| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* Copyright 2002 Andi Kleen */ |
| 2 | |
| 3 | #include <asm/cpufeature.h> |
| 4 | /* |
| 5 | * memcpy - Copy a memory block. |
| 6 | * |
| 7 | * Input: |
| 8 | * rdi destination |
| 9 | * rsi source |
| 10 | * rdx count |
| 11 | * |
| 12 | * Output: |
| 13 | * rax original destination |
| 14 | */ |
| 15 | |
| 16 | .globl __memcpy |
| 17 | .globl memcpy |
| 18 | .p2align 4 |
| 19 | __memcpy: |
| 20 | memcpy: |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 21 | pushq %rbx |
| 22 | movq %rdi,%rax |
| 23 | |
| 24 | movl %edx,%ecx |
| 25 | shrl $6,%ecx |
| 26 | jz .Lhandle_tail |
| 27 | |
| 28 | .p2align 4 |
| 29 | .Lloop_64: |
| 30 | decl %ecx |
| 31 | |
| 32 | movq (%rsi),%r11 |
| 33 | movq 8(%rsi),%r8 |
| 34 | |
| 35 | movq %r11,(%rdi) |
| 36 | movq %r8,1*8(%rdi) |
| 37 | |
| 38 | movq 2*8(%rsi),%r9 |
| 39 | movq 3*8(%rsi),%r10 |
| 40 | |
| 41 | movq %r9,2*8(%rdi) |
| 42 | movq %r10,3*8(%rdi) |
| 43 | |
| 44 | movq 4*8(%rsi),%r11 |
| 45 | movq 5*8(%rsi),%r8 |
| 46 | |
| 47 | movq %r11,4*8(%rdi) |
| 48 | movq %r8,5*8(%rdi) |
| 49 | |
| 50 | movq 6*8(%rsi),%r9 |
| 51 | movq 7*8(%rsi),%r10 |
| 52 | |
| 53 | movq %r9,6*8(%rdi) |
| 54 | movq %r10,7*8(%rdi) |
| 55 | |
| 56 | leaq 64(%rsi),%rsi |
| 57 | leaq 64(%rdi),%rdi |
| 58 | jnz .Lloop_64 |
| 59 | |
| 60 | .Lhandle_tail: |
| 61 | movl %edx,%ecx |
| 62 | andl $63,%ecx |
| 63 | shrl $3,%ecx |
| 64 | jz .Lhandle_7 |
| 65 | .p2align 4 |
| 66 | .Lloop_8: |
| 67 | decl %ecx |
| 68 | movq (%rsi),%r8 |
| 69 | movq %r8,(%rdi) |
| 70 | leaq 8(%rdi),%rdi |
| 71 | leaq 8(%rsi),%rsi |
| 72 | jnz .Lloop_8 |
| 73 | |
| 74 | .Lhandle_7: |
| 75 | movl %edx,%ecx |
| 76 | andl $7,%ecx |
| 77 | jz .Lende |
| 78 | .p2align 4 |
| 79 | .Lloop_1: |
| 80 | movb (%rsi),%r8b |
| 81 | movb %r8b,(%rdi) |
| 82 | incq %rdi |
| 83 | incq %rsi |
| 84 | decl %ecx |
| 85 | jnz .Lloop_1 |
| 86 | |
| 87 | .Lende: |
| 88 | popq %rbx |
| 89 | ret |
| 90 | .Lfinal: |
| 91 | |
| 92 | /* Some CPUs run faster using the string copy instructions. |
| 93 | It is also a lot simpler. Use this when possible */ |
| 94 | |
| 95 | .section .altinstructions,"a" |
| 96 | .align 8 |
| 97 | .quad memcpy |
| 98 | .quad memcpy_c |
| 99 | .byte X86_FEATURE_REP_GOOD |
| 100 | .byte .Lfinal-memcpy |
| 101 | .byte memcpy_c_end-memcpy_c |
| 102 | .previous |
| 103 | |
| 104 | .section .altinstr_replacement,"ax" |
| 105 | /* rdi destination |
| 106 | * rsi source |
| 107 | * rdx count |
| 108 | */ |
| 109 | memcpy_c: |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | movq %rdi,%rax |
| 111 | movl %edx,%ecx |
| 112 | shrl $3,%ecx |
| 113 | andl $7,%edx |
| 114 | rep |
| 115 | movsq |
| 116 | movl %edx,%ecx |
| 117 | rep |
| 118 | movsb |
| 119 | ret |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 120 | memcpy_c_end: |
| 121 | .previous |