[FFmpeg-devel] [PATCH v2 3/4] checkasm: improve print format

[J. Dekker]

Port dav1d's checkasm output format to FFmpeg's checkasm, includes
relative speedups and aligns results.

Signed-off-by: J. Dekker <jdek at itanimul.li>
---
 tests/checkasm/checkasm.c | 53 +++++++++++++++++++++++++++++++++++----
 1 file changed, 48 insertions(+), 5 deletions(-)

diff --git a/tests/checkasm/checkasm.c b/tests/checkasm/checkasm.c
index c5c1eeb07a..f43c1c50f0 100644
--- a/tests/checkasm/checkasm.c
+++ b/tests/checkasm/checkasm.c
@@ -18,6 +18,31 @@
  * You should have received a copy of the GNU General Public License along
  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright © 2018, VideoLAN and dav1d authors
+ * Copyright © 2018, Two Orioles, LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
@@ -575,6 +600,16 @@ static int measure_nop_time(void)
     return nop_sum / 500;
 }
 
+static inline double avg_cycles_per_call(const CheckasmPerf *const p)
+{
+    if (p->iterations) {
+        const double cycles = (double)(10 * p->cycles) / p->iterations - state.nop_time;
+        if (cycles > 0.0)
+            return cycles / 4.0; /* 4 calls per iteration */
+    }
+    return 0.0;
+}
+
 /* Print benchmark results */
 static void print_benchs(CheckasmFunc *f)
 {
@@ -584,17 +619,25 @@ static void print_benchs(CheckasmFunc *f)
         /* Only print functions with at least one assembly version */
         if (f->versions.cpu || f->versions.next) {
             CheckasmFuncVersion *v = &f->versions;
+            const CheckasmPerf *p = &v->perf;
+            const double baseline = avg_cycles_per_call(p);
+            double decicycles;
             do {
-                CheckasmPerf *p = &v->perf;
                 if (p->iterations) {
-                    int decicycles = (10*p->cycles/p->iterations - state.nop_time) / 4;
+                    p = &v->perf;
+                    decicycles = avg_cycles_per_call(p);
                     if (state.csv || state.tsv) {
                         const char sep = state.csv ? ',' : '\t';
-                        printf("%s%c%s%c%d.%d\n", f->name, sep,
+                        printf("%s%c%s%c%.1f\n", f->name, sep,
                                cpu_suffix(v->cpu), sep,
-                               decicycles / 10, decicycles % 10);
+                               decicycles / 10.0);
                     } else {
-                        printf("%s_%s: %d.%d\n", f->name, cpu_suffix(v->cpu), decicycles/10, decicycles%10);
+                        const int pad_length = 10 + 50 -
+                            printf("%s_%s:", f->name, cpu_suffix(v->cpu));
+                        const double ratio = decicycles ?
+                            baseline / decicycles : 0.0;
+                        printf("%*.1f (%5.2fx)\n", FFMAX(pad_length, 0),
+                            decicycles / 10.0, ratio);
                     }
                 }
             } while ((v = v->next));
-- 
2.44.1