| ;------------------------------------------------------------------------------ | |
| ; | |
| ; Copyright (c) 2006 - 2022, Intel Corporation. All rights reserved.<BR> | |
| ; SPDX-License-Identifier: BSD-2-Clause-Patent | |
| ; | |
| ; Module Name: | |
| ; | |
| ; CopyMem.nasm | |
| ; | |
| ; Abstract: | |
| ; | |
| ; CopyMem function | |
| ; | |
| ; Notes: | |
| ; | |
| ;------------------------------------------------------------------------------ | |
| DEFAULT REL | |
| SECTION .text | |
| ;------------------------------------------------------------------------------ | |
| ; VOID * | |
| ; EFIAPI | |
| ; InternalMemCopyMem ( | |
| ; OUT VOID *DestinationBuffer, | |
| ; IN CONST VOID *SourceBuffer, | |
| ; IN UINTN Length | |
| ; ); | |
| ;------------------------------------------------------------------------------ | |
| global ASM_PFX(InternalMemCopyMem) | |
| ASM_PFX(InternalMemCopyMem): | |
| push rsi | |
| push rdi | |
| mov rsi, rdx ; rsi <- Source | |
| mov rdi, rcx ; rdi <- Destination | |
| lea r9, [rsi + r8 - 1] ; r9 <- End of Source | |
| cmp rsi, rdi | |
| mov rax, rdi ; rax <- Destination as return value | |
| jae .0 | |
| cmp r9, rdi | |
| jae @CopyBackward ; Copy backward if overlapped | |
| .0: | |
| mov rcx, r8 | |
| and r8, 7 | |
| shr rcx, 3 ; rcx <- # of Qwords to copy | |
| jz @CopyBytes | |
| movq r10, mm0 | |
| .1: | |
| movq mm0, [rsi] | |
| movntq [rdi], mm0 | |
| add rsi, 8 | |
| add rdi, 8 | |
| loop .1 | |
| mfence | |
| movq mm0, r10 | |
| jmp @CopyBytes | |
| @CopyBackward: | |
| mov rsi, r9 ; rsi <- End of Source | |
| lea rdi, [rdi + r8 - 1] ; rdi <- End of Destination | |
| std ; set direction flag | |
| @CopyBytes: | |
| mov rcx, r8 | |
| rep movsb ; Copy bytes backward | |
| cld | |
| pop rdi | |
| pop rsi | |
| ret | |