6023350082
We were previously reading metadata via `ar p`, but as learned from rustdoc
awhile back, spawning a process to do something is pretty slow. Turns out LLVM
has an Archive class to read archives, but it cannot write archives.
This commits adds bindings to the read-only version of the LLVM archive class
(with a new type that only has a read() method), and then it uses this class
when reading the metadata out of rlibs. When you put this in tandem of not
compressing the metadata, reading the metadata is 4x faster than it used to be
The timings I got for reading metadata from the respective libraries was:
libstd-04ff901e-0.9-pre.dylib => 100ms
libstd-04ff901e-0.9-pre.rlib => 23ms
librustuv-7945354c-0.9-pre.dylib => 4ms
librustuv-7945354c-0.9-pre.rlib => 1ms
librustc-5b94a16f-0.9-pre.dylib => 87ms
librustc-5b94a16f-0.9-pre.rlib => 35ms
libextra-a6ebb16f-0.9-pre.dylib => 63ms
libextra-a6ebb16f-0.9-pre.rlib => 15ms
libsyntax-2e4c0458-0.9-pre.dylib => 86ms
libsyntax-2e4c0458-0.9-pre.rlib => 22ms
In order to always take advantage of these faster metadata read-times, I sort
the files in filesearch based on whether they have an rlib extension or not
(prefer all rlib files first).
Overall, this halved the compile time for a `fn main() {}` crate from 0.185s to
0.095s on my system (when preferring dynamic linking). Reading metadata is still
the slowest pass of the compiler at 0.035s, but it's getting pretty close to
linking at 0.021s! The next best optimization is to just not copy the metadata
from LLVM because that's the most expensive part of reading metadata right now.
|
||
|---|---|---|
| .. | ||
| compiletest | ||
| driver | ||
| etc | ||
| gyp@f407f09c94 | ||
| libextra | ||
| librustc | ||
| librustdoc | ||
| librustpkg | ||
| librustuv | ||
| libstd | ||
| libsyntax | ||
| libuv@2207d4ab07 | ||
| llvm@eac6ff795c | ||
| rt | ||
| rustllvm | ||
| test | ||
| README.txt | ||
| snapshots.txt | ||
This is a preliminary version of the Rust compiler, libraries and tools Source layout: librustc/ The self-hosted compiler libstd/ The standard library (imported and linked by default) libextra/ The "extras" library (slightly more peripheral code) libsyntax/ The Rust parser and pretty-printer rt/ The runtime system rt/rust_*.cpp - The majority of the runtime services rt/isaac - The PRNG used for pseudo-random choices in the runtime rt/bigint - The bigint library used for the 'big' type rt/uthash - Small hashtable-and-list library for C, used in runtime rt/sync - Concurrency utils rt/util - Small utility classes for the runtime. rt/vg - Valgrind headers rt/msvc - MSVC support test/ Testsuite test/compile-fail - Tests that should fail to compile test/run-fail - Tests that should compile, run and fail test/run-pass - Tests that should compile, run and succeed test/bench - Benchmarks and miscellanea test/pretty - Pretty-printer tests test/auxiliary - Dependencies of tests compiletest/ The test runner librustpkg/ The package manager and build system librustdoc/ The Rust API documentation tool llvm/ The LLVM submodule libuv/ The libuv submodule rustllvm/ LLVM support code libfuzzer/ A collection of fuzz testers etc/ Scripts, editor support, misc