https://github.com/rust-lang/rust http://git.dreamy.place/mirrors/rust/atom?h=1.58.1 2022-01-05T20:21:05+00:00 2022-01-05T20:21:05+00:00 Simonas Kazlauskas git@kazlauskas.me 2021-11-24T19:13:53+00:00 urn:sha1:ce3d508f507949b2eec552237b540c129be3bc98 cc #91128 2021-11-09T18:00:45+00:00 Matthias Krüger matthias.krueger@famsik.de 2021-11-09T18:00:45+00:00 urn:sha1:fd5a4f42ad425a19c022fcafe482341e2612f29e Record more artifact sizes during self-profiling. This PR adds artifact size recording for - "linked artifacts" (executables, RLIBs, dylibs, static libs) - object files - dwo files - assembly files - crate metadata - LLVM bitcode files - LLVM IR files - codegen unit size estimates Currently the identifiers emitted for these are hard-coded as string literals. Is it worth adding constants to https://github.com/rust-lang/measureme/blob/master/measureme/src/rustc.rs instead? We don't do that for query names and the like -- but artifact kinds might be more stable than query names. 2021-11-08T16:02:40+00:00 Michael Woerister michaelwoerister@posteo 2021-11-08T15:59:36+00:00 urn:sha1:fefe1e9192696c07f1655ed2726c4e114b70b096 2021-11-08T01:22:28+00:00 Joshua Nelson jyn514@gmail.com 2021-07-21T03:23:22+00:00 urn:sha1:0ac13bd430cdd433a1b7f5a821fdd538737ae34e The only reason to use `abort_if_errors` is when the program is so broken that either: 1. later passes get confused and ICE 2. any diagnostics from later passes would be noise This is never the case for lints, because the compiler has to be able to deal with `allow`-ed lints. So it can continue to lint and compile even if there are lint errors. 2021-10-25T20:59:46+00:00 Matthias Krüger matthias.krueger@famsik.de 2021-10-25T20:59:46+00:00 urn:sha1:2f6764760665a2ac776293edf8b6772d17f3e266 Add -Z no-unique-section-names to reduce ELF header bloat. This change adds a new compiler flag that can help reduce the size of ELF binaries that contain many functions. By default, when enabling function sections (which is the default for most targets), the LLVM backend will generate different section names for each function. For example, a function `func` would generate a section called `.text.func`. Normally this is fine because the linker will merge all those sections into a single one in the binary. However, starting with [LLVM 12](https://github.com/llvm/llvm-project/commit/ee5d1a04), the backend will also generate unique section names for exception handling, resulting in thousands of `.gcc_except_table.*` sections ending up in the final binary because some linkers like LLD don't currently merge or strip these EH sections (see discussion [here](https://reviews.llvm.org/D83655)). This can bloat the ELF headers and string table significantly in binaries that contain many functions. The new option is analogous to Clang's `-fno-unique-section-names`, and instructs LLVM to generate the same `.text` and `.gcc_except_table` section for each function, resulting in a smaller final binary. The motivation to add this new option was because we have a binary that ended up with so many ELF sections (over 65,000) that it broke some existing ELF tools, which couldn't handle so many sections. Here's our old binary: ``` $ readelf --sections old.elf | head -1 There are 71746 section headers, starting at offset 0x2a246508: $ readelf --sections old.elf | grep shstrtab [71742] .shstrtab STRTAB 0000000000000000 2977204c ad44bb 00 0 0 1 ``` That's an 11MB+ string table. Here's the new binary using this option: ``` $ readelf --sections new.elf | head -1 There are 43 section headers, starting at offset 0x29143ca8: $ readelf --sections new.elf | grep shstrtab [40] .shstrtab STRTAB 0000000000000000 29143acc 0001db 00 0 0 1 ``` The whole binary size went down by over 20MB, which is quite significant. 2021-10-11T19:09:32+00:00 Javier Blazquez jblazquez@riotgames.com 2021-10-11T19:09:32+00:00 urn:sha1:4ed846ad4d4e0be96efc4837fa416aabce1882db This change adds a new compiler flag that can help reduce the size of ELF binaries that contain many functions. By default, when enabling function sections (which is the default for most targets), the LLVM backend will generate different section names for each function. For example, a function "func" would generate a section called ".text.func". Normally this is fine because the linker will merge all those sections into a single one in the binary. However, starting with LLVM 12 (llvm/llvm-project@ee5d1a0), the backend will also generate unique section names for exception handling, resulting in thousands of ".gcc_except_table.*" sections ending up in the final binary because some linkers don't currently merge or strip these EH sections. This can bloat the ELF headers and string table significantly in binaries that contain many functions. The new option is analogous to Clang's -fno-unique-section-names, and instructs LLVM to generate the same ".text" and ".gcc_except_table" section for each function, resulting in smaller object files and potentially a smaller final binary. 2021-10-08T13:05:07+00:00 Hans Kratz hans@appfour.com 2021-10-08T10:10:52+00:00 urn:sha1:4593d78e96253ccf8440605f8db49c09ece48b8c 2021-10-06T19:36:52+00:00 Michael Benfield mbenfield@google.com 2021-05-07T07:41:37+00:00 urn:sha1:a17193dbb931ea0c8b66d82f640385bce8b4929a This largely involves implementing the options debug-info-for-profiling and profile-sample-use and forwarding them on to LLVM. AutoFDO can be used on x86-64 Linux like this: rustc -O -Cdebug-info-for-profiling main.rs -o main perf record -b ./main create_llvm_prof --binary=main --out=code.prof rustc -O -Cprofile-sample-use=code.prof main.rs -o main2 Now `main2` will have feedback directed optimization applied to it. The create_llvm_prof tool can be obtained from this github repository: https://github.com/google/autofdo Fixes #64892. 2021-10-02T10:52:09+00:00 bors bors@rust-lang.org 2021-10-02T10:52:09+00:00 urn:sha1:b27661eb33c74cb514dba059b47d86b6582ac1c2 Fix clippy lints I'm currently working on allowing clippy to run on librustdoc after a discussion I had with `@Mark-Simulacrum.` So in the meantime, I fixed a few lints on the compiler crates. 2021-10-01T21:46:49+00:00 Manish Goregaokar manishsmail@gmail.com 2021-10-01T21:46:49+00:00 urn:sha1:1781e4b81af0440ce58b6905724df5d3e2afd548 Fix use after drop in self-profile with llvm events self-profile with `-Z self-profile-events=llvm` have failed with a segmentation fault due to this use after drop. this type of events can be more useful now that the new passmanager is the default.