diff options
Diffstat (limited to 'arch/x86_64/lib/memset.S')
| -rw-r--r-- | arch/x86_64/lib/memset.S | 79 |
1 files changed, 44 insertions, 35 deletions
diff --git a/arch/x86_64/lib/memset.S b/arch/x86_64/lib/memset.S index ad397f2c7de..09ed1f6b0ea 100644 --- a/arch/x86_64/lib/memset.S +++ b/arch/x86_64/lib/memset.S @@ -1,4 +1,9 @@ /* Copyright 2002 Andi Kleen, SuSE Labs */ + +#include <linux/config.h> +#include <linux/linkage.h> +#include <asm/dwarf2.h> + /* * ISO C memset - set a memory block to a byte value. * @@ -8,11 +13,29 @@ * * rax original destination */ - .globl __memset - .globl memset - .p2align 4 -memset: -__memset: + ALIGN +memset_c: + CFI_STARTPROC + movq %rdi,%r9 + movl %edx,%r8d + andl $7,%r8d + movl %edx,%ecx + shrl $3,%ecx + /* expand byte value */ + movzbl %sil,%esi + movabs $0x0101010101010101,%rax + mulq %rsi /* with rax, clobbers rdx */ + rep stosq + movl %r8d,%ecx + rep stosb + movq %r9,%rax + ret + CFI_ENDPROC +ENDPROC(memset_c) + +ENTRY(memset) +ENTRY(__memset) + CFI_STARTPROC movq %rdi,%r10 movq %rdx,%r11 @@ -25,6 +48,7 @@ __memset: movl %edi,%r9d andl $7,%r9d jnz .Lbad_alignment + CFI_REMEMBER_STATE .Lafter_bad_alignment: movl %r11d,%ecx @@ -75,6 +99,7 @@ __memset: movq %r10,%rax ret + CFI_RESTORE_STATE .Lbad_alignment: cmpq $7,%r11 jbe .Lhandle_7 @@ -84,42 +109,26 @@ __memset: addq %r8,%rdi subq %r8,%r11 jmp .Lafter_bad_alignment +.Lfinal: + CFI_ENDPROC +ENDPROC(memset) +ENDPROC(__memset) /* Some CPUs run faster using the string instructions. It is also a lot simpler. Use this when possible */ #include <asm/cpufeature.h> + .section .altinstr_replacement,"ax" +1: .byte 0xeb /* jmp <disp8> */ + .byte (memset_c - memset) - (2f - 1b) /* offset */ +2: + .previous .section .altinstructions,"a" .align 8 - .quad memset - .quad memset_c - .byte X86_FEATURE_REP_GOOD - .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 - movl %edx,%ecx - shrl $3,%ecx - /* expand byte value */ - movzbl %sil,%esi - movabs $0x0101010101010101,%rax - mulq %rsi /* with rax, clobbers rdx */ - rep - stosq - movl %r8d,%ecx - rep - stosb - movq %r9,%rax - ret -memset_c_end: + .quad memset + .quad 1b + .byte X86_FEATURE_REP_GOOD + .byte .Lfinal - memset + .byte 2b - 1b .previous |