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Diffstat (limited to 'newlib/libc/stdlib/strtod.c')
| -rw-r--r-- | newlib/libc/stdlib/strtod.c | 754 |
1 files changed, 0 insertions, 754 deletions
diff --git a/newlib/libc/stdlib/strtod.c b/newlib/libc/stdlib/strtod.c deleted file mode 100644 index 9b70dfc3c..000000000 --- a/newlib/libc/stdlib/strtod.c +++ /dev/null @@ -1,754 +0,0 @@ -/* -FUNCTION - <<strtod>>, <<strtof>>---string to double or float - -INDEX - strtod -INDEX - _strtod_r -INDEX - strtof - -ANSI_SYNOPSIS - #include <stdlib.h> - double strtod(const char *<[str]>, char **<[tail]>); - float strtof(const char *<[str]>, char **<[tail]>); - - double _strtod_r(void *<[reent]>, - const char *<[str]>, char **<[tail]>); - -TRAD_SYNOPSIS - #include <stdlib.h> - double strtod(<[str]>,<[tail]>) - char *<[str]>; - char **<[tail]>; - - float strtof(<[str]>,<[tail]>) - char *<[str]>; - char **<[tail]>; - - double _strtod_r(<[reent]>,<[str]>,<[tail]>) - char *<[reent]>; - char *<[str]>; - char **<[tail]>; - -DESCRIPTION - The function <<strtod>> parses the character string <[str]>, - producing a substring which can be converted to a double - value. The substring converted is the longest initial - subsequence of <[str]>, beginning with the first - non-whitespace character, that has the format: - .[+|-]<[digits]>[.][<[digits]>][(e|E)[+|-]<[digits]>] - The substring contains no characters if <[str]> is empty, consists - entirely of whitespace, or if the first non-whitespace - character is something other than <<+>>, <<->>, <<.>>, or a - digit. If the substring is empty, no conversion is done, and - the value of <[str]> is stored in <<*<[tail]>>>. Otherwise, - the substring is converted, and a pointer to the final string - (which will contain at least the terminating null character of - <[str]>) is stored in <<*<[tail]>>>. If you want no - assignment to <<*<[tail]>>>, pass a null pointer as <[tail]>. - <<strtof>> is identical to <<strtod>> except for its return type. - - This implementation returns the nearest machine number to the - input decimal string. Ties are broken by using the IEEE - round-even rule. - - The alternate function <<_strtod_r>> is a reentrant version. - The extra argument <[reent]> is a pointer to a reentrancy structure. - -RETURNS - <<strtod>> returns the converted substring value, if any. If - no conversion could be performed, 0 is returned. If the - correct value is out of the range of representable values, - plus or minus <<HUGE_VAL>> is returned, and <<ERANGE>> is - stored in errno. If the correct value would cause underflow, 0 - is returned and <<ERANGE>> is stored in errno. - -Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, -<<lseek>>, <<read>>, <<sbrk>>, <<write>>. -*/ - -/**************************************************************** - * - * The author of this software is David M. Gay. - * - * Copyright (c) 1991 by AT&T. - * - * Permission to use, copy, modify, and distribute this software for any - * purpose without fee is hereby granted, provided that this entire notice - * is included in all copies of any software which is or includes a copy - * or modification of this software and in all copies of the supporting - * documentation for such software. - * - * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED - * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY - * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY - * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. - * - ***************************************************************/ - -/* Please send bug reports to - David M. Gay - AT&T Bell Laboratories, Room 2C-463 - 600 Mountain Avenue - Murray Hill, NJ 07974-2070 - U.S.A. - dmg@research.att.com or research!dmg - */ - -#include <_ansi.h> -#include <reent.h> -#include <string.h> -#include "mprec.h" - -double -_DEFUN (_strtod_r, (ptr, s00, se), - struct _reent *ptr _AND - _CONST char *s00 _AND - char **se) -{ - int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign, e1, esign, i, j, - k, nd, nd0, nf, nz, nz0, sign; - long e; - _CONST char *s, *s0, *s1, *s2; - double aadj, aadj1, adj; - long L; - unsigned long z; - __ULong y; - union double_union rv, rv0; - int nanflag; - - _Bigint *bb, *bb1, *bd, *bd0, *bs, *delta; - sign = nz0 = nz = nanflag = 0; - rv.d = 0.; - for (s = s00;; s++) - switch (*s) - { - case '-': - sign = 1; - /* no break */ - case '+': - if (*++s) - goto break2; - /* no break */ - case 0: - s = s00; - goto ret; - case '\t': - case '\n': - case '\v': - case '\f': - case '\r': - case ' ': - continue; - default: - goto break2; - } -break2: - if (*s == 'n' || *s == 'N') - { - ++s; - if (*s == 'a' || *s == 'A') - { - ++s; - if (*s == 'n' || *s == 'N') - { - nanflag = 1; - ++s; - goto ret; - } - } - s = s00; - goto ret; - } - else if (*s == '0') - { - nz0 = 1; - while (*++s == '0'); - if (!*s) - goto ret; - } - s0 = s; - y = z = 0; - for (nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++) - if (nd < 9) - y = 10 * y + c - '0'; - else if (nd < 16) - z = 10 * z + c - '0'; - nd0 = nd; - if (c == '.') - { - c = *++s; - if (!nd) - { - for (; c == '0'; c = *++s) - nz++; - if (c > '0' && c <= '9') - { - s0 = s; - nf += nz; - nz = 0; - goto have_dig; - } - goto dig_done; - } - for (; c >= '0' && c <= '9'; c = *++s) - { - have_dig: - nz++; - if (c -= '0') - { - nf += nz; - for (i = 1; i < nz; i++) - if (nd++ < 9) - y *= 10; - else if (nd <= DBL_DIG + 1) - z *= 10; - if (nd++ < 9) - y = 10 * y + c; - else if (nd <= DBL_DIG + 1) - z = 10 * z + c; - nz = 0; - } - } - } -dig_done: - e = 0; - if (c == 'e' || c == 'E') - { - if (!nd && !nz && !nz0) - { - s = s00; - goto ret; - } - s2 = s; - esign = 0; - switch (c = *++s) - { - case '-': - esign = 1; - case '+': - c = *++s; - } - if (c >= '0' && c <= '9') - { - while (c == '0') - c = *++s; - if (c > '0' && c <= '9') - { - e = c - '0'; - s1 = s; - while ((c = *++s) >= '0' && c <= '9') - e = 10 * e + c - '0'; - if (s - s1 > 8) - /* Avoid confusion from exponents - * so large that e might overflow. - */ - e = 9999999L; - if (esign) - e = -e; - } - else - e = 0; - } - else - s = s2; - } - if (!nd) - { - if (!nz && !nz0) - s = s00; - goto ret; - } - e1 = e -= nf; - - /* Now we have nd0 digits, starting at s0, followed by a - * decimal point, followed by nd-nd0 digits. The number we're - * after is the integer represented by those digits times - * 10**e */ - - if (!nd0) - nd0 = nd; - k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1; - rv.d = y; - if (k > 9) - rv.d = tens[k - 9] * rv.d + z; - bd0 = 0; - if (nd <= DBL_DIG -#ifndef RND_PRODQUOT - && FLT_ROUNDS == 1 -#endif - ) - { - if (!e) - goto ret; - if (e > 0) - { - if (e <= Ten_pmax) - { -#ifdef VAX - goto vax_ovfl_check; -#else - /* rv.d = */ rounded_product (rv.d, tens[e]); - goto ret; -#endif - } - i = DBL_DIG - nd; - if (e <= Ten_pmax + i) - { - /* A fancier test would sometimes let us do - * this for larger i values. - */ - e -= i; - rv.d *= tens[i]; -#ifdef VAX - /* VAX exponent range is so narrow we must - * worry about overflow here... - */ - vax_ovfl_check: - word0 (rv) -= P * Exp_msk1; - /* rv.d = */ rounded_product (rv.d, tens[e]); - if ((word0 (rv) & Exp_mask) - > Exp_msk1 * (DBL_MAX_EXP + Bias - 1 - P)) - goto ovfl; - word0 (rv) += P * Exp_msk1; -#else - /* rv.d = */ rounded_product (rv.d, tens[e]); -#endif - goto ret; - } - } -#ifndef Inaccurate_Divide - else if (e >= -Ten_pmax) - { - /* rv.d = */ rounded_quotient (rv.d, tens[-e]); - goto ret; - } -#endif - } - e1 += nd - k; - - /* Get starting approximation = rv.d * 10**e1 */ - - if (e1 > 0) - { - if ((i = e1 & 15) != 0) - rv.d *= tens[i]; - if (e1 &= ~15) - { - if (e1 > DBL_MAX_10_EXP) - { - ovfl: - ptr->_errno = ERANGE; -#ifdef _HAVE_STDC - rv.d = HUGE_VAL; -#else - /* Can't trust HUGE_VAL */ -#ifdef IEEE_Arith - word0 (rv) = Exp_mask; -#ifndef _DOUBLE_IS_32BITS - word1 (rv) = 0; -#endif -#else - word0 (rv) = Big0; -#ifndef _DOUBLE_IS_32BITS - word1 (rv) = Big1; -#endif -#endif -#endif - if (bd0) - goto retfree; - goto ret; - } - if (e1 >>= 4) - { - for (j = 0; e1 > 1; j++, e1 >>= 1) - if (e1 & 1) - rv.d *= bigtens[j]; - /* The last multiplication could overflow. */ - word0 (rv) -= P * Exp_msk1; - rv.d *= bigtens[j]; - if ((z = word0 (rv) & Exp_mask) - > Exp_msk1 * (DBL_MAX_EXP + Bias - P)) - goto ovfl; - if (z > Exp_msk1 * (DBL_MAX_EXP + Bias - 1 - P)) - { - /* set to largest number */ - /* (Can't trust DBL_MAX) */ - word0 (rv) = Big0; -#ifndef _DOUBLE_IS_32BITS - word1 (rv) = Big1; -#endif - } - else - word0 (rv) += P * Exp_msk1; - } - - } - } - else if (e1 < 0) - { - e1 = -e1; - if ((i = e1 & 15) != 0) - rv.d /= tens[i]; - if (e1 &= ~15) - { - e1 >>= 4; - if (e1 >= 1 << n_bigtens) - goto undfl; - for (j = 0; e1 > 1; j++, e1 >>= 1) - if (e1 & 1) - rv.d *= tinytens[j]; - /* The last multiplication could underflow. */ - rv0.d = rv.d; - rv.d *= tinytens[j]; - if (!rv.d) - { - rv.d = 2. * rv0.d; - rv.d *= tinytens[j]; - if (!rv.d) - { - undfl: - rv.d = 0.; - ptr->_errno = ERANGE; - if (bd0) - goto retfree; - goto ret; - } -#ifndef _DOUBLE_IS_32BITS - word0 (rv) = Tiny0; - word1 (rv) = Tiny1; -#else - word0 (rv) = Tiny1; -#endif - /* The refinement below will clean - * this approximation up. - */ - } - } - } - - /* Now the hard part -- adjusting rv to the correct value.*/ - - /* Put digits into bd: true value = bd * 10^e */ - - bd0 = s2b (ptr, s0, nd0, nd, y); - - for (;;) - { - bd = Balloc (ptr, bd0->_k); - Bcopy (bd, bd0); - bb = d2b (ptr, rv.d, &bbe, &bbbits); /* rv.d = bb * 2^bbe */ - bs = i2b (ptr, 1); - - if (e >= 0) - { - bb2 = bb5 = 0; - bd2 = bd5 = e; - } - else - { - bb2 = bb5 = -e; - bd2 = bd5 = 0; - } - if (bbe >= 0) - bb2 += bbe; - else - bd2 -= bbe; - bs2 = bb2; -#ifdef Sudden_Underflow -#ifdef IBM - j = 1 + 4 * P - 3 - bbbits + ((bbe + bbbits - 1) & 3); -#else - j = P + 1 - bbbits; -#endif -#else - i = bbe + bbbits - 1; /* logb(rv.d) */ - if (i < Emin) /* denormal */ - j = bbe + (P - Emin); - else - j = P + 1 - bbbits; -#endif - bb2 += j; - bd2 += j; - i = bb2 < bd2 ? bb2 : bd2; - if (i > bs2) - i = bs2; - if (i > 0) - { - bb2 -= i; - bd2 -= i; - bs2 -= i; - } - if (bb5 > 0) - { - bs = pow5mult (ptr, bs, bb5); - bb1 = mult (ptr, bs, bb); - Bfree (ptr, bb); - bb = bb1; - } - if (bb2 > 0) - bb = lshift (ptr, bb, bb2); - if (bd5 > 0) - bd = pow5mult (ptr, bd, bd5); - if (bd2 > 0) - bd = lshift (ptr, bd, bd2); - if (bs2 > 0) - bs = lshift (ptr, bs, bs2); - delta = diff (ptr, bb, bd); - dsign = delta->_sign; - delta->_sign = 0; - i = cmp (delta, bs); - if (i < 0) - { - /* Error is less than half an ulp -- check for - * special case of mantissa a power of two. - */ - if (dsign || word1 (rv) || word0 (rv) & Bndry_mask) - break; - delta = lshift (ptr, delta, Log2P); - if (cmp (delta, bs) > 0) - goto drop_down; - break; - } - if (i == 0) - { - /* exactly half-way between */ - if (dsign) - { - if ((word0 (rv) & Bndry_mask1) == Bndry_mask1 - && word1 (rv) == 0xffffffff) - { - /*boundary case -- increment exponent*/ - word0 (rv) = (word0 (rv) & Exp_mask) - + Exp_msk1 -#ifdef IBM - | Exp_msk1 >> 4 -#endif - ; -#ifndef _DOUBLE_IS_32BITS - word1 (rv) = 0; -#endif - break; - } - } - else if (!(word0 (rv) & Bndry_mask) && !word1 (rv)) - { - drop_down: - /* boundary case -- decrement exponent */ -#ifdef Sudden_Underflow - L = word0 (rv) & Exp_mask; -#ifdef IBM - if (L < Exp_msk1) -#else - if (L <= Exp_msk1) -#endif - goto undfl; - L -= Exp_msk1; -#else - L = (word0 (rv) & Exp_mask) - Exp_msk1; -#endif - word0 (rv) = L | Bndry_mask1; -#ifndef _DOUBLE_IS_32BITS - word1 (rv) = 0xffffffff; -#endif -#ifdef IBM - goto cont; -#else - break; -#endif - } -#ifndef ROUND_BIASED - if (!(word1 (rv) & LSB)) - break; -#endif - if (dsign) - rv.d += ulp (rv.d); -#ifndef ROUND_BIASED - else - { - rv.d -= ulp (rv.d); -#ifndef Sudden_Underflow - if (!rv.d) - goto undfl; -#endif - } -#endif - break; - } - if ((aadj = ratio (delta, bs)) <= 2.) - { - if (dsign) - aadj = aadj1 = 1.; - else if (word1 (rv) || word0 (rv) & Bndry_mask) - { -#ifndef Sudden_Underflow - if (word1 (rv) == Tiny1 && !word0 (rv)) - goto undfl; -#endif - aadj = 1.; - aadj1 = -1.; - } - else - { - /* special case -- power of FLT_RADIX to be */ - /* rounded down... */ - - if (aadj < 2. / FLT_RADIX) - aadj = 1. / FLT_RADIX; - else - aadj *= 0.5; - aadj1 = -aadj; - } - } - else - { - aadj *= 0.5; - aadj1 = dsign ? aadj : -aadj; -#ifdef Check_FLT_ROUNDS - switch (FLT_ROUNDS) - { - case 2: /* towards +infinity */ - aadj1 -= 0.5; - break; - case 0: /* towards 0 */ - case 3: /* towards -infinity */ - aadj1 += 0.5; - } -#else - if (FLT_ROUNDS == 0) - aadj1 += 0.5; -#endif - } - y = word0 (rv) & Exp_mask; - - /* Check for overflow */ - - if (y == Exp_msk1 * (DBL_MAX_EXP + Bias - 1)) - { - rv0.d = rv.d; - word0 (rv) -= P * Exp_msk1; - adj = aadj1 * ulp (rv.d); - rv.d += adj; - if ((word0 (rv) & Exp_mask) >= - Exp_msk1 * (DBL_MAX_EXP + Bias - P)) - { - if (word0 (rv0) == Big0 && word1 (rv0) == Big1) - goto ovfl; -#ifdef _DOUBLE_IS_32BITS - word0 (rv) = Big1; -#else - word0 (rv) = Big0; - word1 (rv) = Big1; -#endif - goto cont; - } - else - word0 (rv) += P * Exp_msk1; - } - else - { -#ifdef Sudden_Underflow - if ((word0 (rv) & Exp_mask) <= P * Exp_msk1) - { - rv0.d = rv.d; - word0 (rv) += P * Exp_msk1; - adj = aadj1 * ulp (rv.d); - rv.d += adj; -#ifdef IBM - if ((word0 (rv) & Exp_mask) < P * Exp_msk1) -#else - if ((word0 (rv) & Exp_mask) <= P * Exp_msk1) -#endif - { - if (word0 (rv0) == Tiny0 - && word1 (rv0) == Tiny1) - goto undfl; - word0 (rv) = Tiny0; - word1 (rv) = Tiny1; - goto cont; - } - else - word0 (rv) -= P * Exp_msk1; - } - else - { - adj = aadj1 * ulp (rv.d); - rv.d += adj; - } -#else - /* Compute adj so that the IEEE rounding rules will - * correctly round rv.d + adj in some half-way cases. - * If rv.d * ulp(rv.d) is denormalized (i.e., - * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid - * trouble from bits lost to denormalization; - * example: 1.2e-307 . - */ - if (y <= (P - 1) * Exp_msk1 && aadj >= 1.) - { - aadj1 = (double) (int) (aadj + 0.5); - if (!dsign) - aadj1 = -aadj1; - } - adj = aadj1 * ulp (rv.d); - rv.d += adj; -#endif - } - z = word0 (rv) & Exp_mask; - if (y == z) - { - /* Can we stop now? */ - L = aadj; - aadj -= L; - /* The tolerances below are conservative. */ - if (dsign || word1 (rv) || word0 (rv) & Bndry_mask) - { - if (aadj < .4999999 || aadj > .5000001) - break; - } - else if (aadj < .4999999 / FLT_RADIX) - break; - } - cont: - Bfree (ptr, bb); - Bfree (ptr, bd); - Bfree (ptr, bs); - Bfree (ptr, delta); - } -retfree: - Bfree (ptr, bb); - Bfree (ptr, bd); - Bfree (ptr, bs); - Bfree (ptr, bd0); - Bfree (ptr, delta); -ret: - if (se) - *se = (char *) s; - - if (nanflag) - return nan (NULL); - return (sign && (s != s00)) ? -rv.d : rv.d; -} - -#ifndef NO_REENT - -double -_DEFUN (strtod, (s00, se), - _CONST char *s00 _AND char **se) -{ - return _strtod_r (_REENT, s00, se); -} - -float -_DEFUN (strtof, (s00, se), - _CONST char *s00 _AND - char **se) -{ - double retval = _strtod_r (_REENT, s00, se); - if (isnan (retval)) - return nanf (NULL); - return (float)retval; -} - -#endif |