checkasm: Improve benchmarking of functions that modify their input

Alternate between buffers when benchmarking in order to more
accurately measure throughout instead of latency.

7 files changed, 35 insertions, 25 deletions

diff --git a/tests/checkasm/cdef.c b/tests/checkasm/cdef.c
index 833fa4b..6f9f0cd 100644
--- a/tests/checkasm/cdef.c
+++ b/tests/checkasm/cdef.c
@@ -104,7 +104,7 @@ static void check_cdef_filter(const cdef_fn fn, const int w, const int h) {
                      */
                     pri_strength = (edges & 1) << bitdepth_min_8;
                     sec_strength = (edges & 2) << bitdepth_min_8;
-                    bench_new(a_dst, stride, left, top, bot, pri_strength,
+                    bench_new(alternate(c_dst, a_dst), stride, left, top, bot, pri_strength,
                               sec_strength, dir, damping, edges HIGHBD_TAIL_SUFFIX);
                 }
             }
diff --git a/tests/checkasm/checkasm.h b/tests/checkasm/checkasm.h
index a804c0e..fb5f8ed 100644
--- a/tests/checkasm/checkasm.h
+++ b/tests/checkasm/checkasm.h
@@ -284,15 +284,19 @@ void checkasm_stack_clobber(uint64_t clobber, ...);
 #define bench_new(...)\
     do {\
         if (checkasm_bench_func()) {\
-            func_type *tfunc = func_new;\
+            func_type *const tfunc = func_new;\
             checkasm_set_signal_handler_state(1);\
             uint64_t tsum = 0;\
             int tcount = 0;\
             for (int ti = 0; ti < BENCH_RUNS; ti++) {\
                 uint64_t t = readtime();\
+                int talt = 0; (void)talt;\
                 tfunc(__VA_ARGS__);\
+                talt = 1;\
                 tfunc(__VA_ARGS__);\
+                talt = 0;\
                 tfunc(__VA_ARGS__);\
+                talt = 1;\
                 tfunc(__VA_ARGS__);\
                 t = readtime() - t;\
                 if (t*tcount <= tsum*4 && ti > 0) {\
@@ -303,6 +307,7 @@ void checkasm_stack_clobber(uint64_t clobber, ...);
             checkasm_set_signal_handler_state(0);\
             checkasm_update_bench(tcount, tsum);\
         } else {\
+            const int talt = 0; (void)talt;\
             call_new(__VA_ARGS__);\
         }\
     } while (0)
@@ -310,6 +315,10 @@ void checkasm_stack_clobber(uint64_t clobber, ...);
 #define bench_new(...) do {} while (0)
 #endif
 
+/* Alternates between two pointers. Intended to be used within bench_new()
+ * calls for functions which modifies their input buffer(s) to ensure that
+ * throughput, and not latency, is measured. */
+#define alternate(a, b) (talt ? (b) : (a))
 
 #define ROUND_UP(x,a) (((x)+((a)-1)) & ~((a)-1))
 #define PIXEL_RECT(name, w, h) \
diff --git a/tests/checkasm/itx.c b/tests/checkasm/itx.c
index 6b6cda0..c7cc411 100644
--- a/tests/checkasm/itx.c
+++ b/tests/checkasm/itx.c
@@ -294,8 +294,8 @@ static void check_itxfm_add(Dav1dInvTxfmDSPContext *const c,
                     if (memcmp(coeff[0], coeff[1], sizeof(*coeff)))
                         fail();
 
-                    bench_new(a_dst, a_dst_stride, coeff[0], eob
-                              HIGHBD_TAIL_SUFFIX);
+                    bench_new(alternate(c_dst, a_dst), a_dst_stride,
+                              alternate(coeff[0], coeff[1]), eob HIGHBD_TAIL_SUFFIX);
                 }
     }
     report("add_%dx%d", w, h);
diff --git a/tests/checkasm/loopfilter.c b/tests/checkasm/loopfilter.c
index 438f080..f4901fb 100644
--- a/tests/checkasm/loopfilter.c
+++ b/tests/checkasm/loopfilter.c
@@ -174,18 +174,18 @@ static void check_lpf_sb(loopfilter_sb_fn fn, const char *const name,
             }
             memcpy(a_dst_mem, c_dst_mem, 128 * sizeof(pixel) * 16);
 
-            call_ref(c_dst, stride,
-                     vmask, (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx], b4_stride,
-                     &lut, n_blks HIGHBD_TAIL_SUFFIX);
-            call_new(a_dst, stride,
-                     vmask, (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx], b4_stride,
-                     &lut, n_blks HIGHBD_TAIL_SUFFIX);
+            call_ref(c_dst, stride, vmask,
+                     (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx],
+                     b4_stride, &lut, n_blks HIGHBD_TAIL_SUFFIX);
+            call_new(a_dst, stride, vmask,
+                     (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx],
+                     b4_stride, &lut, n_blks HIGHBD_TAIL_SUFFIX);
 
             checkasm_check_pixel(c_dst_mem, stride, a_dst_mem, stride,
                                  w, h, "dst");
-            bench_new(a_dst, stride,
-                      vmask, (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx], b4_stride,
-                      &lut, n_blks HIGHBD_TAIL_SUFFIX);
+            bench_new(alternate(c_dst, a_dst), stride, vmask,
+                      (const uint8_t(*)[4]) &l[dir ? 32 : 1][lf_idx],
+                      b4_stride, &lut, n_blks HIGHBD_TAIL_SUFFIX);
         }
     }
     report(name);
diff --git a/tests/checkasm/looprestoration.c b/tests/checkasm/looprestoration.c
index c542901..d84f3c4 100644
--- a/tests/checkasm/looprestoration.c
+++ b/tests/checkasm/looprestoration.c
@@ -109,8 +109,8 @@ static void check_wiener(Dav1dLoopRestorationDSPContext *const c, const int bpc)
                     break;
                 }
             }
-            bench_new(a_dst, 448 * sizeof(pixel), left, h_edge,
-                      256, 64, &params, 0xf HIGHBD_TAIL_SUFFIX);
+            bench_new(alternate(c_dst, a_dst), 448 * sizeof(pixel), left,
+                      h_edge, 256, 64, &params, 0xf HIGHBD_TAIL_SUFFIX);
         }
     }
 }
@@ -169,8 +169,8 @@ static void check_sgr(Dav1dLoopRestorationDSPContext *const c, const int bpc) {
                     break;
                 }
             }
-            bench_new(a_dst, 448 * sizeof(pixel), left, h_edge,
-                      256, 64, &params, 0xf HIGHBD_TAIL_SUFFIX);
+            bench_new(alternate(c_dst, a_dst), 448 * sizeof(pixel), left,
+                      h_edge, 256, 64, &params, 0xf HIGHBD_TAIL_SUFFIX);
         }
     }
 }
diff --git a/tests/checkasm/mc.c b/tests/checkasm/mc.c
index c8f2dc5..6b3b146 100644
--- a/tests/checkasm/mc.c
+++ b/tests/checkasm/mc.c
@@ -477,7 +477,7 @@ static void check_blend(Dav1dMCDSPContext *const c) {
                 checkasm_check_pixel_padded(c_dst, c_dst_stride, a_dst, a_dst_stride,
                                             w, h, "dst");
 
-                bench_new(a_dst, a_dst_stride, tmp, w, h, mask);
+                bench_new(alternate(c_dst, a_dst), a_dst_stride, tmp, w, h, mask);
             }
     }
     report("blend");
@@ -516,7 +516,7 @@ static void check_blend_v(Dav1dMCDSPContext *const c) {
                 checkasm_check_pixel_padded(c_dst, c_dst_stride, a_dst, a_dst_stride,
                                             w, h, "dst");
 
-                bench_new(a_dst, a_dst_stride, tmp, w, h);
+                bench_new(alternate(c_dst, a_dst), a_dst_stride, tmp, w, h);
             }
     }
     report("blend_v");
@@ -554,7 +554,7 @@ static void check_blend_h(Dav1dMCDSPContext *const c) {
                 checkasm_check_pixel_padded(c_dst, c_dst_stride, a_dst, a_dst_stride,
                                             w, h, "dst");
 
-                bench_new(a_dst, a_dst_stride, tmp, w, h);
+                bench_new(alternate(c_dst, a_dst), a_dst_stride, tmp, w, h);
             }
     }
     report("blend_h");
diff --git a/tests/checkasm/msac.c b/tests/checkasm/msac.c
index 4e73789..b9c89b4 100644
--- a/tests/checkasm/msac.c
+++ b/tests/checkasm/msac.c
@@ -125,7 +125,8 @@ static void msac_dump(unsigned c_res, unsigned a_res,
                     }                                                      \
                 }                                                          \
                 if (cdf_update && ns == n - 1)                             \
-                    bench_new(&s_a, cdf[1], ns);                           \
+                    bench_new(alternate(&s_c, &s_a),                       \
+                              alternate(cdf[0], cdf[1]), ns);              \
             }                                                              \
         }                                                                  \
     }                                                                      \
@@ -164,7 +165,7 @@ static void check_decode_bool_adapt(MsacDSPContext *const c, uint8_t *const buf)
                 }
             }
             if (cdf_update)
-                bench_new(&s_a, cdf[1]);
+                bench_new(alternate(&s_c, &s_a), alternate(cdf[0], cdf[1]));
         }
     }
 }
@@ -184,7 +185,7 @@ static void check_decode_bool_equi(MsacDSPContext *const c, uint8_t *const buf)
                     msac_dump(c_res, a_res, &s_c, &s_a, NULL, NULL, 0);
             }
         }
-        bench_new(&s_a);
+        bench_new(alternate(&s_c, &s_a));
     }
 }
 
@@ -204,7 +205,7 @@ static void check_decode_bool(MsacDSPContext *const c, uint8_t *const buf) {
                     msac_dump(c_res, a_res, &s_c, &s_a, NULL, NULL, 0);
             }
         }
-        bench_new(&s_a, 16384);
+        bench_new(alternate(&s_c, &s_a), 16384);
     }
 
 }
@@ -239,7 +240,7 @@ static void check_decode_hi_tok(MsacDSPContext *const c, uint8_t *const buf) {
                 }
             }
             if (cdf_update)
-                bench_new(&s_a, cdf[1]);
+                bench_new(alternate(&s_c, &s_a), alternate(cdf[0], cdf[1]));
         }
     }
     report("decode_hi_tok");