2fd060815f
core: add likely and unlikely intrinsics I'm no good at reading assembly, but I have tried a stage1 compiler with this patch, and it does cause different asm output. Additionally, testing this compiler on my httparse crate with some `likely` usage added in to the branches does affect benchmarks. However, I'm sure a codegen test should be included, if anyone knows what it should look like. There isn't an entry in `librustc_trans/context.rs` in this diff, because it already exists (`llvm.expect.i1` is used for array indices). ---- Even though this does affect httparse benchmarks, it doesn't seem to affect it the same way GCC's `__builtin_expect` affects picohttpparser. I was confused that the deviation on the benchmarks grew hugely when testing this, especially since I'm absolutely certain that the branchs where I added `likely` were always `true`. I chalk that up to GCC and LLVM handle branch prediction differently. cc #26179 |
||
|---|---|---|
| .. | ||
| back | ||
| debuginfo | ||
| mir | ||
| abi.rs | ||
| adt.rs | ||
| asm.rs | ||
| assert_module_sources.rs | ||
| attributes.rs | ||
| base.rs | ||
| basic_block.rs | ||
| build.rs | ||
| builder.rs | ||
| cabi_aarch64.rs | ||
| cabi_arm.rs | ||
| cabi_asmjs.rs | ||
| cabi_mips64.rs | ||
| cabi_mips.rs | ||
| cabi_powerpc64.rs | ||
| cabi_powerpc.rs | ||
| cabi_s390x.rs | ||
| cabi_x86_64.rs | ||
| cabi_x86_win64.rs | ||
| cabi_x86.rs | ||
| callee.rs | ||
| Cargo.toml | ||
| cleanup.rs | ||
| closure.rs | ||
| collector.rs | ||
| common.rs | ||
| consts.rs | ||
| context.rs | ||
| declare.rs | ||
| diagnostics.rs | ||
| disr.rs | ||
| glue.rs | ||
| intrinsic.rs | ||
| lib.rs | ||
| machine.rs | ||
| macros.rs | ||
| meth.rs | ||
| monomorphize.rs | ||
| partitioning.rs | ||
| README.txt | ||
| symbol_map.rs | ||
| symbol_names_test.rs | ||
| trans_item.rs | ||
| tvec.rs | ||
| type_.rs | ||
| type_of.rs | ||
| value.rs | ||
See the README.md in ../librustc.