commit 5cb6329652696e79d6d576165ea87e332c9de106

Author: H.J. Lu <hjl.tools@gmail.com>

Date:   Mon Feb 7 05:55:15 2022 -0800

    x86-64: Optimize bzero

    memset with zero as the value to set is by far the majority value (99%+

    for Python3 and GCC).

    bzero can be slightly more optimized for this case by using a zero-idiom

    xor for broadcasting the set value to a register (vector or GPR).

    Co-developed-by: Noah Goldstein <goldstein.w.n@gmail.com>

    (cherry picked from commit 3d9f171bfb5325bd5f427e9fc386453358c6e840)

diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S

index 954471e5a5bf225b..0358210c7ff3a976 100644

--- a/sysdeps/x86_64/memset.S

+++ b/sysdeps/x86_64/memset.S

@@ -35,6 +35,9 @@

   punpcklwd %xmm0, %xmm0; \

   pshufd $0, %xmm0, %xmm0

+# define BZERO_ZERO_VEC0() \

+  pxor %xmm0, %xmm0

+

 # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \

   movd d, %xmm0; \

   pshufd $0, %xmm0, %xmm0; \

@@ -53,6 +56,10 @@

 # define MEMSET_SYMBOL(p,s)	memset

 #endif

+#ifndef BZERO_SYMBOL

+# define BZERO_SYMBOL(p,s)	__bzero

+#endif

+

 #ifndef WMEMSET_SYMBOL

 # define WMEMSET_CHK_SYMBOL(p,s) p

 # define WMEMSET_SYMBOL(p,s)	__wmemset

@@ -63,6 +70,7 @@

 libc_hidden_builtin_def (memset)

 #if IS_IN (libc)

+weak_alias (__bzero, bzero)

 libc_hidden_def (__wmemset)

 weak_alias (__wmemset, wmemset)

 libc_hidden_weak (wmemset)

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

index 26be40959ce62895..37d8d6f0bd2d10cc 100644

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

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

@@ -1,85 +1,130 @@

 ifeq ($(subdir),string)

-sysdep_routines += strncat-c stpncpy-c strncpy-c \

-		   strcmp-sse2 strcmp-sse2-unaligned strcmp-ssse3  \

-		   strcmp-sse4_2 strcmp-avx2 \

-		   strncmp-sse2 strncmp-ssse3 strncmp-sse4_2 strncmp-avx2 \

-		   memchr-sse2 rawmemchr-sse2 memchr-avx2 rawmemchr-avx2 \

-		   memrchr-sse2 memrchr-avx2 \

-		   memcmp-sse2 \

-		   memcmp-avx2-movbe \

-		   memcmp-sse4 memcpy-ssse3 \

-		   memmove-ssse3 \

-		   memcpy-ssse3-back \

-		   memmove-ssse3-back \

-		   memmove-avx512-no-vzeroupper \

-		   strcasecmp_l-sse2 strcasecmp_l-ssse3 \

-		   strcasecmp_l-sse4_2 strcasecmp_l-avx \

-		   strncase_l-sse2 strncase_l-ssse3 \

-		   strncase_l-sse4_2 strncase_l-avx \

-		   strchr-sse2 strchrnul-sse2 strchr-avx2 strchrnul-avx2 \

-		   strrchr-sse2 strrchr-avx2 \

-		   strlen-sse2 strnlen-sse2 strlen-avx2 strnlen-avx2 \

-		   strcat-avx2 strncat-avx2 \

-		   strcat-ssse3 strncat-ssse3\

-		   strcpy-avx2 strncpy-avx2 \

-		   strcpy-sse2 stpcpy-sse2 \

-		   strcpy-ssse3 strncpy-ssse3 stpcpy-ssse3 stpncpy-ssse3 \

-		   strcpy-sse2-unaligned strncpy-sse2-unaligned \

-		   stpcpy-sse2-unaligned stpncpy-sse2-unaligned \

-		   stpcpy-avx2 stpncpy-avx2 \

-		   strcat-sse2 \

-		   strcat-sse2-unaligned strncat-sse2-unaligned \

-		   strchr-sse2-no-bsf memcmp-ssse3 strstr-sse2-unaligned \

-		   strcspn-sse2 strpbrk-sse2 strspn-sse2 \

-		   strcspn-c strpbrk-c strspn-c varshift \

-		   memset-avx512-no-vzeroupper \

-		   memmove-sse2-unaligned-erms \

-		   memmove-avx-unaligned-erms \

-		   memmove-avx512-unaligned-erms \

-		   memset-sse2-unaligned-erms \

-		   memset-avx2-unaligned-erms \

-		   memset-avx512-unaligned-erms \

-		   memchr-avx2-rtm \

-		   memcmp-avx2-movbe-rtm \

-		   memmove-avx-unaligned-erms-rtm \

-		   memrchr-avx2-rtm \

-		   memset-avx2-unaligned-erms-rtm \

-		   rawmemchr-avx2-rtm \

-		   strchr-avx2-rtm \

-		   strcmp-avx2-rtm \

-		   strchrnul-avx2-rtm \

-		   stpcpy-avx2-rtm \

-		   stpncpy-avx2-rtm \

-		   strcat-avx2-rtm \

-		   strcpy-avx2-rtm \

-		   strlen-avx2-rtm \

-		   strncat-avx2-rtm \

-		   strncmp-avx2-rtm \

-		   strncpy-avx2-rtm \

-		   strnlen-avx2-rtm \

-		   strrchr-avx2-rtm \

-		   memchr-evex \

-		   memcmp-evex-movbe \

-		   memmove-evex-unaligned-erms \

-		   memrchr-evex \

-		   memset-evex-unaligned-erms \

-		   rawmemchr-evex \

-		   stpcpy-evex \

-		   stpncpy-evex \

-		   strcat-evex \

-		   strchr-evex \

-		   strchrnul-evex \

-		   strcmp-evex \

-		   strcpy-evex \

-		   strlen-evex \

-		   strncat-evex \

-		   strncmp-evex \

-		   strncpy-evex \

-		   strnlen-evex \

-		   strrchr-evex \

-		   memchr-evex-rtm \

-		   rawmemchr-evex-rtm

+sysdep_routines += \

+  bzero \

+  memchr-avx2 \

+  memchr-avx2-rtm \

+  memchr-evex \

+  memchr-evex-rtm \

+  memchr-sse2 \

+  memcmp-avx2-movbe \

+  memcmp-avx2-movbe-rtm \

+  memcmp-evex-movbe \

+  memcmp-sse2 \

+  memcmp-sse4 \

+  memcmp-ssse3 \

+  memcpy-ssse3 \

+  memcpy-ssse3-back \

+  memmove-avx-unaligned-erms \

+  memmove-avx-unaligned-erms-rtm \

+  memmove-avx512-no-vzeroupper \

+  memmove-avx512-unaligned-erms \

+  memmove-evex-unaligned-erms \

+  memmove-sse2-unaligned-erms \

+  memmove-ssse3 \

+  memmove-ssse3-back \

+  memrchr-avx2 \

+  memrchr-avx2-rtm \

+  memrchr-evex \

+  memrchr-sse2 \

+  memset-avx2-unaligned-erms \

+  memset-avx2-unaligned-erms-rtm \

+  memset-avx512-no-vzeroupper \

+  memset-avx512-unaligned-erms \

+  memset-evex-unaligned-erms \

+  memset-sse2-unaligned-erms \

+  rawmemchr-avx2 \

+  rawmemchr-avx2-rtm \

+  rawmemchr-evex \

+  rawmemchr-evex-rtm \

+  rawmemchr-sse2 \

+  stpcpy-avx2 \

+  stpcpy-avx2-rtm \

+  stpcpy-evex \

+  stpcpy-sse2 \

+  stpcpy-sse2-unaligned \

+  stpcpy-ssse3 \

+  stpncpy-avx2 \

+  stpncpy-avx2-rtm \

+  stpncpy-c \

+  stpncpy-evex \

+  stpncpy-sse2-unaligned \

+  stpncpy-ssse3 \

+  strcasecmp_l-avx \

+  strcasecmp_l-sse2 \

+  strcasecmp_l-sse4_2 \

+  strcasecmp_l-ssse3 \

+  strcat-avx2 \

+  strcat-avx2-rtm \

+  strcat-evex \

+  strcat-sse2 \

+  strcat-sse2-unaligned \

+  strcat-ssse3 \

+  strchr-avx2 \

+  strchr-avx2-rtm \

+  strchr-evex \

+  strchr-sse2 \

+  strchr-sse2-no-bsf \

+  strchrnul-avx2 \

+  strchrnul-avx2-rtm \

+  strchrnul-evex \

+  strchrnul-sse2 \

+  strcmp-avx2 \

+  strcmp-avx2-rtm \

+  strcmp-evex \

+  strcmp-sse2 \

+  strcmp-sse2-unaligned \

+  strcmp-sse4_2 \

+  strcmp-ssse3 \

+  strcpy-avx2 \

+  strcpy-avx2-rtm \

+  strcpy-evex \

+  strcpy-sse2 \

+  strcpy-sse2-unaligned \

+  strcpy-ssse3 \

+  strcspn-c \

+  strcspn-sse2 \

+  strlen-avx2 \

+  strlen-avx2-rtm \

+  strlen-evex \

+  strlen-sse2 \

+  strncase_l-avx \

+  strncase_l-sse2 \

+  strncase_l-sse4_2 \

+  strncase_l-ssse3 \

+  strncat-avx2 \

+  strncat-avx2-rtm \

+  strncat-c \

+  strncat-evex \

+  strncat-sse2-unaligned \

+  strncat-ssse3 \

+  strncmp-avx2 \

+  strncmp-avx2-rtm \

+  strncmp-evex \

+  strncmp-sse2 \

+  strncmp-sse4_2 \

+  strncmp-ssse3 \

+  strncpy-avx2 \

+  strncpy-avx2-rtm \

+  strncpy-c \

+  strncpy-evex \

+  strncpy-sse2-unaligned \

+  strncpy-ssse3 \

+  strnlen-avx2 \

+  strnlen-avx2-rtm \

+  strnlen-evex \

+  strnlen-sse2 \

+  strpbrk-c \

+  strpbrk-sse2 \

+  strrchr-avx2 \

+  strrchr-avx2-rtm \

+  strrchr-evex \

+  strrchr-sse2 \

+  strspn-c \

+  strspn-sse2 \

+  strstr-sse2-unaligned \

+  varshift \

+# sysdep_routines

 CFLAGS-varshift.c += -msse4

 CFLAGS-strcspn-c.c += -msse4

 CFLAGS-strpbrk-c.c += -msse4

diff --git a/sysdeps/x86_64/multiarch/bzero.c b/sysdeps/x86_64/multiarch/bzero.c

new file mode 100644

index 0000000000000000..13e399a9a1fbdeb2

--- /dev/null

+++ b/sysdeps/x86_64/multiarch/bzero.c

@@ -0,0 +1,108 @@

+/* Multiple versions of bzero.

+   All versions must be listed in ifunc-impl-list.c.

+   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/>.  */

+

+/* Define multiple versions only for the definition in libc.  */

+#if IS_IN (libc)

+# define __bzero __redirect___bzero

+# include <string.h>

+# undef __bzero

+

+/* OPTIMIZE1 definition required for bzero patch.  */

+# define OPTIMIZE1(name)	EVALUATOR1 (SYMBOL_NAME, name)

+# define SYMBOL_NAME __bzero

+# include <init-arch.h>

+

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned)

+  attribute_hidden;

+extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms)

+  attribute_hidden;

+

+static inline void *

+IFUNC_SELECTOR (void)

+{

+  const struct cpu_features* cpu_features = __get_cpu_features ();

+

+  if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)

+      && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))

+    {

+      if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)

+          && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)

+          && CPU_FEATURE_USABLE_P (cpu_features, BMI2))

+	{

+	  if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))

+	    return OPTIMIZE1 (avx512_unaligned_erms);

+

+	  return OPTIMIZE1 (avx512_unaligned);

+	}

+    }

+

+  if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))

+    {

+      if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)

+          && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)

+          && CPU_FEATURE_USABLE_P (cpu_features, BMI2))

+	{

+	  if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))

+	    return OPTIMIZE1 (evex_unaligned_erms);

+

+	  return OPTIMIZE1 (evex_unaligned);

+	}

+

+      if (CPU_FEATURE_USABLE_P (cpu_features, RTM))

+	{

+	  if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))

+	    return OPTIMIZE1 (avx2_unaligned_erms_rtm);

+

+	  return OPTIMIZE1 (avx2_unaligned_rtm);

+	}

+

+      if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))

+	{

+	  if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))

+	    return OPTIMIZE1 (avx2_unaligned_erms);

+

+	  return OPTIMIZE1 (avx2_unaligned);

+	}

+    }

+

+  if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))

+    return OPTIMIZE1 (sse2_unaligned_erms);

+

+  return OPTIMIZE1 (sse2_unaligned);

+}

+

+libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ());

+

+weak_alias (__bzero, bzero)

+#endif

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

index 39ab10613bb0ffea..4992d7bd3206a7c0 100644

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

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

@@ -282,6 +282,48 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,

 			      __memset_avx512_no_vzeroupper)

 	     )

+  /* Support sysdeps/x86_64/multiarch/bzero.c.  */

+  IFUNC_IMPL (i, name, bzero,

+	      IFUNC_IMPL_ADD (array, i, bzero, 1,

+			      __bzero_sse2_unaligned)

+	      IFUNC_IMPL_ADD (array, i, bzero, 1,

+			      __bzero_sse2_unaligned_erms)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      CPU_FEATURE_USABLE (AVX2),

+			      __bzero_avx2_unaligned)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      CPU_FEATURE_USABLE (AVX2),

+			      __bzero_avx2_unaligned_erms)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX2)

+			       && CPU_FEATURE_USABLE (RTM)),

+			      __bzero_avx2_unaligned_rtm)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX2)

+			       && CPU_FEATURE_USABLE (RTM)),

+			      __bzero_avx2_unaligned_erms_rtm)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)

+			       && CPU_FEATURE_USABLE (BMI2)),

+			      __bzero_evex_unaligned)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)

+			       && CPU_FEATURE_USABLE (BMI2)),

+			      __bzero_evex_unaligned_erms)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)

+			       && CPU_FEATURE_USABLE (BMI2)),

+			      __bzero_avx512_unaligned_erms)

+	      IFUNC_IMPL_ADD (array, i, bzero,

+			      (CPU_FEATURE_USABLE (AVX512VL)

+			       && CPU_FEATURE_USABLE (AVX512BW)

+			       && CPU_FEATURE_USABLE (BMI2)),

+			      __bzero_avx512_unaligned)

+	     )

+

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

   IFUNC_IMPL (i, name, rawmemchr,

 	      IFUNC_IMPL_ADD (array, i, rawmemchr,

diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S

index 8ac3e479bba488be..5a5ee6f67299400b 100644

--- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S

+++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S

@@ -5,6 +5,7 @@

 #define SECTION(p) p##.avx.rtm

 #define MEMSET_SYMBOL(p,s)	p##_avx2_##s##_rtm

+#define BZERO_SYMBOL(p,s)	p##_avx2_##s##_rtm

 #define WMEMSET_SYMBOL(p,s)	p##_avx2_##s##_rtm

 #include "memset-avx2-unaligned-erms.S"

diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S

index c0bf2875d03d51ab..a093a2831f3dfa0d 100644

--- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S

+++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S

@@ -14,6 +14,9 @@

   vmovd d, %xmm0; \

   movq r, %rax;

+# define BZERO_ZERO_VEC0() \

+  vpxor %xmm0, %xmm0, %xmm0

+

 # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \

   MEMSET_SET_VEC0_AND_SET_RETURN(d, r)

@@ -29,6 +32,9 @@

 # ifndef MEMSET_SYMBOL

 #  define MEMSET_SYMBOL(p,s)	p##_avx2_##s

 # endif

+# ifndef BZERO_SYMBOL

+#  define BZERO_SYMBOL(p,s)	p##_avx2_##s

+# endif

 # ifndef WMEMSET_SYMBOL

 #  define WMEMSET_SYMBOL(p,s)	p##_avx2_##s

 # endif

diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S

index 5241216a77bf72b7..727c92133a15900f 100644

--- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S

+++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S

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

   vpbroadcastb d, %VEC0; \

   movq r, %rax

+# define BZERO_ZERO_VEC0() \

+  vpxorq %XMM0, %XMM0, %XMM0

+

 # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \

   vpbroadcastd d, %VEC0; \

   movq r, %rax

diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S

index 637002150659123c..5d8fa78f05476b10 100644

--- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S

+++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S

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

   vpbroadcastb d, %VEC0; \

   movq r, %rax

+# define BZERO_ZERO_VEC0() \

+  vpxorq %XMM0, %XMM0, %XMM0

+

 # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \

   vpbroadcastd d, %VEC0; \

   movq r, %rax

diff --git a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S

index e4e95fc19fe48d2d..bac74ac37fd3c144 100644

--- a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S

+++ b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S

@@ -22,6 +22,7 @@

 #if IS_IN (libc)

 # define MEMSET_SYMBOL(p,s)	p##_sse2_##s

+# define BZERO_SYMBOL(p,s)	MEMSET_SYMBOL (p, s)

 # define WMEMSET_SYMBOL(p,s)	p##_sse2_##s

 # ifdef SHARED

diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S

index c8db87dcbf69f0d8..39a096a594ccb5b6 100644

--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S

+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S

@@ -26,6 +26,10 @@

 #include <sysdep.h>

+#ifndef BZERO_SYMBOL

+# define BZERO_SYMBOL(p,s)		MEMSET_SYMBOL (p, s)

+#endif

+

 #ifndef MEMSET_CHK_SYMBOL

 # define MEMSET_CHK_SYMBOL(p,s)		MEMSET_SYMBOL(p, s)

 #endif

@@ -87,6 +91,18 @@

 # define XMM_SMALL	0

 #endif

+#ifdef USE_LESS_VEC_MASK_STORE

+# define SET_REG64	rcx

+# define SET_REG32	ecx

+# define SET_REG16	cx

+# define SET_REG8	cl

+#else

+# define SET_REG64	rsi

+# define SET_REG32	esi

+# define SET_REG16	si

+# define SET_REG8	sil

+#endif

+

 #define PAGE_SIZE 4096

 /* Macro to calculate size of small memset block for aligning

@@ -96,18 +112,6 @@

 #ifndef SECTION

 # error SECTION is not defined!

-#endif

-

-	.section SECTION(.text),"ax",@progbits

-#if VEC_SIZE == 16 && IS_IN (libc)

-ENTRY (__bzero)

-	mov	%RDI_LP, %RAX_LP /* Set return value.  */

-	mov	%RSI_LP, %RDX_LP /* Set n.  */

-	xorl	%esi, %esi

-	pxor	%XMM0, %XMM0

-	jmp	L(entry_from_bzero)

-END (__bzero)

-weak_alias (__bzero, bzero)

 #endif

 #if IS_IN (libc)

@@ -123,12 +127,37 @@ ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))

 	WMEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)

 	WMEMSET_VDUP_TO_VEC0_LOW()

 	cmpq	$VEC_SIZE, %rdx

-	jb	L(less_vec_no_vdup)

+	jb	L(less_vec_from_wmemset)

 	WMEMSET_VDUP_TO_VEC0_HIGH()

 	jmp	L(entry_from_wmemset)

 END (WMEMSET_SYMBOL (__wmemset, unaligned))

 #endif

+ENTRY (BZERO_SYMBOL(__bzero, unaligned))

+#if VEC_SIZE > 16

+	BZERO_ZERO_VEC0 ()

+#endif

+	mov	%RDI_LP, %RAX_LP

+	mov	%RSI_LP, %RDX_LP

+#ifndef USE_LESS_VEC_MASK_STORE

+	xorl	%esi, %esi

+#endif

+	cmp	$VEC_SIZE, %RDX_LP

+	jb	L(less_vec_no_vdup)

+#ifdef USE_LESS_VEC_MASK_STORE

+	xorl	%esi, %esi

+#endif

+#if VEC_SIZE <= 16

+	BZERO_ZERO_VEC0 ()

+#endif

+	cmp	$(VEC_SIZE * 2), %RDX_LP

+	ja	L(more_2x_vec)

+	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */

+	VMOVU	%VEC(0), (%rdi)

+	VMOVU	%VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)

+	VZEROUPPER_RETURN

+END (BZERO_SYMBOL(__bzero, unaligned))

+

 #if defined SHARED && IS_IN (libc)

 ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))

 	cmp	%RDX_LP, %RCX_LP

@@ -142,7 +171,6 @@ ENTRY (MEMSET_SYMBOL (__memset, unaligned))

 	/* Clear the upper 32 bits.  */

 	mov	%edx, %edx

 # endif

-L(entry_from_bzero):

 	cmpq	$VEC_SIZE, %rdx

 	jb	L(less_vec)

 	MEMSET_VDUP_TO_VEC0_HIGH()

@@ -187,6 +215,31 @@ END (__memset_erms)

 END (MEMSET_SYMBOL (__memset, erms))

 # endif

+ENTRY_P2ALIGN (BZERO_SYMBOL(__bzero, unaligned_erms), 6)

+# if VEC_SIZE > 16

+	BZERO_ZERO_VEC0 ()

+# endif

+	mov	%RDI_LP, %RAX_LP

+	mov	%RSI_LP, %RDX_LP

+# ifndef USE_LESS_VEC_MASK_STORE

+	xorl	%esi, %esi

+# endif

+	cmp	$VEC_SIZE, %RDX_LP

+	jb	L(less_vec_no_vdup)

+# ifdef USE_LESS_VEC_MASK_STORE

+	xorl	%esi, %esi

+# endif

+# if VEC_SIZE <= 16

+	BZERO_ZERO_VEC0 ()

+# endif

+	cmp	$(VEC_SIZE * 2), %RDX_LP

+	ja	L(stosb_more_2x_vec)

+	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */

+	VMOVU	%VEC(0), (%rdi)

+	VMOVU	%VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)

+	VZEROUPPER_RETURN

+END (BZERO_SYMBOL(__bzero, unaligned_erms))

+

 # if defined SHARED && IS_IN (libc)

 ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))

 	cmp	%RDX_LP, %RCX_LP

@@ -229,6 +282,7 @@ L(last_2x_vec):

 	.p2align 4,, 10

 L(less_vec):

 L(less_vec_no_vdup):

+L(less_vec_from_wmemset):

 	/* Less than 1 VEC.  */

 # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64

 #  error Unsupported VEC_SIZE!

@@ -374,8 +428,11 @@ L(less_vec):

 	/* Broadcast esi to partial register (i.e VEC_SIZE == 32 broadcast to

 	   xmm). This is only does anything for AVX2.  */

 	MEMSET_VDUP_TO_VEC0_LOW ()

+L(less_vec_from_wmemset):

+#if VEC_SIZE > 16

 L(less_vec_no_vdup):

 #endif

+#endif

 L(cross_page):

 #if VEC_SIZE > 32

 	cmpl	$32, %edx

@@ -386,7 +443,10 @@ L(cross_page):

 	jge	L(between_16_31)

 #endif

 #ifndef USE_XMM_LESS_VEC

-	MOVQ	%XMM0, %rcx

+	MOVQ	%XMM0, %SET_REG64

+#endif

+#if VEC_SIZE <= 16

+L(less_vec_no_vdup):

 #endif

 	cmpl	$8, %edx

 	jge	L(between_8_15)

@@ -395,7 +455,7 @@ L(cross_page):

 	cmpl	$1, %edx

 	jg	L(between_2_3)

 	jl	L(between_0_0)

-	movb	%sil, (%LESS_VEC_REG)

+	movb	%SET_REG8, (%LESS_VEC_REG)

 L(between_0_0):

 	ret

@@ -428,8 +488,8 @@ L(between_8_15):

 	MOVQ	%XMM0, (%rdi)

 	MOVQ	%XMM0, -8(%rdi, %rdx)

 #else

-	movq	%rcx, (%LESS_VEC_REG)

-	movq	%rcx, -8(%LESS_VEC_REG, %rdx)

+	movq	%SET_REG64, (%LESS_VEC_REG)

+	movq	%SET_REG64, -8(%LESS_VEC_REG, %rdx)

 #endif

 	ret

@@ -442,8 +502,8 @@ L(between_4_7):

 	MOVD	%XMM0, (%rdi)

 	MOVD	%XMM0, -4(%rdi, %rdx)

 #else

-	movl	%ecx, (%LESS_VEC_REG)

-	movl	%ecx, -4(%LESS_VEC_REG, %rdx)

+	movl	%SET_REG32, (%LESS_VEC_REG)

+	movl	%SET_REG32, -4(%LESS_VEC_REG, %rdx)

 #endif

 	ret

@@ -452,12 +512,12 @@ L(between_4_7):

 L(between_2_3):

 	/* From 2 to 3.  No branch when size == 2.  */

 #ifdef USE_XMM_LESS_VEC

-	movb	%sil, (%rdi)

-	movb	%sil, 1(%rdi)

-	movb	%sil, -1(%rdi, %rdx)

+	movb	%SET_REG8, (%rdi)

+	movb	%SET_REG8, 1(%rdi)

+	movb	%SET_REG8, -1(%rdi, %rdx)

 #else

-	movw	%cx, (%LESS_VEC_REG)

-	movb	%sil, -1(%LESS_VEC_REG, %rdx)

+	movw	%SET_REG16, (%LESS_VEC_REG)

+	movb	%SET_REG8, -1(%LESS_VEC_REG, %rdx)

 #endif

 	ret

 END (MEMSET_SYMBOL (__memset, unaligned_erms))