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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/e_fmodf.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/e_fmodf.c')
-rw-r--r--sysdeps/libm-ieee754/e_fmodf.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/e_fmodf.c b/sysdeps/libm-ieee754/e_fmodf.c
new file mode 100644
index 0000000000..47b312392c
--- /dev/null
+++ b/sysdeps/libm-ieee754/e_fmodf.c
@@ -0,0 +1,113 @@
+/* e_fmodf.c -- float version of e_fmod.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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: e_fmodf.c,v 1.4 1995/05/10 20:45:10 jtc Exp $";
+#endif
+
+/* 
+ * __ieee754_fmodf(x,y)
+ * Return x mod y in exact arithmetic
+ * Method: shift and subtract
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const float one = 1.0, Zero[] = {0.0, -0.0,};
+#else
+static float one = 1.0, Zero[] = {0.0, -0.0,};
+#endif
+
+#ifdef __STDC__
+	float __ieee754_fmodf(float x, float y)
+#else
+	float __ieee754_fmodf(x,y)
+	float x,y ;
+#endif
+{
+	int32_t n,hx,hy,hz,ix,iy,sx,i;
+
+	GET_FLOAT_WORD(hx,x);
+	GET_FLOAT_WORD(hy,y);
+	sx = hx&0x80000000;		/* sign of x */
+	hx ^=sx;		/* |x| */
+	hy &= 0x7fffffff;	/* |y| */
+
+    /* purge off exception values */
+	if(hy==0||(hx>=0x7f800000)||		/* y=0,or x not finite */
+	   (hy>0x7f800000))			/* or y is NaN */
+	    return (x*y)/(x*y);
+	if(hx<hy) return x;			/* |x|<|y| return x */
+	if(hx==hy)
+	    return Zero[(u_int32_t)sx>>31];	/* |x|=|y| return x*0*/
+
+    /* determine ix = ilogb(x) */
+	if(hx<0x00800000) {	/* subnormal x */
+	    for (ix = -126,i=(hx<<8); i>0; i<<=1) ix -=1;
+	} else ix = (hx>>23)-127;
+
+    /* determine iy = ilogb(y) */
+	if(hy<0x00800000) {	/* subnormal y */
+	    for (iy = -126,i=(hy<<8); i>=0; i<<=1) iy -=1;
+	} else iy = (hy>>23)-127;
+
+    /* set up {hx,lx}, {hy,ly} and align y to x */
+	if(ix >= -126) 
+	    hx = 0x00800000|(0x007fffff&hx);
+	else {		/* subnormal x, shift x to normal */
+	    n = -126-ix;
+	    hx = hx<<n;
+	}
+	if(iy >= -126) 
+	    hy = 0x00800000|(0x007fffff&hy);
+	else {		/* subnormal y, shift y to normal */
+	    n = -126-iy;
+	    hy = hy<<n;
+	}
+
+    /* fix point fmod */
+	n = ix - iy;
+	while(n--) {
+	    hz=hx-hy;
+	    if(hz<0){hx = hx+hx;}
+	    else {
+	    	if(hz==0) 		/* return sign(x)*0 */
+		    return Zero[(u_int32_t)sx>>31];
+	    	hx = hz+hz;
+	    }
+	}
+	hz=hx-hy;
+	if(hz>=0) {hx=hz;}
+
+    /* convert back to floating value and restore the sign */
+	if(hx==0) 			/* return sign(x)*0 */
+	    return Zero[(u_int32_t)sx>>31];	
+	while(hx<0x00800000) {		/* normalize x */
+	    hx = hx+hx;
+	    iy -= 1;
+	}
+	if(iy>= -126) {		/* normalize output */
+	    hx = ((hx-0x00800000)|((iy+127)<<23));
+	    SET_FLOAT_WORD(x,hx|sx);
+	} else {		/* subnormal output */
+	    n = -126 - iy;
+	    hx >>= n;
+	    SET_FLOAT_WORD(x,hx|sx);
+	    x *= one;		/* create necessary signal */
+	}
+	return x;		/* exact output */
+}