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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 <zap/priv.h>
#include <zap/mem.h>
#include <stddef.h>
#include <stdint.h>
#if zap_priv_fastimpl
__asm__ (
".globl zap_memfill\n"
"zap_memfill:\n"
/*
void const * ptr
size_t num
unsigned char val
*/
#if defined(sus_arch_amd64)
/* rdi: Address of the current element. */
/* rsi: Address of the element after the last element. */
"addq %rdi,%rsi\n"
".loop:\n"
"cmpq %rdi,%rsi\n"
"je .done\n" /* Exit loop if we have reached the final element. */
"movb %dl,(%rdi)\n"
"incq %rdi\n"
"jmp .loop\n" /* Continue to next element. */
".done:\n"
"ret\n"
#elif defined(sus_arch_ia32)
/* eax: Address of the current element. */
"movl 0x4(%esp),%eax\n"
/* ecx: Address of the element after the last element. */
"movl 0x4(%esp),%ecx\n"
"addl 0x8(%esp),%ecx\n"
/* edx: Byte value. */
"movb 0xC(%esp),%dl\n"
".loop:\n"
"cmpl %eax,%ecx\n"
"je .done\n" /* Exit loop if we have reached the final element. */
"movb %dl,(%eax)\n"
"incl %eax\n"
"jmp .loop\n" /* Continue to next element. */
".done:\n"
"ret\n"
#endif
);
#else
void zap_memfill(void * const _ptr,size_t const _num,unsigned char const _byte) {
unsigned char * pos = _ptr;
unsigned char * const afterbuf = pos + _num;
for (;pos != afterbuf;++pos) {*pos = _byte;}
}
#endif
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