| 3eb9473e |
1 | ;------------------------------------------------------------------------------\r |
| 2 | ;\r |
| 3 | ; Copyright (c) 2007, Intel Corporation\r |
| 4 | ; All rights reserved. This program and the accompanying materials\r |
| 5 | ; are licensed and made available under the terms and conditions of the BSD License\r |
| 6 | ; which accompanies this distribution. The full text of the license may be found at\r |
| 7 | ; http://opensource.org/licenses/bsd-license.php\r |
| 8 | ;\r |
| 9 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
| 10 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
| 11 | ;\r |
| 12 | ; Module Name:\r |
| 13 | ;\r |
| 14 | ; CopyMem.asm\r |
| 15 | ;\r |
| 16 | ; Abstract:\r |
| 17 | ;\r |
| 18 | ; memcpy function\r |
| 19 | ;\r |
| 20 | ; Notes:\r |
| 21 | ;\r |
| 22 | ;------------------------------------------------------------------------------\r |
| 23 | \r |
| 24 | .686\r |
| 25 | .model flat,C\r |
| 26 | .xmm\r |
| 27 | .code\r |
| 28 | \r |
| 29 | ;------------------------------------------------------------------------------\r |
| 30 | ; VOID *\r |
| 31 | ; memcpy (\r |
| 32 | ; IN VOID *Destination,\r |
| 33 | ; IN VOID *Source,\r |
| 34 | ; IN UINTN Count\r |
| 35 | ; );\r |
| 36 | ;------------------------------------------------------------------------------\r |
| 37 | memcpy PROC USES esi edi\r |
| 38 | mov esi, [esp + 16] ; esi <- Source\r |
| 39 | mov edi, [esp + 12] ; edi <- Destination\r |
| 40 | mov edx, [esp + 20] ; edx <- Count\r |
| 41 | lea eax, [esi + edx - 1] ; eax <- End of Source\r |
| 42 | cmp esi, edi\r |
| 43 | je @CopyMemDone\r |
| 44 | cmp edx, 0\r |
| 45 | je @CopyMemDone\r |
| 46 | cmp esi, edi\r |
| 47 | jae @F\r |
| 48 | cmp eax, edi ; Overlapped?\r |
| 49 | jae @CopyBackward ; Copy backward if overlapped\r |
| 50 | @@:\r |
| 51 | xor ecx, ecx\r |
| 52 | sub ecx, edi\r |
| 53 | and ecx, 15 ; ecx + edi aligns on 16-byte boundary\r |
| 54 | jz @F\r |
| 55 | cmp ecx, edx\r |
| 56 | cmova ecx, edx\r |
| 57 | sub edx, ecx ; edx <- remaining bytes to copy\r |
| 58 | rep movsb\r |
| 59 | @@:\r |
| 60 | mov ecx, edx\r |
| 61 | and edx, 15\r |
| 62 | shr ecx, 4 ; ecx <- # of DQwords to copy\r |
| 63 | jz @CopyBytes\r |
| 64 | add esp, -16\r |
| 65 | @@:\r |
| 66 | movdqu xmm0, [esi] ; esi may not be 16-bytes aligned\r |
| 67 | movdqa [edi], xmm0 ; edi should be 16-bytes aligned\r |
| 68 | add esi, 16\r |
| 69 | add edi, 16\r |
| 70 | loop @B\r |
| 71 | add esp, 16 ; stack cleanup\r |
| 72 | jmp @CopyBytes\r |
| 73 | @CopyBackward:\r |
| 74 | mov esi, eax ; esi <- Last byte in Source\r |
| 75 | lea edi, [edi + edx - 1] ; edi <- Last byte in Destination\r |
| 76 | std\r |
| 77 | @CopyBytes:\r |
| 78 | mov ecx, edx\r |
| 79 | rep movsb\r |
| 80 | cld\r |
| 81 | @CopyMemDone: \r |
| 82 | mov eax, [esp + 12]\r |
| 83 | ret\r |
| 84 | memcpy ENDP\r |
| 85 | \r |
| 86 | END\r |
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