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
200 lines
4.9 KiB
C
200 lines
4.9 KiB
C
/* k_rem_pio2f.c -- float version of k_rem_pio2.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: k_rem_pio2f.c,v 1.8 2010/04/23 19:17:07 drochner Exp $");
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#endif
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#include "namespace.h"
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#include "math.h"
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#include "math_private.h"
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/* In the float version, the input parameter x contains 8 bit
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integers, not 24 bit integers. 113 bit precision is not supported. */
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static const int init_jk[] = {4,7,9}; /* initial value for jk */
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static const float PIo2[] = {
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1.5703125000e+00, /* 0x3fc90000 */
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4.5776367188e-04, /* 0x39f00000 */
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2.5987625122e-05, /* 0x37da0000 */
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7.5437128544e-08, /* 0x33a20000 */
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6.0026650317e-11, /* 0x2e840000 */
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7.3896444519e-13, /* 0x2b500000 */
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5.3845816694e-15, /* 0x27c20000 */
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5.6378512969e-18, /* 0x22d00000 */
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8.3009228831e-20, /* 0x1fc40000 */
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3.2756352257e-22, /* 0x1bc60000 */
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6.3331015649e-25, /* 0x17440000 */
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};
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static const float
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zero = 0.0,
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one = 1.0,
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two8 = 2.5600000000e+02, /* 0x43800000 */
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twon8 = 3.9062500000e-03; /* 0x3b800000 */
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int
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__kernel_rem_pio2f(float *x, float *y, int e0, int nx, int prec, const int32_t *ipio2)
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{
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int32_t jz,jx,jv,jp,jk,carry,n,iq[20],i,j,k,m,q0,ih;
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float z,fw,f[20],fq[20],q[20];
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/* initialize jk*/
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jk = init_jk[prec];
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jp = jk;
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/* determine jx,jv,q0, note that 3>q0 */
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jx = nx-1;
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jv = (e0-3)/8; if(jv<0) jv=0;
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q0 = e0-8*(jv+1);
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/* set up f[0] to f[jx+jk] where f[jx+jk] = ipio2[jv+jk] */
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j = jv-jx; m = jx+jk;
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for(i=0;i<=m;i++,j++) f[i] = (j<0)? zero : (float) ipio2[j];
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/* compute q[0],q[1],...q[jk] */
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for (i=0;i<=jk;i++) {
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for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j]; q[i] = fw;
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}
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jz = jk;
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recompute:
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/* distill q[] into iq[] reversingly */
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for(i=0,j=jz,z=q[jz];j>0;i++,j--) {
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fw = (float)((int32_t)(twon8* z));
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iq[i] = (int32_t)(z-two8*fw);
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z = q[j-1]+fw;
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}
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/* compute n */
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z = scalbnf(z,q0); /* actual value of z */
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z -= (float)8.0*floorf(z*(float)0.125); /* trim off integer >= 8 */
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n = (int32_t) z;
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z -= (float)n;
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ih = 0;
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if(q0>0) { /* need iq[jz-1] to determine n */
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i = (iq[jz-1]>>(8-q0)); n += i;
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iq[jz-1] -= i<<(8-q0);
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ih = iq[jz-1]>>(7-q0);
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}
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else if(q0==0) ih = iq[jz-1]>>8;
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else if(z>=(float)0.5) ih=2;
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if(ih>0) { /* q > 0.5 */
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n += 1; carry = 0;
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for(i=0;i<jz ;i++) { /* compute 1-q */
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j = iq[i];
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if(carry==0) {
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if(j!=0) {
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carry = 1; iq[i] = 0x100- j;
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}
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} else iq[i] = 0xff - j;
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}
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if(q0>0) { /* rare case: chance is 1 in 12 */
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switch(q0) {
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case 1:
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iq[jz-1] &= 0x7f; break;
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case 2:
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iq[jz-1] &= 0x3f; break;
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}
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}
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if(ih==2) {
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z = one - z;
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if(carry!=0) z -= scalbnf(one,q0);
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}
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}
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/* check if recomputation is needed */
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if(z==zero) {
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j = 0;
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for (i=jz-1;i>=jk;i--) j |= iq[i];
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if(j==0) { /* need recomputation */
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for(k=1;iq[jk-k]==0;k++); /* k = no. of terms needed */
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for(i=jz+1;i<=jz+k;i++) { /* add q[jz+1] to q[jz+k] */
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f[jx+i] = (float) ipio2[jv+i];
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for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j];
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q[i] = fw;
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}
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jz += k;
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goto recompute;
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}
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}
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/* chop off zero terms */
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if(z==(float)0.0) {
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jz -= 1; q0 -= 8;
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while(iq[jz]==0) { jz--; q0-=8;}
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} else { /* break z into 8-bit if necessary */
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z = scalbnf(z,-q0);
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if(z>=two8) {
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fw = (float)((int32_t)(twon8*z));
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iq[jz] = (int32_t)(z-two8*fw);
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jz += 1; q0 += 8;
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iq[jz] = (int32_t) fw;
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} else iq[jz] = (int32_t) z ;
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}
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/* convert integer "bit" chunk to floating-point value */
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fw = scalbnf(one,q0);
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for(i=jz;i>=0;i--) {
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q[i] = fw*(float)iq[i]; fw*=twon8;
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}
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/* compute PIo2[0,...,jp]*q[jz,...,0] */
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for(i=jz;i>=0;i--) {
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for(fw=0.0,k=0;k<=jp&&k<=jz-i;k++) fw += PIo2[k]*q[i+k];
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fq[jz-i] = fw;
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}
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/* compress fq[] into y[] */
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switch(prec) {
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case 0:
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fw = 0.0;
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for (i=jz;i>=0;i--) fw += fq[i];
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y[0] = (ih==0)? fw: -fw;
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break;
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case 1:
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case 2:
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fw = 0.0;
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for (i=jz;i>=0;i--) fw += fq[i];
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y[0] = (ih==0)? fw: -fw;
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fw = fq[0]-fw;
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for (i=1;i<=jz;i++) fw += fq[i];
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y[1] = (ih==0)? fw: -fw;
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break;
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case 3: /* painful */
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for (i=jz;i>0;i--) {
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fw = fq[i-1]+fq[i];
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fq[i] += fq[i-1]-fw;
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fq[i-1] = fw;
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}
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for (i=jz;i>1;i--) {
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fw = fq[i-1]+fq[i];
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fq[i] += fq[i-1]-fw;
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fq[i-1] = fw;
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}
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for (fw=0.0,i=jz;i>=2;i--) fw += fq[i];
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if(ih==0) {
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y[0] = fq[0]; y[1] = fq[1]; y[2] = fw;
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} else {
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y[0] = -fq[0]; y[1] = -fq[1]; y[2] = -fw;
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}
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}
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return n&7;
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}
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