glibc/sysdeps/libm-ieee754/s_modf.c
Roland McGrath f7eac6eb50 Mon Mar 4 20:54:40 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
* Makeconfig ($(common-objpfx)config.make): Depend on config.h.in.


Mon Mar  4 17:35:09 1996  Roland McGrath  <roland@charlie-brown.gnu.ai.mit.edu>

	* hurd/catch-signal.c (hurd_safe_memmove): New function.
	(hurd_safe_copyin, hurd_safe_copyout): New functions.
	* hurd/hurd/sigpreempt.h: Declare them.

Sun Mar  3 08:43:44 1996  Roland McGrath  <roland@charlie-brown.gnu.ai.mit.edu>

	Replace math code with fdlibm from Sun as modified for netbsd by
	JT Conklin and Ian Taylor, including x86 FPU support.
	* sysdeps/libm-ieee754, sysdeps/libm-i387: New directories.
	* math/math_private.h: New file.
	* sysdeps/i386/fpu/Implies: New file.
	* sysdeps/ieee754/Implies: New file.
	* math/machine/asm.h, math/machine/endian.h: New files.
	* math/Makefile, math/math.h: Rewritten.
	* mathcalls.h, math/mathcalls.h: New file, broken out of math.h.
	* math/finite.c: File removed.
	* sysdeps/generic/Makefile [$(subdir)=math]: Frobnication removed.

	* math/test-math.c: Include errno.h and string.h.

	* sysdeps/unix/bsd/dirstream.h: File removed.
	* sysdeps/unix/bsd/readdir.c: File removed.
1996-03-05 21:41:30 +00:00

85 lines
2.0 KiB
C

/* @(#)s_modf.c 5.1 93/09/24 */
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: s_modf.c,v 1.8 1995/05/10 20:47:55 jtc Exp $";
#endif
/*
* modf(double x, double *iptr)
* return fraction part of x, and return x's integral part in *iptr.
* Method:
* Bit twiddling.
*
* Exception:
* No exception.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const double one = 1.0;
#else
static double one = 1.0;
#endif
#ifdef __STDC__
double __modf(double x, double *iptr)
#else
double __modf(x, iptr)
double x,*iptr;
#endif
{
int32_t i0,i1,j0;
u_int32_t i;
EXTRACT_WORDS(i0,i1,x);
j0 = ((i0>>20)&0x7ff)-0x3ff; /* exponent of x */
if(j0<20) { /* integer part in high x */
if(j0<0) { /* |x|<1 */
INSERT_WORDS(*iptr,i0&0x80000000,0); /* *iptr = +-0 */
return x;
} else {
i = (0x000fffff)>>j0;
if(((i0&i)|i1)==0) { /* x is integral */
u_int32_t high;
*iptr = x;
GET_HIGH_WORD(high,x);
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
return x;
} else {
INSERT_WORDS(*iptr,i0&(~i),0);
return x - *iptr;
}
}
} else if (j0>51) { /* no fraction part */
u_int32_t high;
*iptr = x*one;
GET_HIGH_WORD(high,x);
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
return x;
} else { /* fraction part in low x */
i = ((u_int32_t)(0xffffffff))>>(j0-20);
if((i1&i)==0) { /* x is integral */
u_int32_t high;
*iptr = x;
GET_HIGH_WORD(high,x);
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
return x;
} else {
INSERT_WORDS(*iptr,i0,i1&(~i));
return x - *iptr;
}
}
}
weak_alias (__modf, modf)