From 8210930c1451abad9af8bd97a2fdd6c83ab46651 Mon Sep 17 00:00:00 2001
From: Erich Elsen <eriche@google.com>
Date: Wed, 7 Jun 2017 16:57:25 -0700
Subject: [PATCH 1/1] convert memcmp.S to memcmp.c
---
sysdeps/x86_64/memcmp.S | 8 +++
sysdeps/x86_64/multiarch/Makefile | 1 +
.../x86_64/multiarch/{memcmp.S => memcmp-sse2.S} | 36 +------------
sysdeps/x86_64/multiarch/memcmp.c | 60 ++++++++++++++++++++++
4 files changed, 70 insertions(+), 35 deletions(-)
rename sysdeps/x86_64/multiarch/{memcmp.S => memcmp-sse2.S} (70%)
create mode 100644 sysdeps/x86_64/multiarch/memcmp.c
@@ -20,7 +20,11 @@
#include <sysdep.h>
.text
+#if IS_IN(libc)
+ENTRY (__memcmp_sse2)
+#else
ENTRY (memcmp)
+#endif
test %rdx, %rdx
jz L(finz)
cmpq $1, %rdx
@@ -351,7 +355,11 @@ L(ATR32res):
jmp L(small)
/* Align to 16byte to improve instruction fetch. */
.p2align 4,, 4
+#if IS_IN(libc)
+END(__memcmp_sse2)
+#else
END(memcmp)
+#endif
#undef bcmp
weak_alias (memcmp, bcmp)
@@ -6,6 +6,7 @@ ifeq ($(subdir),string)
sysdep_routines += strncat-c stpncpy-c strncpy-c strcmp-ssse3 \
strcmp-sse2-unaligned strncmp-ssse3 \
+ memcmp-sse2 \
memcmp-avx2-movbe \
memcmp-sse4 memcpy-ssse3 \
memmove-ssse3 \
similarity index 70%
rename from sysdeps/x86_64/multiarch/memcmp.S
rename to sysdeps/x86_64/multiarch/memcmp-sse2.S
@@ -1,4 +1,4 @@
-/* Multiple versions of memcmp
+/* memcmp with SSE2.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2010-2017 Free Software Foundation, Inc.
Contributed by Intel Corporation.
@@ -18,41 +18,7 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <sysdep.h>
-#include <init-arch.h>
-
-/* Define multiple versions only for the definition in libc. */
#if IS_IN (libc)
- .text
-ENTRY(memcmp)
- .type memcmp, @gnu_indirect_function
- LOAD_RTLD_GLOBAL_RO_RDX
- HAS_ARCH_FEATURE (Prefer_No_VZEROUPPER)
- jnz 1f
- HAS_ARCH_FEATURE (AVX2_Usable)
- jz 1f
- HAS_CPU_FEATURE (MOVBE)
- jz 1f
- HAS_ARCH_FEATURE (AVX_Fast_Unaligned_Load)
- jz 1f
- leaq __memcmp_avx2_movbe(%rip), %rax
- ret
-
-1: HAS_CPU_FEATURE (SSSE3)
- jnz 2f
- leaq __memcmp_sse2(%rip), %rax
- ret
-
-2: HAS_CPU_FEATURE (SSE4_1)
- jz 3f
- leaq __memcmp_sse4_1(%rip), %rax
- ret
-
-3: leaq __memcmp_ssse3(%rip), %rax
- ret
-
-END(memcmp)
-
# undef ENTRY
# define ENTRY(name) \
.type __memcmp_sse2, @function; \
new file mode 100644
@@ -0,0 +1,60 @@
+/* Multiple versions of memcmp.
+ All versions must be listed in ifunc-impl-list.c.
+ Copyright (C) 2016-2017 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
+ <http://www.gnu.org/licenses/>. */
+
+/* Define multiple versions only for the definition in lib and for
+ DSO. */
+#if IS_IN (libc)
+# define memcmp __redirect_memcmp
+# include <string.h>
+# undef memcmp
+
+# include <init-arch.h>
+# define SYMBOL_NAME memcmp
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (avx2_movbe) attribute_hidden;
+extern __typeof (REDIRECT_NAME) OPTIMIZE (sse4_1) attribute_hidden;
+
+static inline void *
+IFUNC_SELECTOR (void)
+{
+ const struct cpu_features* cpu_features = __get_cpu_features ();
+
+ if (CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER) ||
+ !CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable) ||
+ !CPU_FEATURES_CPU_P (cpu_features, MOVBE) ||
+ !CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
+ {
+ if (!CPU_FEATURES_CPU_P (cpu_features, SSSE3))
+ return OPTIMIZE (sse2);
+
+ if (CPU_FEATURES_CPU_P (cpu_features, SSE4_1))
+ return OPTIMIZE (sse4_1);
+
+ return OPTIMIZE (ssse3);
+ }
+
+ return OPTIMIZE (avx2_movbe);
+}
+
+extern __typeof (__redirect_memcmp) __libc_memcmp;
+
+libc_ifunc(__libc_memcmp, IFUNC_SELECTOR())
+strong_alias (__libc_memcmp, memcmp);
+#endif
--
2.13.0.506.g27d5fe0cd-goog