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From: "H.J. Lu" <hjl.tools@gmail.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: libc-alpha@sourceware.org, carlos@systemhalted.org
Subject: Re: [PATCH v3 2/5] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions
Date: Fri, 4 Nov 2022 14:46:33 -0700	[thread overview]
Message-ID: <Y2WIOVTTdaM+J97V@gmail.com> (raw)
In-Reply-To: <20221104201314.401813-2-goldstein.w.n@gmail.com>

On Fri, Nov 04, 2022 at 01:13:11PM -0700, Noah Goldstein 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 |  110 ++
>  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, 2100 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..9530d7b683
> --- /dev/null
> +++ b/sysdeps/x86_64/multiarch/strcat-strlen-evex.S
> @@ -0,0 +1,110 @@
> +/* strlen used for begining of str{n}cat using EVEX 256/512.
> +   Copyright (C) 2011-2022 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/>.  */
> +
> +
> +/* NOTE: This file is meant to be included by strcat-evex or
> +   strncat-evex and does not standalone.  Before including %rdi
> +   must be saved in %rax.  */

Since this file isn't standalone, please rename it to .h.

> +
> +
> +/* 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

Please add a copyright notice.

> @@ -0,0 +1,65 @@
> +#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

Do we have a function with both AVX and AVX2 versions? If not, should
keep just 1.

> +#    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
>  

H.J.

  reply	other threads:[~2022-11-04 21:46 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-03  8:53 [PATCH v1 1/4] benchtests: Make str{n}{cat|cpy} benchmarks output json Noah Goldstein
2022-11-03  8:53 ` [PATCH v1 2/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions Noah Goldstein
2022-11-03  8:55   ` Noah Goldstein
2022-11-04 23:04   ` [PATCH v4 1/4] " Noah Goldstein
2022-11-04 23:04     ` [PATCH v4 2/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-avx2 functions Noah Goldstein
2022-11-04 23:04     ` [PATCH v4 3/4] x86: Add evex optimized functions for the wchar_t strcpy family Noah Goldstein
2022-11-04 23:04     ` [PATCH v4 4/4] x86: Add avx2 " Noah Goldstein
2022-11-04 23:34     ` [PATCH v4 1/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions H.J. Lu
2022-11-09  1:38   ` [PATCH v5 " Noah Goldstein
2022-11-09  1:38     ` [PATCH v5 2/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-avx2 functions Noah Goldstein
2022-11-09  3:00       ` H.J. Lu
2022-11-09  1:38     ` [PATCH v5 3/4] x86: Add evex optimized functions for the wchar_t strcpy family Noah Goldstein
2022-11-09  3:01       ` H.J. Lu
2022-11-09  1:38     ` [PATCH v5 4/4] x86: Add avx2 " Noah Goldstein
2022-11-09  3:01       ` H.J. Lu
2022-11-09  3:00     ` [PATCH v5 1/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions H.J. Lu
2022-11-03  8:53 ` [PATCH v1 3/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-avx2 functions Noah Goldstein
2022-11-03  8:55   ` Noah Goldstein
2022-11-03  8:53 ` [PATCH v1 4/4] x86: Add optimized functions for the wide-character strcpy family Noah Goldstein
2022-11-03  9:06 ` [PATCH v1 1/4] benchtests: Make str{n}{cat|cpy} benchmarks output json Noah Goldstein
2022-11-04  8:20 ` [PATCH v2 " Noah Goldstein
2022-11-04  8:20   ` [PATCH v2 2/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions Noah Goldstein
2022-11-04 16:33     ` H.J. Lu
2022-11-04 20:20       ` Noah Goldstein
2022-11-04  8:20   ` [PATCH v2 3/4] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-avx2 functions Noah Goldstein
2022-11-04 16:45     ` H.J. Lu
2022-11-04 20:21       ` Noah Goldstein
2022-11-04  8:20   ` [PATCH v2 4/4] x86: Add optimized functions for the wide-character strcpy family Noah Goldstein
2022-11-04 16:47     ` H.J. Lu
2022-11-04 20:22       ` Noah Goldstein
2022-11-04 16:26   ` [PATCH v2 1/4] benchtests: Make str{n}{cat|cpy} benchmarks output json H.J. Lu
2022-11-04 20:13 ` [PATCH v3 1/5] " Noah Goldstein
2022-11-04 20:13   ` [PATCH v3 2/5] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-evex functions Noah Goldstein
2022-11-04 21:46     ` H.J. Lu [this message]
2022-11-04 22:27       ` Noah Goldstein
2022-11-04 22:47         ` H.J. Lu
2022-11-04 23:06           ` Noah Goldstein
2022-11-04 20:13   ` [PATCH v3 3/5] x86: Optimize and shrink st{r|p}{n}{cat|cpy}-avx2 functions Noah Goldstein
2022-11-04 20:13   ` [PATCH v3 4/5] x86: Add evex optimized functions for the wchar_t strcpy family Noah Goldstein
2022-11-04 20:13   ` [PATCH v3 5/5] x86: Add avx2 " Noah Goldstein
2022-11-04 21:01   ` [PATCH v3 1/5] benchtests: Make str{n}{cat|cpy} benchmarks output json H.J. Lu
2022-11-04 21:24     ` Noah Goldstein

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