Refactor the benchmark code.

Changes:
- Modify the benchmarks to derive from a single Benchmark object.
- Rewrite the main iteration code. This includes changing the iteration
  code to use the actual total time calculated by the benchmark as a basis
  for determining whether there are enough iterations instead of using
  the time it takes to run the benchmark.
- Allow benchmarks to take no argument, int, or double.
- Fix the PrettyInt printer for negative integers.
- Modify the max column width name to include the whole name including
  the arg part.
- Reformat property_benchmark.cpp in line with the rest of the code.
- Modify a few of the math benchmarks to take an argument instead of
  separate benchmarks for the same function with different args.
- Create a vector of regex_t structs to represent the args all at
  once instead of when running each benchmark.

This change is in preparation for adding new math based benchmarks.

Tested by running on a nexus flo running at max using the new code
and the old code and comparing. All of the numbers are similar, but
some of the iterations are different due to the slightly different
algorithm used.

Change-Id: I57ad1f3ff083282b9ffeb72e687cab369ce3523a
diff --git a/benchmarks/Android.mk b/benchmarks/Android.mk
index c3eb6d3..ae0541f 100644
--- a/benchmarks/Android.mk
+++ b/benchmarks/Android.mk
@@ -20,12 +20,29 @@
 # Benchmarks library, usable by projects outside this directory.
 # -----------------------------------------------------------------------------
 
+benchmark_cflags := \
+    -O2 \
+    -fno-builtin \
+    -Wall \
+    -Wextra \
+    -Werror \
+    -Wunused \
+
+benchmark_cppflags := \
+    -std=gnu++11 \
+
+benchmarklib_src_files := \
+    Benchmark.cpp \
+    utils.cpp \
+    main.cpp \
+
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbenchmark
-LOCAL_CFLAGS += -O2 -Wall -Wextra -Werror
-LOCAL_SRC_FILES := benchmark_main.cpp
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
-LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_CFLAGS := $(benchmark_cflags)
+LOCAL_CPPFLAGS := $(benchmark_cppflags)
+LOCAL_SRC_FILES := $(benchmarklib_src_files)
+LOCAL_C_INCLUDES := $(benchmark_c_includes)
+LOCAL_STATIC_LIBRARIES := libutils
 include $(BUILD_STATIC_LIBRARY)
 
 # Only supported on linux systems.
@@ -33,11 +50,12 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libbenchmark
-LOCAL_CFLAGS += -O2 -Wall -Wextra -Werror
-LOCAL_SRC_FILES := benchmark_main.cpp
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
-LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_CFLAGS := $(benchmark_cflags)
+LOCAL_CPPFLAGS := $(benchmark_cppflags)
+LOCAL_SRC_FILES := $(benchmarklib_src_files)
+LOCAL_C_INCLUDES := $(benchmark_c_includes)
 LOCAL_MULTILIB := both
+LOCAL_STATIC_LIBRARIES := libutils
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 endif
@@ -45,16 +63,9 @@
 # -----------------------------------------------------------------------------
 # Benchmarks.
 # -----------------------------------------------------------------------------
-
-benchmark_c_flags = \
-    -O2 \
-    -Wall -Wextra -Wunused \
-    -Werror \
-    -fno-builtin \
-    -std=gnu++11 \
-
-benchmark_src_files = \
+benchmark_src_files := \
     math_benchmark.cpp \
+    property_benchmark.cpp \
     pthread_benchmark.cpp \
     semaphore_benchmark.cpp \
     stdio_benchmark.cpp \
@@ -70,9 +81,10 @@
 LOCAL_MODULE_STEM_32 := bionic-benchmarks32
 LOCAL_MODULE_STEM_64 := bionic-benchmarks64
 LOCAL_MULTILIB := both
-LOCAL_CFLAGS += $(benchmark_c_flags)
-LOCAL_SRC_FILES := $(benchmark_src_files) property_benchmark.cpp
-LOCAL_STATIC_LIBRARIES += libbenchmark
+LOCAL_CFLAGS := $(benchmark_cflags)
+LOCAL_CPPFLAGS := $(benchmark_cppflags)
+LOCAL_SRC_FILES := $(benchmark_src_files)
+LOCAL_STATIC_LIBRARIES := libbenchmark libutils
 include $(BUILD_EXECUTABLE)
 
 # We don't build a static benchmark executable because it's not usually
@@ -90,10 +102,11 @@
 LOCAL_MODULE_STEM_32 := bionic-benchmarks-glibc32
 LOCAL_MODULE_STEM_64 := bionic-benchmarks-glibc64
 LOCAL_MULTILIB := both
-LOCAL_CFLAGS += $(benchmark_c_flags)
-LOCAL_LDFLAGS += -lrt
+LOCAL_CFLAGS := $(benchmark_cflags)
+LOCAL_CPPFLAGS := $(benchmark_cppflags)
+LOCAL_LDFLAGS := -lrt
 LOCAL_SRC_FILES := $(benchmark_src_files)
-LOCAL_STATIC_LIBRARIES += libbenchmark
+LOCAL_STATIC_LIBRARIES := libbenchmark libutils
 include $(BUILD_HOST_EXECUTABLE)
 
 endif