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authorUlrich Drepper <drepper@redhat.com>2009-06-05 16:54:50 -0700
committerUlrich Drepper <drepper@redhat.com>2009-06-05 16:54:50 -0700
commitb77c93232978db6506c75d708df851895ab3d48c (patch)
treee95b8c743e4d16983d0998211f5668c23e8d2fd5 /sysdeps
parent6f9eea15bf8d49d64ca1f3fd6d1a528c40f658a4 (diff)
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Add SSE4.2 optimized rawmemchr implementation for x86-64.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/x86_64/multiarch/rawmemchr.S93
-rw-r--r--sysdeps/x86_64/rawmemchr.S7
2 files changed, 96 insertions, 4 deletions
diff --git a/sysdeps/x86_64/multiarch/rawmemchr.S b/sysdeps/x86_64/multiarch/rawmemchr.S
new file mode 100644
index 0000000000..93ca631633
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/rawmemchr.S
@@ -0,0 +1,93 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+ Contributed by Ulrich Drepper <drepper@redhat.com>.
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <sysdep.h>
+#include <ifunc-defines.h>
+
+
+/* Define multiple versions only for the definition in lib. */
+#ifndef NOT_IN_libc
+ .text
+ENTRY(rawmemchr)
+ .type rawmemchr, @gnu_indirect_function
+ cmpl $0, __cpu_features+KIND_OFFSET(%rip)
+ jne 1f
+ call __init_cpu_features
+1: leaq __rawmemchr_sse2(%rip), %rax
+ testl $(1<<20), __cpu_features+CPUID_OFFSET+COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET(%rip)
+ jz 2f
+ leaq __rawmemchr_sse42(%rip), %rax
+2: ret
+END(rawmemchr)
+strong_alias (rawmemchr, __rawmemchr)
+
+
+ .align 16
+ .type __rawmemchr_sse42, @function
+__rawmemchr_sse42:
+ cfi_startproc
+ CALL_MCOUNT
+ movd %esi, %xmm1
+ movq %rdi, %rcx
+ punpcklbw %xmm1, %xmm1
+ andq $~15, %rdi
+ punpcklbw %xmm1, %xmm1
+ orl $0xffffffff, %esi
+ movdqa (%rdi), %xmm0
+ pshufd $0, %xmm1, %xmm1
+ subq %rdi, %rcx
+ pcmpeqb %xmm1, %xmm0
+ shl %cl, %esi
+ pmovmskb %xmm0, %ecx
+ movl $16, %eax
+ movl $16, %edx
+ andl %esi, %ecx
+ jnz 1f
+
+2: pcmpestri $0x08, 16(%rdi), %xmm1
+ leaq 16(%rdi), %rdi
+ jnc 2b
+
+ leaq (%rdi,%rcx), %rax
+ ret
+
+1: bsfl %ecx, %eax
+ addq %rdi, %rax
+ ret
+ cfi_endproc
+ .size __rawmemchr_sse42, .-__rawmemchr_sse42
+
+
+# undef ENTRY
+# define ENTRY(name) \
+ .type __rawmemchr_sse2, @function; \
+ __rawmemchr_sse2: cfi_startproc; \
+ CALL_MCOUNT
+# undef END
+# define END(name) \
+ cfi_endproc; .size __rawmemchr_sse2, .-__rawmemchr_sse2
+# undef libc_hidden_builtin_def
+/* It doesn't make sense to send libc-internal rawmemchr calls through a PLT.
+ The speedup we get from using SSE4.2 instruction is likely eaten away
+ by the indirect call in the PLT. */
+# define libc_hidden_builtin_def(name) \
+ .globl __GI___rawmemchr; __GI___rawmemchr = __rawmemchr_sse2
+#endif
+
+#include "../rawmemchr.S"
diff --git a/sysdeps/x86_64/rawmemchr.S b/sysdeps/x86_64/rawmemchr.S
index c3bd771635..cfb4cebf68 100644
--- a/sysdeps/x86_64/rawmemchr.S
+++ b/sysdeps/x86_64/rawmemchr.S
@@ -34,19 +34,18 @@ ENTRY (rawmemchr)
pcmpeqb %xmm1, %xmm0
shl %cl, %esi
pmovmskb %xmm0, %ecx
- leaq 16(%rdi), %rdi
andl %esi, %ecx
jnz 1f
-2: movdqa (%rdi), %xmm0
+2: movdqa 16(%rdi), %xmm0
leaq 16(%rdi), %rdi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %ecx
testl %ecx, %ecx
jz 2b
-1: bsfl %ecx, %ecx
- leaq -16(%rcx,%rdi), %rax
+1: bsfl %ecx, %eax
+ addq %rdi, %rax
ret
END (rawmemchr)