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Replace %xmm8 with %xmm0

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Since ld.so preserves vector registers now, we can use %xmm0 to avoid
the REX prefix.

	* sysdeps/x86_64/memset.S: Replace %xmm8 with %xmm0.
This commit is contained in:
H.J. Lu 2015-08-25 08:48:21 -07:00
parent 4bd228c8a6
commit 5f92ec52e7
2 changed files with 30 additions and 26 deletions
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4
ChangeLog
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@ -1,3 +1,7 @@
2015-08-25 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/memset.S: Replace %xmm8 with %xmm0.
2015-08-25 Ondřej Bílka <neleai@seznam.cz>
* debug/strcpy_chk.c: Improve performance.

52
sysdeps/x86_64/memset.S
View File

@ -24,7 +24,7 @@
ENTRY(__bzero)
movq %rdi, %rax /* Set return value. */
movq %rsi, %rdx /* Set n. */
pxor %xmm8, %xmm8
pxor %xmm0, %xmm0
jmp L(entry_from_bzero)
END(__bzero)
weak_alias (__bzero, bzero)
@ -33,10 +33,10 @@ weak_alias (__bzero, bzero)
ENTRY(__memset_tail)
movq %rcx, %rax /* Set return value. */
movd %esi, %xmm8
punpcklbw %xmm8, %xmm8
punpcklwd %xmm8, %xmm8
pshufd $0, %xmm8, %xmm8
movd %esi, %xmm0
punpcklbw %xmm0, %xmm0
punpcklwd %xmm0, %xmm0
pshufd $0, %xmm0, %xmm0
jmp L(entry_from_bzero)
END(__memset_tail)
@ -50,57 +50,57 @@ END_CHK (__memset_chk)
#endif
ENTRY (memset)
movd %esi, %xmm8
movd %esi, %xmm0
movq %rdi, %rax
punpcklbw %xmm8, %xmm8
punpcklwd %xmm8, %xmm8
pshufd $0, %xmm8, %xmm8
punpcklbw %xmm0, %xmm0
punpcklwd %xmm0, %xmm0
pshufd $0, %xmm0, %xmm0
L(entry_from_bzero):
cmpq $64, %rdx
ja L(loop_start)
cmpq $16, %rdx
jbe L(less_16_bytes)
cmpq $32, %rdx
movdqu %xmm8, (%rdi)
movdqu %xmm8, -16(%rdi,%rdx)
movdqu %xmm0, (%rdi)
movdqu %xmm0, -16(%rdi,%rdx)
ja L(between_32_64_bytes)
L(return):
rep
ret
.p2align 4
L(between_32_64_bytes):
movdqu %xmm8, 16(%rdi)
movdqu %xmm8, -32(%rdi,%rdx)
movdqu %xmm0, 16(%rdi)
movdqu %xmm0, -32(%rdi,%rdx)
ret
.p2align 4
L(loop_start):
leaq 64(%rdi), %rcx
movdqu %xmm8, (%rdi)
movdqu %xmm0, (%rdi)
andq $-64, %rcx
movdqu %xmm8, -16(%rdi,%rdx)
movdqu %xmm8, 16(%rdi)
movdqu %xmm8, -32(%rdi,%rdx)
movdqu %xmm8, 32(%rdi)
movdqu %xmm8, -48(%rdi,%rdx)
movdqu %xmm8, 48(%rdi)
movdqu %xmm8, -64(%rdi,%rdx)
movdqu %xmm0, -16(%rdi,%rdx)
movdqu %xmm0, 16(%rdi)
movdqu %xmm0, -32(%rdi,%rdx)
movdqu %xmm0, 32(%rdi)
movdqu %xmm0, -48(%rdi,%rdx)
movdqu %xmm0, 48(%rdi)
movdqu %xmm0, -64(%rdi,%rdx)
addq %rdi, %rdx
andq $-64, %rdx
cmpq %rdx, %rcx
je L(return)
.p2align 4
L(loop):
movdqa %xmm8, (%rcx)
movdqa %xmm8, 16(%rcx)
movdqa %xmm8, 32(%rcx)
movdqa %xmm8, 48(%rcx)
movdqa %xmm0, (%rcx)
movdqa %xmm0, 16(%rcx)
movdqa %xmm0, 32(%rcx)
movdqa %xmm0, 48(%rcx)
addq $64, %rcx
cmpq %rcx, %rdx
jne L(loop)
rep
ret
L(less_16_bytes):
movq %xmm8, %rcx
movq %xmm0, %rcx
testb $24, %dl
jne L(between8_16bytes)
testb $4, %dl