[FFmpeg-devel] [PATCH 2/2] checkasm: float_dsp: Scale FLT/DBL_EPSILON sufficiently when comparing

[Martin Storsjö]

This fixes the float_dsp checkasm test for some seeds, when built
with clang for mingw/x86_32.
---
 tests/checkasm/float_dsp.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tests/checkasm/float_dsp.c b/tests/checkasm/float_dsp.c
index 2abe4eccbd..9f7caa1456 100644
--- a/tests/checkasm/float_dsp.c
+++ b/tests/checkasm/float_dsp.c
@@ -51,7 +51,11 @@ static void test_vector_fmul(const float *src0, const float *src1)
     call_ref(cdst, src0, src1, LEN);
     call_new(odst, src0, src1, LEN);
     for (i = 0; i < LEN; i++) {
-        if (!float_near_abs_eps(cdst[i], odst[i], FLT_EPSILON)) {
+        // EPSILON corresponds to 1 ulp at 1.0, but the output here can be
+        // much larger (the two input values have a stddev of 10), so the
+        // product can be significantly larger.
+        if (!float_near_abs_eps(cdst[i], odst[i],
+                                fabsf(cdst[i]) *  2 * FLT_EPSILON)) {
             fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                     i, cdst[i], odst[i], cdst[i] - odst[i]);
             fail();
@@ -73,7 +77,11 @@ static void test_vector_dmul(const double *src0, const double *src1)
     call_ref(cdst, src0, src1, LEN);
     call_new(odst, src0, src1, LEN);
     for (i = 0; i < LEN; i++) {
-        if (!double_near_abs_eps(cdst[i], odst[i], DBL_EPSILON)) {
+        // EPSILON corresponds to 1 ulp at 1.0, but the output here can be
+        // much larger (the two input values have a stddev of 10), so the
+        // product can be significantly larger.
+        if (!double_near_abs_eps(cdst[i], odst[i],
+                                 fabs(cdst[i]) * 2 * DBL_EPSILON)) {
             fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                     i, cdst[i], odst[i], cdst[i] - odst[i]);
             fail();
@@ -117,7 +125,8 @@ static void test_vector_fmul_scalar(const float *src0, const float *src1)
     call_ref(cdst, src0, src1[0], LEN);
     call_new(odst, src0, src1[0], LEN);
         for (i = 0; i < LEN; i++) {
-            if (!float_near_abs_eps(cdst[i], odst[i], FLT_EPSILON)) {
+            if (!float_near_abs_eps(cdst[i], odst[i],
+                                    fabsf(cdst[i]) * 2 * FLT_EPSILON)) {
                 fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                         i, cdst[i], odst[i], cdst[i] - odst[i]);
                 fail();
-- 
2.17.1