2fe8fb192f
There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
91 lines
2 KiB
C
91 lines
2 KiB
C
/* e_sqrtf.c -- float version of e_sqrt.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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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: e_sqrtf.c,v 1.7 2002/05/26 22:01:53 wiz Exp $");
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#endif
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#include "math.h"
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#include "math_private.h"
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static const float one = 1.0, tiny=1.0e-30;
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float
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__ieee754_sqrtf(float x)
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{
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float z;
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int32_t sign = (int)0x80000000;
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int32_t ix,s,q,m,t,i;
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u_int32_t r;
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GET_FLOAT_WORD(ix,x);
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/* take care of Inf and NaN */
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if((ix&0x7f800000)==0x7f800000) {
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return x*x+x; /* sqrt(NaN)=NaN, sqrt(+inf)=+inf
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sqrt(-inf)=sNaN */
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}
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/* take care of zero */
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if(ix<=0) {
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if((ix&(~sign))==0) return x;/* sqrt(+-0) = +-0 */
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else if(ix<0)
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return (x-x)/(x-x); /* sqrt(-ve) = sNaN */
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}
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/* normalize x */
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m = (ix>>23);
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if(m==0) { /* subnormal x */
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for(i=0;(ix&0x00800000)==0;i++) ix<<=1;
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m -= i-1;
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}
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m -= 127; /* unbias exponent */
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ix = (ix&0x007fffff)|0x00800000;
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if(m&1) /* odd m, double x to make it even */
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ix += ix;
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m >>= 1; /* m = [m/2] */
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/* generate sqrt(x) bit by bit */
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ix += ix;
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q = s = 0; /* q = sqrt(x) */
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r = 0x01000000; /* r = moving bit from right to left */
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while(r!=0) {
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t = s+r;
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if(t<=ix) {
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s = t+r;
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ix -= t;
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q += r;
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}
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ix += ix;
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r>>=1;
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}
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/* use floating add to find out rounding direction */
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if(ix!=0) {
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z = one-tiny; /* trigger inexact flag */
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if (z>=one) {
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z = one+tiny;
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if (z>one)
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q += 2;
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else
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q += (q&1);
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}
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}
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ix = (q>>1)+0x3f000000;
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ix += (m <<23);
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SET_FLOAT_WORD(z,ix);
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return z;
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}
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