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authorRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
committerRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
commitf7eac6eb504f4baf13dbb4d26717942df050ebe6 (patch)
tree95ff129c06c7f6f246a5e2bfa489ba6382659d19 /sysdeps/libm-ieee754/s_modf.c
parent1521668f2afae1dc2ef5d7ffaeb84353b36874dd (diff)
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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.
Diffstat (limited to 'sysdeps/libm-ieee754/s_modf.c')
-rw-r--r--sysdeps/libm-ieee754/s_modf.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_modf.c b/sysdeps/libm-ieee754/s_modf.c
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+/* @(#)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)