Add test code to check reliablity of fixexp(), for sufficently large absolute values (>0.00013) our error is below 0.2%)HEADmaster

1 files changed, 10 insertions, 4 deletions

diff --git a/fixpow.c b/fixpow.c
index 3db6df3..a023f7a 100644
--- a/fixpow.c
+++ b/fixpow.c
@@ -256,10 +256,16 @@ int main()
 
   // Testing fixexp
   for (input=-2147483648; input < TO_Q26(10.39720770839918); ++input ) {
-    int32_t expected = TO_Q16(exp(FROM_Q26(input)));
-    int32_t output   = fixexp(input);
-    if( abs(output-expected) > 16 )
-        printf( "%08X : %08X = %08X (%08d)\n", output, expected, abs(output-expected), input );
+    double  expected     = exp(FROM_Q26(input));
+    int32_t expected_int = TO_Q16(expected);
+    int32_t output_int   = fixexp(input);
+    double  output       = FROM_Q16(output_int);
+    if( abs(output_int-expected_int) > 8 ) {
+        if( expected > output && output > 0 && expected / output > 1.002 )
+            printf( "%08X : %08X = %08X (%08d)\n", output_int, expected_int, abs(output_int-expected_int), input );
+        if( expected < output && expected > 0 && output / expected > 1.002 )
+            printf( "%08X : %08X = %08X (%08d)\n", output_int, expected_int, abs(output_int-expected_int), input );
+    }
   }
 
   printf( "pow(%lf,%lf)=%lf (%s)\n", base, exponent, FROM_Q16(result), error?"ERROR":"OK" );