61 lines
1.0 KiB
ArmAsm
61 lines
1.0 KiB
ArmAsm
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format elf64
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section '.text' executable
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; x64fastcall void* memset(void* dest, int data, size_t count)
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;
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; Input: (void* rcx, int rdx, size_t r8)
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; Output: void* rax
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; Clobbers: r10, flags
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public memset
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memset:
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mov rax, rcx
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lea r10, [rcx+r8]
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memset_loop:
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mov byte[rcx], dl
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inc rcx
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cmp rcx, r10
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jne memset_loop
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ret
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; x64fastcall void* memmove(void* dest, const void* src, size_t count)
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;
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; Input: (void* rcx, void* rdx, size_t r8)
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; Output: void* rax
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; Clobbers: r9, r10, r11, flags
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public memmove
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memmove:
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mov rax, rcx
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lea r10, [rcx+r8] ; past-the-end for *dest
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lea r11, [rdx+r8] ; past-the-end for *src
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cmp rdx, rcx
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je memmove_end ; return if move buffers are the same
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jl memmove_back ; *src < *dest: overlaps, copy backward
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memmove_front: ; *src > *dest: overlaps, copy forward
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mov r9b, byte[rdx]
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mov byte[rcx], r9b
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inc rcx
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inc rdx
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cmp rcx, r10
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jne memmove_front
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jmp memmove_end
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memmove_back:
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dec r10
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dec r11
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mov r9b, byte[r11]
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mov byte[r10], r9b
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cmp rcx, r10
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jne memmove_back
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memmove_end:
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ret
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