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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libquadmath/] [strtod/] [strtod_l.c] - Rev 790
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/* Convert string representing a number to float value, using given locale. Copyright (C) 1997,1998,2002,2004,2005,2006,2007,2008,2009,2010 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <config.h> #include <stdarg.h> #include <string.h> #include <float.h> #include <math.h> #define NDEBUG 1 #include <assert.h> #ifdef HAVE_ERRNO_H #include <errno.h> #endif #include "../printf/quadmath-printf.h" #include "../printf/fpioconst.h" #undef L_ #ifdef USE_WIDE_CHAR # define STRING_TYPE wchar_t # define CHAR_TYPE wint_t # define L_(Ch) L##Ch # define ISSPACE(Ch) __iswspace_l ((Ch), loc) # define ISDIGIT(Ch) __iswdigit_l ((Ch), loc) # define ISXDIGIT(Ch) __iswxdigit_l ((Ch), loc) # define TOLOWER(Ch) __towlower_l ((Ch), loc) # define TOLOWER_C(Ch) __towlower_l ((Ch), _nl_C_locobj_ptr) # define STRNCASECMP(S1, S2, N) \ __wcsncasecmp_l ((S1), (S2), (N), _nl_C_locobj_ptr) # define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0, loc) #else # define STRING_TYPE char # define CHAR_TYPE char # define L_(Ch) Ch # define ISSPACE(Ch) isspace (Ch) # define ISDIGIT(Ch) isdigit (Ch) # define ISXDIGIT(Ch) isxdigit (Ch) # define TOLOWER(Ch) tolower (Ch) # define TOLOWER_C(Ch) \ ({__typeof(Ch) __tlc = (Ch); \ (__tlc >= 'A' && __tlc <= 'Z') ? __tlc - 'A' + 'a' : __tlc; }) # define STRNCASECMP(S1, S2, N) \ __quadmath_strncasecmp_c (S1, S2, N) # ifdef HAVE_STRTOULL # define STRTOULL(S, E, B) strtoull (S, E, B) # else # define STRTOULL(S, E, B) strtoul (S, E, B) # endif static inline int __quadmath_strncasecmp_c (const char *s1, const char *s2, size_t n) { const unsigned char *p1 = (const unsigned char *) s1; const unsigned char *p2 = (const unsigned char *) s2; int result; if (p1 == p2 || n == 0) return 0; while ((result = TOLOWER_C (*p1) - TOLOWER_C (*p2++)) == 0) if (*p1++ == '\0' || --n == 0) break; return result; } #endif /* Constants we need from float.h; select the set for the FLOAT precision. */ #define MANT_DIG PASTE(FLT,_MANT_DIG) #define DIG PASTE(FLT,_DIG) #define MAX_EXP PASTE(FLT,_MAX_EXP) #define MIN_EXP PASTE(FLT,_MIN_EXP) #define MAX_10_EXP PASTE(FLT,_MAX_10_EXP) #define MIN_10_EXP PASTE(FLT,_MIN_10_EXP) /* Extra macros required to get FLT expanded before the pasting. */ #define PASTE(a,b) PASTE1(a,b) #define PASTE1(a,b) a##b /* Function to construct a floating point number from an MP integer containing the fraction bits, a base 2 exponent, and a sign flag. */ extern FLOAT MPN2FLOAT (mp_srcptr mpn, int exponent, int negative); /* Definitions according to limb size used. */ #if BITS_PER_MP_LIMB == 32 # define MAX_DIG_PER_LIMB 9 # define MAX_FAC_PER_LIMB 1000000000UL #elif BITS_PER_MP_LIMB == 64 # define MAX_DIG_PER_LIMB 19 # define MAX_FAC_PER_LIMB 10000000000000000000ULL #else # error "mp_limb_t size " BITS_PER_MP_LIMB "not accounted for" #endif #define _tens_in_limb __quadmath_tens_in_limb extern const mp_limb_t _tens_in_limb[MAX_DIG_PER_LIMB + 1] attribute_hidden; #ifndef howmany #define howmany(x,y) (((x)+((y)-1))/(y)) #endif #define SWAP(x, y) ({ typeof(x) _tmp = x; x = y; y = _tmp; }) #define NDIG (MAX_10_EXP - MIN_10_EXP + 2 * MANT_DIG) #define HEXNDIG ((MAX_EXP - MIN_EXP + 7) / 8 + 2 * MANT_DIG) #define RETURN_LIMB_SIZE howmany (MANT_DIG, BITS_PER_MP_LIMB) #define RETURN(val,end) \ do { if (endptr != NULL) *endptr = (STRING_TYPE *) (end); \ return val; } while (0) /* Maximum size necessary for mpn integers to hold floating point numbers. */ #define MPNSIZE (howmany (MAX_EXP + 2 * MANT_DIG, BITS_PER_MP_LIMB) \ + 2) /* Declare an mpn integer variable that big. */ #define MPN_VAR(name) mp_limb_t name[MPNSIZE]; mp_size_t name##size /* Copy an mpn integer value. */ #define MPN_ASSIGN(dst, src) \ memcpy (dst, src, (dst##size = src##size) * sizeof (mp_limb_t)) /* Return a floating point number of the needed type according to the given multi-precision number after possible rounding. */ static FLOAT round_and_return (mp_limb_t *retval, int exponent, int negative, mp_limb_t round_limb, mp_size_t round_bit, int more_bits) { if (exponent < MIN_EXP - 1) { mp_size_t shift = MIN_EXP - 1 - exponent; if (shift > MANT_DIG) { #if defined HAVE_ERRNO_H && defined EDOM errno = EDOM; #endif return 0.0; } more_bits |= (round_limb & ((((mp_limb_t) 1) << round_bit) - 1)) != 0; if (shift == MANT_DIG) /* This is a special case to handle the very seldom case where the mantissa will be empty after the shift. */ { int i; round_limb = retval[RETURN_LIMB_SIZE - 1]; round_bit = (MANT_DIG - 1) % BITS_PER_MP_LIMB; for (i = 0; i < RETURN_LIMB_SIZE; ++i) more_bits |= retval[i] != 0; MPN_ZERO (retval, RETURN_LIMB_SIZE); } else if (shift >= BITS_PER_MP_LIMB) { int i; round_limb = retval[(shift - 1) / BITS_PER_MP_LIMB]; round_bit = (shift - 1) % BITS_PER_MP_LIMB; for (i = 0; i < (shift - 1) / BITS_PER_MP_LIMB; ++i) more_bits |= retval[i] != 0; more_bits |= ((round_limb & ((((mp_limb_t) 1) << round_bit) - 1)) != 0); (void) mpn_rshift (retval, &retval[shift / BITS_PER_MP_LIMB], RETURN_LIMB_SIZE - (shift / BITS_PER_MP_LIMB), shift % BITS_PER_MP_LIMB); MPN_ZERO (&retval[RETURN_LIMB_SIZE - (shift / BITS_PER_MP_LIMB)], shift / BITS_PER_MP_LIMB); } else if (shift > 0) { round_limb = retval[0]; round_bit = shift - 1; (void) mpn_rshift (retval, retval, RETURN_LIMB_SIZE, shift); } /* This is a hook for the m68k long double format, where the exponent bias is the same for normalized and denormalized numbers. */ #ifndef DENORM_EXP # define DENORM_EXP (MIN_EXP - 2) #endif exponent = DENORM_EXP; #if defined HAVE_ERRNO_H && defined ERANGE errno = ERANGE; #endif } if ((round_limb & (((mp_limb_t) 1) << round_bit)) != 0 && (more_bits || (retval[0] & 1) != 0 || (round_limb & ((((mp_limb_t) 1) << round_bit) - 1)) != 0)) { mp_limb_t cy = mpn_add_1 (retval, retval, RETURN_LIMB_SIZE, 1); if (((MANT_DIG % BITS_PER_MP_LIMB) == 0 && cy) || ((MANT_DIG % BITS_PER_MP_LIMB) != 0 && (retval[RETURN_LIMB_SIZE - 1] & (((mp_limb_t) 1) << (MANT_DIG % BITS_PER_MP_LIMB))) != 0)) { ++exponent; (void) mpn_rshift (retval, retval, RETURN_LIMB_SIZE, 1); retval[RETURN_LIMB_SIZE - 1] |= ((mp_limb_t) 1) << ((MANT_DIG - 1) % BITS_PER_MP_LIMB); } else if (exponent == DENORM_EXP && (retval[RETURN_LIMB_SIZE - 1] & (((mp_limb_t) 1) << ((MANT_DIG - 1) % BITS_PER_MP_LIMB))) != 0) /* The number was denormalized but now normalized. */ exponent = MIN_EXP - 1; } if (exponent > MAX_EXP) return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; return MPN2FLOAT (retval, exponent, negative); } /* Read a multi-precision integer starting at STR with exactly DIGCNT digits into N. Return the size of the number limbs in NSIZE at the first character od the string that is not part of the integer as the function value. If the EXPONENT is small enough to be taken as an additional factor for the resulting number (see code) multiply by it. */ static const STRING_TYPE * str_to_mpn (const STRING_TYPE *str, int digcnt, mp_limb_t *n, mp_size_t *nsize, int *exponent #ifndef USE_WIDE_CHAR , const char *decimal, size_t decimal_len, const char *thousands #endif ) { /* Number of digits for actual limb. */ int cnt = 0; mp_limb_t low = 0; mp_limb_t start; *nsize = 0; assert (digcnt > 0); do { if (cnt == MAX_DIG_PER_LIMB) { if (*nsize == 0) { n[0] = low; *nsize = 1; } else { mp_limb_t cy; cy = mpn_mul_1 (n, n, *nsize, MAX_FAC_PER_LIMB); cy += mpn_add_1 (n, n, *nsize, low); if (cy != 0) { n[*nsize] = cy; ++(*nsize); } } cnt = 0; low = 0; } /* There might be thousands separators or radix characters in the string. But these all can be ignored because we know the format of the number is correct and we have an exact number of characters to read. */ #ifdef USE_WIDE_CHAR if (*str < L'0' || *str > L'9') ++str; #else if (*str < '0' || *str > '9') { int inner = 0; if (thousands != NULL && *str == *thousands && ({ for (inner = 1; thousands[inner] != '\0'; ++inner) if (thousands[inner] != str[inner]) break; thousands[inner] == '\0'; })) str += inner; else str += decimal_len; } #endif low = low * 10 + *str++ - L_('0'); ++cnt; } while (--digcnt > 0); if (*exponent > 0 && cnt + *exponent <= MAX_DIG_PER_LIMB) { low *= _tens_in_limb[*exponent]; start = _tens_in_limb[cnt + *exponent]; *exponent = 0; } else start = _tens_in_limb[cnt]; if (*nsize == 0) { n[0] = low; *nsize = 1; } else { mp_limb_t cy; cy = mpn_mul_1 (n, n, *nsize, start); cy += mpn_add_1 (n, n, *nsize, low); if (cy != 0) n[(*nsize)++] = cy; } return str; } /* Shift {PTR, SIZE} COUNT bits to the left, and fill the vacated bits with the COUNT most significant bits of LIMB. Tege doesn't like this function so I have to write it here myself. :) --drepper */ static inline void __attribute ((always_inline)) mpn_lshift_1 (mp_limb_t *ptr, mp_size_t size, unsigned int count, mp_limb_t limb) { if (__builtin_constant_p (count) && count == BITS_PER_MP_LIMB) { /* Optimize the case of shifting by exactly a word: just copy words, with no actual bit-shifting. */ mp_size_t i; for (i = size - 1; i > 0; --i) ptr[i] = ptr[i - 1]; ptr[0] = limb; } else { (void) mpn_lshift (ptr, ptr, size, count); ptr[0] |= limb >> (BITS_PER_MP_LIMB - count); } } #define INTERNAL(x) INTERNAL1(x) #define INTERNAL1(x) __##x##_internal #ifndef ____STRTOF_INTERNAL # define ____STRTOF_INTERNAL INTERNAL (__STRTOF) #endif /* This file defines a function to check for correct grouping. */ #include "grouping.h" /* Return a floating point number with the value of the given string NPTR. Set *ENDPTR to the character after the last used one. If the number is smaller than the smallest representable number, set `errno' to ERANGE and return 0.0. If the number is too big to be represented, set `errno' to ERANGE and return HUGE_VAL with the appropriate sign. */ FLOAT ____STRTOF_INTERNAL (nptr, endptr, group) const STRING_TYPE *nptr; STRING_TYPE **endptr; int group; { int negative; /* The sign of the number. */ MPN_VAR (num); /* MP representation of the number. */ int exponent; /* Exponent of the number. */ /* Numbers starting `0X' or `0x' have to be processed with base 16. */ int base = 10; /* When we have to compute fractional digits we form a fraction with a second multi-precision number (and we sometimes need a second for temporary results). */ MPN_VAR (den); /* Representation for the return value. */ mp_limb_t retval[RETURN_LIMB_SIZE]; /* Number of bits currently in result value. */ int bits; /* Running pointer after the last character processed in the string. */ const STRING_TYPE *cp, *tp; /* Start of significant part of the number. */ const STRING_TYPE *startp, *start_of_digits; /* Points at the character following the integer and fractional digits. */ const STRING_TYPE *expp; /* Total number of digit and number of digits in integer part. */ int dig_no, int_no, lead_zero; /* Contains the last character read. */ CHAR_TYPE c; /* The radix character of the current locale. */ #ifdef USE_WIDE_CHAR wchar_t decimal; #else const char *decimal; size_t decimal_len; #endif /* The thousands character of the current locale. */ #ifdef USE_WIDE_CHAR wchar_t thousands = L'\0'; #else const char *thousands = NULL; #endif /* The numeric grouping specification of the current locale, in the format described in <locale.h>. */ const char *grouping; /* Used in several places. */ int cnt; #if defined USE_LOCALECONV && !defined USE_NL_LANGINFO const struct lconv *lc = localeconv (); #endif if (__builtin_expect (group, 0)) { #ifdef USE_NL_LANGINFO grouping = nl_langinfo (GROUPING); if (*grouping <= 0 || *grouping == CHAR_MAX) grouping = NULL; else { /* Figure out the thousands separator character. */ #ifdef USE_WIDE_CHAR thousands = nl_langinfo_wc (_NL_NUMERIC_THOUSANDS_SEP_WC); if (thousands == L'\0') grouping = NULL; #else thousands = nl_langinfo (THOUSANDS_SEP); if (*thousands == '\0') { thousands = NULL; grouping = NULL; } #endif } #elif defined USE_LOCALECONV grouping = lc->grouping; if (grouping == NULL || *grouping <= 0 || *grouping == CHAR_MAX) grouping = NULL; else { /* Figure out the thousands separator character. */ thousands = lc->thousands_sep; if (thousands == NULL || *thousands == '\0') { thousands = NULL; grouping = NULL; } } #else grouping = NULL; #endif } else grouping = NULL; /* Find the locale's decimal point character. */ #ifdef USE_WIDE_CHAR decimal = nl_langinfo_wc (_NL_NUMERIC_DECIMAL_POINT_WC); assert (decimal != L'\0'); # define decimal_len 1 #else #ifdef USE_NL_LANGINFO decimal = nl_langinfo (DECIMAL_POINT); decimal_len = strlen (decimal); assert (decimal_len > 0); #elif defined USE_LOCALECONV decimal = lc->decimal_point; if (decimal == NULL || *decimal == '\0') decimal = "."; decimal_len = strlen (decimal); #else decimal = "."; decimal_len = 1; #endif #endif /* Prepare number representation. */ exponent = 0; negative = 0; bits = 0; /* Parse string to get maximal legal prefix. We need the number of characters of the integer part, the fractional part and the exponent. */ cp = nptr - 1; /* Ignore leading white space. */ do c = *++cp; while (ISSPACE (c)); /* Get sign of the result. */ if (c == L_('-')) { negative = 1; c = *++cp; } else if (c == L_('+')) c = *++cp; /* Return 0.0 if no legal string is found. No character is used even if a sign was found. */ #ifdef USE_WIDE_CHAR if (c == (wint_t) decimal && (wint_t) cp[1] >= L'0' && (wint_t) cp[1] <= L'9') { /* We accept it. This funny construct is here only to indent the code correctly. */ } #else for (cnt = 0; decimal[cnt] != '\0'; ++cnt) if (cp[cnt] != decimal[cnt]) break; if (decimal[cnt] == '\0' && cp[cnt] >= '0' && cp[cnt] <= '9') { /* We accept it. This funny construct is here only to indent the code correctly. */ } #endif else if (c < L_('0') || c > L_('9')) { /* Check for `INF' or `INFINITY'. */ CHAR_TYPE lowc = TOLOWER_C (c); if (lowc == L_('i') && STRNCASECMP (cp, L_("inf"), 3) == 0) { /* Return +/- infinity. */ if (endptr != NULL) *endptr = (STRING_TYPE *) (cp + (STRNCASECMP (cp + 3, L_("inity"), 5) == 0 ? 8 : 3)); return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; } if (lowc == L_('n') && STRNCASECMP (cp, L_("nan"), 3) == 0) { /* Return NaN. */ FLOAT retval = NAN; cp += 3; /* Match `(n-char-sequence-digit)'. */ if (*cp == L_('(')) { const STRING_TYPE *startp = cp; do ++cp; while ((*cp >= L_('0') && *cp <= L_('9')) || ({ CHAR_TYPE lo = TOLOWER (*cp); lo >= L_('a') && lo <= L_('z'); }) || *cp == L_('_')); if (*cp != L_(')')) /* The closing brace is missing. Only match the NAN part. */ cp = startp; else { /* This is a system-dependent way to specify the bitmask used for the NaN. We expect it to be a number which is put in the mantissa of the number. */ STRING_TYPE *endp; unsigned long long int mant; mant = STRTOULL (startp + 1, &endp, 0); if (endp == cp) SET_MANTISSA (retval, mant); /* Consume the closing brace. */ ++cp; } } if (endptr != NULL) *endptr = (STRING_TYPE *) cp; return retval; } /* It is really a text we do not recognize. */ RETURN (0.0, nptr); } /* First look whether we are faced with a hexadecimal number. */ if (c == L_('0') && TOLOWER (cp[1]) == L_('x')) { /* Okay, it is a hexa-decimal number. Remember this and skip the characters. BTW: hexadecimal numbers must not be grouped. */ base = 16; cp += 2; c = *cp; grouping = NULL; } /* Record the start of the digits, in case we will check their grouping. */ start_of_digits = startp = cp; /* Ignore leading zeroes. This helps us to avoid useless computations. */ #ifdef USE_WIDE_CHAR while (c == L'0' || ((wint_t) thousands != L'\0' && c == (wint_t) thousands)) c = *++cp; #else if (__builtin_expect (thousands == NULL, 1)) while (c == '0') c = *++cp; else { /* We also have the multibyte thousands string. */ while (1) { if (c != '0') { for (cnt = 0; thousands[cnt] != '\0'; ++cnt) if (thousands[cnt] != cp[cnt]) break; if (thousands[cnt] != '\0') break; cp += cnt - 1; } c = *++cp; } } #endif /* If no other digit but a '0' is found the result is 0.0. Return current read pointer. */ CHAR_TYPE lowc = TOLOWER (c); if (!((c >= L_('0') && c <= L_('9')) || (base == 16 && lowc >= L_('a') && lowc <= L_('f')) || ( #ifdef USE_WIDE_CHAR c == (wint_t) decimal #else ({ for (cnt = 0; decimal[cnt] != '\0'; ++cnt) if (decimal[cnt] != cp[cnt]) break; decimal[cnt] == '\0'; }) #endif /* '0x.' alone is not a valid hexadecimal number. '.' alone is not valid either, but that has been checked already earlier. */ && (base != 16 || cp != start_of_digits || (cp[decimal_len] >= L_('0') && cp[decimal_len] <= L_('9')) || ({ CHAR_TYPE lo = TOLOWER (cp[decimal_len]); lo >= L_('a') && lo <= L_('f'); }))) || (base == 16 && (cp != start_of_digits && lowc == L_('p'))) || (base != 16 && lowc == L_('e')))) { #ifdef USE_WIDE_CHAR tp = __correctly_grouped_prefixwc (start_of_digits, cp, thousands, grouping); #else tp = __correctly_grouped_prefixmb (start_of_digits, cp, thousands, grouping); #endif /* If TP is at the start of the digits, there was no correctly grouped prefix of the string; so no number found. */ RETURN (negative ? -0.0 : 0.0, tp == start_of_digits ? (base == 16 ? cp - 1 : nptr) : tp); } /* Remember first significant digit and read following characters until the decimal point, exponent character or any non-FP number character. */ startp = cp; dig_no = 0; while (1) { if ((c >= L_('0') && c <= L_('9')) || (base == 16 && ({ CHAR_TYPE lo = TOLOWER (c); lo >= L_('a') && lo <= L_('f'); }))) ++dig_no; else { #ifdef USE_WIDE_CHAR if (__builtin_expect ((wint_t) thousands == L'\0', 1) || c != (wint_t) thousands) /* Not a digit or separator: end of the integer part. */ break; #else if (__builtin_expect (thousands == NULL, 1)) break; else { for (cnt = 0; thousands[cnt] != '\0'; ++cnt) if (thousands[cnt] != cp[cnt]) break; if (thousands[cnt] != '\0') break; cp += cnt - 1; } #endif } c = *++cp; } if (__builtin_expect (grouping != NULL, 0) && cp > start_of_digits) { /* Check the grouping of the digits. */ #ifdef USE_WIDE_CHAR tp = __correctly_grouped_prefixwc (start_of_digits, cp, thousands, grouping); #else tp = __correctly_grouped_prefixmb (start_of_digits, cp, thousands, grouping); #endif if (cp != tp) { /* Less than the entire string was correctly grouped. */ if (tp == start_of_digits) /* No valid group of numbers at all: no valid number. */ RETURN (0.0, nptr); if (tp < startp) /* The number is validly grouped, but consists only of zeroes. The whole value is zero. */ RETURN (negative ? -0.0 : 0.0, tp); /* Recompute DIG_NO so we won't read more digits than are properly grouped. */ cp = tp; dig_no = 0; for (tp = startp; tp < cp; ++tp) if (*tp >= L_('0') && *tp <= L_('9')) ++dig_no; int_no = dig_no; lead_zero = 0; goto number_parsed; } } /* We have the number of digits in the integer part. Whether these are all or any is really a fractional digit will be decided later. */ int_no = dig_no; lead_zero = int_no == 0 ? -1 : 0; /* Read the fractional digits. A special case are the 'american style' numbers like `16.' i.e. with decimal point but without trailing digits. */ if ( #ifdef USE_WIDE_CHAR c == (wint_t) decimal #else ({ for (cnt = 0; decimal[cnt] != '\0'; ++cnt) if (decimal[cnt] != cp[cnt]) break; decimal[cnt] == '\0'; }) #endif ) { cp += decimal_len; c = *cp; while ((c >= L_('0') && c <= L_('9')) || (base == 16 && ({ CHAR_TYPE lo = TOLOWER (c); lo >= L_('a') && lo <= L_('f'); }))) { if (c != L_('0') && lead_zero == -1) lead_zero = dig_no - int_no; ++dig_no; c = *++cp; } } /* Remember start of exponent (if any). */ expp = cp; /* Read exponent. */ lowc = TOLOWER (c); if ((base == 16 && lowc == L_('p')) || (base != 16 && lowc == L_('e'))) { int exp_negative = 0; c = *++cp; if (c == L_('-')) { exp_negative = 1; c = *++cp; } else if (c == L_('+')) c = *++cp; if (c >= L_('0') && c <= L_('9')) { int exp_limit; /* Get the exponent limit. */ if (base == 16) exp_limit = (exp_negative ? -MIN_EXP + MANT_DIG + 4 * int_no : MAX_EXP - 4 * int_no + 4 * lead_zero + 3); else exp_limit = (exp_negative ? -MIN_10_EXP + MANT_DIG + int_no : MAX_10_EXP - int_no + lead_zero + 1); do { exponent *= 10; exponent += c - L_('0'); if (__builtin_expect (exponent > exp_limit, 0)) /* The exponent is too large/small to represent a valid number. */ { FLOAT result; /* We have to take care for special situation: a joker might have written "0.0e100000" which is in fact zero. */ if (lead_zero == -1) result = negative ? -0.0 : 0.0; else { /* Overflow or underflow. */ #if defined HAVE_ERRNO_H && defined ERANGE errno = ERANGE; #endif result = (exp_negative ? (negative ? -0.0 : 0.0) : negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL); } /* Accept all following digits as part of the exponent. */ do ++cp; while (*cp >= L_('0') && *cp <= L_('9')); RETURN (result, cp); /* NOTREACHED */ } c = *++cp; } while (c >= L_('0') && c <= L_('9')); if (exp_negative) exponent = -exponent; } else cp = expp; } /* We don't want to have to work with trailing zeroes after the radix. */ if (dig_no > int_no) { while (expp[-1] == L_('0')) { --expp; --dig_no; } assert (dig_no >= int_no); } if (dig_no == int_no && dig_no > 0 && exponent < 0) do { while (! (base == 16 ? ISXDIGIT (expp[-1]) : ISDIGIT (expp[-1]))) --expp; if (expp[-1] != L_('0')) break; --expp; --dig_no; --int_no; exponent += base == 16 ? 4 : 1; } while (dig_no > 0 && exponent < 0); number_parsed: /* The whole string is parsed. Store the address of the next character. */ if (endptr) *endptr = (STRING_TYPE *) cp; if (dig_no == 0) return negative ? -0.0 : 0.0; if (lead_zero) { /* Find the decimal point */ #ifdef USE_WIDE_CHAR while (*startp != decimal) ++startp; #else while (1) { if (*startp == decimal[0]) { for (cnt = 1; decimal[cnt] != '\0'; ++cnt) if (decimal[cnt] != startp[cnt]) break; if (decimal[cnt] == '\0') break; } ++startp; } #endif startp += lead_zero + decimal_len; exponent -= base == 16 ? 4 * lead_zero : lead_zero; dig_no -= lead_zero; } /* If the BASE is 16 we can use a simpler algorithm. */ if (base == 16) { static const int nbits[16] = { 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 }; int idx = (MANT_DIG - 1) / BITS_PER_MP_LIMB; int pos = (MANT_DIG - 1) % BITS_PER_MP_LIMB; mp_limb_t val; while (!ISXDIGIT (*startp)) ++startp; while (*startp == L_('0')) ++startp; if (ISDIGIT (*startp)) val = *startp++ - L_('0'); else val = 10 + TOLOWER (*startp++) - L_('a'); bits = nbits[val]; /* We cannot have a leading zero. */ assert (bits != 0); if (pos + 1 >= 4 || pos + 1 >= bits) { /* We don't have to care for wrapping. This is the normal case so we add the first clause in the `if' expression as an optimization. It is a compile-time constant and so does not cost anything. */ retval[idx] = val << (pos - bits + 1); pos -= bits; } else { retval[idx--] = val >> (bits - pos - 1); retval[idx] = val << (BITS_PER_MP_LIMB - (bits - pos - 1)); pos = BITS_PER_MP_LIMB - 1 - (bits - pos - 1); } /* Adjust the exponent for the bits we are shifting in. */ exponent += bits - 1 + (int_no - 1) * 4; while (--dig_no > 0 && idx >= 0) { if (!ISXDIGIT (*startp)) startp += decimal_len; if (ISDIGIT (*startp)) val = *startp++ - L_('0'); else val = 10 + TOLOWER (*startp++) - L_('a'); if (pos + 1 >= 4) { retval[idx] |= val << (pos - 4 + 1); pos -= 4; } else { retval[idx--] |= val >> (4 - pos - 1); val <<= BITS_PER_MP_LIMB - (4 - pos - 1); if (idx < 0) return round_and_return (retval, exponent, negative, val, BITS_PER_MP_LIMB - 1, dig_no > 0); retval[idx] = val; pos = BITS_PER_MP_LIMB - 1 - (4 - pos - 1); } } /* We ran out of digits. */ MPN_ZERO (retval, idx); return round_and_return (retval, exponent, negative, 0, 0, 0); } /* Now we have the number of digits in total and the integer digits as well as the exponent and its sign. We can decide whether the read digits are really integer digits or belong to the fractional part; i.e. we normalize 123e-2 to 1.23. */ { register int incr = (exponent < 0 ? MAX (-int_no, exponent) : MIN (dig_no - int_no, exponent)); int_no += incr; exponent -= incr; } if (__builtin_expect (int_no + exponent > MAX_10_EXP + 1, 0)) { #if defined HAVE_ERRNO_H && defined ERANGE errno = ERANGE; #endif return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; } if (__builtin_expect (exponent < MIN_10_EXP - (DIG + 1), 0)) { #if defined HAVE_ERRNO_H && defined ERANGE errno = ERANGE; #endif return negative ? -0.0 : 0.0; } if (int_no > 0) { /* Read the integer part as a multi-precision number to NUM. */ startp = str_to_mpn (startp, int_no, num, &numsize, &exponent #ifndef USE_WIDE_CHAR , decimal, decimal_len, thousands #endif ); if (exponent > 0) { /* We now multiply the gained number by the given power of ten. */ mp_limb_t *psrc = num; mp_limb_t *pdest = den; int expbit = 1; const struct mp_power *ttab = &_fpioconst_pow10[0]; do { if ((exponent & expbit) != 0) { size_t size = ttab->arraysize - _FPIO_CONST_OFFSET; mp_limb_t cy; exponent ^= expbit; /* FIXME: not the whole multiplication has to be done. If we have the needed number of bits we only need the information whether more non-zero bits follow. */ if (numsize >= ttab->arraysize - _FPIO_CONST_OFFSET) cy = mpn_mul (pdest, psrc, numsize, &__tens[ttab->arrayoff + _FPIO_CONST_OFFSET], size); else cy = mpn_mul (pdest, &__tens[ttab->arrayoff + _FPIO_CONST_OFFSET], size, psrc, numsize); numsize += size; if (cy == 0) --numsize; (void) SWAP (psrc, pdest); } expbit <<= 1; ++ttab; } while (exponent != 0); if (psrc == den) memcpy (num, den, numsize * sizeof (mp_limb_t)); } /* Determine how many bits of the result we already have. */ count_leading_zeros (bits, num[numsize - 1]); bits = numsize * BITS_PER_MP_LIMB - bits; /* Now we know the exponent of the number in base two. Check it against the maximum possible exponent. */ if (__builtin_expect (bits > MAX_EXP, 0)) { #if defined HAVE_ERRNO_H && defined ERANGE errno = ERANGE; #endif return negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL; } /* We have already the first BITS bits of the result. Together with the information whether more non-zero bits follow this is enough to determine the result. */ if (bits > MANT_DIG) { int i; const mp_size_t least_idx = (bits - MANT_DIG) / BITS_PER_MP_LIMB; const mp_size_t least_bit = (bits - MANT_DIG) % BITS_PER_MP_LIMB; const mp_size_t round_idx = least_bit == 0 ? least_idx - 1 : least_idx; const mp_size_t round_bit = least_bit == 0 ? BITS_PER_MP_LIMB - 1 : least_bit - 1; if (least_bit == 0) memcpy (retval, &num[least_idx], RETURN_LIMB_SIZE * sizeof (mp_limb_t)); else { for (i = least_idx; i < numsize - 1; ++i) retval[i - least_idx] = (num[i] >> least_bit) | (num[i + 1] << (BITS_PER_MP_LIMB - least_bit)); if (i - least_idx < RETURN_LIMB_SIZE) retval[RETURN_LIMB_SIZE - 1] = num[i] >> least_bit; } /* Check whether any limb beside the ones in RETVAL are non-zero. */ for (i = 0; num[i] == 0; ++i) ; return round_and_return (retval, bits - 1, negative, num[round_idx], round_bit, int_no < dig_no || i < round_idx); /* NOTREACHED */ } else if (dig_no == int_no) { const mp_size_t target_bit = (MANT_DIG - 1) % BITS_PER_MP_LIMB; const mp_size_t is_bit = (bits - 1) % BITS_PER_MP_LIMB; if (target_bit == is_bit) { memcpy (&retval[RETURN_LIMB_SIZE - numsize], num, numsize * sizeof (mp_limb_t)); /* FIXME: the following loop can be avoided if we assume a maximal MANT_DIG value. */ MPN_ZERO (retval, RETURN_LIMB_SIZE - numsize); } else if (target_bit > is_bit) { (void) mpn_lshift (&retval[RETURN_LIMB_SIZE - numsize], num, numsize, target_bit - is_bit); /* FIXME: the following loop can be avoided if we assume a maximal MANT_DIG value. */ MPN_ZERO (retval, RETURN_LIMB_SIZE - numsize); } else { mp_limb_t cy; assert (numsize < RETURN_LIMB_SIZE); cy = mpn_rshift (&retval[RETURN_LIMB_SIZE - numsize], num, numsize, is_bit - target_bit); retval[RETURN_LIMB_SIZE - numsize - 1] = cy; /* FIXME: the following loop can be avoided if we assume a maximal MANT_DIG value. */ MPN_ZERO (retval, RETURN_LIMB_SIZE - numsize - 1); } return round_and_return (retval, bits - 1, negative, 0, 0, 0); /* NOTREACHED */ } /* Store the bits we already have. */ memcpy (retval, num, numsize * sizeof (mp_limb_t)); #if RETURN_LIMB_SIZE > 1 if (numsize < RETURN_LIMB_SIZE) # if RETURN_LIMB_SIZE == 2 retval[numsize] = 0; # else MPN_ZERO (retval + numsize, RETURN_LIMB_SIZE - numsize); # endif #endif } /* We have to compute at least some of the fractional digits. */ { /* We construct a fraction and the result of the division gives us the needed digits. The denominator is 1.0 multiplied by the exponent of the lowest digit; i.e. 0.123 gives 123 / 1000 and 123e-6 gives 123 / 1000000. */ int expbit; int neg_exp; int more_bits; mp_limb_t cy; mp_limb_t *psrc = den; mp_limb_t *pdest = num; const struct mp_power *ttab = &_fpioconst_pow10[0]; assert (dig_no > int_no && exponent <= 0); /* For the fractional part we need not process too many digits. One decimal digits gives us log_2(10) ~ 3.32 bits. If we now compute ceil(BITS / 3) =: N digits we should have enough bits for the result. The remaining decimal digits give us the information that more bits are following. This can be used while rounding. (Two added as a safety margin.) */ if (dig_no - int_no > (MANT_DIG - bits + 2) / 3 + 2) { dig_no = int_no + (MANT_DIG - bits + 2) / 3 + 2; more_bits = 1; } else more_bits = 0; neg_exp = dig_no - int_no - exponent; /* Construct the denominator. */ densize = 0; expbit = 1; do { if ((neg_exp & expbit) != 0) { mp_limb_t cy; neg_exp ^= expbit; if (densize == 0) { densize = ttab->arraysize - _FPIO_CONST_OFFSET; memcpy (psrc, &__tens[ttab->arrayoff + _FPIO_CONST_OFFSET], densize * sizeof (mp_limb_t)); } else { cy = mpn_mul (pdest, &__tens[ttab->arrayoff + _FPIO_CONST_OFFSET], ttab->arraysize - _FPIO_CONST_OFFSET, psrc, densize); densize += ttab->arraysize - _FPIO_CONST_OFFSET; if (cy == 0) --densize; (void) SWAP (psrc, pdest); } } expbit <<= 1; ++ttab; } while (neg_exp != 0); if (psrc == num) memcpy (den, num, densize * sizeof (mp_limb_t)); /* Read the fractional digits from the string. */ (void) str_to_mpn (startp, dig_no - int_no, num, &numsize, &exponent #ifndef USE_WIDE_CHAR , decimal, decimal_len, thousands #endif ); /* We now have to shift both numbers so that the highest bit in the denominator is set. In the same process we copy the numerator to a high place in the array so that the division constructs the wanted digits. This is done by a "quasi fix point" number representation. num: ddddddddddd . 0000000000000000000000 |--- m ---| den: ddddddddddd n >= m |--- n ---| */ count_leading_zeros (cnt, den[densize - 1]); if (cnt > 0) { /* Don't call `mpn_shift' with a count of zero since the specification does not allow this. */ (void) mpn_lshift (den, den, densize, cnt); cy = mpn_lshift (num, num, numsize, cnt); if (cy != 0) num[numsize++] = cy; } /* Now we are ready for the division. But it is not necessary to do a full multi-precision division because we only need a small number of bits for the result. So we do not use mpn_divmod here but instead do the division here by hand and stop whenever the needed number of bits is reached. The code itself comes from the GNU MP Library by Torbj\"orn Granlund. */ exponent = bits; switch (densize) { case 1: { mp_limb_t d, n, quot; int used = 0; n = num[0]; d = den[0]; assert (numsize == 1 && n < d); do { udiv_qrnnd (quot, n, n, 0, d); #define got_limb \ if (bits == 0) \ { \ register int cnt; \ if (quot == 0) \ cnt = BITS_PER_MP_LIMB; \ else \ count_leading_zeros (cnt, quot); \ exponent -= cnt; \ if (BITS_PER_MP_LIMB - cnt > MANT_DIG) \ { \ used = MANT_DIG + cnt; \ retval[0] = quot >> (BITS_PER_MP_LIMB - used); \ bits = MANT_DIG + 1; \ } \ else \ { \ /* Note that we only clear the second element. */ \ /* The conditional is determined at compile time. */ \ if (RETURN_LIMB_SIZE > 1) \ retval[1] = 0; \ retval[0] = quot; \ bits = -cnt; \ } \ } \ else if (bits + BITS_PER_MP_LIMB <= MANT_DIG) \ mpn_lshift_1 (retval, RETURN_LIMB_SIZE, BITS_PER_MP_LIMB, \ quot); \ else \ { \ used = MANT_DIG - bits; \ if (used > 0) \ mpn_lshift_1 (retval, RETURN_LIMB_SIZE, used, quot); \ } \ bits += BITS_PER_MP_LIMB got_limb; } while (bits <= MANT_DIG); return round_and_return (retval, exponent - 1, negative, quot, BITS_PER_MP_LIMB - 1 - used, more_bits || n != 0); } case 2: { mp_limb_t d0, d1, n0, n1; mp_limb_t quot = 0; int used = 0; d0 = den[0]; d1 = den[1]; if (numsize < densize) { if (num[0] >= d1) { /* The numerator of the number occupies fewer bits than the denominator but the one limb is bigger than the high limb of the numerator. */ n1 = 0; n0 = num[0]; } else { if (bits <= 0) exponent -= BITS_PER_MP_LIMB; else { if (bits + BITS_PER_MP_LIMB <= MANT_DIG) mpn_lshift_1 (retval, RETURN_LIMB_SIZE, BITS_PER_MP_LIMB, 0); else { used = MANT_DIG - bits; if (used > 0) mpn_lshift_1 (retval, RETURN_LIMB_SIZE, used, 0); } bits += BITS_PER_MP_LIMB; } n1 = num[0]; n0 = 0; } } else { n1 = num[1]; n0 = num[0]; } while (bits <= MANT_DIG) { mp_limb_t r; if (n1 == d1) { /* QUOT should be either 111..111 or 111..110. We need special treatment of this rare case as normal division would give overflow. */ quot = ~(mp_limb_t) 0; r = n0 + d1; if (r < d1) /* Carry in the addition? */ { add_ssaaaa (n1, n0, r - d0, 0, 0, d0); goto have_quot; } n1 = d0 - (d0 != 0); n0 = -d0; } else { udiv_qrnnd (quot, r, n1, n0, d1); umul_ppmm (n1, n0, d0, quot); } q_test: if (n1 > r || (n1 == r && n0 > 0)) { /* The estimated QUOT was too large. */ --quot; sub_ddmmss (n1, n0, n1, n0, 0, d0); r += d1; if (r >= d1) /* If not carry, test QUOT again. */ goto q_test; } sub_ddmmss (n1, n0, r, 0, n1, n0); have_quot: got_limb; } return round_and_return (retval, exponent - 1, negative, quot, BITS_PER_MP_LIMB - 1 - used, more_bits || n1 != 0 || n0 != 0); } default: { int i; mp_limb_t cy, dX, d1, n0, n1; mp_limb_t quot = 0; int used = 0; dX = den[densize - 1]; d1 = den[densize - 2]; /* The division does not work if the upper limb of the two-limb numerator is greater than the denominator. */ if (mpn_cmp (num, &den[densize - numsize], numsize) > 0) num[numsize++] = 0; if (numsize < densize) { mp_size_t empty = densize - numsize; register int i; if (bits <= 0) exponent -= empty * BITS_PER_MP_LIMB; else { if (bits + empty * BITS_PER_MP_LIMB <= MANT_DIG) { /* We make a difference here because the compiler cannot optimize the `else' case that good and this reflects all currently used FLOAT types and GMP implementations. */ #if RETURN_LIMB_SIZE <= 2 assert (empty == 1); mpn_lshift_1 (retval, RETURN_LIMB_SIZE, BITS_PER_MP_LIMB, 0); #else for (i = RETURN_LIMB_SIZE - 1; i >= empty; --i) retval[i] = retval[i - empty]; while (i >= 0) retval[i--] = 0; #endif } else { used = MANT_DIG - bits; if (used >= BITS_PER_MP_LIMB) { register int i; (void) mpn_lshift (&retval[used / BITS_PER_MP_LIMB], retval, (RETURN_LIMB_SIZE - used / BITS_PER_MP_LIMB), used % BITS_PER_MP_LIMB); for (i = used / BITS_PER_MP_LIMB - 1; i >= 0; --i) retval[i] = 0; } else if (used > 0) mpn_lshift_1 (retval, RETURN_LIMB_SIZE, used, 0); } bits += empty * BITS_PER_MP_LIMB; } for (i = numsize; i > 0; --i) num[i + empty] = num[i - 1]; MPN_ZERO (num, empty + 1); } else { int i; assert (numsize == densize); for (i = numsize; i > 0; --i) num[i] = num[i - 1]; } den[densize] = 0; n0 = num[densize]; while (bits <= MANT_DIG) { if (n0 == dX) /* This might over-estimate QUOT, but it's probably not worth the extra code here to find out. */ quot = ~(mp_limb_t) 0; else { mp_limb_t r; udiv_qrnnd (quot, r, n0, num[densize - 1], dX); umul_ppmm (n1, n0, d1, quot); while (n1 > r || (n1 == r && n0 > num[densize - 2])) { --quot; r += dX; if (r < dX) /* I.e. "carry in previous addition?" */ break; n1 -= n0 < d1; n0 -= d1; } } /* Possible optimization: We already have (q * n0) and (1 * n1) after the calculation of QUOT. Taking advantage of this, we could make this loop make two iterations less. */ cy = mpn_submul_1 (num, den, densize + 1, quot); if (num[densize] != cy) { cy = mpn_add_n (num, num, den, densize); assert (cy != 0); --quot; } n0 = num[densize] = num[densize - 1]; for (i = densize - 1; i > 0; --i) num[i] = num[i - 1]; got_limb; } for (i = densize; num[i] == 0 && i >= 0; --i) ; return round_and_return (retval, exponent - 1, negative, quot, BITS_PER_MP_LIMB - 1 - used, more_bits || i >= 0); } } } /* NOTREACHED */ }
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