f7eac6eb50
* 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.
114 lines
2.8 KiB
C
114 lines
2.8 KiB
C
/* e_fmodf.c -- float version of e_fmod.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: e_fmodf.c,v 1.4 1995/05/10 20:45:10 jtc Exp $";
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#endif
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/*
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* __ieee754_fmodf(x,y)
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* Return x mod y in exact arithmetic
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* Method: shift and subtract
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const float one = 1.0, Zero[] = {0.0, -0.0,};
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#else
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static float one = 1.0, Zero[] = {0.0, -0.0,};
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#endif
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#ifdef __STDC__
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float __ieee754_fmodf(float x, float y)
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#else
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float __ieee754_fmodf(x,y)
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float x,y ;
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#endif
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{
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int32_t n,hx,hy,hz,ix,iy,sx,i;
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GET_FLOAT_WORD(hx,x);
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GET_FLOAT_WORD(hy,y);
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sx = hx&0x80000000; /* sign of x */
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hx ^=sx; /* |x| */
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hy &= 0x7fffffff; /* |y| */
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/* purge off exception values */
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if(hy==0||(hx>=0x7f800000)|| /* y=0,or x not finite */
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(hy>0x7f800000)) /* or y is NaN */
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return (x*y)/(x*y);
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if(hx<hy) return x; /* |x|<|y| return x */
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if(hx==hy)
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return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/
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/* determine ix = ilogb(x) */
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if(hx<0x00800000) { /* subnormal x */
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for (ix = -126,i=(hx<<8); i>0; i<<=1) ix -=1;
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} else ix = (hx>>23)-127;
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/* determine iy = ilogb(y) */
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if(hy<0x00800000) { /* subnormal y */
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for (iy = -126,i=(hy<<8); i>=0; i<<=1) iy -=1;
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} else iy = (hy>>23)-127;
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/* set up {hx,lx}, {hy,ly} and align y to x */
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if(ix >= -126)
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hx = 0x00800000|(0x007fffff&hx);
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else { /* subnormal x, shift x to normal */
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n = -126-ix;
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hx = hx<<n;
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}
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if(iy >= -126)
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hy = 0x00800000|(0x007fffff&hy);
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else { /* subnormal y, shift y to normal */
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n = -126-iy;
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hy = hy<<n;
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}
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/* fix point fmod */
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n = ix - iy;
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while(n--) {
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hz=hx-hy;
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if(hz<0){hx = hx+hx;}
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else {
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if(hz==0) /* return sign(x)*0 */
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return Zero[(u_int32_t)sx>>31];
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hx = hz+hz;
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}
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}
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hz=hx-hy;
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if(hz>=0) {hx=hz;}
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/* convert back to floating value and restore the sign */
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if(hx==0) /* return sign(x)*0 */
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return Zero[(u_int32_t)sx>>31];
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while(hx<0x00800000) { /* normalize x */
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hx = hx+hx;
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iy -= 1;
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}
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if(iy>= -126) { /* normalize output */
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hx = ((hx-0x00800000)|((iy+127)<<23));
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SET_FLOAT_WORD(x,hx|sx);
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} else { /* subnormal output */
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n = -126 - iy;
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hx >>= n;
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SET_FLOAT_WORD(x,hx|sx);
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x *= one; /* create necessary signal */
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}
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return x; /* exact output */
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}
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