Upgrade in-tree google benchmark to v1.1

llvm-svn: 286029

1 files changed, 28 insertions, 0 deletions

diff --git a/libcxx/utils/google-benchmark/README.md b/libcxx/utils/google-benchmark/README.md
index 0c081ff8e26..9109430984c 100644
--- a/libcxx/utils/google-benchmark/README.md
+++ b/libcxx/utils/google-benchmark/README.md
@@ -9,6 +9,8 @@ Discussion group: https://groups.google.com/d/forum/benchmark-discuss
 
 IRC channel: https://freenode.net #googlebenchmark
 
+[Known issues and common problems](#known-issues)
+
 ## Example usage
 ### Basic usage
 Define a function that executes the code to be measured.
@@ -460,6 +462,24 @@ static void BM_test(benchmark::State& state) {
 }
 ```
 
+## Running a subset of the benchmarks
+
+The `--benchmark_filter=<regex>` option can be used to only run the benchmarks
+which match the specified `<regex>`. For example:
+
+```bash
+$ ./run_benchmarks.x --benchmark_filter=BM_memcpy/32
+Run on (1 X 2300 MHz CPU )
+2016-06-25 19:34:24
+Benchmark              Time           CPU Iterations
+----------------------------------------------------
+BM_memcpy/32          11 ns         11 ns   79545455
+BM_memcpy/32k       2181 ns       2185 ns     324074
+BM_memcpy/32          12 ns         12 ns   54687500
+BM_memcpy/32k       1834 ns       1837 ns     357143
+```
+
+
 ## Output Formats
 The library supports multiple output formats. Use the
 `--benchmark_format=<console|json|csv>` flag to set the format type. `console`
@@ -567,3 +587,11 @@ Anything older *may* work.
 
 Note: Using the library and its headers in C++03 is supported. C++11 is only
 required to build the library.
+
+# Known Issues
+
+### Windows
+
+* Users must manually link `shlwapi.lib`. Failure to do so may result
+in unresolved symbols.
+