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908fc5b26d
Reoptimize layout array This way it's one check instead of two, so hopefully (cc #99117) it'll be simpler for rustc perf too 🤞 Quick demonstration: ```rust pub fn demo(n: usize) -> Option<Layout> { Layout::array::<i32>(n).ok() } ``` Nightly: <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=e97bf33508aa03f38968101cdeb5322d> ```nasm mov rax, rdi mov ecx, 4 mul rcx seto cl movabs rdx, 9223372036854775805 xor esi, esi cmp rax, rdx setb sil shl rsi, 2 xor edx, edx test cl, cl cmove rdx, rsi ret ``` This PR (note no `mul`, in addition to being much shorter): ```nasm xor edx, edx lea rax, [4*rcx] shr rcx, 61 sete dl shl rdx, 2 ret ``` This is built atop `@CAD97` 's #99136; the new changes are cb8aba66ef6a0e17f08a0574e4820653e31b45a0. I added a bunch more tests for `Layout::from_size_align` and `Layout::array` too.
This directory contains the source code of the rust project, including:
- The test suite
- The bootstrapping build system
- Various submodules for tools, like rustdoc, rls, etc.
For more information on how various parts of the compiler work, see the rustc dev guide.