Add bench_duration function

tests/bench.c

@@ -45,12 +45,16 @@ void bench_stop(bench *b) {
 }
 
 double bench_iteration_speed(bench *b) {
-    return b->N / (b->end - b->start);
+    return (b->N * b->R) / (b->end - b->start);
+}
+
+double bench_duration(bench *b) {
+    return (b->end - b->start);
 }
 
 void bench_print_summary(bench *b) {
     printf("%ld runs, ", b->R);
     printf("%ld iterations each run, ", b->N);
-    printf("finished in %lf seconds\n", b->end - b->start );
+    printf("finished in %lf seconds\n", bench_duration(b) );
-    printf("%.2f i/sec\n", (b->N * b->R) / (b->end - b->start) );
+    printf("%.2f i/sec\n", bench_iteration_speed(b) );
 }

tests/bench.h

@@ -35,6 +35,8 @@ double bench_iteration_speed(bench *b);
 
 void bench_print_summary(bench *b);
 
+double bench_duration(bench *b);
+
 #define BENCHMARK(B) \
         bench B; B.N = 5000000; B.R = 3; \
         bench_start(&B); \

tests/bench_str.csv

@@ -449,3 +449,5 @@
 1400748826,12902583.84
 1400748965,13584323.91
 1400749175,13518288.33
+1400749320,13445606.30
+1400749326,13242705.99