4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync/* $NetBSD: strtodg.c,v 1.5.14.1 2008/04/08 21:10:55 jdc Exp $ */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync/****************************************************************
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncThe author of this software is David M. Gay.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncCopyright (C) 1998-2001 by Lucent Technologies
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncAll Rights Reserved
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncPermission to use, copy, modify, and distribute this software and
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncits documentation for any purpose and without fee is hereby
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncgranted, provided that the above copyright notice appear in all
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsynccopies and that both that the copyright notice and this
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncpermission notice and warranty disclaimer appear in supporting
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncdocumentation, and that the name of Lucent or any of its entities
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncnot be used in advertising or publicity pertaining to
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncdistribution of the software without specific, written prior
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncLUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncINCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncIN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncSPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncWHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncIN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncTHIS SOFTWARE.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync****************************************************************/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync/* Please send bug reports to David M. Gay (dmg at acm dot org,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * with " at " changed at "@" and " dot " changed to "."). */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Disable warnings about assignment within conditional expressions.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync } while(x < xe);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync *x++ = y & 0xffff;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync } while(x < xe);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync *x++ = 0xffffffffUL;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync while(x < xe);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync *x++ = y & 0xffff;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync k = (unsigned int)(n + ((1 << kshift) - 1)) >> kshift;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (b->k < k) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync k = (unsigned int)n >> kshift;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync double d; CONST FPI *fpi; Long *expt; ULong *bits; int exact, rd, *irv;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync (double d, CONST FPI *fpi, Long *expt, ULong *bits, int exact, int rd, int *irv)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (bdif <= 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (P == nb) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync default: /* round near */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (b->x[0] & 2)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (b->x[(unsigned int)k>>kshift] & ((ULong)1 << (k & kmask)))
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* "break" cases: round up 1 bit, then truncate; bdif > 0 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (bdif < 0)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync *irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if ( (L = word1(d)) !=0)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync return P - lo0bits(&L);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /* !VAX */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync CONST char *s00; char **se; CONST FPI *fpi; Long *expt; ULong *bits;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync (CONST char *s00, char **se, CONST FPI *fpi, Long *expt, ULong *bits)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync int bb0, bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, denorm;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync int dsign, e, e1, e2, emin, esign, finished, i, inex, irv;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync int j, k, nbits, nd, nd0, nf, nz, nz0, rd, rvbits, rve, rve1, sign;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Bigint *ab, *bb, *bb1, *bd, *bd0, *bs, *delta, *rvb, *rvb0;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(s = s00;;s++) switch(*s) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (*s == '0') {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch(s[1]) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync while(*++s == '0') ;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(decpt = nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (c == '.')
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(; c == '0'; c = *++s)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (c -= '0') {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync y = 10*y + c;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync z = 10*z + c;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch(c = *++s) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync while(c == '0')
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync L = c - '0';
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Avoid confusion from exponents
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * so large that e might overflow.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync e = (int)L;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Check for Nan and Infinity */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch(c) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /* INFNAN_CHECK */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Now we have nd0 digits, starting at s0, followed by a
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * decimal point, followed by nd-nd0 digits. The number we're
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * after is the integer represented by those digits times
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (e > 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (e <= Ten_pmax + i) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* A fancier test would sometimes let us do
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * this for larger i values.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* VAX exponent range is so narrow we must
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * worry about overflow here...
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (e >= -Ten_pmax) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Get starting approximation = rv * 10**e1 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (e1 < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* e2 is a correction to the (base 2) exponent of the return
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * value, reflecting adjustments above to avoid overflow in the
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * native arithmetic. For native IBM (base 16) arithmetic, we
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * must multiply e2 by 4 to change from base 16 to 2.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync rvb = d2b(dval(rv), &rve, &rvbits); /* rv = rvb * 2^rve */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (j > 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (j < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Now the hard part -- adjusting rv to the correct value.*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Put digits into bd: true value = bd * 10^e */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (e >= 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i > 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (bb2 < 0)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (rd && i <= 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync i++, j -= ULbits) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Error is less than half an ulp -- check for
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * special case of mantissa a power of two.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i == 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* exactly half-way between */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /*boundary case -- increment exponent*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* boundary case -- decrement exponent */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if ((bbbits < nbits && !denorm) || !(rvb->x[0] & 1))
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* adj *= ulp(dval(rv)); */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* if (asub) rv -= adj; else rv += adj; */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (abe > 0)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* rv -= adj; */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* do nothing */;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* unlikely; can only have lost 1 high bit */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (y == z && L) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Can we stop now? */