From a5b250a428aabc619ace872f8220a7d0b8f7d557 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 5 Nov 2005 17:25:54 +0100 Subject: [PATCH] x86_64: Remove optimization for B stepping AMD K8 B stepping were the first shipping Opterons. memcpy/memset/copy_page/ clear_page had special optimized version for them. These are really old and in the minority now and the difference to the generic versions (using rep microcode) is not that big anyways. So just remove them. TODO: figure out optimized versions for Intel Netburst based EM64T Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/lib/memset.S | 94 ------------------------------------------------ 1 file changed, 94 deletions(-) (limited to 'arch/x86_64/lib/memset.S') diff --git a/arch/x86_64/lib/memset.S b/arch/x86_64/lib/memset.S index 4b4c40638640..2aa48f24ed1e 100644 --- a/arch/x86_64/lib/memset.S +++ b/arch/x86_64/lib/memset.S @@ -13,98 +13,6 @@ .p2align 4 memset: __memset: - movq %rdi,%r10 - movq %rdx,%r11 - - /* expand byte value */ - movzbl %sil,%ecx - movabs $0x0101010101010101,%rax - mul %rcx /* with rax, clobbers rdx */ - - /* align dst */ - movl %edi,%r9d - andl $7,%r9d - jnz .Lbad_alignment -.Lafter_bad_alignment: - - movl %r11d,%ecx - shrl $6,%ecx - jz .Lhandle_tail - - .p2align 4 -.Lloop_64: - decl %ecx - movq %rax,(%rdi) - movq %rax,8(%rdi) - movq %rax,16(%rdi) - movq %rax,24(%rdi) - movq %rax,32(%rdi) - movq %rax,40(%rdi) - movq %rax,48(%rdi) - movq %rax,56(%rdi) - leaq 64(%rdi),%rdi - jnz .Lloop_64 - - /* Handle tail in loops. The loops should be faster than hard - to predict jump tables. */ - .p2align 4 -.Lhandle_tail: - movl %r11d,%ecx - andl $63&(~7),%ecx - jz .Lhandle_7 - shrl $3,%ecx - .p2align 4 -.Lloop_8: - decl %ecx - movq %rax,(%rdi) - leaq 8(%rdi),%rdi - jnz .Lloop_8 - -.Lhandle_7: - movl %r11d,%ecx - andl $7,%ecx - jz .Lende - .p2align 4 -.Lloop_1: - decl %ecx - movb %al,(%rdi) - leaq 1(%rdi),%rdi - jnz .Lloop_1 - -.Lende: - movq %r10,%rax - ret - -.Lbad_alignment: - cmpq $7,%r11 - jbe .Lhandle_7 - movq %rax,(%rdi) /* unaligned store */ - movq $8,%r8 - subq %r9,%r8 - addq %r8,%rdi - subq %r8,%r11 - jmp .Lafter_bad_alignment - - /* C stepping K8 run faster using the string instructions. - It is also a lot simpler. Use this when possible */ - -#include - - .section .altinstructions,"a" - .align 8 - .quad memset - .quad memset_c - .byte X86_FEATURE_K8_C - .byte memset_c_end-memset_c - .byte memset_c_end-memset_c - .previous - - .section .altinstr_replacement,"ax" - /* rdi destination - * rsi value - * rdx count - */ -memset_c: movq %rdi,%r9 movl %edx,%r8d andl $7,%r8d @@ -121,5 +29,3 @@ memset_c: stosb movq %r9,%rax ret -memset_c_end: - .previous -- cgit v1.2.3-59-g8ed1b