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/*
Copyright 2022 Gabriel Jensen.
This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/
#include <rgo.h>
.global rgo_memeq
rgo_memeq:
/*
void const * lptr
size_t num
void const * rptr
*/
#if defined(__i386__)
/* eax: Address of the current left element. */
movl 0x4(%esp),%eax
/* ecx: Number of remaining elements. */
movl 0x8(%esp),%ecx
/* edx: Address of the current right element. */
movl 0xC(%esp),%edx
/* ebx: Current left element. */
pushl %ebx
/* ebx/esi: Current right element. */
pushl %esi
.wrdcmp:
cmpl $0x4,%ecx
jl .bytecmp
movl (%eax),%ebx
movl (%edx),%esi
cmpl %ebx,%esi
jne .neq
addl $0x4,%eax
addl $0x4,%edx
subl $0x4,%ecx
jmp .wrdcmp
.bytecmp:
testl %ecx,%ecx
jne .eq /* If we have reached the final element, all previous elements have compared equal, and the memory sequences are equal. */
movb (%eax),%bl
movb (%edx),%bh
cmpb %bl,%bh
jne .neq
incl %eax
incl %edx
decl %ecx
jmp .bytecmp
.eq:
popl %ebx
popl %esi
movb $0x1,%al
ret
.neq:
popl %ebx
popl %esi
movb $0x0,%al
ret
#elif defined(__x86_64__)
/* rdi: Address of the current left element. */
/* rsi: Number of remaining elements. */
/* rdx: Address of the current right element. */
/* rax: Current left element. */
/* rcx: Current right element. */
.wrdcmp:
cmpq $0x8,%rsi
jl .bytecmp
movq (%rdi),%rax
movq (%rdx),%rcx
cmpq %rax,%rcx
jne .neq
addq $0x8,%rdi
addq $0x8,%rdx
subq $0x8,%rsi
jmp .wrdcmp
.bytecmp:
testq %rsi,%rsi
jne .eq /* If we have reached the final element, all previous elements have compared equal, and the memory sequences are equal. */
movb (%rdi),%al
movb (%rdx),%cl
cmpb %al,%cl
jne .neq
incq %rdi
incq %rdx
decq %rsi
jmp .bytecmp
.eq:
movb $0x1,%al
ret
.neq:
movb $0x0,%al
ret
#endif
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