in certain cases excessive trailing zeros could cause incorrect
rounding from long double to double or float in decfloat.
e.g. in strtof("
9444733528689243848704.000000", 0) the argument
is 0x1.000001p+73, exactly halfway between two representible floats,
this incorrectly got rounded to 0x1.000002p+73 instead of 0x1p+73,
but with less trailing 0 the rounding was fine.
the fix makes sure that the z index always points one past the last
non-zero digit in the base 10^9 representation, this way trailing
zeros don't affect the rounding logic.
return sign * (long double)x[0] * p10s[rp-10];
}
+ /* Drop trailing zeros */
+ for (; !x[z-1]; z--);
+
/* Align radix point to B1B digit boundary */
if (rp % 9) {
int rpm9 = rp>=0 ? rp%9 : rp%9+9;