Update in-tree Google Benchmark to current ToT.
I've put some work into the Google Benchmark library in order to make it easier
to benchmark libc++. These changes have already been upstreamed into
Google Benchmark and this patch applies the changes to the in-tree version.
The main improvement in the addition of a 'compare_bench.py' script which
makes it very easy to compare benchmarks. For example to compare the native
STL to libc++ you would run:
`$ compare_bench.py ./util_smartptr.native.out ./util_smartptr.libcxx.out`
And the output would look like:
RUNNING: ./util_smartptr.native.out
Benchmark Time CPU Iterations
----------------------------------------------------------------
BM_SharedPtrCreateDestroy 62 ns 62 ns 10937500
BM_SharedPtrIncDecRef 31 ns 31 ns 23972603
BM_WeakPtrIncDecRef 28 ns 28 ns 23648649
RUNNING: ./util_smartptr.libcxx.out
Benchmark Time CPU Iterations
----------------------------------------------------------------
BM_SharedPtrCreateDestroy 46 ns 46 ns 14957265
BM_SharedPtrIncDecRef 31 ns 31 ns 22435897
BM_WeakPtrIncDecRef 34 ns 34 ns 21084337
Comparing ./util_smartptr.native.out to ./util_smartptr.libcxx.out
Benchmark Time CPU
-----------------------------------------------------
BM_SharedPtrCreateDestroy -0.26 -0.26
BM_SharedPtrIncDecRef +0.00 +0.00
BM_WeakPtrIncDecRef +0.21 +0.21
llvm-svn: 278147
diff --git a/libcxx/utils/google-benchmark/tools/gbench/util.py b/libcxx/utils/google-benchmark/tools/gbench/util.py
new file mode 100644
index 0000000..169b71c
--- /dev/null
+++ b/libcxx/utils/google-benchmark/tools/gbench/util.py
@@ -0,0 +1,130 @@
+"""util.py - General utilities for running, loading, and processing benchmarks
+"""
+import json
+import os
+import tempfile
+import subprocess
+import sys
+
+# Input file type enumeration
+IT_Invalid = 0
+IT_JSON = 1
+IT_Executable = 2
+
+_num_magic_bytes = 2 if sys.platform.startswith('win') else 4
+def is_executable_file(filename):
+ """
+ Return 'True' if 'filename' names a valid file which is likely
+ an executable. A file is considered an executable if it starts with the
+ magic bytes for a EXE, Mach O, or ELF file.
+ """
+ if not os.path.isfile(filename):
+ return False
+ with open(filename, 'r') as f:
+ magic_bytes = f.read(_num_magic_bytes)
+ if sys.platform == 'darwin':
+ return magic_bytes in [
+ '\xfe\xed\xfa\xce', # MH_MAGIC
+ '\xce\xfa\xed\xfe', # MH_CIGAM
+ '\xfe\xed\xfa\xcf', # MH_MAGIC_64
+ '\xcf\xfa\xed\xfe', # MH_CIGAM_64
+ '\xca\xfe\xba\xbe', # FAT_MAGIC
+ '\xbe\xba\xfe\xca' # FAT_CIGAM
+ ]
+ elif sys.platform.startswith('win'):
+ return magic_bytes == 'MZ'
+ else:
+ return magic_bytes == '\x7FELF'
+
+
+def is_json_file(filename):
+ """
+ Returns 'True' if 'filename' names a valid JSON output file.
+ 'False' otherwise.
+ """
+ try:
+ with open(filename, 'r') as f:
+ json.load(f)
+ return True
+ except:
+ pass
+ return False
+
+
+def classify_input_file(filename):
+ """
+ Return a tuple (type, msg) where 'type' specifies the classified type
+ of 'filename'. If 'type' is 'IT_Invalid' then 'msg' is a human readable
+ string represeting the error.
+ """
+ ftype = IT_Invalid
+ err_msg = None
+ if not os.path.exists(filename):
+ err_msg = "'%s' does not exist" % filename
+ elif not os.path.isfile(filename):
+ err_msg = "'%s' does not name a file" % filename
+ elif is_executable_file(filename):
+ ftype = IT_Executable
+ elif is_json_file(filename):
+ ftype = IT_JSON
+ else:
+ err_msg = "'%s' does not name a valid benchmark executable or JSON file"
+ return ftype, err_msg
+
+
+def check_input_file(filename):
+ """
+ Classify the file named by 'filename' and return the classification.
+ If the file is classified as 'IT_Invalid' print an error message and exit
+ the program.
+ """
+ ftype, msg = classify_input_file(filename)
+ if ftype == IT_Invalid:
+ print "Invalid input file: %s" % msg
+ sys.exit(1)
+ return ftype
+
+
+def load_benchmark_results(fname):
+ """
+ Read benchmark output from a file and return the JSON object.
+ REQUIRES: 'fname' names a file containing JSON benchmark output.
+ """
+ with open(fname, 'r') as f:
+ return json.load(f)
+
+
+def run_benchmark(exe_name, benchmark_flags):
+ """
+ Run a benchmark specified by 'exe_name' with the specified
+ 'benchmark_flags'. The benchmark is run directly as a subprocess to preserve
+ real time console output.
+ RETURNS: A JSON object representing the benchmark output
+ """
+ thandle, tname = tempfile.mkstemp()
+ os.close(thandle)
+ cmd = [exe_name] + benchmark_flags
+ print("RUNNING: %s" % ' '.join(cmd))
+ exitCode = subprocess.call(cmd + ['--benchmark_out=%s' % tname])
+ if exitCode != 0:
+ print('TEST FAILED...')
+ sys.exit(exitCode)
+ json_res = load_benchmark_results(tname)
+ os.unlink(tname)
+ return json_res
+
+
+def run_or_load_benchmark(filename, benchmark_flags):
+ """
+ Get the results for a specified benchmark. If 'filename' specifies
+ an executable benchmark then the results are generated by running the
+ benchmark. Otherwise 'filename' must name a valid JSON output file,
+ which is loaded and the result returned.
+ """
+ ftype = check_input_file(filename)
+ if ftype == IT_JSON:
+ return load_benchmark_results(filename)
+ elif ftype == IT_Executable:
+ return run_benchmark(filename, benchmark_flags)
+ else:
+ assert False # This branch is unreachable
\ No newline at end of file