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misc: Use assembly for memory functions on x86

This commit is contained in:
mintsuki 2023-07-09 03:09:45 +02:00
parent 17e26c8c95
commit 79e50a82af
5 changed files with 208 additions and 53 deletions
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55
common/lib/mem.asm_x86_64 Normal file
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@ -0,0 +1,55 @@
section .text
global memcpy
memcpy:
mov rcx, rdx
mov rax, rdi
rep movsb
ret
global memset
memset:
push rdi
mov rax, rsi
mov rcx, rdx
rep stosb
pop rax
ret
global memmove
memmove:
mov rcx, rdx
mov rax, rdi
cmp rdi, rsi
ja .copy_backwards
rep movsb
jmp .done
.copy_backwards:
lea rdi, [rdi+rcx-1]
lea rsi, [rsi+rcx-1]
std
rep movsb
cld
.done:
ret
global memcmp
memcmp:
mov rcx, rdx
repe cmpsb
je .equal
mov al, byte [rdi-1]
sub al, byte [rsi-1]
movsx rax, al
jmp .done
.equal:
xor eax, eax
.done:
ret

74
common/lib/mem.s2.asm_ia32
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@ -1,5 +1,79 @@
section .text
global memcpy
memcpy:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
rep movsb
pop edi
pop esi
ret
global memset
memset:
push edi
mov edx, dword [esp+8]
mov edi, edx
mov eax, dword [esp+12]
mov ecx, dword [esp+16]
rep stosb
mov eax, edx
pop edi
ret
global memmove
memmove:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
cmp edi, esi
ja .copy_backwards
rep movsb
jmp .done
.copy_backwards:
lea edi, [edi+ecx-1]
lea esi, [esi+ecx-1]
std
rep movsb
cld
.done:
pop edi
pop esi
ret
global memcmp
memcmp:
push esi
push edi
mov edi, dword [esp+12]
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
repe cmpsb
je .equal
mov al, byte [edi-1]
sub al, byte [esi-1]
movsx eax, al
jmp .done
.equal:
xor eax, eax
.done:
pop edi
pop esi
ret
global memcpy32to64
memcpy32to64:
push ebp

4
common/lib/memory.s2.c
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@ -1,3 +1,5 @@
#if !defined (__x86_64__) && !defined (__i386__)
#include <stdint.h>
#include <stddef.h>
@ -51,3 +53,5 @@ int memcmp(const void *s1, const void *s2, size_t n) {
return 0;
}
#endif

75
decompressor/mem.asm Normal file
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@ -0,0 +1,75 @@
section .text
global memcpy
memcpy:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
rep movsb
pop edi
pop esi
ret
global memset
memset:
push edi
mov edx, dword [esp+8]
mov edi, edx
mov eax, dword [esp+12]
mov ecx, dword [esp+16]
rep stosb
mov eax, edx
pop edi
ret
global memmove
memmove:
push esi
push edi
mov eax, dword [esp+12]
mov edi, eax
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
cmp edi, esi
ja .copy_backwards
rep movsb
jmp .done
.copy_backwards:
lea edi, [edi+ecx-1]
lea esi, [esi+ecx-1]
std
rep movsb
cld
.done:
pop edi
pop esi
ret
global memcmp
memcmp:
push esi
push edi
mov edi, dword [esp+12]
mov esi, dword [esp+16]
mov ecx, dword [esp+20]
repe cmpsb
je .equal
mov al, byte [edi-1]
sub al, byte [esi-1]
movsx eax, al
jmp .done
.equal:
xor eax, eax
.done:
pop edi
pop esi
ret

53
decompressor/memory.c
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@ -1,53 +0,0 @@
#include <stdint.h>
#include <stddef.h>
void *memcpy(void *dest, const void *src, size_t n) {
uint8_t *pdest = (uint8_t *)dest;
const uint8_t *psrc = (const uint8_t *)src;
for (size_t i = 0; i < n; i++) {
pdest[i] = psrc[i];
}
return dest;
}
void *memset(void *s, int c, size_t n) {
uint8_t *p = (uint8_t *)s;
for (size_t i = 0; i < n; i++) {
p[i] = (uint8_t)c;
}
return s;
}
void *memmove(void *dest, const void *src, size_t n) {
uint8_t *pdest = (uint8_t *)dest;
const uint8_t *psrc = (const uint8_t *)src;
if (src > dest) {
for (size_t i = 0; i < n; i++) {
pdest[i] = psrc[i];
}
} else if (src < dest) {
for (size_t i = n; i > 0; i--) {
pdest[i-1] = psrc[i-1];
}
}
return dest;
}
int memcmp(const void *s1, const void *s2, size_t n) {
const uint8_t *p1 = (const uint8_t *)s1;
const uint8_t *p2 = (const uint8_t *)s2;
for (size_t i = 0; i < n; i++) {
if (p1[i] != p2[i]) {
return p1[i] < p2[i] ? -1 : 1;
}
}
return 0;
}