Merge branch 'master'

1 files changed, 91 insertions, 2 deletions

diff --git a/arch/x86_64/lib/memcpy.S b/arch/x86_64/lib/memcpy.S
index 92dd80544602..5554948b5554 100644
--- a/arch/x86_64/lib/memcpy.S
+++ b/arch/x86_64/lib/memcpy.S
@@ -11,8 +11,6 @@
  * 
  * Output:
  * rax original destination
- * 
- * TODO: check best memcpy for PSC
  */	
 
  	.globl __memcpy
@@ -20,6 +18,95 @@
 	.p2align 4
 __memcpy:
 memcpy:		
+	pushq %rbx
+	movq %rdi,%rax
+
+	movl %edx,%ecx
+	shrl $6,%ecx
+	jz .Lhandle_tail
+
+	.p2align 4
+.Lloop_64:
+	decl %ecx
+
+	movq (%rsi),%r11
+	movq 8(%rsi),%r8
+
+	movq %r11,(%rdi)
+	movq %r8,1*8(%rdi)
+
+	movq 2*8(%rsi),%r9
+	movq 3*8(%rsi),%r10
+
+	movq %r9,2*8(%rdi)
+	movq %r10,3*8(%rdi)
+
+	movq 4*8(%rsi),%r11
+	movq 5*8(%rsi),%r8
+
+	movq %r11,4*8(%rdi)
+	movq %r8,5*8(%rdi)
+
+	movq 6*8(%rsi),%r9
+	movq 7*8(%rsi),%r10
+
+	movq %r9,6*8(%rdi)
+	movq %r10,7*8(%rdi)
+
+	leaq 64(%rsi),%rsi
+	leaq 64(%rdi),%rdi
+	jnz  .Lloop_64
+
+.Lhandle_tail:
+	movl %edx,%ecx
+	andl $63,%ecx
+	shrl $3,%ecx
+	jz   .Lhandle_7
+	.p2align 4
+.Lloop_8:
+	decl %ecx
+	movq (%rsi),%r8
+	movq %r8,(%rdi)
+	leaq 8(%rdi),%rdi
+	leaq 8(%rsi),%rsi
+	jnz  .Lloop_8
+
+.Lhandle_7:
+	movl %edx,%ecx
+	andl $7,%ecx
+	jz .Lende
+	.p2align 4
+.Lloop_1:
+	movb (%rsi),%r8b
+	movb %r8b,(%rdi)
+	incq %rdi
+	incq %rsi
+	decl %ecx
+	jnz .Lloop_1
+
+.Lende:
+	popq %rbx
+	ret
+.Lfinal:
+
+	/* Some CPUs run faster using the string copy instructions.
+	   It is also a lot simpler. Use this when possible */
+
+	.section .altinstructions,"a"
+	.align 8
+	.quad  memcpy
+	.quad  memcpy_c
+	.byte  X86_FEATURE_REP_GOOD
+	.byte  .Lfinal-memcpy
+	.byte  memcpy_c_end-memcpy_c
+	.previous
+
+	.section .altinstr_replacement,"ax"
+ /* rdi	destination
+  * rsi source
+  * rdx count
+  */
+memcpy_c:
 	movq %rdi,%rax
 	movl %edx,%ecx
 	shrl $3,%ecx
@@ -30,3 +117,5 @@ memcpy:
 	rep
 	movsb
 	ret
+memcpy_c_end:
+	.previous