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* mingwex/math/powl.c (powl): Revert change of 2004-02-01. 

(__convert_inf_to_maxnum): New.static inline.
	(reducl): Use it to protect against Inf - Inf.
	(__fast_ldexpl): New function.  Use in lieu of ldexpl.
This commit is contained in:
Danny Smith 2004-07-28 11:25:27 +00:00
parent 57bbec1391
commit ab8cc34bb7
2 changed files with 42 additions and 14 deletions
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7
winsup/mingw/ChangeLog
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@ -1,3 +1,10 @@
2004-07-28 Danny Smith <dannysmith@users.sourceforge.net>
* mingwex/math/powl.c (powl): Revert change of 2004-02-01.
(__convert_inf_to_maxnum): New.static inline.
(reducl): Use it to protect against Inf - Inf.
(__fast_ldexpl): New function. Use in lieu of ldexpl.
2004-07-27 Danny Smith <dannysmith@users.sourceforge.net>
* mingwex/math/expl.c (expl): Move body of code to new static

49
winsup/mingw/mingwex/math/powl.c
View File

@ -411,7 +411,7 @@ long double floorl(), fabsl(), frexpl(), ldexpl();
long double polevll(), p1evll(), __powil();
static long double reducl();
int isnanl(), isfinitel(), signbitl();
#endif
#endif /* __MINGW32__ */
#ifdef INFINITIES
extern long double INFINITYL;
@ -428,6 +428,24 @@ extern long double NEGZEROL;
#endif /* __MINGW32__ */
#ifdef __MINGW32__
/* No error checking. We handle Infs and zeros ourselves. */
static __inline__ long double
__fast_ldexpl (long double x, int expn)
{
long double res;
__asm__ ("fscale"
: "=t" (res)
: "0" (x), "u" ((long double) expn));
return res;
}
#define ldexpl __fast_ldexpl
#endif
long double powl( x, y )
long double x, y;
{
@ -690,25 +708,16 @@ Fa = reducl(F);
Fb = F - Fa;
G = Fa + w * ya;
if (isinf (G))
{
/* Bail out: G - reducl(G) will result in NAN
that will propagate through rest of calculations */
_SET_ERRNO (ERANGE);
mtherr( fname, OVERFLOW );
return( MAXNUML );
}
Ga = reducl(G);
Gb = G - Ga;
H = Fb + Gb;
Ha = reducl(H);
w = ldexpl( Ga+Ha, LNXT );
w = ldexpl( Ga + Ha, LNXT );
/* Test the power of 2 for overflow */
if( w > MEXP )
{
/* printf( "w = %.4Le ", w ); */
_SET_ERRNO (ERANGE);
mtherr( fname, OVERFLOW );
return( MAXNUML );
@ -716,7 +725,6 @@ if( w > MEXP )
if( w < MNEXP )
{
/* printf( "w = %.4Le ", w ); */
_SET_ERRNO (ERANGE);
mtherr( fname, UNDERFLOW );
return( 0.0L );
@ -768,6 +776,15 @@ if( nflg )
return( z );
}
static __inline__ long double
__convert_inf_to_maxnum(long double x)
{
if (isinf(x))
return (x > 0.0L ? MAXNUML : -MAXNUML);
else
return x;
}
/* Find a multiple of 1/NXT that is within 1/NXT of x. */
static __inline__ long double reducl(x)
@ -775,9 +792,13 @@ long double x;
{
long double t;
t = ldexpl( x, LNXT );
/* If the call to ldexpl overflows, set it to MAXNUML.
This avoids Inf - Inf = Nan result when calculating the 'small'
part of a reduction. Instead, the small part becomes Inf,
causing under/overflow when adding it to the 'large' part.
There must be a cleaner way of doing this. */
t = __convert_inf_to_maxnum (ldexpl( x, LNXT ));
t = floorl( t );
t = ldexpl( t, -LNXT );
return(t);
}