[llvm-cov] Multi-threaded implementation of prepareFileReports method.
Summary:
Local testing has demonstrated a great speed improvement, compare the following:
1) Existing version:
```
$ time llvm-cov show -format=html -output-dir=report -instr-profile=... ...
The tool has been launched: 00:00:00
Loading coverage data: 00:00:00
Get unique source files: 00:00:33
Creating an index out of the source files: 00:00:34
Going into prepareFileReports: 00:00:34
Going to emit summary information for each file: 00:28:55 <-- 28:21 min!
Going to emit links to files with no function: 00:28:55
Launching 32 threads for generating HTML files: 00:28:55
real 37m43.651s
user 112m5.540s
sys 7m39.872s
```
2) Multi-threaded version with 32 CPUs:
```
$ time llvm-cov show -format=html -output-dir=report -instr-profile=... ...
The tool has been launched: 00:00:00
Loading coverage data: 00:00:00
Get unique source files: 00:00:38
Creating an index out of the source files: 00:00:40
Going into prepareFileReports: 00:00:40
Preparing file reports using 32 threads: 00:00:40
# Creating thread tasks for the following number of files: 16422
Going to emit summary information for each file: 00:01:57 <-- 1:17 min!
Going to emit links to files with no function: 00:01:58
Launching 32 threads for generating HTML files: 00:01:58
real 11m2.044s
user 134m48.124s
sys 7m53.388s
```
Reviewers: vsk, morehouse
Reviewed By: vsk
Subscribers: Dor1s, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D41206
llvm-svn: 321871
diff --git a/llvm/tools/llvm-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index 59743f5..a1f2fd2 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -33,8 +33,8 @@
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/ScopedPrinter.h"
-#include "llvm/Support/Threading.h"
#include "llvm/Support/ThreadPool.h"
+#include "llvm/Support/Threading.h"
#include "llvm/Support/ToolOutputFile.h"
#include <functional>
@@ -637,6 +637,12 @@
"summary-only", cl::Optional,
cl::desc("Export only summary information for each source file"));
+ cl::opt<unsigned> NumThreads(
+ "num-threads", cl::init(0),
+ cl::desc("Number of merge threads to use (default: autodetect)"));
+ cl::alias NumThreadsA("j", cl::desc("Alias for --num-threads"),
+ cl::aliasopt(NumThreads));
+
auto commandLineParser = [&, this](int argc, const char **argv) -> int {
cl::ParseCommandLineOptions(argc, argv, "LLVM code coverage tool\n");
ViewOpts.Debug = DebugDump;
@@ -750,6 +756,7 @@
ViewOpts.ShowRegionSummary = RegionSummary;
ViewOpts.ShowInstantiationSummary = InstantiationSummary;
ViewOpts.ExportSummaryOnly = SummaryOnly;
+ ViewOpts.NumThreads = NumThreads;
return 0;
};
@@ -809,12 +816,6 @@
"project-title", cl::Optional,
cl::desc("Set project title for the coverage report"));
- cl::opt<unsigned> NumThreads(
- "num-threads", cl::init(0),
- cl::desc("Number of merge threads to use (default: autodetect)"));
- cl::alias NumThreadsA("j", cl::desc("Alias for --num-threads"),
- cl::aliasopt(NumThreads));
-
auto Err = commandLineParser(argc, argv);
if (Err)
return Err;
@@ -911,6 +912,8 @@
(SourceFiles.size() != 1) || ViewOpts.hasOutputDirectory() ||
(ViewOpts.Format == CoverageViewOptions::OutputFormat::HTML);
+ auto NumThreads = ViewOpts.NumThreads;
+
// If NumThreads is not specified, auto-detect a good default.
if (NumThreads == 0)
NumThreads =