4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync/* $NetBSD: strtod.c,v 1.4.14.1 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/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync/* flag unnecessarily. It leads to a song and dance at the end of strtod. */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsyncstatic CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync//#ifndef __HAVE_LONG_DOUBLE
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync//__strong_alias(_strtold, strtod)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync//__weak_alias(strtold, _strtold)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#if defined(_MSC_VER) /* Handle Microsoft VC++ compiler specifics. */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync// Disable: warning C4700: uninitialized local variable 'xx' used
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /* defined(_MSC_VER) */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, dsign,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Bigint *bd = NULL, *bs = NULL, *delta = NULL; /* pacify gcc */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(s = s00;;s++) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch(*s) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (*s == '0') {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI };
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch(s[1]) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#if defined(FE_DOWNWARD) && defined(FE_TONEAREST) && defined(FE_TOWARDZERO) && defined(FE_UPWARD)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync switch((i = gethex(&s, &fpi, &expt, &bb, sign)) & STRTOG_Retmask) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* FALLTHROUGH */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync while(*++s == '0') ;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(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#endif // No_Hex_NaN
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 if (k > 9) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (e > 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* round correctly FLT_ROUNDS = 2 or 3 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (e <= Ten_pmax + i) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* A fancier test would sometimes let us do
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * this for larger i values.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* round correctly FLT_ROUNDS = 2 or 3 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* VAX exponent range is so narrow we must
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * worry about overflow here...
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (e >= -Ten_pmax) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* round correctly FLT_ROUNDS = 2 or 3 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*IEEE_Arith*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Get starting approximation = rv * 10**e1 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Can't trust HUGE_VAL */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync case 0: /* toward 0 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*Honor_FLT_ROUNDS*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Honor_FLT_ROUNDS*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* set overflow bit */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*IEEE_Arith*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*IEEE_Arith*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(j = 0; e1 > 1; j++, e1 = (unsigned int)e1 >> 1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* The last multiplication could overflow. */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* set to largest number */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* (Can't trust DBL_MAX) */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (e1 < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (scale && (j = 2*P + 1 - ((word0(rv) & Exp_mask)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* scaled rv is denormal; zap j low bits */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (j >= 32) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (j >= 53)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* The last multiplication could underflow. */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* The refinement below will clean
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * this approximation up.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Now the hard part -- adjusting rv to the correct value.*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Put digits into bd: true value = bd * 10^e */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync bb = d2b(dval(rv), &bbe, &bbbits); /* rv = bb * 2^bbe */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (e >= 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i > 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Error is less than an ulp */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* exact */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (!dsign) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* adj = rounding ? ceil(adj) : floor(adj); */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (y != adj) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Honor_FLT_ROUNDS*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i < 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Error is less than half an ulp -- check for
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * special case of mantissa a power of two.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* exact result */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (i == 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* exactly half-way between */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync ? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync 0xffffffff)) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /*boundary case -- increment exponent*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* boundary case -- decrement exponent */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*IBM*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*Sudden_Underflow}{*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* round even ==> */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* accept rv */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* rv = smallest denormal */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Sudden_Underflow}*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* special case -- power of FLT_RADIX to be */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* rounded down... */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync case 0: /* towards 0 */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Check_FLT_ROUNDS*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Check for overflow */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync aadj = (double)z;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#else /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Compute adj so that the IEEE rounding rules will
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * correctly round rv + adj in some half-way cases.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * If rv * ulp(rv) is denormalized (i.e.,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * trouble from bits lost to denormalization;
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync * example: 1.2e-307 .
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Sudden_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /*Avoid_Underflow*/
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (y == z) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* Can we stop now? */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* The tolerances below are conservative. */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* try to avoid the bug of testing an 8087 register value */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync#endif /* Avoid_Underflow */
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync /* set underflow bit */