commit b13a2e68eb3b84f2a7b587132ec2ea813815febf

Author: Noah Goldstein <goldstein.w.n@gmail.com>

Date:   Thu Mar 24 18:56:13 2022 -0500

    x86: Add EVEX optimized str{n}casecmp

    geometric_mean(N=40) of all benchmarks EVEX / SSE42: .621

    All string/memory tests pass.

    Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

    (cherry picked from commit 84e7c46df4086873eae28a1fb87d2cf5388b1e16)

diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile

index 711ecf2ee45d61b9..359712c1491a2431 100644

--- a/sysdeps/x86_64/multiarch/Makefile

+++ b/sysdeps/x86_64/multiarch/Makefile

@@ -53,6 +53,7 @@ sysdep_routines += \

   strcasecmp_l-avx \

   strcasecmp_l-avx2 \

   strcasecmp_l-avx2-rtm \

+  strcasecmp_l-evex \

   strcasecmp_l-sse2 \

   strcasecmp_l-sse4_2 \

   strcasecmp_l-ssse3 \

@@ -93,6 +94,7 @@ sysdep_routines += \

   strncase_l-avx \

   strncase_l-avx2 \

   strncase_l-avx2-rtm \

+  strncase_l-evex \

   strncase_l-sse2 \

   strncase_l-sse4_2 \

   strncase_l-ssse3 \

diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c

index a687b387c91aa9ae..f6994e5406933d53 100644

--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c

+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c

@@ -418,6 +418,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,

   /* Support sysdeps/x86_64/multiarch/strcasecmp_l.c.  */

   IFUNC_IMPL (i, name, strcasecmp,

+	      IFUNC_IMPL_ADD (array, i, strcasecmp,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)),

+			      __strcasecmp_evex)

 	      IFUNC_IMPL_ADD (array, i, strcasecmp,

 			      CPU_FEATURE_USABLE (AVX2),

 			      __strcasecmp_avx2)

@@ -438,6 +442,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,

   /* Support sysdeps/x86_64/multiarch/strcasecmp_l.c.  */

   IFUNC_IMPL (i, name, strcasecmp_l,

+	      IFUNC_IMPL_ADD (array, i, strcasecmp,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)),

+			      __strcasecmp_l_evex)

 	      IFUNC_IMPL_ADD (array, i, strcasecmp,

 			      CPU_FEATURE_USABLE (AVX2),

 			      __strcasecmp_l_avx2)

@@ -572,6 +580,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,

   /* Support sysdeps/x86_64/multiarch/strncase_l.c.  */

   IFUNC_IMPL (i, name, strncasecmp,

+	      IFUNC_IMPL_ADD (array, i, strncasecmp,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)),

+			      __strncasecmp_evex)

 	      IFUNC_IMPL_ADD (array, i, strncasecmp,

 			      CPU_FEATURE_USABLE (AVX2),

 			      __strncasecmp_avx2)

@@ -593,6 +605,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,

   /* Support sysdeps/x86_64/multiarch/strncase_l.c.  */

   IFUNC_IMPL (i, name, strncasecmp_l,

+	      IFUNC_IMPL_ADD (array, i, strncasecmp,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)),

+			      __strncasecmp_l_evex)

 	      IFUNC_IMPL_ADD (array, i, strncasecmp,

 			      CPU_FEATURE_USABLE (AVX2),

 			      __strncasecmp_l_avx2)

diff --git a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h

index 64d0cd6ef25f73c0..488e99e4997f379b 100644

--- a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h

+++ b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h

@@ -25,6 +25,7 @@ extern __typeof (REDIRECT_NAME) OPTIMIZE (sse42) attribute_hidden;

 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx) attribute_hidden;

 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2) attribute_hidden;

 extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_rtm) attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE (evex) attribute_hidden;

 static inline void *

 IFUNC_SELECTOR (void)

@@ -34,6 +35,10 @@ IFUNC_SELECTOR (void)

   if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)

       && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))

     {

+      if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)

+          && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW))

+        return OPTIMIZE (evex);

+

       if (CPU_FEATURE_USABLE_P (cpu_features, RTM))

         return OPTIMIZE (avx2_rtm);

diff --git a/sysdeps/x86_64/multiarch/strcasecmp_l-evex.S b/sysdeps/x86_64/multiarch/strcasecmp_l-evex.S

new file mode 100644

index 0000000000000000..58642db748e3db71

--- /dev/null

+++ b/sysdeps/x86_64/multiarch/strcasecmp_l-evex.S

@@ -0,0 +1,23 @@

+/* strcasecmp_l optimized with EVEX.

+   Copyright (C) 2017-2022 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/>.  */

+

+#ifndef STRCMP

+# define STRCMP	__strcasecmp_l_evex

+#endif

+#define USE_AS_STRCASECMP_L

+#include "strcmp-evex.S"

diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S

index 0dfa62bd149c02b4..b81b57753c38db1f 100644

--- a/sysdeps/x86_64/multiarch/strcmp-evex.S

+++ b/sysdeps/x86_64/multiarch/strcmp-evex.S

@@ -19,6 +19,9 @@

 #if IS_IN (libc)

 # include <sysdep.h>

+# if defined USE_AS_STRCASECMP_L

+#  include "locale-defines.h"

+# endif

 # ifndef STRCMP

 #  define STRCMP	__strcmp_evex

@@ -34,19 +37,29 @@

 # define VMOVA	vmovdqa64

 # ifdef USE_AS_WCSCMP

-#  define TESTEQ	subl	$0xff,

+#  ifndef OVERFLOW_STRCMP

+#   define OVERFLOW_STRCMP	__wcscmp_evex

+#  endif

+

+#  define TESTEQ	subl $0xff,

 	/* Compare packed dwords.  */

 #  define VPCMP	vpcmpd

 #  define VPMINU	vpminud

 #  define VPTESTM	vptestmd

+#  define VPTESTNM	vptestnmd

 	/* 1 dword char == 4 bytes.  */

 #  define SIZE_OF_CHAR	4

 # else

+#  ifndef OVERFLOW_STRCMP

+#   define OVERFLOW_STRCMP	__strcmp_evex

+#  endif

+

 #  define TESTEQ	incl

 	/* Compare packed bytes.  */

 #  define VPCMP	vpcmpb

 #  define VPMINU	vpminub

 #  define VPTESTM	vptestmb

+#  define VPTESTNM	vptestnmb

 	/* 1 byte char == 1 byte.  */

 #  define SIZE_OF_CHAR	1

 # endif

@@ -73,11 +86,16 @@

 #  define VEC_OFFSET	(-VEC_SIZE)

 # endif

-# define XMMZERO	xmm16

 # define XMM0	xmm17

 # define XMM1	xmm18

-# define YMMZERO	ymm16

+# define XMM10	xmm27

+# define XMM11	xmm28

+# define XMM12	xmm29

+# define XMM13	xmm30

+# define XMM14	xmm31

+

+

 # define YMM0	ymm17

 # define YMM1	ymm18

 # define YMM2	ymm19

@@ -89,6 +107,87 @@

 # define YMM8	ymm25

 # define YMM9	ymm26

 # define YMM10	ymm27

+# define YMM11	ymm28

+# define YMM12	ymm29

+# define YMM13	ymm30

+# define YMM14	ymm31

+

+# ifdef USE_AS_STRCASECMP_L

+#  define BYTE_LOOP_REG	OFFSET_REG

+# else

+#  define BYTE_LOOP_REG	ecx

+# endif

+

+# ifdef USE_AS_STRCASECMP_L

+#  ifdef USE_AS_STRNCMP

+#   define STRCASECMP	__strncasecmp_evex

+#   define LOCALE_REG	rcx

+#   define LOCALE_REG_LP	RCX_LP

+#   define STRCASECMP_NONASCII	__strncasecmp_l_nonascii

+#  else

+#   define STRCASECMP	__strcasecmp_evex

+#   define LOCALE_REG	rdx

+#   define LOCALE_REG_LP	RDX_LP

+#   define STRCASECMP_NONASCII	__strcasecmp_l_nonascii

+#  endif

+# endif

+

+# define LCASE_MIN_YMM	%YMM12

+# define LCASE_MAX_YMM	%YMM13

+# define CASE_ADD_YMM	%YMM14

+

+# define LCASE_MIN_XMM	%XMM12

+# define LCASE_MAX_XMM	%XMM13

+# define CASE_ADD_XMM	%XMM14

+

+	/* NB: wcsncmp uses r11 but strcasecmp is never used in

+	   conjunction with wcscmp.  */

+# define TOLOWER_BASE	%r11

+

+# ifdef USE_AS_STRCASECMP_L

+#  define _REG(x, y) x ## y

+#  define REG(x, y) _REG(x, y)

+#  define TOLOWER(reg1, reg2, ext)										\

+	vpsubb	REG(LCASE_MIN_, ext), reg1, REG(%ext, 10);					\

+	vpsubb	REG(LCASE_MIN_, ext), reg2, REG(%ext, 11);					\

+	vpcmpub	$1, REG(LCASE_MAX_, ext), REG(%ext, 10), %k5;				\

+	vpcmpub	$1, REG(LCASE_MAX_, ext), REG(%ext, 11), %k6;				\

+	vpaddb	reg1, REG(CASE_ADD_, ext), reg1{%k5};						\

+	vpaddb	reg2, REG(CASE_ADD_, ext), reg2{%k6}

+

+#  define TOLOWER_gpr(src, dst) movl (TOLOWER_BASE, src, 4), dst

+#  define TOLOWER_YMM(...)	TOLOWER(__VA_ARGS__, YMM)

+#  define TOLOWER_XMM(...)	TOLOWER(__VA_ARGS__, XMM)

+

+#  define CMP_R1_R2(s1_reg, s2_reg, reg_out, ext)						\

+	TOLOWER	(s1_reg, s2_reg, ext);										\

+	VPCMP	$0, s1_reg, s2_reg, reg_out

+

+#  define CMP_R1_S2(s1_reg, s2_mem, s2_reg, reg_out, ext)				\

+	VMOVU	s2_mem, s2_reg;												\

+	CMP_R1_R2(s1_reg, s2_reg, reg_out, ext)

+

+#  define CMP_R1_R2_YMM(...) CMP_R1_R2(__VA_ARGS__, YMM)

+#  define CMP_R1_R2_XMM(...) CMP_R1_R2(__VA_ARGS__, XMM)

+

+#  define CMP_R1_S2_YMM(...) CMP_R1_S2(__VA_ARGS__, YMM)

+#  define CMP_R1_S2_XMM(...) CMP_R1_S2(__VA_ARGS__, XMM)

+

+# else

+#  define TOLOWER_gpr(...)

+#  define TOLOWER_YMM(...)

+#  define TOLOWER_XMM(...)

+

+#  define CMP_R1_R2_YMM(s1_reg, s2_reg, reg_out)						\

+	VPCMP	$0, s2_reg, s1_reg, reg_out

+

+#  define CMP_R1_R2_XMM(...) CMP_R1_R2_YMM(__VA_ARGS__)

+

+#  define CMP_R1_S2_YMM(s1_reg, s2_mem, unused, reg_out)				\

+	VPCMP	$0, s2_mem, s1_reg, reg_out

+

+#  define CMP_R1_S2_XMM(...) CMP_R1_S2_YMM(__VA_ARGS__)

+# endif

 /* Warning!

            wcscmp/wcsncmp have to use SIGNED comparison for elements.

@@ -112,8 +211,45 @@

    returned.  */

 	.section .text.evex, "ax", @progbits

-ENTRY(STRCMP)

+	.align	16

+	.type	STRCMP, @function

+	.globl	STRCMP

+	.hidden	STRCMP

+

+# ifdef USE_AS_STRCASECMP_L

+ENTRY (STRCASECMP)

+	movq	__libc_tsd_LOCALE@gottpoff(%rip), %rax

+	mov	%fs:(%rax), %LOCALE_REG_LP

+

+	/* Either 1 or 5 bytes (dependeing if CET is enabled).  */

+	.p2align 4

+END (STRCASECMP)

+	/* FALLTHROUGH to strcasecmp/strncasecmp_l.  */

+# endif

+

+	.p2align 4

+STRCMP:

+	cfi_startproc

+	_CET_ENDBR

+	CALL_MCOUNT

+

+# if defined USE_AS_STRCASECMP_L

+	/* We have to fall back on the C implementation for locales with

+	   encodings not matching ASCII for single bytes.  */

+#  if LOCALE_T___LOCALES != 0 || LC_CTYPE != 0

+	mov	LOCALE_T___LOCALES + LC_CTYPE * LP_SIZE(%LOCALE_REG), %RAX_LP

+#  else

+	mov	(%LOCALE_REG), %RAX_LP

+#  endif

+	testl	$1, LOCALE_DATA_VALUES + _NL_CTYPE_NONASCII_CASE * SIZEOF_VALUES(%rax)

+	jne	STRCASECMP_NONASCII

+	leaq	_nl_C_LC_CTYPE_tolower + 128 * 4(%rip), TOLOWER_BASE

+# endif

+

 # ifdef USE_AS_STRNCMP

+	/* Don't overwrite LOCALE_REG (rcx) until we have pass

+	   L(one_or_less). Otherwise we might use the wrong locale in

+	   the OVERFLOW_STRCMP (strcasecmp_l).  */

 #  ifdef __ILP32__

 	/* Clear the upper 32 bits.  */

 	movl	%edx, %edx

@@ -125,6 +261,32 @@ ENTRY(STRCMP)

 	   actually bound the buffer.  */

 	jle	L(one_or_less)

 # endif

+

+# if defined USE_AS_STRCASECMP_L

+	.section .rodata.cst32, "aM", @progbits, 32

+	.align	32

+L(lcase_min):

+	.quad	0x4141414141414141

+	.quad	0x4141414141414141

+	.quad	0x4141414141414141

+	.quad	0x4141414141414141

+L(lcase_max):

+	.quad	0x1a1a1a1a1a1a1a1a

+	.quad	0x1a1a1a1a1a1a1a1a

+	.quad	0x1a1a1a1a1a1a1a1a

+	.quad	0x1a1a1a1a1a1a1a1a

+L(case_add):

+	.quad	0x2020202020202020

+	.quad	0x2020202020202020

+	.quad	0x2020202020202020

+	.quad	0x2020202020202020

+	.previous

+

+	vmovdqa64 L(lcase_min)(%rip), LCASE_MIN_YMM

+	vmovdqa64 L(lcase_max)(%rip), LCASE_MAX_YMM

+	vmovdqa64 L(case_add)(%rip), CASE_ADD_YMM

+# endif

+

 	movl	%edi, %eax

 	orl	%esi, %eax

 	/* Shift out the bits irrelivant to page boundary ([63:12]).  */

@@ -139,7 +301,7 @@ L(no_page_cross):

 	VPTESTM	%YMM0, %YMM0, %k2

 	/* Each bit cleared in K1 represents a mismatch or a null CHAR

 	   in YMM0 and 32 bytes at (%rsi).  */

-	VPCMP	$0, (%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 # ifdef USE_AS_STRNCMP

 	cmpq	$CHAR_PER_VEC, %rdx

@@ -169,6 +331,8 @@ L(return_vec_0):

 # else

 	movzbl	(%rdi, %rcx), %eax

 	movzbl	(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 # endif

 L(ret0):

@@ -188,11 +352,15 @@ L(ret_zero):

 	.p2align 4,, 5

 L(one_or_less):

+#  ifdef USE_AS_STRCASECMP_L

+	/* Set locale argument for strcasecmp.  */

+	movq	%LOCALE_REG, %rdx

+#  endif

 	jb	L(ret_zero)

-#  ifdef USE_AS_WCSCMP

 	/* 'nbe' covers the case where length is negative (large

 	   unsigned).  */

-	jnbe	__wcscmp_evex

+	jnbe	OVERFLOW_STRCMP

+#  ifdef USE_AS_WCSCMP

 	movl	(%rdi), %edx

 	xorl	%eax, %eax

 	cmpl	(%rsi), %edx

@@ -201,11 +369,10 @@ L(one_or_less):

 	negl	%eax

 	orl	$1, %eax

 #  else

-	/* 'nbe' covers the case where length is negative (large

-	   unsigned).  */

-	jnbe	__strcmp_evex

 	movzbl	(%rdi), %eax

 	movzbl	(%rsi), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 #  endif

 L(ret1):

@@ -233,6 +400,8 @@ L(return_vec_1):

 # else

 	movzbl	VEC_SIZE(%rdi, %rcx), %eax

 	movzbl	VEC_SIZE(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 # endif

 L(ret2):

@@ -270,6 +439,8 @@ L(return_vec_2):

 # else

 	movzbl	(VEC_SIZE * 2)(%rdi, %rcx), %eax

 	movzbl	(VEC_SIZE * 2)(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 # endif

 L(ret3):

@@ -290,6 +461,8 @@ L(return_vec_3):

 #  else

 	movzbl	(VEC_SIZE * 3)(%rdi, %rcx), %eax

 	movzbl	(VEC_SIZE * 3)(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 #  endif

 L(ret4):

@@ -303,7 +476,7 @@ L(more_3x_vec):

 	/* Safe to compare 4x vectors.  */

 	VMOVU	(VEC_SIZE)(%rdi), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (VEC_SIZE)(%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, VEC_SIZE(%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_1)

@@ -315,14 +488,14 @@ L(more_3x_vec):

 	VMOVU	(VEC_SIZE * 2)(%rdi), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (VEC_SIZE * 2)(%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (VEC_SIZE * 2)(%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_2)

 	VMOVU	(VEC_SIZE * 3)(%rdi), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (VEC_SIZE * 3)(%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (VEC_SIZE * 3)(%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_3)

@@ -381,7 +554,6 @@ L(prepare_loop_aligned):

 	subl	%esi, %eax

 	andl	$(PAGE_SIZE - 1), %eax

-	vpxorq	%YMMZERO, %YMMZERO, %YMMZERO

 	/* Loop 4x comparisons at a time.  */

 	.p2align 4

@@ -413,22 +585,35 @@ L(loop_skip_page_cross_check):

 	/* A zero CHAR in YMM9 means that there is a null CHAR.  */

 	VPMINU	%YMM8, %YMM9, %YMM9

-	/* Each bit set in K1 represents a non-null CHAR in YMM8.  */

+	/* Each bit set in K1 represents a non-null CHAR in YMM9.  */

 	VPTESTM	%YMM9, %YMM9, %k1

-

+# ifndef USE_AS_STRCASECMP_L

 	vpxorq	(VEC_SIZE * 0)(%rsi), %YMM0, %YMM1

 	vpxorq	(VEC_SIZE * 1)(%rsi), %YMM2, %YMM3

 	vpxorq	(VEC_SIZE * 2)(%rsi), %YMM4, %YMM5

 	/* Ternary logic to xor (VEC_SIZE * 3)(%rsi) with YMM6 while

 	   oring with YMM1. Result is stored in YMM6.  */

 	vpternlogd $0xde, (VEC_SIZE * 3)(%rsi), %YMM1, %YMM6

-

+# else

+	VMOVU	(VEC_SIZE * 0)(%rsi), %YMM1

+	TOLOWER_YMM (%YMM0, %YMM1)

+	VMOVU	(VEC_SIZE * 1)(%rsi), %YMM3

+	TOLOWER_YMM (%YMM2, %YMM3)

+	VMOVU	(VEC_SIZE * 2)(%rsi), %YMM5

+	TOLOWER_YMM (%YMM4, %YMM5)

+	VMOVU	(VEC_SIZE * 3)(%rsi), %YMM7

+	TOLOWER_YMM (%YMM6, %YMM7)

+	vpxorq	%YMM0, %YMM1, %YMM1

+	vpxorq	%YMM2, %YMM3, %YMM3

+	vpxorq	%YMM4, %YMM5, %YMM5

+	vpternlogd $0xde, %YMM7, %YMM1, %YMM6

+# endif

 	/* Or together YMM3, YMM5, and YMM6.  */

 	vpternlogd $0xfe, %YMM3, %YMM5, %YMM6

 	/* A non-zero CHAR in YMM6 represents a mismatch.  */

-	VPCMP	$0, %YMMZERO, %YMM6, %k0{%k1}

+	VPTESTNM %YMM6, %YMM6, %k0{%k1}

 	kmovd	%k0, %LOOP_REG

 	TESTEQ	%LOOP_REG

@@ -437,13 +622,13 @@ L(loop_skip_page_cross_check):

 	/* Find which VEC has the mismatch of end of string.  */

 	VPTESTM	%YMM0, %YMM0, %k1

-	VPCMP	$0, %YMMZERO, %YMM1, %k0{%k1}

+	VPTESTNM %YMM1, %YMM1, %k0{%k1}

 	kmovd	%k0, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_0_end)

 	VPTESTM	%YMM2, %YMM2, %k1

-	VPCMP	$0, %YMMZERO, %YMM3, %k0{%k1}

+	VPTESTNM %YMM3, %YMM3, %k0{%k1}

 	kmovd	%k0, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_1_end)

@@ -457,7 +642,7 @@ L(return_vec_2_3_end):

 # endif

 	VPTESTM	%YMM4, %YMM4, %k1

-	VPCMP	$0, %YMMZERO, %YMM5, %k0{%k1}

+	VPTESTNM %YMM5, %YMM5, %k0{%k1}

 	kmovd	%k0, %ecx

 	TESTEQ	%ecx

 # if CHAR_PER_VEC <= 16

@@ -493,6 +678,8 @@ L(return_vec_3_end):

 # else

 	movzbl	(VEC_SIZE * 2)(%rdi, %LOOP_REG64), %eax

 	movzbl	(VEC_SIZE * 2)(%rsi, %LOOP_REG64), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	xorl	%r8d, %eax

 	subl	%r8d, %eax

@@ -545,6 +732,8 @@ L(return_vec_0_end):

 # else

 	movzbl	(%rdi, %rcx), %eax

 	movzbl	(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	/* Flip `eax` if `rdi` and `rsi` where swapped in page cross

 	   logic. Subtract `r8d` after xor for zero case.  */

@@ -569,6 +758,8 @@ L(return_vec_1_end):

 #  else

 	movzbl	VEC_SIZE(%rdi, %rcx), %eax

 	movzbl	VEC_SIZE(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	xorl	%r8d, %eax

 	subl	%r8d, %eax

@@ -598,7 +789,7 @@ L(page_cross_during_loop):

 	VMOVA	(%rdi), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_0_end)

@@ -619,8 +810,7 @@ L(less_1x_vec_till_page_cross):

 	   been loaded earlier so must be valid.  */

 	VMOVU	-VEC_SIZE(%rdi, %rax), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, -VEC_SIZE(%rsi, %rax), %YMM0, %k1{%k2}

-

+	CMP_R1_S2_YMM (%YMM0, -VEC_SIZE(%rsi, %rax), %YMM1, %k1){%k2}

 	/* Mask of potentially valid bits. The lower bits can be out of

 	   range comparisons (but safe regarding page crosses).  */

@@ -642,6 +832,8 @@ L(less_1x_vec_till_page_cross):

 # ifdef USE_AS_STRNCMP

 #  ifdef USE_AS_WCSCMP

+	/* NB: strcasecmp not used with WCSCMP so this access to r11 is

+	   safe.  */

 	movl	%eax, %r11d

 	shrl	$2, %r11d

 	cmpq	%r11, %rdx

@@ -679,6 +871,8 @@ L(return_page_cross_cmp_mem):

 # else

 	movzbl	VEC_OFFSET(%rdi, %rcx), %eax

 	movzbl	VEC_OFFSET(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	xorl	%r8d, %eax

 	subl	%r8d, %eax

@@ -709,7 +903,7 @@ L(more_2x_vec_till_page_cross):

 	VMOVA	VEC_SIZE(%rdi), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, VEC_SIZE(%rsi), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, VEC_SIZE(%rsi), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_1_end)

@@ -724,14 +918,14 @@ L(more_2x_vec_till_page_cross):

 	/* Safe to include comparisons from lower bytes.  */

 	VMOVU	-(VEC_SIZE * 2)(%rdi, %rax), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, -(VEC_SIZE * 2)(%rsi, %rax), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, -(VEC_SIZE * 2)(%rsi, %rax), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_page_cross_0)

 	VMOVU	-(VEC_SIZE * 1)(%rdi, %rax), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, -(VEC_SIZE * 1)(%rsi, %rax), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, -(VEC_SIZE * 1)(%rsi, %rax), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(return_vec_page_cross_1)

@@ -740,6 +934,8 @@ L(more_2x_vec_till_page_cross):

 	/* Must check length here as length might proclude reading next

 	   page.  */

 #  ifdef USE_AS_WCSCMP

+	/* NB: strcasecmp not used with WCSCMP so this access to r11 is

+	   safe.  */

 	movl	%eax, %r11d

 	shrl	$2, %r11d

 	cmpq	%r11, %rdx

@@ -754,12 +950,19 @@ L(more_2x_vec_till_page_cross):

 	VMOVA	(VEC_SIZE * 3)(%rdi), %YMM6

 	VPMINU	%YMM4, %YMM6, %YMM9

 	VPTESTM	%YMM9, %YMM9, %k1

-

+# ifndef USE_AS_STRCASECMP_L

 	vpxorq	(VEC_SIZE * 2)(%rsi), %YMM4, %YMM5

 	/* YMM6 = YMM5 | ((VEC_SIZE * 3)(%rsi) ^ YMM6).  */

 	vpternlogd $0xde, (VEC_SIZE * 3)(%rsi), %YMM5, %YMM6

-

-	VPCMP	$0, %YMMZERO, %YMM6, %k0{%k1}

+# else

+	VMOVU	(VEC_SIZE * 2)(%rsi), %YMM5

+	TOLOWER_YMM (%YMM4, %YMM5)

+	VMOVU	(VEC_SIZE * 3)(%rsi), %YMM7

+	TOLOWER_YMM (%YMM6, %YMM7)

+	vpxorq	%YMM4, %YMM5, %YMM5

+	vpternlogd $0xde, %YMM7, %YMM5, %YMM6

+# endif

+	VPTESTNM %YMM6, %YMM6, %k0{%k1}

 	kmovd	%k0, %LOOP_REG

 	TESTEQ	%LOOP_REG

 	jnz	L(return_vec_2_3_end)

@@ -815,6 +1018,8 @@ L(return_vec_page_cross_1):

 # else

 	movzbl	VEC_OFFSET(%rdi, %rcx), %eax

 	movzbl	VEC_OFFSET(%rsi, %rcx), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	xorl	%r8d, %eax

 	subl	%r8d, %eax

@@ -871,7 +1076,7 @@ L(page_cross):

 L(page_cross_loop):

 	VMOVU	(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 	TESTEQ	%ecx

 	jnz	L(check_ret_vec_page_cross)

@@ -895,7 +1100,7 @@ L(page_cross_loop):

 	 */

 	VMOVU	(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0

 	VPTESTM	%YMM0, %YMM0, %k2

-	VPCMP	$0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM0, %k1{%k2}

+	CMP_R1_S2_YMM (%YMM0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %YMM1, %k1){%k2}

 	kmovd	%k1, %ecx

 # ifdef USE_AS_STRNCMP

@@ -930,6 +1135,8 @@ L(ret_vec_page_cross_cont):

 # else

 	movzbl	(%rdi, %rcx, SIZE_OF_CHAR), %eax

 	movzbl	(%rsi, %rcx, SIZE_OF_CHAR), %ecx

+	TOLOWER_gpr (%rax, %eax)

+	TOLOWER_gpr (%rcx, %ecx)

 	subl	%ecx, %eax

 	xorl	%r8d, %eax

 	subl	%r8d, %eax

@@ -989,7 +1196,7 @@ L(less_1x_vec_till_page):

 	/* Use 16 byte comparison.  */

 	vmovdqu	(%rdi), %xmm0

 	VPTESTM	%xmm0, %xmm0, %k2

-	VPCMP	$0, (%rsi), %xmm0, %k1{%k2}

+	CMP_R1_S2_XMM (%xmm0, (%rsi), %xmm1, %k1){%k2}

 	kmovd	%k1, %ecx

 # ifdef USE_AS_WCSCMP

 	subl	$0xf, %ecx

@@ -1009,7 +1216,7 @@ L(less_1x_vec_till_page):

 # endif

 	vmovdqu	(%rdi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0

 	VPTESTM	%xmm0, %xmm0, %k2

-	VPCMP	$0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm0, %k1{%k2}

+	CMP_R1_S2_XMM (%xmm0, (%rsi, %OFFSET_REG64, SIZE_OF_CHAR), %xmm1, %k1){%k2}

 	kmovd	%k1, %ecx

 # ifdef USE_AS_WCSCMP

 	subl	$0xf, %ecx

@@ -1048,7 +1255,7 @@ L(less_16_till_page):

 	vmovq	(%rdi), %xmm0