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| author | Alex Crichton <alex@alexcrichton.com> | 2018-08-19 23:44:25 -0700 |
|---|---|---|
| committer | Alex Crichton <alex@alexcrichton.com> | 2018-08-19 23:46:32 -0700 |
| commit | 9d54bf8df2677dd5f985838c5686efaa24a73b6c (patch) | |
| tree | 6db4939f40969431412f1ec2b2e77d31e71d5bae /src/rustllvm/PassWrapper.cpp | |
| parent | 3ac79c718475fd29b8be34dde667b683390c2aee (diff) | |
| download | rust-9d54bf8df2677dd5f985838c5686efaa24a73b6c.tar.gz rust-9d54bf8df2677dd5f985838c5686efaa24a73b6c.zip | |
Buffer LLVM's object output stream
In some profiling on OSX I saw the `write` syscall as quite high up on the profiling graph, which is definitely not good! It looks like we're setting the output stream of an object file as directly to a file descriptor which means that we run the risk of doing lots of little writes rather than a few large writes. This commit fixes this issue by adding a buffered stream on the output, causing the `write` syscall to disappear from the profiles on OSX.
Diffstat (limited to 'src/rustllvm/PassWrapper.cpp')
| -rw-r--r-- | src/rustllvm/PassWrapper.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp index d9fbd494ab3..46825efeee2 100644 --- a/src/rustllvm/PassWrapper.cpp +++ b/src/rustllvm/PassWrapper.cpp @@ -556,7 +556,8 @@ LLVMRustWriteOutputFile(LLVMTargetMachineRef Target, LLVMPassManagerRef PMR, } #if LLVM_VERSION_GE(7, 0) - unwrap(Target)->addPassesToEmitFile(*PM, OS, nullptr, FileType, false); + buffer_ostream BOS(OS); + unwrap(Target)->addPassesToEmitFile(*PM, BOS, nullptr, FileType, false); #else unwrap(Target)->addPassesToEmitFile(*PM, OS, FileType, false); #endif |