| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* Copyright 2002 Andi Kleen */ |
| Dave Jones | 038b0a6 | 2006-10-04 03:38:54 -0400 | [diff] [blame] | 2 | |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 3 | #include <linux/linkage.h> |
| 4 | #include <asm/dwarf2.h> |
| 5 | #include <asm/cpufeature.h> |
| 6 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | /* |
| 8 | * memcpy - Copy a memory block. |
| 9 | * |
| 10 | * Input: |
| 11 | * rdi destination |
| 12 | * rsi source |
| 13 | * rdx count |
| 14 | * |
| 15 | * Output: |
| 16 | * rax original destination |
| 17 | */ |
| 18 | |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 19 | ALIGN |
| 20 | memcpy_c: |
| 21 | CFI_STARTPROC |
| 22 | movq %rdi,%rax |
| 23 | movl %edx,%ecx |
| 24 | shrl $3,%ecx |
| 25 | andl $7,%edx |
| 26 | rep movsq |
| 27 | movl %edx,%ecx |
| 28 | rep movsb |
| 29 | ret |
| 30 | CFI_ENDPROC |
| 31 | ENDPROC(memcpy_c) |
| 32 | |
| 33 | ENTRY(__memcpy) |
| 34 | ENTRY(memcpy) |
| 35 | CFI_STARTPROC |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 36 | pushq %rbx |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 37 | CFI_ADJUST_CFA_OFFSET 8 |
| 38 | CFI_REL_OFFSET rbx, 0 |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 39 | movq %rdi,%rax |
| 40 | |
| 41 | movl %edx,%ecx |
| 42 | shrl $6,%ecx |
| 43 | jz .Lhandle_tail |
| 44 | |
| 45 | .p2align 4 |
| 46 | .Lloop_64: |
| 47 | decl %ecx |
| 48 | |
| 49 | movq (%rsi),%r11 |
| 50 | movq 8(%rsi),%r8 |
| 51 | |
| 52 | movq %r11,(%rdi) |
| 53 | movq %r8,1*8(%rdi) |
| 54 | |
| 55 | movq 2*8(%rsi),%r9 |
| 56 | movq 3*8(%rsi),%r10 |
| 57 | |
| 58 | movq %r9,2*8(%rdi) |
| 59 | movq %r10,3*8(%rdi) |
| 60 | |
| 61 | movq 4*8(%rsi),%r11 |
| 62 | movq 5*8(%rsi),%r8 |
| 63 | |
| 64 | movq %r11,4*8(%rdi) |
| 65 | movq %r8,5*8(%rdi) |
| 66 | |
| 67 | movq 6*8(%rsi),%r9 |
| 68 | movq 7*8(%rsi),%r10 |
| 69 | |
| 70 | movq %r9,6*8(%rdi) |
| 71 | movq %r10,7*8(%rdi) |
| 72 | |
| 73 | leaq 64(%rsi),%rsi |
| 74 | leaq 64(%rdi),%rdi |
| 75 | jnz .Lloop_64 |
| 76 | |
| 77 | .Lhandle_tail: |
| 78 | movl %edx,%ecx |
| 79 | andl $63,%ecx |
| 80 | shrl $3,%ecx |
| 81 | jz .Lhandle_7 |
| 82 | .p2align 4 |
| 83 | .Lloop_8: |
| 84 | decl %ecx |
| 85 | movq (%rsi),%r8 |
| 86 | movq %r8,(%rdi) |
| 87 | leaq 8(%rdi),%rdi |
| 88 | leaq 8(%rsi),%rsi |
| 89 | jnz .Lloop_8 |
| 90 | |
| 91 | .Lhandle_7: |
| 92 | movl %edx,%ecx |
| 93 | andl $7,%ecx |
| 94 | jz .Lende |
| 95 | .p2align 4 |
| 96 | .Lloop_1: |
| 97 | movb (%rsi),%r8b |
| 98 | movb %r8b,(%rdi) |
| 99 | incq %rdi |
| 100 | incq %rsi |
| 101 | decl %ecx |
| 102 | jnz .Lloop_1 |
| 103 | |
| 104 | .Lende: |
| 105 | popq %rbx |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 106 | CFI_ADJUST_CFA_OFFSET -8 |
| 107 | CFI_RESTORE rbx |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 108 | ret |
| 109 | .Lfinal: |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 110 | CFI_ENDPROC |
| 111 | ENDPROC(memcpy) |
| 112 | ENDPROC(__memcpy) |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 113 | |
| 114 | /* Some CPUs run faster using the string copy instructions. |
| 115 | It is also a lot simpler. Use this when possible */ |
| 116 | |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 117 | .section .altinstr_replacement,"ax" |
| 118 | 1: .byte 0xeb /* jmp <disp8> */ |
| 119 | .byte (memcpy_c - memcpy) - (2f - 1b) /* offset */ |
| 120 | 2: |
| 121 | .previous |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 122 | .section .altinstructions,"a" |
| 123 | .align 8 |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 124 | .quad memcpy |
| 125 | .quad 1b |
| 126 | .byte X86_FEATURE_REP_GOOD |
| 127 | .byte .Lfinal - memcpy |
| 128 | .byte 2b - 1b |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 129 | .previous |