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From: Noah Goldstein via Libc-alpha <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Subject: [PATCH v2 1/5] x86_64: Add support for bcmp using sse2, sse4_1, avx2, and evex
Date: Tue, 14 Sep 2021 01:30:35 -0500	[thread overview]
Message-ID: <20210914063039.1126196-1-goldstein.w.n@gmail.com> (raw)
In-Reply-To: <20210913230506.546749-1-goldstein.w.n@gmail.com>

No bug. This commit adds support for an optimized bcmp implementation.
Support is for sse2, sse4_1, avx2, and evex.

All string tests passing and build succeeding.
---
 benchtests/Makefile                        |  2 +-
 benchtests/bench-bcmp.c                    | 20 ++++++++
 benchtests/bench-memcmp.c                  |  4 +-
 string/Makefile                            |  4 +-
 string/bcmp.c                              | 25 ++++++++++
 string/test-bcmp.c                         | 21 +++++++++
 string/test-memcmp.c                       | 27 +++++++----
 sysdeps/x86_64/memcmp.S                    |  2 -
 sysdeps/x86_64/multiarch/Makefile          |  3 ++
 sysdeps/x86_64/multiarch/bcmp-avx2-rtm.S   | 12 +++++
 sysdeps/x86_64/multiarch/bcmp-avx2.S       | 23 ++++++++++
 sysdeps/x86_64/multiarch/bcmp-evex.S       | 23 ++++++++++
 sysdeps/x86_64/multiarch/bcmp-sse2.S       | 23 ++++++++++
 sysdeps/x86_64/multiarch/bcmp-sse4.S       | 23 ++++++++++
 sysdeps/x86_64/multiarch/bcmp.c            | 35 ++++++++++++++
 sysdeps/x86_64/multiarch/ifunc-bcmp.h      | 53 ++++++++++++++++++++++
 sysdeps/x86_64/multiarch/ifunc-impl-list.c | 23 ++++++++++
 sysdeps/x86_64/multiarch/memcmp-sse2.S     |  4 +-
 sysdeps/x86_64/multiarch/memcmp.c          |  2 -
 19 files changed, 311 insertions(+), 18 deletions(-)
 create mode 100644 benchtests/bench-bcmp.c
 create mode 100644 string/bcmp.c
 create mode 100644 string/test-bcmp.c
 create mode 100644 sysdeps/x86_64/multiarch/bcmp-avx2-rtm.S
 create mode 100644 sysdeps/x86_64/multiarch/bcmp-avx2.S
 create mode 100644 sysdeps/x86_64/multiarch/bcmp-evex.S
 create mode 100644 sysdeps/x86_64/multiarch/bcmp-sse2.S
 create mode 100644 sysdeps/x86_64/multiarch/bcmp-sse4.S
 create mode 100644 sysdeps/x86_64/multiarch/bcmp.c
 create mode 100644 sysdeps/x86_64/multiarch/ifunc-bcmp.h

diff --git a/benchtests/Makefile b/benchtests/Makefile
index 1530939a8c..5fc495eb57 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -47,7 +47,7 @@ bench := $(foreach B,$(filter bench-%,${BENCHSET}), ${${B}})
 endif
 
 # String function benchmarks.
-string-benchset := memccpy memchr memcmp memcpy memmem memmove \
+string-benchset := bcmp memccpy memchr memcmp memcpy memmem memmove \
 		   mempcpy memset rawmemchr stpcpy stpncpy strcasecmp strcasestr \
 		   strcat strchr strchrnul strcmp strcpy strcspn strlen \
 		   strncasecmp strncat strncmp strncpy strnlen strpbrk strrchr \
diff --git a/benchtests/bench-bcmp.c b/benchtests/bench-bcmp.c
new file mode 100644
index 0000000000..1023639787
--- /dev/null
+++ b/benchtests/bench-bcmp.c
@@ -0,0 +1,20 @@
+/* Measure bcmp functions.
+   Copyright (C) 2015-2021 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 TEST_BCMP 1
+#include "bench-memcmp.c"
diff --git a/benchtests/bench-memcmp.c b/benchtests/bench-memcmp.c
index 744c7ec5ba..4d5f8fb766 100644
--- a/benchtests/bench-memcmp.c
+++ b/benchtests/bench-memcmp.c
@@ -17,7 +17,9 @@
    <https://www.gnu.org/licenses/>.  */
 
 #define TEST_MAIN
-#ifdef WIDE
+#ifdef TEST_BCMP
+# define TEST_NAME "bcmp"
+#elif defined WIDE
 # define TEST_NAME "wmemcmp"
 #else
 # define TEST_NAME "memcmp"
diff --git a/string/Makefile b/string/Makefile
index f0fce2a0b8..f1f67ee157 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -35,7 +35,7 @@ routines	:= strcat strchr strcmp strcoll strcpy strcspn		\
 		   strncat strncmp strncpy				\
 		   strrchr strpbrk strsignal strspn strstr strtok	\
 		   strtok_r strxfrm memchr memcmp memmove memset	\
-		   mempcpy bcopy bzero ffs ffsll stpcpy stpncpy		\
+		   mempcpy bcmp bcopy bzero ffs ffsll stpcpy stpncpy		\
 		   strcasecmp strncase strcasecmp_l strncase_l		\
 		   memccpy memcpy wordcopy strsep strcasestr		\
 		   swab strfry memfrob memmem rawmemchr strchrnul	\
@@ -52,7 +52,7 @@ strop-tests	:= memchr memcmp memcpy memmove mempcpy memset memccpy	\
 		   stpcpy stpncpy strcat strchr strcmp strcpy strcspn	\
 		   strlen strncmp strncpy strpbrk strrchr strspn memmem	\
 		   strstr strcasestr strnlen strcasecmp strncasecmp	\
-		   strncat rawmemchr strchrnul bcopy bzero memrchr	\
+		   strncat rawmemchr strchrnul bcmp bcopy bzero memrchr	\
 		   explicit_bzero
 tests		:= tester inl-tester noinl-tester testcopy test-ffs	\
 		   tst-strlen stratcliff tst-svc tst-inlcall		\
diff --git a/string/bcmp.c b/string/bcmp.c
new file mode 100644
index 0000000000..2f5c446124
--- /dev/null
+++ b/string/bcmp.c
@@ -0,0 +1,25 @@
+/* Copyright (C) 1991-2021 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/>.  */
+
+
+/* This file is intentionally left empty. It exists so that both
+   architectures which implement bcmp seperately from memcmp and
+   architectures which implement bcmp by having it alias memcmp will
+   build.
+
+   The alias for bcmp to memcmp for the C implementation is in
+   memcmp.c.  */
diff --git a/string/test-bcmp.c b/string/test-bcmp.c
new file mode 100644
index 0000000000..6d19a4a87c
--- /dev/null
+++ b/string/test-bcmp.c
@@ -0,0 +1,21 @@
+/* Test and measure bcmp functions.
+   Copyright (C) 2012-2021 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 BAD_RESULT(result, expec) ((!(result)) != (!(expec)))
+#define TEST_BCMP 1
+#include "test-memcmp.c"
diff --git a/string/test-memcmp.c b/string/test-memcmp.c
index 6ddbc05d2f..c630e6799d 100644
--- a/string/test-memcmp.c
+++ b/string/test-memcmp.c
@@ -17,11 +17,14 @@
    <https://www.gnu.org/licenses/>.  */
 
 #define TEST_MAIN
-#ifdef WIDE
+#ifdef TEST_BCMP
+# define TEST_NAME "bcmp"
+#elif defined WIDE
 # define TEST_NAME "wmemcmp"
 #else
 # define TEST_NAME "memcmp"
 #endif
+
 #include "test-string.h"
 #ifdef WIDE
 # include <inttypes.h>
@@ -35,6 +38,7 @@
 # define CHARBYTES 4
 # define CHAR__MIN WCHAR_MIN
 # define CHAR__MAX WCHAR_MAX
+
 int
 simple_wmemcmp (const wchar_t *s1, const wchar_t *s2, size_t n)
 {
@@ -48,8 +52,11 @@ simple_wmemcmp (const wchar_t *s1, const wchar_t *s2, size_t n)
 }
 #else
 # include <limits.h>
-
-# define MEMCMP memcmp
+# ifdef TEST_BCMP
+#  define MEMCMP bcmp
+# else
+#  define MEMCMP memcmp
+# endif
 # define MEMCPY memcpy
 # define SIMPLE_MEMCMP simple_memcmp
 # define CHAR char
@@ -69,6 +76,12 @@ simple_memcmp (const char *s1, const char *s2, size_t n)
 }
 #endif
 
+# ifndef BAD_RESULT
+#  define BAD_RESULT(result, expec)                                     \
+    (((result) == 0 && (expec)) || ((result) < 0 && (expec) >= 0) ||    \
+     ((result) > 0 && (expec) <= 0))
+#  endif
+
 typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
 
 IMPL (SIMPLE_MEMCMP, 0)
@@ -79,9 +92,7 @@ check_result (impl_t *impl, const CHAR *s1, const CHAR *s2, size_t len,
 	      int exp_result)
 {
   int result = CALL (impl, s1, s2, len);
-  if ((exp_result == 0 && result != 0)
-      || (exp_result < 0 && result >= 0)
-      || (exp_result > 0 && result <= 0))
+  if (BAD_RESULT(result, exp_result))
     {
       error (0, 0, "Wrong result in function %s %d %d", impl->name,
 	     result, exp_result);
@@ -186,9 +197,7 @@ do_random_tests (void)
 	{
 	  r = CALL (impl, (CHAR *) p1 + align1, (const CHAR *) p2 + align2,
 		    len);
-	  if ((r == 0 && result)
-	      || (r < 0 && result >= 0)
-	      || (r > 0 && result <= 0))
+	  if (BAD_RESULT(r, result))
 	    {
 	      error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %zd, %zd, %zd) %ld != %d, p1 %p p2 %p",
 		     n, impl->name, align1 * CHARBYTES & 63,  align2 * CHARBYTES & 63, len, pos, r, result, p1, p2);
diff --git a/sysdeps/x86_64/memcmp.S b/sysdeps/x86_64/memcmp.S
index 870e15c5a0..dfd0269db2 100644
--- a/sysdeps/x86_64/memcmp.S
+++ b/sysdeps/x86_64/memcmp.S
@@ -356,6 +356,4 @@ L(ATR32res):
 	.p2align 4,, 4
 END(memcmp)
 
-#undef bcmp
-weak_alias (memcmp, bcmp)
 libc_hidden_builtin_def (memcmp)
diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
index 26be40959c..9dd0d8c3ff 100644
--- a/sysdeps/x86_64/multiarch/Makefile
+++ b/sysdeps/x86_64/multiarch/Makefile
@@ -1,6 +1,7 @@
 ifeq ($(subdir),string)
 
 sysdep_routines += strncat-c stpncpy-c strncpy-c \
+		   bcmp-sse2 bcmp-sse4 bcmp-avx2 \
 		   strcmp-sse2 strcmp-sse2-unaligned strcmp-ssse3  \
 		   strcmp-sse4_2 strcmp-avx2 \
 		   strncmp-sse2 strncmp-ssse3 strncmp-sse4_2 strncmp-avx2 \
@@ -40,6 +41,7 @@ sysdep_routines += strncat-c stpncpy-c strncpy-c \
 		   memset-sse2-unaligned-erms \
 		   memset-avx2-unaligned-erms \
 		   memset-avx512-unaligned-erms \
+		   bcmp-avx2-rtm \
 		   memchr-avx2-rtm \
 		   memcmp-avx2-movbe-rtm \
 		   memmove-avx-unaligned-erms-rtm \
@@ -59,6 +61,7 @@ sysdep_routines += strncat-c stpncpy-c strncpy-c \
 		   strncpy-avx2-rtm \
 		   strnlen-avx2-rtm \
 		   strrchr-avx2-rtm \
+		   bcmp-evex \
 		   memchr-evex \
 		   memcmp-evex-movbe \
 		   memmove-evex-unaligned-erms \
diff --git a/sysdeps/x86_64/multiarch/bcmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/bcmp-avx2-rtm.S
new file mode 100644
index 0000000000..d742257e4e
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp-avx2-rtm.S
@@ -0,0 +1,12 @@
+#ifndef MEMCMP
+# define MEMCMP __bcmp_avx2_rtm
+#endif
+
+#define ZERO_UPPER_VEC_REGISTERS_RETURN \
+  ZERO_UPPER_VEC_REGISTERS_RETURN_XTEST
+
+#define VZEROUPPER_RETURN jmp	 L(return_vzeroupper)
+
+#define SECTION(p) p##.avx.rtm
+
+#include "bcmp-avx2.S"
diff --git a/sysdeps/x86_64/multiarch/bcmp-avx2.S b/sysdeps/x86_64/multiarch/bcmp-avx2.S
new file mode 100644
index 0000000000..93a9a20b17
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp-avx2.S
@@ -0,0 +1,23 @@
+/* bcmp optimized with AVX2.
+   Copyright (C) 2017-2021 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 MEMCMP
+# define MEMCMP	__bcmp_avx2
+#endif
+
+#include "bcmp-avx2.S"
diff --git a/sysdeps/x86_64/multiarch/bcmp-evex.S b/sysdeps/x86_64/multiarch/bcmp-evex.S
new file mode 100644
index 0000000000..ade52e8c68
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp-evex.S
@@ -0,0 +1,23 @@
+/* bcmp optimized with EVEX.
+   Copyright (C) 2017-2021 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 MEMCMP
+# define MEMCMP	__bcmp_evex
+#endif
+
+#include "memcmp-evex-movbe.S"
diff --git a/sysdeps/x86_64/multiarch/bcmp-sse2.S b/sysdeps/x86_64/multiarch/bcmp-sse2.S
new file mode 100644
index 0000000000..b18d570386
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp-sse2.S
@@ -0,0 +1,23 @@
+/* bcmp optimized with SSE2
+   Copyright (C) 2017-2021 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 memcmp
+#  define memcmp	__bcmp_sse2
+# endif
+# define USE_AS_BCMP	1
+#include "memcmp-sse2.S"
diff --git a/sysdeps/x86_64/multiarch/bcmp-sse4.S b/sysdeps/x86_64/multiarch/bcmp-sse4.S
new file mode 100644
index 0000000000..ed9804053f
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp-sse4.S
@@ -0,0 +1,23 @@
+/* bcmp optimized with SSE4.1
+   Copyright (C) 2017-2021 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 MEMCMP
+#  define MEMCMP	__bcmp_sse4_1
+# endif
+# define USE_AS_BCMP	1
+#include "memcmp-sse4.S"
diff --git a/sysdeps/x86_64/multiarch/bcmp.c b/sysdeps/x86_64/multiarch/bcmp.c
new file mode 100644
index 0000000000..6e26b73ecc
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bcmp.c
@@ -0,0 +1,35 @@
+/* Multiple versions of bcmp.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2017-2021 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 bcmp __redirect_bcmp
+# include <string.h>
+# undef bcmp
+
+# define SYMBOL_NAME bcmp
+# include "ifunc-bcmp.h"
+
+libc_ifunc_redirected (__redirect_bcmp, bcmp, IFUNC_SELECTOR ());
+
+# ifdef SHARED
+__hidden_ver1 (bcmp, __GI_bcmp, __redirect_bcmp)
+  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (bcmp);
+# endif
+#endif
diff --git a/sysdeps/x86_64/multiarch/ifunc-bcmp.h b/sysdeps/x86_64/multiarch/ifunc-bcmp.h
new file mode 100644
index 0000000000..b0dacd8526
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/ifunc-bcmp.h
@@ -0,0 +1,53 @@
+/* Common definition for bcmp ifunc selections.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2017-2021 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 <init-arch.h>
+
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse4_1) 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)
+{
+  const struct cpu_features* cpu_features = __get_cpu_features ();
+
+  if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
+      && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
+      && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
+      && 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);
+
+      if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
+	return OPTIMIZE (avx2);
+    }
+
+  if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_1))
+    return OPTIMIZE (sse4_1);
+
+  return OPTIMIZE (sse2);
+}
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index 39ab10613b..dd0c393c7d 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -38,6 +38,29 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 
   size_t i = 0;
 
+  /* Support sysdeps/x86_64/multiarch/bcmp.c.  */
+  IFUNC_IMPL (i, name, bcmp,
+	      IFUNC_IMPL_ADD (array, i, bcmp,
+			      (CPU_FEATURE_USABLE (AVX2)
+                   && CPU_FEATURE_USABLE (MOVBE)
+			       && CPU_FEATURE_USABLE (BMI2)),
+			      __bcmp_avx2)
+	      IFUNC_IMPL_ADD (array, i, bcmp,
+			      (CPU_FEATURE_USABLE (AVX2)
+			       && CPU_FEATURE_USABLE (BMI2)
+                   && CPU_FEATURE_USABLE (MOVBE)
+			       && CPU_FEATURE_USABLE (RTM)),
+			      __bcmp_avx2_rtm)
+	      IFUNC_IMPL_ADD (array, i, bcmp,
+			      (CPU_FEATURE_USABLE (AVX512VL)
+			       && CPU_FEATURE_USABLE (AVX512BW)
+                   && CPU_FEATURE_USABLE (MOVBE)
+			       && CPU_FEATURE_USABLE (BMI2)),
+			      __bcmp_evex)
+	      IFUNC_IMPL_ADD (array, i, bcmp, CPU_FEATURE_USABLE (SSE4_1),
+			      __bcmp_sse4_1)
+	      IFUNC_IMPL_ADD (array, i, bcmp, 1, __bcmp_sse2))
+
   /* Support sysdeps/x86_64/multiarch/memchr.c.  */
   IFUNC_IMPL (i, name, memchr,
 	      IFUNC_IMPL_ADD (array, i, memchr,
diff --git a/sysdeps/x86_64/multiarch/memcmp-sse2.S b/sysdeps/x86_64/multiarch/memcmp-sse2.S
index b135fa2d40..2a4867ad18 100644
--- a/sysdeps/x86_64/multiarch/memcmp-sse2.S
+++ b/sysdeps/x86_64/multiarch/memcmp-sse2.S
@@ -17,7 +17,9 @@
    <https://www.gnu.org/licenses/>.  */
 
 #if IS_IN (libc)
-# define memcmp __memcmp_sse2
+# ifndef memcmp
+#  define memcmp __memcmp_sse2
+# endif
 
 # ifdef SHARED
 #  undef libc_hidden_builtin_def
diff --git a/sysdeps/x86_64/multiarch/memcmp.c b/sysdeps/x86_64/multiarch/memcmp.c
index fe725f3563..1760e045df 100644
--- a/sysdeps/x86_64/multiarch/memcmp.c
+++ b/sysdeps/x86_64/multiarch/memcmp.c
@@ -27,8 +27,6 @@
 # include "ifunc-memcmp.h"
 
 libc_ifunc_redirected (__redirect_memcmp, memcmp, IFUNC_SELECTOR ());
-# undef bcmp
-weak_alias (memcmp, bcmp)
 
 # ifdef SHARED
 __hidden_ver1 (memcmp, __GI_memcmp, __redirect_memcmp)
-- 
2.25.1


  parent reply	other threads:[~2021-09-14  6:31 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 23:05 [PATCH 1/5] x86_64: Add support for bcmp using sse2, sse4_1, avx2, and evex Noah Goldstein via Libc-alpha
2021-09-13 23:05 ` [PATCH 2/5] x86_64: Add sse2 optimized bcmp implementation in memcmp.S Noah Goldstein via Libc-alpha
2021-09-13 23:05 ` [PATCH 3/5] x86_64: Add sse4_1 optimized bcmp implementation in memcmp-sse4.S Noah Goldstein via Libc-alpha
2021-09-13 23:05 ` [PATCH 4/5] x86_64: Add avx2 optimized bcmp implementation in bcmp-avx2.S Noah Goldstein via Libc-alpha
2021-09-13 23:05 ` [PATCH 5/5] x86_64: Add evex optimized bcmp implementation in bcmp-evex.S Noah Goldstein via Libc-alpha
2021-09-14  1:18   ` Carlos O'Donell via Libc-alpha
2021-09-14  2:05     ` Noah Goldstein via Libc-alpha
2021-09-14  2:35       ` Carlos O'Donell via Libc-alpha
2021-09-14  2:55         ` DJ Delorie via Libc-alpha
2021-09-14  3:24           ` Noah Goldstein via Libc-alpha
2021-09-14  3:40         ` Noah Goldstein via Libc-alpha
2021-09-14  4:21           ` DJ Delorie via Libc-alpha
2021-09-14  5:29             ` Noah Goldstein via Libc-alpha
2021-09-14  5:42               ` DJ Delorie via Libc-alpha
2021-09-14  5:55                 ` Noah Goldstein via Libc-alpha
2021-09-13 23:22 ` [PATCH 1/5] x86_64: Add support for bcmp using sse2, sse4_1, avx2, and evex Noah Goldstein via Libc-alpha
2021-09-14  6:30 ` Noah Goldstein via Libc-alpha [this message]
2021-09-14  6:30   ` [PATCH v2 2/5] x86_64: Add sse2 optimized bcmp implementation in memcmp.S Noah Goldstein via Libc-alpha
2021-09-14  6:30   ` [PATCH v2 3/5] x86_64: Add sse4_1 optimized bcmp implementation in memcmp-sse4.S Noah Goldstein via Libc-alpha
2021-09-14  6:30   ` [PATCH v2 4/5] x86_64: Add avx2 optimized bcmp implementation in bcmp-avx2.S Noah Goldstein via Libc-alpha
2021-09-14  6:30   ` [PATCH v2 5/5] x86_64: Add evex optimized bcmp implementation in bcmp-evex.S Noah Goldstein via Libc-alpha
2021-09-14 14:40   ` [PATCH v2 1/5] x86_64: Add support for bcmp using sse2, sse4_1, avx2, and evex H.J. Lu via Libc-alpha
2021-09-14 19:23     ` Noah Goldstein via Libc-alpha
2021-09-14 20:30     ` Florian Weimer via Libc-alpha
2021-09-15  0:00 ` [PATCH " Joseph Myers
2021-09-15 13:37   ` Zack Weinberg via Libc-alpha
2021-09-15 14:01     ` Re: [PATCH 1/5] x86_64: Add support for bcmp using sse2, sse 4_1, " Florian Weimer via Libc-alpha
2021-09-15 18:06       ` Noah Goldstein via Libc-alpha
2021-09-15 18:30         ` Joseph Myers
2021-09-27  1:35           ` Noah Goldstein via Libc-alpha
2021-09-27  7:29             ` Florian Weimer via Libc-alpha
2021-09-27 16:49               ` Noah Goldstein via Libc-alpha
2021-09-27 16:54                 ` Florian Weimer via Libc-alpha
2021-09-27 17:54                   ` Noah Goldstein via Libc-alpha
2021-09-27 17:56                     ` Florian Weimer via Libc-alpha
2021-09-27 18:05                       ` Noah Goldstein via Libc-alpha
2021-09-27 18:10                         ` Florian Weimer via Libc-alpha
2021-09-27 18:15                           ` Noah Goldstein via Libc-alpha
2021-09-27 18:22                             ` Florian Weimer via Libc-alpha
2021-09-27 18:34                               ` Noah Goldstein via Libc-alpha
2021-09-27 18:56                                 ` Florian Weimer via Libc-alpha
2021-09-27 19:20                                   ` Noah Goldstein via Libc-alpha
2021-09-27 19:34                                     ` Florian Weimer via Libc-alpha
2021-09-27 19:43                                       ` Noah Goldstein via Libc-alpha
2021-09-27 19:59                                         ` Florian Weimer via Libc-alpha
2021-09-27 20:22                                           ` Noah Goldstein via Libc-alpha
2021-09-27 20:24                                             ` Florian Weimer via Libc-alpha
2021-09-27 20:38                                               ` Noah Goldstein via Libc-alpha
2021-09-28  0:07                                                 ` Noah Goldstein via Libc-alpha
2021-09-27 17:42               ` Joseph Myers
2021-09-27 17:48                 ` Noah Goldstein via Libc-alpha

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