16_31):
> > +       /* Use xmm1 explicitly here as it won't require a `vzeroupper`
> > +          and will save code size.  */
> > +       vmovdqu -(16)(%rsi, %rdx, CHAR_SIZE), %xmm1
> > +       VMOVU   %VMM_128(0), (%rdi)
> > +       vmovdqu %xmm1, -(16)(%rdi, %rdx, CHAR_SIZE)
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +
> > +       .p2align 4,, 2
> > +L(copy_8_15):
> > +       movq    -(8)(%rsi, %rdx, CHAR_SIZE), %rcx
> > +       vmovq   %VMM_128(0), (%rdi)
> > +       movq    %rcx, -(8)(%rdi, %rdx, CHAR_SIZE)
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +
> > +#  ifndef USE_AS_WCSCPY
> > +       .p2align 4,, 12
> > +L(copy_4_7):
> > +       movl    -(4)(%rsi, %rdx, CHAR_SIZE), %ecx
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       movl    %ecx, -(4)(%rdi, %rdx, CHAR_SIZE)
> > +       movNULL $0, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +#  endif
> > +
> > +# endif
> > +       .p2align 4,, 4
> > +L(zero_len):
> > +# ifdef USE_AS_WCSCPY
> > +       test    %rdx, %rdx
> > +# endif
> > +       jne     OVERFLOW_STRCAT
> > +       ret
> >
> > -#define USE_AS_STRNCAT
> > -#define STRCAT STRNCAT
> > -#include "strcat-evex.S"
> > +       .p2align 4,, 8
> > +L(more_1x_vec):
> > +       VMOVU   %VMM(0), (%rdi)
> > +
> > +       /* We are going to align rsi here so will need to be able to re-
> > +          adjust rdi/rdx afterwords. NB: We filtered out huge lengths
> > +          so rsi + rdx * CHAR_SIZE cannot overflow.  */
> > +
> > +       leaq    (VEC_SIZE * -1)(%rsi, %rdx, CHAR_SIZE), %rdx
> > +       subq    %rsi, %rdi
> > +       andq    $-(VEC_SIZE), %rsi
> > +L(loop_last_4x_vec):
> > +       addq    %rsi, %rdi
> > +       subq    %rsi, %rdx
> > +# ifdef USE_AS_WCSCPY
> > +       shrq    $2, %rdx
> > +# endif
> > +
> > +       /* Will need this regardless.  */
> > +       VMOVA   (VEC_SIZE * 1)(%rsi), %VMM(1)
> > +       VPTESTN %VMM(1), %VMM(1), %k0
> > +       KMOV    %k0, %VMASK_REG
> > +
> > +       cmpq    $(CHAR_PER_VEC * 2), %rdx
> > +       ja      L(more_2x_vec)
> > +
> > +L(last_2x_vec):
> > +       FIND_FIRST_ONE (VMASK_REG, VRCX)
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_vec_x1_len)
> > +
> > +       /* If there were no zero-CHARs (rcx was zero before
> > +          FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC.  */
> > +       cmpl    $CHAR_PER_VEC, %ecx
> > +       jne     L(ret_vec_x1)
> > +
> > +       VMOVA   (VEC_SIZE * 2)(%rsi), %VMM(2)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1)(%rdi)
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       addl    $-CHAR_PER_VEC, %edx
> > +       bzhi    %VRDX, %VRCX, %VR8
> > +       jz      L(ret_vec_x2_len)
> > +L(ret_vec_x2):
> > +       bsf     %VRCX, %VRDX
> > +L(ret_vec_x2_len):
> > +       VMOVU   (VEC_SIZE * 2 -(VEC_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       movNULL $0, (VEC_SIZE * 2)(%rdi, %rdx, CHAR_SIZE)
> > +       VMOVU   %VMM(0), (VEC_SIZE * 2 -(VEC_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +
> > +       .p2align 4,, 4
> > +L(ret_vec_x1_len):
> > +       movl    %edx, %ecx
> > +L(ret_vec_x1):
> > +       VMOVU   (VEC_SIZE -(VEC_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       movNULL $0, (VEC_SIZE)(%rdi, %rcx, CHAR_SIZE)
> > +       VMOVU   %VMM(0), (VEC_SIZE-(VEC_SIZE))(%rdi, %rcx, CHAR_SIZE)
> > +       VZEROUPPER_RETURN
> > +
> > +
> > +       .p2align 4,, 8
> > +L(last_4x_vec):
> > +       addl    $-(CHAR_PER_VEC * 4), %edx
> > +       VMOVA   (VEC_SIZE * 5)(%rsi), %VMM(1)
> > +       VPTESTN %VMM(1), %VMM(1), %k0
> > +       KMOV    %k0, %VMASK_REG
> > +       subq    $-(VEC_SIZE * 4), %rsi
> > +       subq    $-(VEC_SIZE * 4), %rdi
> > +       cmpl    $(CHAR_PER_VEC * 2), %edx
> > +       jbe     L(last_2x_vec)
> > +       .p2align 4,, 8
> > +L(more_2x_vec):
> > +# ifdef USE_AS_WCSCPY
> > +       xorl    %ecx, %ecx
> > +# endif
> > +       bsf     %VMASK_REG, %VRCX
> > +       jnz     L(ret_vec_x1)
> > +
> > +       VMOVA   (VEC_SIZE * 2)(%rsi), %VMM(2)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1)(%rdi)
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x2)
> > +
> > +       VMOVA   (VEC_SIZE * 3)(%rsi), %VMM(3)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 2)(%rdi)
> > +       VPTESTN %VMM(3), %VMM(3), %k0
> > +       KMOV    %k0, %VMASK_REG
> > +
> > +       cmpq    $(CHAR_PER_VEC * 4), %rdx
> > +       ja      L(more_4x_vec)
> > +
> > +       /* Adjust length before going to L(ret_vec_x3_len) or
> > +          L(ret_vec_x3).  */
> > +       addl    $(CHAR_PER_VEC * -2), %edx
> > +
> > +       FIND_FIRST_ONE (VMASK_REG, VRCX)
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_vec_x3_len)
> > +
> > +       /* If there were no zero-CHARs (rcx was zero before
> > +          FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC.  */
> > +       cmpl    $CHAR_PER_VEC, %ecx
> > +       jne     L(ret_vec_x3)
> > +
> > +       VMOVA   (VEC_SIZE * 4)(%rsi), %VMM(4)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       VPTESTN %VMM(4), %VMM(4), %k0
> > +       KMOV    %k0, %VRCX
> > +       addl    $-CHAR_PER_VEC, %edx
> > +       bzhi    %VRDX, %VRCX, %VR8
> > +       jz      L(ret_vec_x4_len)
> > +L(ret_vec_x4):
> > +       bsf     %VRCX, %VRDX
> > +L(ret_vec_x4_len):
> > +       VMOVU   (VEC_SIZE * 4 -(VEC_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       movNULL $0, (VEC_SIZE * 4)(%rdi, %rdx, CHAR_SIZE)
> > +       VMOVU   %VMM(0), (VEC_SIZE * 4 -(VEC_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +
> > +       .p2align 4,, 4
> > +L(ret_vec_x3_len):
> > +       movl    %edx, %ecx
> > +L(ret_vec_x3):
> > +       VMOVU   (VEC_SIZE * 3 -(VEC_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       movNULL $0, (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE)
> > +       VMOVU   %VMM(0), (VEC_SIZE * 3-(VEC_SIZE))(%rdi, %rcx, CHAR_SIZE)
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(more_4x_vec):
> > +# ifdef USE_AS_WCSCPY
> > +       xorl    %ecx, %ecx
> > +# endif
> > +       bsf     %VMASK_REG, %VRCX
> > +       jnz     L(ret_vec_x3)
> > +
> > +       VMOVA   (VEC_SIZE * 4)(%rsi), %VMM(4)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       VPTESTN %VMM(4), %VMM(4), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x4)
> > +
> > +       VMOVU   %VMM(4), (VEC_SIZE * 4)(%rdi)
> > +
> > +       /* Check if we are near the end before aligning.  */
> > +       cmpq    $(CHAR_PER_VEC * 8), %rdx
> > +       jbe     L(last_4x_vec)
> > +
> > +
> > +       /* Add rsi to rdx (length) before aligning rsi. NB: Since we
> > +          filtered out huge lengths this cannot overflow.  */
> > +# ifdef USE_AS_WCSCPY
> > +       leaq    (%rsi, %rdx, CHAR_SIZE), %rdx
> > +# else
> > +       addq    %rsi, %rdx
> > +# endif
> > +
> > +       /* Subtract rsi from rdi before aligning (add back will have
> > +          correct rdi for aligned rsi).  */
> > +       subq    %rsi, %rdi
> > +       subq    $-(VEC_SIZE * 5), %rsi
> > +       andq    $(VEC_SIZE * -4), %rsi
> > +
> > +       /* Load first half of the loop before entry.  */
> > +       VMOVA   (VEC_SIZE * 0 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(3)
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +
> > +       /* Offset rsi by VEC_SIZE so that we can jump to
> > +          L(loop_last_4x_vec).  */
> > +       addq    $-(VEC_SIZE), %rsi
> > +       KORTEST %k2, %k4
> > +       jnz     L(loop_4x_done)
> > +
> > +       /* Store loop end in r9.  */
> > +       leaq    -(VEC_SIZE * 5)(%rdx), %r9
> > +
> > +       .p2align 4,, 11
> > +L(loop_4x_vec):
> > +       VMOVU   %VMM(0), (VEC_SIZE * 1 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 2 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 3 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 4 + 0)(%rdi, %rsi)
> > +
> > +       subq    $(VEC_SIZE * -4), %rsi
> > +       cmpq    %rsi, %r9
> > +       jbe     L(loop_last_4x_vec)
> > +
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 4 + 0)(%rsi), %VMM(3)
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +       KORTEST %k2, %k4
> > +       jz      L(loop_4x_vec)
> > +
> > +L(loop_4x_done):
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +       /* Restore rdi (dst).  */
> > +       addq    %rsi, %rdi
> > +
> > +       /* L(ret_vec_x1) expects rcx to have position of zero-CHAR so
> > +          test with bsf.  */
> > +       bsf     %VRCX, %VRCX
> > +       jnz     L(ret_vec_x1)
> > +       VMOVU   %VMM(0), (VEC_SIZE * 1 + 0)(%rdi)
> > +
> > +       KMOV    %k2, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x2)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 2 + 0)(%rdi)
> > +
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       bsf     %VRCX, %VRCX
> > +       jnz     L(ret_vec_x3)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 3 + 0)(%rdi)
> > +
> > +       KMOV    %k4, %VRCX
> > +       bsf     %VRCX, %VRCX
> > +       VMOVU   ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 4 + 0)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rcx, CHAR_SIZE)
> > +       ret
> > +
> > +
> > +       .p2align 4,, 4
> > +L(page_cross):
> > +       movq    %rsi, %r8
> > +       andq    $(VEC_SIZE * -1), %r8
> > +       VPCMPEQ (%r8), %VZERO, %k0
> > +
> > +# ifdef USE_AS_WCSCPY
> > +       KMOV    %k0, %VR9
> > +       shrl    $2, %ecx
> > +       andl    $(CHAR_PER_VEC - 1), %ecx
> > +       shrx    %VRCX, %VR9, %VRCX
> > +# else
> > +       KMOV    %k0, %VRCX
> > +       shrx    %VRSI, %VRCX, %VRCX
> > +# endif
> > +
> > +       subl    %esi, %r8d
> > +       andl    $(VEC_SIZE - 1), %r8d
> > +# ifdef USE_AS_WCSCPY
> > +       shrl    $2, %r8d
> > +# endif
> > +       cmpq    %r8, %rdx
> > +       jbe     L(page_cross_small)
> > +       /* Optimizing more for space as this is very cold code. This
> > +          saves 2x cache lines.  */
> > +
> > +       /* This adds once to the later result which will get correct
> > +          copy bounds. NB: this can never zero-out a non-zero RCX as
> > +          to be in the page cross case rsi cannot be aligned and we
> > +          already right-shift rcx by the misalignment.  */
> > +       shl     %VRCX
> > +       jz      L(page_cross_continue)
> > +       bsf     %VRCX, %VRCX
> > +       REP_MOVS
> > +       ret
> > +
> > +L(page_cross_small):
> > +       tzcnt   %VRCX, %VRCX
> > +       jz      L(page_cross_setz)
> > +       cmpl    %edx, %ecx
> > +       cmova   %edx, %ecx
> > +
> > +# ifdef USE_AS_WCSCPY
> > +       rep     movsd
> > +# else
> > +       rep     movsb
> > +# endif
> > +L(page_cross_setz):
> > +       movNULL $0, (%rdi)
> > +       ret
> > +END(STRNCAT)
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/strncpy-evex.S b/sysdeps/x86_64/multiarch/strncpy-evex.S
> > index 1b3426d511..49eaf4cbd9 100644
> > --- a/sysdeps/x86_64/multiarch/strncpy-evex.S
> > +++ b/sysdeps/x86_64/multiarch/strncpy-evex.S
> > @@ -1,7 +1,990 @@
> > -#ifndef STRNCPY
> > -# define STRNCPY       __strncpy_evex
> > -#endif
> > +/* {wcs|wcp|str|stp}ncpy with 256/512-bit EVEX instructions.
> > +   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 <isa-level.h>
> > +
> > +#if ISA_SHOULD_BUILD (4)
> > +
> > +       /* Use evex-masked stores for small sizes. Turned off at the
> > +          moment.  */
> > +# define USE_EVEX_MASKED_STORE 0
> > +
> > +
> > +# include <sysdep.h>
> > +# ifndef VEC_SIZE
> > +#  include "x86-evex256-vecs.h"
> > +# endif
> > +
> > +
> > +# ifndef STRNCPY
> > +#  define STRNCPY      __strncpy_evex
> > +# endif
> > +
> > +# ifdef USE_AS_WCSCPY
> > +#  define VMOVU_MASK   vmovdqu32
> > +#  define VPCMPEQ      vpcmpeqd
> > +#  define VPMIN        vpminud
> > +#  define VPTESTN      vptestnmd
> > +#  define VPTEST       vptestmd
> > +#  define CHAR_SIZE    4
> > +
> > +#  define REP_MOVS     rep movsd
> > +#  define REP_STOS     rep stosl
> > +
> > +#  define USE_WIDE_CHAR
> > +
> > +# else
> > +#  define VMOVU_MASK   vmovdqu8
> > +#  define VPCMPEQ      vpcmpeqb
> > +#  define VPMIN        vpminub
> > +#  define VPTESTN      vptestnmb
> > +#  define VPTEST       vptestmb
> > +#  define CHAR_SIZE    1
> > +
> > +#  define REP_MOVS     rep movsb
> > +#  define REP_STOS     rep stosb
> > +# endif
> > +
> > +# include "strncpy-or-cat-overflow-def.h"
> > +
> > +# define PAGE_SIZE     4096
> > +# define CHAR_PER_VEC  (VEC_SIZE / CHAR_SIZE)
> > +
> > +# include "reg-macros.h"
> > +
> > +
> > +# define VZERO VMM(7)
> > +# define VZERO_256     VMM_256(7)
> > +# define VZERO_128     VMM_128(7)
> > +
> > +# if VEC_SIZE == 64
> > +#  define VZERO_HALF   VZERO_256
> > +# else
> > +#  define VZERO_HALF   VZERO_128
> > +# endif
> > +
> > +       .section SECTION(.text), "ax", @progbits
> > +ENTRY(STRNCPY)
> > +       /* Filter zero length strings and very long strings.  Zero
> > +          length strings just return, very long strings are handled by
> > +          just running rep stos{b|l} to zero set (which will almost
> > +          certainly segfault), if that succeeds then just calling
> > +          OVERFLOW_STRCPY (strcpy, stpcpy, wcscpy, wcpcpy).  */
> > +# ifdef USE_AS_WCSCPY
> > +       decq    %rdx
> > +       movq    %rdx, %rax
> > +       /* 56 is end of max supported address space.  */
> > +       shr     $56, %rax
> > +       jnz     L(zero_len)
> > +# else
> > +       decq    %rdx
> > +       /* If the flag needs to become `jb` replace `dec` with `sub`.
> > +        */
> > +       jl      L(zero_len)
> > +# endif
> > +
> > +       vpxorq  %VZERO_128, %VZERO_128, %VZERO_128
> > +       movl    %esi, %eax
> > +       andl    $(PAGE_SIZE - 1), %eax
> > +       cmpl    $(PAGE_SIZE - VEC_SIZE), %eax
> > +       ja      L(page_cross)
> > +
> > +L(page_cross_continue):
> > +       VMOVU   (%rsi), %VMM(0)
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +
> > +       /* If no STPCPY just save end ahead of time.  */
> > +# ifndef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +# endif
> > +
> > +
> > +       cmpq    $(CHAR_PER_VEC), %rdx
> > +
> > +       /* If USE_EVEX_MASK_STORE is enabled then we just handle length
> > +          <= CHAR_PER_VEC with masked instructions (which have
> > +          potential for dramatically bad perf if dst splits a page and
> > +          is not in the TLB).  */
> > +# if USE_EVEX_MASKED_STORE
> > +       /* `jae` because length rdx is now length - 1.  */
> > +       jae     L(more_1x_vec)
> > +
> > +       /* If there where multiple zero-CHAR matches in the first VEC,
> > +          VRCX will be overset but thats fine since any oversets where
> > +          at zero-positions anyways.  */
> > +
> > +#  ifdef USE_AS_STPCPY
> > +       tzcnt   %VRCX, %VRAX
> > +       cmpl    %eax, %edx
> > +       cmovb   %edx, %eax
> > +#   ifdef USE_AS_WCSCPY
> > +       adcl    $0, %eax
> > +       leaq    (%rdi, %rax, CHAR_SIZE), %rax
> > +#   else
> > +       adcq    %rdi, %rax
> > +#   endif
> > +#  endif
> > +       dec     %VRCX
> > +
> > +       /* Zero out all non-zero CHAR's after the first zero match.  */
> > +       KMOV    %VRCX, %k1
> > +
> > +       /* Use VZERO as destination so this can be reused for
> > +          L(zfill_less_vec) (which if jumped to by subsequent logic
> > +          will have zerod out VZERO.  */
> > +       VMOVU_MASK %VMM(0), %VZERO{%k1}{z}
> > +L(zfill_less_vec):
> > +       /* Get mask for what we need to set.  */
> > +       incl    %edx
> > +       mov     $-1, %VRCX
> > +       bzhi    %VRDX, %VRCX, %VRCX
> > +       KMOV    %VRCX, %k1
> > +       VMOVU_MASK %VZERO, (%rdi){%k1}
> > +       ret
> > +
> > +       .p2align 4,, 4
> > +L(zero_len):
> > +       cmpq    $-1, %rdx
> > +       jne     L(best_effort_strncpy)
> > +       movq    %rdi, %rax
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(more_1x_vec):
> > +# else
> > +       /* `jb` because length rdx is now length - 1.  */
> > +       jb      L(less_1x_vec)
> > +# endif
> > +
> > +
> > +       /* This may overset but thats fine because we still need to zero
> > +          fill.  */
> > +       VMOVU   %VMM(0), (%rdi)
> > +
> > +
> > +       /* Length must be >= CHAR_PER_VEC so match here means we must
> > +          zero-fill.  */
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill)
> > +
> > +
> > +       /* We are going to align rsi here so will need to be able to re-
> > +          adjust rdi/rdx afterwords. NB: We filtered out huge lengths
> > +          so rsi + rdx * CHAR_SIZE cannot overflow.  */
> > +       leaq    (VEC_SIZE * -1)(%rsi, %rdx, CHAR_SIZE), %rdx
> > +       subq    %rsi, %rdi
> > +       andq    $-(VEC_SIZE), %rsi
> > +
> > +L(loop_last_4x_vec):
> > +       addq    %rsi, %rdi
> > +       subq    %rsi, %rdx
> > +# ifdef USE_AS_WCSCPY
> > +       shrq    $2, %rdx
> > +# endif
> > +
> > +       VMOVA   (VEC_SIZE * 1)(%rsi), %VMM(1)
> > +       VPTESTN %VMM(1), %VMM(1), %k0
> > +       KMOV    %k0, %VRCX
> > +
> > +       /* -1 because of the `dec %rdx` earlier.  */
> > +       cmpq    $(CHAR_PER_VEC * 2 - 1), %rdx
> > +       ja      L(more_2x_vec)
> > +
> > +L(last_2x_vec):
> > +       /* This will be need to be computed no matter what. We do it
> > +          ahead of time for CHAR_PER_VEC == 64 because we can't adjust
> > +          the value of `tzcnt` with a shift.  */
> > +# if CHAR_PER_VEC == 64
> > +       tzcntq  %rcx, %rcx
> > +# endif
> > +
> > +       cmpl    $(CHAR_PER_VEC), %edx
> > +       jb      L(ret_vec_x1_len)
> > +
> > +       /* Seperate logic for CHAR_PER_VEC == 64 because we already did
> > +          `tzcnt` on VRCX.  */
> > +# if CHAR_PER_VEC == 64
> > +       /* cl == CHAR_PER_VEC iff it was zero before the `tzcnt`.  */
> > +       cmpb    $CHAR_PER_VEC, %cl
> > +       jnz     L(ret_vec_x1_no_bsf)
> > +# else
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x1)
> > +# endif
> > +
> > +
> > +
> > +       VPCMPEQ (VEC_SIZE * 2)(%rsi), %VZERO, %k0
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1)(%rdi)
> > +       KMOV    %k0, %VRCX
> > +
> > +# if CHAR_PER_VEC < 64
> > +       /* This essentiallys adds CHAR_PER_VEC to computed result.  */
> > +       shlq    $CHAR_PER_VEC, %rcx
> > +# else
> > +       tzcntq  %rcx, %rcx
> > +       addl    $CHAR_PER_VEC, %ecx
> > +# endif
> > +
> > +       .p2align 4,, 4
> > +L(ret_vec_x1_len):
> > +       /* If CHAR_PER_VEC < 64 we still need to tzcnt, otherwise it has
> > +          already been done.  */
> > +# if CHAR_PER_VEC < 64
> > +       tzcntq  %rcx, %rcx
> > +# endif
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_vec_x1_len_no_zfill)
> > +       /* Fall through (expectation) is copy len < buffer len.  */
> > +       VMOVU   %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +L(ret_vec_x1_len_no_zfill_mov):
> > +       movl    %ecx, %edx
> > +# ifdef USE_AS_STPCPY
> > +       /* clear flags.  */
> > +       xorl    %ecx, %ecx
> > +# endif
> > +L(ret_vec_x1_len_no_zfill):
> > +       VMOVU   ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +# ifdef USE_AS_STPCPY
> > +#  ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (VEC_SIZE * 1)(%rdi, %rdx, CHAR_SIZE), %rax
> > +#  else
> > +       leal    (VEC_SIZE)(%rdx), %eax
> > +       adcq    %rdi, %rax
> > +#  endif
> > +# endif
> > +       ret
> > +
> > +
> > +       .p2align 4,, 10
> > +L(ret_vec_x1):
> > +       bsf     %VRCX, %VRCX
> > +L(ret_vec_x1_no_bsf):
> > +       VMOVU   %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +       subl    %ecx, %edx
> > +       cmpl    $CHAR_PER_VEC, %edx
> > +       jb      L(ret_vec_x1_len_no_zfill_mov)
> > +       /* Fall through (expectation) is copy len < buffer len.  */
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1)(%rdi)
> > +       VMOVU   %VZERO, (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE)
> > +# ifdef USE_AS_STPCPY
> > +       leaq    (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE), %rax
> > +# endif
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(last_4x_vec):
> > +       /* Seperate logic for CHAR_PER_VEC == 64 because we can do `andl
> > +          $(CHAR_PER_VEC * 4 - 1), %edx` with less code size just
> > +          using `movzbl`.  */
> > +# if CHAR_PER_VEC == 64
> > +       movzbl  %dl, %edx
> > +# else
> > +       andl    $(CHAR_PER_VEC * 4 - 1), %edx
> > +# endif
> > +       VMOVA   (VEC_SIZE * 5)(%rsi), %VMM(1)
> > +       VPTESTN %VMM(1), %VMM(1), %k0
> > +       KMOV    %k0, %VRCX
> > +       subq    $-(VEC_SIZE * 4), %rsi
> > +       subq    $-(VEC_SIZE * 4), %rdi
> > +       cmpl    $(CHAR_PER_VEC * 2 - 1), %edx
> > +       jbe     L(last_2x_vec)
> > +       .p2align 4,, 8
> > +L(more_2x_vec):
> > +       VMOVU   %VMM(1), (VEC_SIZE * 1)(%rdi)
> > +       test    %VRCX, %VRCX
> > +       /* Must fill at least 2x VEC.  */
> > +       jnz     L(zfill_vec1)
> > +
> > +       VMOVA   (VEC_SIZE * 2)(%rsi), %VMM(2)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 2)(%rdi)
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       /* Must fill at least 1x VEC.  */
> > +       jnz     L(zfill_vec2)
> > +
> > +       VMOVA   (VEC_SIZE * 3)(%rsi), %VMM(3)
> > +       VPTESTN %VMM(3), %VMM(3), %k0
> > +       KMOV    %k0, %VRCX
> > +
> > +       /* Check if len is more 4x VEC. -1 because rdx is len - 1.  */
> > +       cmpq    $(CHAR_PER_VEC * 4 - 1), %rdx
> > +       ja      L(more_4x_vec)
> > +
> > +       subl    $(CHAR_PER_VEC * 3), %edx
> > +       jb      L(ret_vec_x3_len)
> > +
> > +       test    %VRCX, %VRCX
> > +       jnz     L(ret_vec_x3)
> > +
> > +       VPCMPEQ (VEC_SIZE * 4)(%rsi), %VZERO, %k0
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       KMOV    %k0, %VRCX
> > +       tzcnt   %VRCX, %VRCX
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_vec_x4_len_no_zfill)
> > +       /* Fall through (expectation) is copy len < buffer len.  */
> > +       VMOVU   %VZERO, ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +       movl    %ecx, %edx
> > +L(ret_vec_x4_len_no_zfill):
> > +       VMOVU   ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +# ifdef USE_AS_STPCPY
> > +#  ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (VEC_SIZE * 4)(%rdi, %rdx, CHAR_SIZE), %rax
> > +#  else
> > +       leal    (VEC_SIZE * 4 + 0)(%rdx), %eax
> > +       adcq    %rdi, %rax
> > +#  endif
> > +# endif
> > +       ret
> > +
> > +
> > +L(ret_vec_x3_len):
> > +       addl    $(CHAR_PER_VEC * 1), %edx
> > +       tzcnt   %VRCX, %VRCX
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_vec_x3_len_no_zfill)
> > +       /* Fall through (expectation) is copy len < buffer len.  */
> > +       VMOVU   %VZERO, ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +L(ret_vec_x3_len_no_zfill_mov):
> > +       movl    %ecx, %edx
> > +# ifdef USE_AS_STPCPY
> > +       /* clear flags.  */
> > +       xorl    %ecx, %ecx
> > +# endif
> > +       .p2align 4,, 4
> > +L(ret_vec_x3_len_no_zfill):
> > +       VMOVU   ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
> > +       VMOVU   %VMM(0), ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
> > +# ifdef USE_AS_STPCPY
> > +#  ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (VEC_SIZE * 3)(%rdi, %rdx, CHAR_SIZE), %rax
> > +#  else
> > +       leal    (VEC_SIZE * 3 + 0)(%rdx), %eax
> > +       adcq    %rdi, %rax
> > +#  endif
> > +# endif
> > +       ret
> > +
> > +
> > +       .p2align 4,, 8
> > +L(ret_vec_x3):
> > +       bsf     %VRCX, %VRCX
> > +       VMOVU   %VZERO, (VEC_SIZE * 4 +(-(VEC_SIZE - CHAR_SIZE)))(%rdi, %rdx, CHAR_SIZE)
> > +       subl    %ecx, %edx
> > +       jl      L(ret_vec_x3_len_no_zfill_mov)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       VMOVU   %VZERO, (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE)
> > +# ifdef USE_AS_STPCPY
> > +       leaq    (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE), %rax
> > +# endif
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(more_4x_vec):
> > +       VMOVU   %VMM(3), (VEC_SIZE * 3)(%rdi)
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill_vec3)
> > +
> > +       VMOVA   (VEC_SIZE * 4)(%rsi), %VMM(4)
> > +       VMOVU   %VMM(4), (VEC_SIZE * 4)(%rdi)
> > +       VPTESTN %VMM(4), %VMM(4), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill_vec4)
> >
> > -#define USE_AS_STRNCPY
> > -#define STRCPY STRNCPY
> > -#include "strcpy-evex.S"
> > +       /* Recheck length before aligning.  */
> > +       cmpq    $(CHAR_PER_VEC * 8 - 1), %rdx
> > +       jbe     L(last_4x_vec)
> > +
> > +       /* Align rsi to VEC_SIZE * 4, need to readjust rdx / rdi.  */
> > +# ifdef USE_AS_WCSCPY
> > +       leaq    (%rsi, %rdx, CHAR_SIZE), %rdx
> > +# else
> > +       addq    %rsi, %rdx
> > +# endif
> > +       subq    %rsi, %rdi
> > +       subq    $-(VEC_SIZE * 5), %rsi
> > +       andq    $(VEC_SIZE * -4), %rsi
> > +
> > +
> > +       /* Load first half of the loop before entry.  */
> > +       VMOVA   (VEC_SIZE * 0 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(3)
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +
> > +
> > +       /* Offset rsi by VEC_SIZE so that we can jump to
> > +          L(loop_last_4x_vec).  */
> > +       addq    $-(VEC_SIZE), %rsi
> > +       KORTEST %k2, %k4
> > +       jnz     L(loop_4x_done)
> > +
> > +       /* Store loop end in r9.  */
> > +       leaq    -(VEC_SIZE * 5 - CHAR_SIZE)(%rdx), %r9
> > +
> > +       .p2align 4,, 11
> > +L(loop_4x_vec):
> > +       VMOVU   %VMM(0), (VEC_SIZE * 1 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(1), (VEC_SIZE * 2 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(2), (VEC_SIZE * 3 + 0)(%rdi, %rsi)
> > +       VMOVU   %VMM(3), (VEC_SIZE * 4 + 0)(%rdi, %rsi)
> > +
> > +       subq    $(VEC_SIZE * -4), %rsi
> > +       cmpq    %rsi, %r9
> > +       jbe     L(loop_last_4x_vec)
> > +
> > +       VMOVA   (VEC_SIZE * 1 + 0)(%rsi), %VMM(0)
> > +       VMOVA   (VEC_SIZE * 2 + 0)(%rsi), %VMM(1)
> > +       VMOVA   (VEC_SIZE * 3 + 0)(%rsi), %VMM(2)
> > +       VMOVA   (VEC_SIZE * 4 + 0)(%rsi), %VMM(3)
> > +
> > +       VPMIN   %VMM(0), %VMM(1), %VMM(4)
> > +       VPMIN   %VMM(2), %VMM(3), %VMM(6)
> > +       VPTESTN %VMM(4), %VMM(4), %k2
> > +       VPTESTN %VMM(6), %VMM(6), %k4
> > +       KORTEST %k2, %k4
> > +       jz      L(loop_4x_vec)
> > +
> > +L(loop_4x_done):
> > +       /* Restore rdx (length).  */
> > +       subq    %rsi, %rdx
> > +# ifdef USE_AS_WCSCPY
> > +       shrq    $2, %rdx
> > +# endif
> > +       VMOVU   %VMM(0), (VEC_SIZE * 1 + 0)(%rdi, %rsi)
> > +       /* Restore rdi (dst).  */
> > +       addq    %rsi, %rdi
> > +       VPTESTN %VMM(0), %VMM(0), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill_vec1)
> > +
> > +       VMOVU   %VMM(1), (VEC_SIZE * 2 + 0)(%rdi)
> > +       KMOV    %k2, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill_vec2)
> > +
> > +       VMOVU   %VMM(2), (VEC_SIZE * 3 + 0)(%rdi)
> > +       VPTESTN %VMM(2), %VMM(2), %k0
> > +       KMOV    %k0, %VRCX
> > +       test    %VRCX, %VRCX
> > +       jnz     L(zfill_vec3)
> > +
> > +       VMOVU   %VMM(3), (VEC_SIZE * 4 + 0)(%rdi)
> > +       KMOV    %k4, %VRCX
> > +       // Zfill more....
> > +
> > +       .p2align 4,, 4
> > +L(zfill_vec4):
> > +       subq    $(VEC_SIZE * -2), %rdi
> > +       addq    $(CHAR_PER_VEC * -2), %rdx
> > +L(zfill_vec2):
> > +       subq    $(VEC_SIZE * -2), %rdi
> > +       addq    $(CHAR_PER_VEC * -1), %rdx
> > +L(zfill):
> > +       /* VRCX must be non-zero.  */
> > +       bsf     %VRCX, %VRCX
> > +
> > +       /* Adjust length / dst for zfill.  */
> > +       subq    %rcx, %rdx
> > +# ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rdi
> > +# else
> > +       addq    %rcx, %rdi
> > +# endif
> > +# ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +# endif
> > +L(zfill_from_page_cross):
> > +
> > +       /* From here on out its just memset(rdi, 0, rdx).  */
> > +       cmpq    $CHAR_PER_VEC, %rdx
> > +       jb      L(zfill_less_vec)
> > +
> > +L(zfill_more_1x_vec):
> > +       VMOVU   %VZERO, (%rdi)
> > +       VMOVU   %VZERO, (CHAR_SIZE - VEC_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +       cmpq    $(CHAR_PER_VEC * 2 - 1), %rdx
> > +       ja      L(zfill_more_2x_vec)
> > +L(zfill_done0):
> > +       ret
> > +
> > +       /* Coming from vec1/vec2 we must be able to zfill at least 2x
> > +          VEC.  */
> > +       .p2align 4,, 8
> > +L(zfill_vec3):
> > +       subq    $(VEC_SIZE * -2), %rdi
> > +       addq    $(CHAR_PER_VEC * -2), %rdx
> > +       .p2align 4,, 2
> > +L(zfill_vec1):
> > +       bsfq    %rcx, %rcx
> > +       /* rdi is currently dst - VEC_SIZE so add back VEC_SIZE here.
> > +        */
> > +       leaq    VEC_SIZE(%rdi, %rcx, CHAR_SIZE), %rdi
> > +       subq    %rcx, %rdx
> > +# ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +# endif
> > +
> > +
> > +       VMOVU   %VZERO, (%rdi)
> > +       VMOVU   %VZERO, (CHAR_SIZE - VEC_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +       cmpq    $(CHAR_PER_VEC * 2), %rdx
> > +       jb      L(zfill_done0)
> > +L(zfill_more_2x_vec):
> > +       VMOVU   %VZERO, (CHAR_SIZE - VEC_SIZE * 2)(%rdi, %rdx, CHAR_SIZE)
> > +       VMOVU   %VZERO, (VEC_SIZE)(%rdi)
> > +       subq    $(CHAR_PER_VEC * 4 - 1), %rdx
> > +       jbe     L(zfill_done)
> > +
> > +# ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rdx
> > +# else
> > +       addq    %rdi, %rdx
> > +# endif
> > +
> > +       VMOVU   %VZERO, (VEC_SIZE * 2)(%rdi)
> > +       VMOVU   %VZERO, (VEC_SIZE * 3)(%rdi)
> > +
> > +
> > +       VMOVU   %VZERO, (VEC_SIZE * 0 + 0)(%rdx)
> > +       VMOVU   %VZERO, (VEC_SIZE * 1 + 0)(%rdx)
> > +
> > +       subq    $-(VEC_SIZE * 4), %rdi
> > +       cmpq    %rdi, %rdx
> > +       jbe     L(zfill_done)
> > +
> > +       /* Align rdi and zfill loop.  */
> > +       andq    $-(VEC_SIZE), %rdi
> > +       .p2align 4,, 12
> > +L(zfill_loop_4x_vec):
> > +       VMOVA   %VZERO, (VEC_SIZE * 0)(%rdi)
> > +       VMOVA   %VZERO, (VEC_SIZE * 1)(%rdi)
> > +       VMOVA   %VZERO, (VEC_SIZE * 2)(%rdi)
> > +       VMOVA   %VZERO, (VEC_SIZE * 3)(%rdi)
> > +       subq    $-(VEC_SIZE * 4), %rdi
> > +       cmpq    %rdi, %rdx
> > +       ja      L(zfill_loop_4x_vec)
> > +L(zfill_done):
> > +       ret
> > +
> > +
> > +       /* Less 1x VEC case if we are not using evex masked store.  */
> > +# if !USE_EVEX_MASKED_STORE
> > +       .p2align 4,, 8
> > +L(copy_1x):
> > +       /* Special case for copy 1x. It can be handled quickly and many
> > +          buffer sizes have convenient alignment.  */
> > +       VMOVU   %VMM(0), (%rdi)
> > +       /* If no zeros then we are done.  */
> > +       testl   %ecx, %ecx
> > +       jz      L(ret_1x_1x)
> > +
> > +       /* Need to zfill, not we know that length <= CHAR_PER_VEC so we
> > +          only handle the small case here.  */
> > +       bsf     %VRCX, %VRCX
> > +L(zfill_less_vec_no_bsf):
> > +       /* Adjust length / dst then just zfill less_vec.  */
> > +       subq    %rcx, %rdx
> > +#  ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rdi
> > +#  else
> > +       addq    %rcx, %rdi
> > +#  endif
> > +#  ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +#  endif
> > +
> > +L(zfill_less_vec):
> > +       cmpl    $((VEC_SIZE / 2) / CHAR_SIZE), %edx
> > +       jb      L(zfill_less_half)
> > +
> > +       VMOVU   %VZERO_HALF, (%rdi)
> > +       VMOVU   %VZERO_HALF, -((VEC_SIZE / 2)- CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +#  ifdef USE_AS_STPCPY
> > +L(ret_1x_1x):
> > +       leaq    CHAR_SIZE(%rdi, %rdx, CHAR_SIZE), %rax
> > +       ret
> > +#  endif
> > +
> > +
> > +#  if VEC_SIZE == 64
> > +       .p2align 4,, 4
> > +L(copy_32_63):
> > +       /* Overfill to avoid branches.  */
> > +       VMOVU   -(32 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1)
> > +       VMOVU   %VMM_256(0), (%rdi)
> > +       VMOVU   %VMM_256(1), -(32 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +
> > +       /* We are taking advantage of the fact that to be here we must
> > +          be writing null-term as (%rdi, %rcx) we have a byte of lee-
> > +          way for overwriting.  */
> > +       cmpl    %ecx, %edx
> > +       ja      L(zfill_less_vec_no_bsf)
> > +#   ifndef USE_AS_STPCPY
> > +L(ret_1x_1x):
> > +#   else
> > +#    ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#    else
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +#    endif
> > +#   endif
> > +       ret
> > +#  endif
> > +
> > +       .p2align 4,, 4
> > +L(copy_16_31):
> > +       /* Overfill to avoid branches.  */
> > +       vmovdqu -(16 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %xmm1
> > +       VMOVU   %VMM_128(0), (%rdi)
> > +       vmovdqu %xmm1, -(16 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +       cmpl    %ecx, %edx
> > +
> > +       /* Seperate logic depending on VEC_SIZE. If VEC_SIZE == 64 then
> > +          we have a larger copy block for 32-63 so this is just falls
> > +          through to zfill 16-31. If VEC_SIZE == 32 then we check for
> > +          full zfill of less 1x VEC.  */
> > +#  if VEC_SIZE == 64
> > +       jbe     L(ret_16_31)
> > +       subl    %ecx, %edx
> > +#   ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rdi
> > +#   else
> > +       addq    %rcx, %rdi
> > +#   endif
> > +#   ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +#   endif
> > +L(zfill_less_half):
> > +L(zfill_less_32):
> > +       cmpl    $(16 / CHAR_SIZE), %edx
> > +       jb      L(zfill_less_16)
> > +       VMOVU   %VZERO_128, (%rdi)
> > +       VMOVU   %VZERO_128, -(16 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +#   ifdef USE_AS_STPCPY
> > +       ret
> > +#   endif
> > +L(ret_16_31):
> > +#   ifdef USE_AS_STPCPY
> > +#    ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#    else
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +#    endif
> > +#   endif
> > +       ret
> > +#  else
> > +       /* VEC_SIZE == 32 begins.  */
> > +       ja      L(zfill_less_vec_no_bsf)
> > +#   ifndef USE_AS_STPCPY
> > +L(ret_1x_1x):
> > +#   else
> > +#    ifdef USE_AS_WCSCPY
> > +       adcq    $0, %rdx
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#    else
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +#    endif
> > +#   endif
> > +       ret
> > +#  endif
> > +
> > +
> > +       .p2align 4,, 4
> > +L(copy_8_15):
> > +       /* Overfill to avoid branches.  */
> > +       movq    -(8 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %rsi
> > +       vmovq   %VMM_128(0), (%rdi)
> > +       movq    %rsi, -(8 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_8_15)
> > +       subl    %ecx, %edx
> > +#  ifdef USE_AS_WCSCPY
> > +       leaq    (%rdi, %rcx, CHAR_SIZE), %rdi
> > +#  else
> > +       addq    %rcx, %rdi
> > +#  endif
> > +#  ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +#  endif
> > +       .p2align 4,, 8
> > +#  if VEC_SIZE == 32
> > +L(zfill_less_half):
> > +#  endif
> > +L(zfill_less_16):
> > +       xorl    %ecx, %ecx
> > +       cmpl    $(8 / CHAR_SIZE), %edx
> > +       jb      L(zfill_less_8)
> > +       movq    %rcx, (%rdi)
> > +       movq    %rcx, -(8 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE)
> > +#  ifndef USE_AS_STPCPY
> > +L(ret_8_15):
> > +#  endif
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(less_1x_vec):
> > +       je      L(copy_1x)
> > +
> > +       /* We will need `tzcnt` result for all other copy sizes.  */
> > +       tzcnt   %VRCX, %VRCX
> > +#  if VEC_SIZE == 64
> > +       cmpl    $(32 / CHAR_SIZE), %edx
> > +       jae     L(copy_32_63)
> > +#  endif
> > +
> > +       cmpl    $(16 / CHAR_SIZE), %edx
> > +       jae     L(copy_16_31)
> > +
> > +       cmpl    $(8 / CHAR_SIZE), %edx
> > +       jae     L(copy_8_15)
> > +#  ifdef USE_AS_WCSCPY
> > +       testl   %ecx, %ecx
> > +       jz      L(zfill_less_8_set_ret)
> > +
> > +       movl    (%rsi, %rdx, CHAR_SIZE), %esi
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       movl    %esi, (%rdi, %rdx, CHAR_SIZE)
> > +#   ifdef USE_AS_STPCPY
> > +       cmpl    %ecx, %edx
> > +L(ret_8_15):
> > +       adcq    $0, %rdx
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#   endif
> > +       ret
> > +L(zfill_less_8_set_ret):
> > +       xorl    %ecx, %ecx
> > +#   ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +#   endif
> > +L(zfill_less_8):
> > +       movl    %ecx, (%rdi)
> > +       movl    %ecx, (%rdi, %rdx, CHAR_SIZE)
> > +       ret
> > +#  else
> > +       cmpl    $3, %edx
> > +       jb      L(copy_0_3)
> > +       /* Overfill to avoid branches.  */
> > +       movl    -3(%rsi, %rdx), %esi
> > +       vmovd   %VMM_128(0), (%rdi)
> > +       movl    %esi, -3(%rdi, %rdx)
> > +       cmpl    %ecx, %edx
> > +       jbe     L(ret_4_7)
> > +       subq    %rcx, %rdx
> > +       addq    %rcx, %rdi
> > +#   ifdef USE_AS_STPCPY
> > +       movq    %rdi, %rax
> > +#   endif
> > +       xorl    %ecx, %ecx
> > +       .p2align 4,, 8
> > +L(zfill_less_8):
> > +       cmpl    $3, %edx
> > +       jb      L(zfill_less_3)
> > +       movl    %ecx, (%rdi)
> > +       movl    %ecx, -3(%rdi, %rdx)
> > +#   ifdef USE_AS_STPCPY
> > +       ret
> > +#   endif
> > +
> > +L(ret_4_7):
> > +#   ifdef USE_AS_STPCPY
> > +L(ret_8_15):
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +#   endif
> > +       ret
> > +
> > +       .p2align 4,, 4
> > +L(zfill_less_3):
> > +       testl   %edx, %edx
> > +       jz      L(zfill_1)
> > +       movw    %cx, (%rdi)
> > +L(zfill_1):
> > +       movb    %cl, (%rdi, %rdx)
> > +       ret
> > +
> > +       .p2align 4,, 8
> > +L(copy_0_3):
> > +       vmovd   %VMM_128(0), %r8d
> > +       testl   %edx, %edx
> > +       jz      L(copy_1)
> > +       movw    %r8w, (%rdi)
> > +       cmpl    %ecx, %edx
> > +       ja      L(zfill_from_1)
> > +       movzbl  (%rsi, %rdx), %r8d
> > +#   ifdef USE_AS_STPCPY
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +       movb    %r8b, (%rdi, %rdx)
> > +       ret
> > +#   endif
> > +
> > +L(copy_1):
> > +#   ifdef USE_AS_STPCPY
> > +       movl    %edx, %eax
> > +       cmpl    %ecx, %edx
> > +       adcq    %rdi, %rax
> > +#   endif
> > +#   ifdef USE_AS_WCSCPY
> > +       vmovd   %VMM_128(0), (%rdi)
> > +#   else
> > +       movb    %r8b, (%rdi, %rdx)
> > +#   endif
> > +       ret
> > +#  endif
> > +
> > +
> > +#  ifndef USE_AS_WCSCPY
> > +       .p2align 4,, 8
> > +L(zfill_from_1):
> > +#   ifdef USE_AS_STPCPY
> > +       leaq    (%rdi, %rcx), %rax
> > +#   endif
> > +       movw    $0, -1(%rdi, %rdx)
> > +       ret
> > +#  endif
> > +
> > +       .p2align 4,, 4
> > +L(zero_len):
> > +       incq    %rdx
> > +       jne     L(best_effort_strncpy)
> > +       movq    %rdi, %rax
> > +       ret
> > +# endif
> > +
> > +
> > +       .p2align 4,, 4
> > +       .p2align 6,, 8
> > +L(page_cross):
> > +       movq    %rsi, %rax
> > +       andq    $(VEC_SIZE * -1), %rax
> > +       VPCMPEQ (%rax), %VZERO, %k0
> > +       KMOV    %k0, %VRCX
> > +# ifdef USE_AS_WCSCPY
> > +       movl    %esi, %r8d
> > +       shrl    $2, %r8d
> > +       andl    $(CHAR_PER_VEC - 1), %r8d
> > +       shrx    %VR8, %VRCX, %VRCX
> > +# else
> > +       shrx    %VRSI, %VRCX, %VRCX
> > +# endif
> > +
> > +       /* Compute amount of bytes we checked.  */
> > +       subl    %esi, %eax
> > +       andl    $(VEC_SIZE - 1), %eax
> > +# ifdef USE_AS_WCSCPY
> > +       shrl    $2, %eax
> > +# endif
> > +
> > +       /* If rax > rdx then we are finishing the copy at the end of the
> > +          page.  */
> > +       cmpq    %rax, %rdx
> > +       jb      L(page_cross_small)
> > +
> > +
> > +       /* If rcx is non-zero then continue.  */
> > +       test    %VRCX, %VRCX
> > +       jz      L(page_cross_continue)
> > +
> > +       /* We found zero-CHAR so need to copy then zfill (we know we
> > +          didn't cover all of length here).  */
> > +       bsf     %VRCX, %VRCX
> > +L(movsb_and_zfill):
> > +       incl    %ecx
> > +       subq    %rcx, %rdx
> > +# ifdef USE_AS_STPCPY
> > +       leaq    -CHAR_SIZE(%rdi, %rcx, CHAR_SIZE), %rax
> > +# else
> > +       movq    %rdi, %rax
> > +# endif
> > +
> > +       REP_MOVS
> > +# ifdef USE_AS_WCSCPY
> > +       movl    $0, (%rdi)
> > +# else
> > +       movb    $0, (%rdi)
> > +# endif
> > +       jmp     L(zfill_from_page_cross)
> > +
> > +L(page_cross_small):
> > +       tzcnt   %VRCX, %VRCX
> > +       cmpl    %ecx, %edx
> > +       jbe     L(page_cross_copy_only)
> > +
> > +       /* Do a zfill of the tail before copying.  */
> > +       movq    %rdi, %r9
> > +       xorl    %eax, %eax
> > +
> > +       movl    %ecx, %r8d
> > +
> > +       subl    %ecx, %edx
> > +       leaq    CHAR_SIZE(%rdi, %rcx, CHAR_SIZE), %rdi
> > +       movl    %edx, %ecx
> > +       REP_STOS
> > +       movq    %r9, %rdi
> > +       movl    %r8d, %edx
> > +L(page_cross_copy_only):
> > +       leal    1(%rdx), %ecx
> > +# ifdef USE_AS_STPCPY
> > +#  ifdef USE_AS_WCSCPY
> > +       adcl    $0, %edx
> > +       leaq    (%rdi, %rdx, CHAR_SIZE), %rax
> > +#  else
> > +       movl    %edx, %eax
> > +       adcq    %rdi, %rax
> > +#  endif
> > +# else
> > +       movq    %rdi, %rax
> > +# endif
> > +       REP_MOVS
> > +       ret
> > +
> > +
> > +L(best_effort_strncpy):
> > +       movq    %rdx, %rcx
> > +       xorl    %eax, %eax
> > +       movq    %rdi, %r8
> > +       /* The length is >= 2^63. We very much so expect to segfault at
> > +          rep stos. If that doesn't happen then just strcpy to finish.
> > +        */
> > +       REP_STOS
> > +       movq    %r8, %rdi
> > +       jmp     OVERFLOW_STRCPY
> > +END(STRNCPY)
> > +#endif
> > diff --git a/sysdeps/x86_64/multiarch/strncpy-or-cat-overflow-def.h b/sysdeps/x86_64/multiarch/strncpy-or-cat-overflow-def.h
> > new file mode 100644
> > index 0000000000..d5ff4cbe50
> > --- /dev/null
> > +++ b/sysdeps/x86_64/multiarch/strncpy-or-cat-overflow-def.h
> > @@ -0,0 +1,65 @@
>
> Copyright notice is missing.
>
> > +#ifndef _STRNCPY_OR_CAT_OVERFLOW_DEF_H_
> > +#define _STRNCPY_OR_CAT_OVERFLOW_DEF_H_ 1
> > +
> > +#if defined USE_MULTIARCH && IS_IN(libc)
> > +#  define UNDERSCORES __
> > +#  ifdef USE_WITH_SSE2
> > +#    define ISA_EXT _sse2
> > +#  elif defined USE_WITH_AVX
> > +#    ifdef USE_WITH_RTM
> > +#      define ISA_EXT _avx_rtm
> > +#    else
> > +#      define ISA_EXT _avx
> > +#    endif
> > +#  elif defined USE_WITH_AVX2
> > +#    ifdef USE_WITH_RTM
> > +#      define ISA_EXT _avx2_rtm
> > +#    else
> > +#      define ISA_EXT _avx2
> > +#    endif
> > +
> > +#  elif defined USE_WITH_EVEX256
> > +#    define ISA_EXT _evex
> > +#  elif defined USE_WITH_EVEX512
> > +#    define ISA_EXT _evex512
> > +#  endif
> > +#else
> > +#  define UNDERSCORES
> > +#  define ISA_EXT
> > +#endif
> > +
> > +#ifdef USE_AS_WCSCPY
> > +#  define STRCPY_PREFIX wc
> > +#  define STRCAT_PREFIX wcs
> > +#  ifdef USE_AS_STPCPY
> > +#    define STRCPY_POSTFIX pcpy
> > +#  else
> > +#    define STRCPY_POSTFIX scpy
> > +#  endif
> > +#else
> > +#  define STRCPY_PREFIX st
> > +#  define STRCAT_PREFIX str
> > +#  ifdef USE_AS_STPCPY
> > +#    define STRCPY_POSTFIX pcpy
> > +#  else
> > +#    define STRCPY_POSTFIX rcpy
> > +#  endif
> > +#endif
> > +#define STRCAT_POSTFIX cat
> > +
> > +#define PRIMITIVE_OF_NAMER(underscores, prefix, postfix, ext)                 \
> > +  underscores##prefix##postfix##ext
> > +
> > +#define OF_NAMER(...) PRIMITIVE_OF_NAMER (__VA_ARGS__)
> > +
> > +#ifndef OVERFLOW_STRCPY
> > +#  define OVERFLOW_STRCPY                                                     \
> > +    OF_NAMER (UNDERSCORES, STRCPY_PREFIX, STRCPY_POSTFIX, ISA_EXT)
> > +#endif
> > +
> > +#ifndef OVERFLOW_STRCAT
> > +#  define OVERFLOW_STRCAT                                                     \
> > +    OF_NAMER (UNDERSCORES, STRCAT_PREFIX, STRCAT_POSTFIX, ISA_EXT)
> > +#endif
> > +
> > +#endif
> > --
> > 2.34.1
> >
>
> OK with copyright notices added.
>
> --
> H.J.


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