diff options
Diffstat (limited to 'zap/source/amd64/mem/fill.s')
| -rw-r--r-- | zap/source/amd64/mem/fill.s | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/zap/source/amd64/mem/fill.s b/zap/source/amd64/mem/fill.s new file mode 100644 index 0000000..0abd2be --- /dev/null +++ b/zap/source/amd64/mem/fill.s @@ -0,0 +1,51 @@ +# Copyright 2022-2023 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>. + +.intel_syntax noprefix + +.globl zap_fill + +zap_fill: + # zap_i8 val1; + # zap_i04 val8; + + movzx rax,sil # val8 = val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + shl rax,0x8 # val8 <<= 0x8u; + mov al,sil # val8 |= val; + # val1 = val8; + +.wrdfill: # wrdfill:; + cmp rdx,0x8 + jl .bytefill # if (num < 0x8u) goto bytefill; + + mov [rdi],rax # *dest = val8; + + add rdi,0x8 # dest += 0x8u; + sub rdx,0x8 # num -= 0x8u; + jmp .wrdfill # goto wrdfill + +.bytefill: # bytefill:; + test rdx,rdx # if (rem == 0x0) + jz .done # goto done + + mov [rsi],al # *dest = val1; + + inc rdi # ++dest; + dec rdx # --rem; + jmp .bytefill # goto bytefill; + +.done: + ret # return |