Merge bitcoin-core/secp256k1#989: Shared benchmark format for command line and CSV outputs

b4b130678db31a7cabc2cde091bc4acbca92b7a3 create csv file from the benchmark output (siv2r)
26a255beb673217c839dcc51790d9a484f9a292d Shared benchmark format for command line and CSV outputs (siv2r)

Pull request description:

ACKs for top commit:
  real-or-random:
    ACK b4b130678db31a7cabc2cde091bc4acbca92b7a3
  jonasnick:
    ACK b4b130678db31a7cabc2cde091bc4acbca92b7a3

Tree-SHA512: 1eebbdd7701ad21d9647434ff05f23827be217d47870bb05a2fdb12447abc365fc6e56306f344e05d8d2ec1ff5532562131b3876261733e4412117357c5c65f8

.gitignore

@@ -14,6 +14,7 @@ valgrind_ctime_test
 *.exe
 *.so
 *.a
+*.csv
 !.gitignore
 
 Makefile

README.md

@@ -100,6 +100,18 @@ To create a HTML report with coloured and annotated source code:
     $ mkdir -p coverage
     $ gcovr --exclude 'src/bench*' --html --html-details -o coverage/coverage.html
 
+Benchmark
+------------
+If configured with `--enable-benchmark` (which is the default), binaries for benchmarking the libsecp256k1 functions will be present in the root directory after the build.
+
+To print the benchmark result to the command line:
+
+    $ ./bench_name
+
+To create a CSV file for the benchmark result :
+
+    $ ./bench_name | sed '2d;s/ \{1,\}//g' > bench_name.csv
+
 Reporting a vulnerability
 ------------
 

src/bench.h

@@ -24,7 +24,7 @@ static int64_t gettime_i64(void) {
 /* Format fixed point number. */
 void print_number(const int64_t x) {
     int64_t x_abs, y;
-    int c, i, rounding;
+    int c, i, rounding, g; /* g = integer part size, c = fractional part size */
     size_t ptr;
     char buffer[30];
 
@@ -56,21 +56,27 @@ void print_number(const int64_t x) {
     /* Format and print the number. */
     ptr = sizeof(buffer) - 1;
     buffer[ptr] = 0;
-    if (c != 0) {
+    g = 0;
+    if (c != 0) { /* non zero fractional part */
         for (i = 0; i < c; ++i) {
             buffer[--ptr] = '0' + (y % 10);
             y /= 10;
         }
-        buffer[--ptr] = '.';
+    } else if (c == 0) { /* fractional part is 0 */
+        buffer[--ptr] = '0'; 
     }
+    buffer[--ptr] = '.';
     do {
         buffer[--ptr] = '0' + (y % 10);
         y /= 10;
+        g++;
     } while (y != 0);
     if (x < 0) {
         buffer[--ptr] = '-';
+        g++;
     }
-    printf("%s", &buffer[ptr]);
+    printf("%5.*s", g, &buffer[ptr]); /* Prints integer part */
+    printf("%-*s", FP_EXP, &buffer[ptr + g]); /* Prints fractional part */
 }
 
 void run_benchmark(char *name, void (*benchmark)(void*, int), void (*setup)(void*), void (*teardown)(void*, int), void* data, int count, int iter) {
@@ -97,13 +103,14 @@ void run_benchmark(char *name, void (*benchmark)(void*, int), void (*setup)(void
         }
         sum += total;
     }
-    printf("%s: min ", name);
+    /* ',' is used as a column delimiter */
+    printf("%-30s, ", name);
     print_number(min * FP_MULT / iter);
-    printf("us / avg ");
+    printf("   , ");
     print_number(((sum * FP_MULT) / count) / iter);
-    printf("us / max ");
+    printf("   , ");
     print_number(max * FP_MULT / iter);
-    printf("us\n");
+    printf("\n");
 }
 
 int have_flag(int argc, char** argv, char *flag) {
@@ -130,4 +137,13 @@ int get_iters(int default_iters) {
     }
 }
 
+void print_output_table_header_row(void) {
+    char* bench_str = "Benchmark";     /* left justified */
+    char* min_str = "    Min(us)    "; /* center alignment */
+    char* avg_str = "    Avg(us)    ";
+    char* max_str = "    Max(us)    ";
+    printf("%-30s,%-15s,%-15s,%-15s\n", bench_str, min_str, avg_str, max_str);
+    printf("\n");
+}
+
 #endif /* SECP256K1_BENCH_H */

src/bench_ecdh.c

@@ -52,6 +52,8 @@ int main(void) {
     /* create a context with no capabilities */
     data.ctx = secp256k1_context_create(SECP256K1_FLAGS_TYPE_CONTEXT);
 
+    print_output_table_header_row();
+
     run_benchmark("ecdh", bench_ecdh, bench_ecdh_setup, NULL, &data, 10, iters);
 
     secp256k1_context_destroy(data.ctx);

src/bench_ecmult.c

@@ -333,6 +333,7 @@ int main(int argc, char **argv) {
     secp256k1_ge_set_all_gej_var(data.pubkeys, data.pubkeys_gej, POINTS);
 
 
+    print_output_table_header_row();
     /* Initialize offset1 and offset2 */
     hash_into_offset(&data, 0);
     run_ecmult_bench(&data, iters);

src/bench_internal.c

@@ -344,6 +344,7 @@ void bench_context_sign(void* arg, int iters) {
 int main(int argc, char **argv) {
     bench_inv data;
     int iters = get_iters(20000);
+    print_output_table_header_row();
 
     if (have_flag(argc, argv, "scalar") || have_flag(argc, argv, "add")) run_benchmark("scalar_add", bench_scalar_add, bench_setup, NULL, &data, 10, iters*100);
     if (have_flag(argc, argv, "scalar") || have_flag(argc, argv, "negate")) run_benchmark("scalar_negate", bench_scalar_negate, bench_setup, NULL, &data, 10, iters*100);

src/bench_recover.c

@@ -55,6 +55,8 @@ int main(void) {
 
     data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
 
+    print_output_table_header_row();
+
     run_benchmark("ecdsa_recover", bench_recover, bench_recover_setup, NULL, &data, 10, iters);
 
     secp256k1_context_destroy(data.ctx);

src/bench_schnorrsig.c

@@ -86,6 +86,7 @@ int main(void) {
         CHECK(secp256k1_xonly_pubkey_serialize(data.ctx, pk_char, &pk) == 1);
     }
 
+    print_output_table_header_row();
     run_benchmark("schnorrsig_sign", bench_schnorrsig_sign, NULL, NULL, (void *) &data, 10, iters);
     run_benchmark("schnorrsig_verify", bench_schnorrsig_verify, NULL, NULL, (void *) &data, 10, iters);
 

src/bench_sign.c

@@ -51,6 +51,8 @@ int main(void) {
 
     data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
 
+    print_output_table_header_row();
+    
     run_benchmark("ecdsa_sign", bench_sign_run, bench_sign_setup, NULL, &data, 10, iters);
 
     secp256k1_context_destroy(data.ctx);

src/bench_verify.c

@@ -63,6 +63,7 @@ int main(void) {
     data.pubkeylen = 33;
     CHECK(secp256k1_ec_pubkey_serialize(data.ctx, data.pubkey, &data.pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED) == 1);
 
+    print_output_table_header_row();
     run_benchmark("ecdsa_verify", bench_verify, NULL, NULL, &data, 10, iters);
 
     secp256k1_context_destroy(data.ctx);