| // Copyright 2021 The Fuchsia Authors |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #include <lib/arch/asm.h> |
| |
| .text |
| |
| // memset implementation relying on Intel's Enhanced REP STOSB optimization |
| // %rax = memset_stosb(%rdi, %rsi, %rdx) |
| .function memset_stosb, global |
| // Save return value. |
| mov %rdi, %r11 |
| |
| mov %sil, %al |
| mov %rdx, %rcx |
| rep stosb // while (rcx-- > 0) *rdi++ = al; |
| |
| mov %r11, %rax |
| ret |
| .end_function |
