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# Fill a region of memory with zeroes.
== code
copy-bytes: # src: (addr byte), dest: (addr byte), size: int
# pseudocode:
# curr-src/esi = src
# curr-dest/edi = dest
# i/ecx = 0
# while true
# if (i >= size) break
# *curr-dest = *curr-src
# ++curr-src
# ++curr-dest
# ++i
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
56/push-esi
57/push-edi
# curr-src/esi = src
8b/-> *(ebp+8) 6/r32/esi
# curr-dest/edi = dest
8b/-> *(ebp+0xc) 7/r32/edi
# var i/ecx: int = 0
b9/copy-to-ecx 0/imm32
# edx = size
8b/-> *(ebp+0x10) 2/r32/edx
{
# if (i >= size) break
39/compare %ecx 2/r32/edx
7d/jump-if->= break/disp8
# *curr-dest = *curr-src
8a/byte-> *esi 0/r32/AL
88/byte<- *edi 0/r32/AL
# update
46/increment-esi
47/increment-edi
41/increment-ecx
eb/jump loop/disp8
}
$copy-bytes:end:
# . restore registers
5f/pop-to-edi
5e/pop-to-esi
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
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