checkasm: float_dsp: Scale FLT/DBL_EPSILON sufficiently when comparing

As the values generated by av_bmg_get can be arbitrarily large
(only the stddev is specified), we can't use a fixed tolerance.

This matches what was done for test_vector_dmul_scalar in
38f966b2.

This fixes the float_dsp checkasm test for some seeds, when built
with clang for mingw/x86_32.
Signed-off-by: Martin Storsjö <martin@martin.st>

tests/checkasm/float_dsp.c

@@ -51,7 +51,8 @@ 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)) {
+        double t = fabs(src0[i]) + fabs(src1[i]) + fabs(src0[i] * src1[i]) + 1.0;
+        if (!float_near_abs_eps(cdst[i], odst[i], t * 2 * FLT_EPSILON)) {
             fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                     i, cdst[i], odst[i], cdst[i] - odst[i]);
             fail();
@@ -73,7 +74,8 @@ 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)) {
+        double t = fabs(src0[i]) + fabs(src1[i]) + fabs(src0[i] * src1[i]) + 1.0;
+        if (!double_near_abs_eps(cdst[i], odst[i], t * 2 * DBL_EPSILON)) {
             fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                     i, cdst[i], odst[i], cdst[i] - odst[i]);
             fail();
@@ -117,7 +119,8 @@ 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)) {
+            double t = fabs(src0[i]) + fabs(src1[0]) + fabs(src0[i] * src1[0]) + 1.0;
+            if (!float_near_abs_eps(cdst[i], odst[i], t * 2 * FLT_EPSILON)) {
                 fprintf(stderr, "%d: %- .12f - %- .12f = % .12g\n",
                         i, cdst[i], odst[i], cdst[i] - odst[i]);
                 fail();