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cosmopolitan/libc/nexgen32e/memmove.S

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Polish up repository and other revisions
2020-06-16 13:38:43 +00:00
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
Initial import
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│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/macros.h"
/ Copies memory.
/
/ DEST and SRC may overlap.
/
/ @param rdi is dest
/ @param rsi is src
/ @param rdx is number of bytes
/ @return original rdi copied to rax
/ @asyncsignalsafe
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
memmove:
mov %rdi,%rax
Initial import
2020-06-15 14:18:57 +00:00
/ 𝑠𝑙𝑖𝑑𝑒
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
.endfn MemMove,globl,hidden
Initial import
2020-06-15 14:18:57 +00:00
Add x86_64-linux-gnu emulator I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 11:23:25 +00:00
MemMove:
Initial import
2020-06-15 14:18:57 +00:00
.leafprologue
.profilable
push %rcx
push %rdi
push %rsi
mov %rdx,%rcx
cmp %rsi,%rdi
jb 1f
lea -1(%rdi,%rcx),%rdi
lea -1(%rsi,%rcx),%rsi
std
1: rep movsb
cld
pop %rsi
pop %rdi
pop %rcx
.leafepilogue
.endfn memmove,globl
Add scouts honor escape hatch for source embedding
2020-06-16 02:01:28 +00:00
.source __FILE__