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Auto merge of #90617 - tmiasko:time-trace-threads, r=wesleywiser

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Initialize LLVM time trace profiler on each code generation thread

In https://reviews.llvm.org/D71059 LLVM 11, the time trace profiler was
extended to support multiple threads.

`timeTraceProfilerInitialize` creates a thread local profiler instance.
When a thread finishes `timeTraceProfilerFinishThread` moves a thread
local instance into a global collection of instances. Finally when all
codegen work is complete `timeTraceProfilerWrite` writes data from the
current thread local instance and the instances in global collection
of instances.

Previously, the profiler was intialized on a single thread only. Since
this thread performs no code generation on its own, the resulting
profile was empty.

Update LLVM codegen to initialize & finish time trace profiler on each
code generation thread.

cc `@tmandry`
r? `@wesleywiser`
This commit is contained in:
bors 2021-11-06 09:55:50 +00:00
commit 3cd3bbecc5
6 changed files with 128 additions and 56 deletions
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5
compiler/rustc_codegen_llvm/src/llvm_util.rs
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@ -113,11 +113,6 @@ unsafe fn configure_llvm(sess: &Session) {
}
if sess.opts.debugging_opts.llvm_time_trace {
// time-trace is not thread safe and running it in parallel will cause seg faults.
if !sess.opts.debugging_opts.no_parallel_llvm {
bug!("`-Z llvm-time-trace` requires `-Z no-parallel-llvm")
}
llvm::LLVMTimeTraceProfilerInitialize();
}