From: Andi Kleen Date: Sat, 5 Nov 2005 16:25:54 +0000 (+0100) Subject: [PATCH] x86_64: Remove optimization for B stepping AMD K8 X-Git-Tag: v2.6.15-rc2~95^2~9 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a5b250a428aabc619ace872f8220a7d0b8f7d557;p=linux-2.6 [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 --- diff --git a/arch/x86_64/lib/clear_page.S b/arch/x86_64/lib/clear_page.S index 30a9da458c..43d9fa1361 100644 --- a/arch/x86_64/lib/clear_page.S +++ b/arch/x86_64/lib/clear_page.S @@ -5,46 +5,8 @@ .globl clear_page .p2align 4 clear_page: - xorl %eax,%eax - movl $4096/64,%ecx - .p2align 4 -.Lloop: - decl %ecx -#define PUT(x) movq %rax,x*8(%rdi) - movq %rax,(%rdi) - PUT(1) - PUT(2) - PUT(3) - PUT(4) - PUT(5) - PUT(6) - PUT(7) - leaq 64(%rdi),%rdi - jnz .Lloop - nop - ret -clear_page_end: - - /* 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 clear_page - .quad clear_page_c - .byte X86_FEATURE_K8_C - .byte clear_page_end-clear_page - .byte clear_page_c_end-clear_page_c - .previous - - .section .altinstr_replacement,"ax" -clear_page_c: movl $4096/8,%ecx xorl %eax,%eax rep stosq ret -clear_page_c_end: - .previous diff --git a/arch/x86_64/lib/copy_page.S b/arch/x86_64/lib/copy_page.S index dd3aa47b6b..621a197694 100644 --- a/arch/x86_64/lib/copy_page.S +++ b/arch/x86_64/lib/copy_page.S @@ -8,94 +8,7 @@ .globl copy_page .p2align 4 copy_page: - subq $3*8,%rsp - movq %rbx,(%rsp) - movq %r12,1*8(%rsp) - movq %r13,2*8(%rsp) - - movl $(4096/64)-5,%ecx - .p2align 4 -.Loop64: - dec %rcx - - movq (%rsi), %rax - movq 8 (%rsi), %rbx - movq 16 (%rsi), %rdx - movq 24 (%rsi), %r8 - movq 32 (%rsi), %r9 - movq 40 (%rsi), %r10 - movq 48 (%rsi), %r11 - movq 56 (%rsi), %r12 - - prefetcht0 5*64(%rsi) - - movq %rax, (%rdi) - movq %rbx, 8 (%rdi) - movq %rdx, 16 (%rdi) - movq %r8, 24 (%rdi) - movq %r9, 32 (%rdi) - movq %r10, 40 (%rdi) - movq %r11, 48 (%rdi) - movq %r12, 56 (%rdi) - - leaq 64 (%rsi), %rsi - leaq 64 (%rdi), %rdi - - jnz .Loop64 - - movl $5,%ecx - .p2align 4 -.Loop2: - decl %ecx - - movq (%rsi), %rax - movq 8 (%rsi), %rbx - movq 16 (%rsi), %rdx - movq 24 (%rsi), %r8 - movq 32 (%rsi), %r9 - movq 40 (%rsi), %r10 - movq 48 (%rsi), %r11 - movq 56 (%rsi), %r12 - - movq %rax, (%rdi) - movq %rbx, 8 (%rdi) - movq %rdx, 16 (%rdi) - movq %r8, 24 (%rdi) - movq %r9, 32 (%rdi) - movq %r10, 40 (%rdi) - movq %r11, 48 (%rdi) - movq %r12, 56 (%rdi) - - leaq 64(%rdi),%rdi - leaq 64(%rsi),%rsi - - jnz .Loop2 - - movq (%rsp),%rbx - movq 1*8(%rsp),%r12 - movq 2*8(%rsp),%r13 - addq $3*8,%rsp - ret - - /* C stepping K8 run faster using the string copy instructions. - It is also a lot simpler. Use this when possible */ - -#include - - .section .altinstructions,"a" - .align 8 - .quad copy_page - .quad copy_page_c - .byte X86_FEATURE_K8_C - .byte copy_page_c_end-copy_page_c - .byte copy_page_c_end-copy_page_c - .previous - - .section .altinstr_replacement,"ax" -copy_page_c: movl $4096/8,%ecx rep movsq ret -copy_page_c_end: - .previous diff --git a/arch/x86_64/lib/memcpy.S b/arch/x86_64/lib/memcpy.S index c6c46494fe..92dd805446 100644 --- a/arch/x86_64/lib/memcpy.S +++ b/arch/x86_64/lib/memcpy.S @@ -11,6 +11,8 @@ * * Output: * rax original destination + * + * TODO: check best memcpy for PSC */ .globl __memcpy @@ -18,95 +20,6 @@ .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: - - /* C stepping K8 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_K8_C - .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 @@ -117,5 +30,3 @@ memcpy_c: rep movsb ret -memcpy_c_end: - .previous diff --git a/arch/x86_64/lib/memset.S b/arch/x86_64/lib/memset.S index 4b4c406386..2aa48f24ed 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