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[libpng16] Added a print out of the maximum observed error to 'tarith ascii'

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This commit is contained in:
John Bowler
2012-03-05 20:41:19 -06:00
committed by Glenn Randers-Pehrson
parent e741cd592e
commit d6cf3a3791
1 changed files with 21 additions and 16 deletions
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37
contrib/libtests/tarith.c
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@@ -77,6 +77,8 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
int showall = 0; int showall = 0;
double max_error=2; /* As a percentage error-in-last-digit/.5 */ double max_error=2; /* As a percentage error-in-last-digit/.5 */
double max_error_abs=17; /* Used when precision is DBL_DIG */ double max_error_abs=17; /* Used when precision is DBL_DIG */
double max = 0;
double max_abs = 0;
double test = 0; /* Important to test this. */ double test = 0; /* Important to test this. */
int precision = 5; int precision = 5;
int nonfinite = 0; int nonfinite = 0;
@@ -185,20 +187,8 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
/* Check the result against the original. */ /* Check the result against the original. */
double out = atof(buffer); double out = atof(buffer);
double change = fabs((out - test)/test); double change = fabs((out - test)/test);
double allow; double allow = .5/pow(10,
double percent; (precision >= DBL_DIG) ? DBL_DIG-1 : precision-1);
if (precision >= DBL_DIG)
{
allow = .5/pow(10, DBL_DIG-1);
percent = max_error_abs;
}
else
{
allow = .5/pow(10, precision-1);
percent = max_error;
}
/* NOTE: if you hit this error case are you compiling with gcc /* NOTE: if you hit this error case are you compiling with gcc
* and -O0? Try -O2 - the errors can accumulate if the FP * and -O0? Try -O2 - the errors can accumulate if the FP
@@ -210,12 +200,25 @@ int validation_ascii_to_fp(int count, int argc, char **argv)
if (change >= allow && (isfinite(out) || if (change >= allow && (isfinite(out) ||
fabs(test/DBL_MAX) <= 1-allow)) fabs(test/DBL_MAX) <= 1-allow))
{ {
if (showall || (change-allow)*100/allow >= percent) double percent = (precision >= DBL_DIG) ? max_error_abs : max_error;
double allowp = (change-allow)*100/allow;
if (precision >= DBL_DIG)
{
if (max_abs < allowp) max_abs = allowp;
}
else
{
if (max < allowp) max = allowp;
}
if (showall || allowp >= percent)
{ {
fprintf(stderr, fprintf(stderr,
"%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n", "%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n",
DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow, DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow,
(int)round((change-allow)*100/allow)); (int)round(allowp));
failed = 1; failed = 1;
} }
else else
@@ -256,6 +259,8 @@ skip:
printf("Tested %d finite values, %d non-finite, %d OK (%d failed) %d minor " printf("Tested %d finite values, %d non-finite, %d OK (%d failed) %d minor "
"arithmetic errors\n", finite, nonfinite, ok, failcount, minorarith); "arithmetic errors\n", finite, nonfinite, ok, failcount, minorarith);
printf(" Error with >=%d digit precision %.2f%%\n", DBL_DIG, max_abs);
printf(" Error with < %d digit precision %.2f%%\n", DBL_DIG, max);
return 0; return 0;
} }