85d37c9994
Some implementations can use the std::nullopt_t constructor of
std::optional to avoid needing to completely zero out the internal
buffer of the optional and instead only set the validity byte within it.
e.g. Consider the following function:
std::optional<std::vector<ShaderDiskCacheRaw>> fn() {
return {};
}
With libc++ this will result in the following code generation on x86-64:
Fn():
mov rax, rdi
vxorps xmm0, xmm0, xmm0
vmovups ymmword ptr [rdi], ymm0
vzeroupper
ret
With libstdc++, we also get the similar equivalent:
Fn():
vpxor xmm0, xmm0, xmm0
mov rax, rdi
vmovdqu XMMWORD PTR [rdi], xmm0
vmovdqu XMMWORD PTR [rdi+16], xmm0
ret
If we change this function to return std::nullopt instead, then this
simplifies both the code gen from libc++ and libstdc++ down to:
Fn():
mov BYTE PTR [rdi+24], 0
mov rax, rdi
ret
Given how little of a change is necessary to result in better code
generation, this is essentially a "free" very minor optimization.
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| .appveyor | ||
| .github | ||
| .travis | ||
| CMakeModules | ||
| dist | ||
| externals | ||
| hooks | ||
| src | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .travis.yml | ||
| appveyor.yml | ||
| bitrise.yml | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| Doxyfile | ||
| keys.tar.enc | ||
| license.txt | ||
| README.md | ||
BEFORE FILING AN ISSUE, READ THE RELEVANT SECTION IN THE CONTRIBUTING FILE!!!
Citra
Citra is an experimental open-source Nintendo 3DS emulator/debugger written in C++. It is written with portability in mind, with builds actively maintained for Windows, Linux and macOS.
Citra emulates a subset of 3DS hardware and therefore is useful for running/debugging homebrew applications, and it is also able to run many commercial games! Some of these do not run at a playable state, but we are working every day to advance the project forward. (Playable here means compatibility of at least "Okay" on our game compatibility list.)
Citra is licensed under the GPLv2 (or any later version). Refer to the license.txt file included. Please read the FAQ before getting started with the project.
Check out our website!
Need help? Check out our asking for help guide.
For development discussion, please join us on our Discord server or at #citra-dev on freenode.
Development
Most of the development happens on GitHub. It's also where our central repository is hosted.
If you want to contribute please take a look at the Contributor's Guide and Developer Information. You should also contact any of the developers in the forum in order to know about the current state of the emulator because the TODO list isn't maintained anymore.
If you want to contribute to the user interface translation, please checkout citra project on transifex. We centralize the translation work there, and periodically upstream translation.
Building
- Windows: Windows Build
- Linux: Linux Build
- macOS: macOS Build
Support
We happily accept monetary donations or donated games and hardware. Please see our donations page for more information on how you can contribute to Citra. Any donations received will go towards things like:
- 3DS consoles for developers to explore the hardware
- 3DS games for testing
- Any equipment required for homebrew
- Infrastructure setup
We also more than gladly accept used 3DS consoles! If you would like to give yours away, don't hesitate to join our Discord server and talk to bunnei.