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Fabian Schriever c56f53a2a0 Fix truncf for sNaN input
Make line 47 in sf_trunc.c reachable. While converting the double
precision function trunc to the single precision version truncf an error
was introduced into the special case. This special case is meant to
catch both NaNs and infinities, however qNaNs and infinities work just
fine with the simple return of x (line 51). The only error occurs for
sNaNs where the same sNaN is returned and no invalid exception is
raised.
2020-03-11 12:10:58 +01:00

67 lines
1.3 KiB
C

/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "fdlibm.h"
#ifdef __STDC__
float truncf(float x)
#else
float truncf(x)
float x;
#endif
{
__int32_t signbit, w, exponent_less_127;
GET_FLOAT_WORD(w,x);
/* Extract sign bit. */
signbit = w & 0x80000000;
/* Extract exponent field. */
exponent_less_127 = ((w & 0x7f800000) >> 23) - 127;
if (exponent_less_127 < 23)
{
if (exponent_less_127 < 0)
{
/* -1 < x < 1, so result is +0 or -0. */
SET_FLOAT_WORD(x, signbit);
}
else
{
SET_FLOAT_WORD(x, signbit | (w & ~(0x007fffff >> exponent_less_127)));
}
}
else
{
if (exponent_less_127 == 128)
/* x is NaN or infinite. */
return x + x;
/* All bits in the fraction field are relevant. */
}
return x;
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double trunc(double x)
#else
double trunc(x)
double x;
#endif
{
return (double) truncf((float) x);
}
#endif /* defined(_DOUBLE_IS_32BITS) */