[benchmarks] DO_NOT_OPTIMIZE macro

2 files changed, 23 insertions, 2 deletions

diff --git a/source/kit_test/bench.h b/source/kit_test/bench.h
index 131d89d..6c701bb 100644
--- a/source/kit_test/bench.h
+++ b/source/kit_test/bench.h
@@ -73,12 +73,21 @@ void kit_bench_register(char const *name, char const *file,
   kit_bench_end_fn_(kit_bench_index_); \
   }
 
+/*  FIXME
+ */
+#define KIT_DO_NOT_OPTIMIZE(x)        \
+  do {                                \
+    volatile void *bench_ptr_ = &(x); \
+    (void) bench_ptr_;                \
+  } while (0)
+
 int kit_run_benchmarks(int argc, char **argv);
 
 #ifndef KIT_DISABLE_SHORT_NAMES
 #  define BENCHMARK KIT_BENCHMARK
 #  define BENCHMARK_BEGIN KIT_BENCHMARK_BEGIN
 #  define BENCHMARK_END KIT_BENCHMARK_END
+#  define DO_NOT_OPTIMIZE KIT_DO_NOT_OPTIMIZE
 
 #  define bench_register kit_bench_register
 #  define run_benchmarks kit_run_benchmarks
diff --git a/source/test/unittests/foo.bench.c b/source/test/unittests/foo.bench.c
index 531f1d8..a3d5c18 100644
--- a/source/test/unittests/foo.bench.c
+++ b/source/test/unittests/foo.bench.c
@@ -1,11 +1,23 @@
 #define KIT_BENCH_FILE foo
 #include "../../kit_test/bench.h"
 
+struct test_foo_ {
+  double f;
+};
+
 BENCHMARK("foo") {
   BENCHMARK_BEGIN;
   {
-    volatile int x = 0;
-    for (int i = 0; i < 200000; i++) x++;
+    int              x = 0;
+    struct test_foo_ f = { 0. };
+
+    for (int i = 0; i < 100000; i++) {
+      x += (1 << 1);
+      x ^= i;
+      f.f += 0.1;
+    }
+    DO_NOT_OPTIMIZE(x);
+    DO_NOT_OPTIMIZE(f);
   }
   BENCHMARK_END;
 }