math: fix exp10 not to raise invalid exception on NaN

This was not caught earlier because gcc incorrectly generates quiet
relational operators that never raise exceptions.
This commit is contained in:
Szabolcs Nagy
2014-09-18 17:02:24 +02:00
parent e2e1bb8148
commit 18daae3135
3 changed files with 13 additions and 4 deletions

View File

@ -2,13 +2,14 @@
#include <float.h>
#include <math.h>
#include "libc.h"
#include "libm.h"
#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double exp10l(long double x)
{
return exp10(x);
}
#else
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
long double exp10l(long double x)
{
static const long double p10[] = {
@ -18,7 +19,9 @@ long double exp10l(long double x)
1e10, 1e11, 1e12, 1e13, 1e14, 1e15
};
long double n, y = modfl(x, &n);
if (fabsl(n) < 16) {
union ldshape u = {n};
/* fabsl(n) < 16 without raising invalid on nan */
if ((u.i.se & 0x7fff) < 0x3fff+4) {
if (!y) return p10[(int)n+15];
y = exp2l(3.32192809488736234787031942948939L * y);
return y * p10[(int)n+15];