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[/] [or1k/] [trunk/] [linux/] [uClibc/] [libc/] [stdlib/] [strtod.c] - Rev 1765
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/* Copyright (C) 2000, 2003 Manuel Novoa III * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Notes: * * The primary objective of this implementation was minimal size and * portablility, while providing robustness and resonable accuracy. * * This implementation depends on IEEE floating point behavior and expects * to be able to generate +/- infinity as a result. * * There are a number of compile-time options below. */ /* July 27, 2003 * * General cleanup and some minor size optimizations. * Change implementation to support __strtofpmax() rather than strtod(). * Now all the strto{floating pt}() funcs are implemented in terms of * of the internal __strtofpmax() function. * Support "nan", "inf", and "infinity" strings (case-insensitive). * Support hexadecimal floating point notation. * Support wchar variants. * Support xlocale variants. * * TODO: * * Consider accumulating blocks of digits in longs to save floating pt mults. * This would likely be much better on anything that only supported floats * where DECIMAL_DIG == 9. Actually, if floats have FLT_MAX_10_EXP == 38, * we could calculate almost all the exponent multipliers (p_base) in * long arithmetic as well. */ /**********************************************************************/ /* OPTIONS */ /**********************************************************************/ /* Defined if we want to recognize "nan", "inf", and "infinity". (C99) */ #define _STRTOD_NAN_INF_STRINGS 1 /* Defined if we want support hexadecimal floating point notation. (C99) */ /* Note! Now controlled by uClibc configuration. See below. */ #define _STRTOD_HEXADECIMAL_FLOATS 1 /* Defined if we want to scale with a O(log2(exp)) multiplications. * This is generally a good thing to do unless you are really tight * on space and do not expect to convert values of large magnitude. */ #define _STRTOD_LOG_SCALING 1 /* WARNING!!! WARNING!!! WARNING!!! WARNING!!! WARNING!!! * * Clearing any of the options below this point is not advised (or tested). * * WARNING!!! WARNING!!! WARNING!!! WARNING!!! WARNING!!! */ /* Defined if we want strtod to set errno appropriately. */ /* NOTE: Implies all options below. */ #define _STRTOD_ERRNO 1 /* Defined if we want support for the endptr arg. */ /* Implied by _STRTOD_ERRNO. */ #define _STRTOD_ENDPTR 1 /* Defined if we want to prevent overflow in accumulating the exponent. */ /* Implied by _STRTOD_ERRNO. */ #define _STRTOD_RESTRICT_EXP 1 /* Defined if we want to process mantissa digits more intelligently. */ /* Implied by _STRTOD_ERRNO. */ #define _STRTOD_RESTRICT_DIGITS 1 /* Defined if we want to skip scaling 0 for the exponent. */ /* Implied by _STRTOD_ERRNO. */ #define _STRTOD_ZERO_CHECK 1 /**********************************************************************/ /* Don't change anything that follows. */ /**********************************************************************/ #ifdef _STRTOD_ERRNO #undef _STRTOD_ENDPTR #undef _STRTOD_RESTRICT_EXP #undef _STRTOD_RESTRICT_DIGITS #undef _STRTOD_ZERO_CHECK #define _STRTOD_ENDPTR 1 #define _STRTOD_RESTRICT_EXP 1 #define _STRTOD_RESTRICT_DIGITS 1 #define _STRTOD_ZERO_CHECK 1 #endif /**********************************************************************/ #define _ISOC99_SOURCE 1 #define _GNU_SOURCE #include <stdlib.h> #include <string.h> #include <ctype.h> #include <errno.h> #include <limits.h> #include <float.h> #include <bits/uClibc_fpmax.h> #include <locale.h> #ifdef __UCLIBC_HAS_WCHAR__ #include <wchar.h> #include <wctype.h> #include <bits/uClibc_uwchar.h> #endif #ifdef __UCLIBC_HAS_XLOCALE__ #include <xlocale.h> #endif /* __UCLIBC_HAS_XLOCALE__ */ /* Handle _STRTOD_HEXADECIMAL_FLOATS via uClibc config now. */ #undef _STRTOD_HEXADECIMAL_FLOATS #ifdef __UCLIBC_HAS_HEXADECIMAL_FLOATS__ #define _STRTOD_HEXADECIMAL_FLOATS 1 #endif /* __UCLIBC_HAS_HEXADECIMAL_FLOATS__ */ /**********************************************************************/ #undef _STRTOD_FPMAX #if FPMAX_TYPE == 3 #define NEED_STRTOLD_WRAPPER #define NEED_STRTOD_WRAPPER #define NEED_STRTOF_WRAPPER #elif FPMAX_TYPE == 2 #define NEED_STRTOD_WRAPPER #define NEED_STRTOF_WRAPPER #elif FPMAX_TYPE == 1 #define NEED_STRTOF_WRAPPER #else #error unknown FPMAX_TYPE! #endif extern void __fp_range_check(__fpmax_t y, __fpmax_t x); /**********************************************************************/ #ifdef _STRTOD_RESTRICT_DIGITS #define EXP_DENORM_ADJUST DECIMAL_DIG #define MAX_ALLOWED_EXP (DECIMAL_DIG + EXP_DENORM_ADJUST - FPMAX_MIN_10_EXP) #if MAX_ALLOWED_EXP > INT_MAX #error size assumption violated for MAX_ALLOWED_EXP #endif #else /* We want some excess if we're not restricting mantissa digits. */ #define MAX_ALLOWED_EXP ((20 - FPMAX_MIN_10_EXP) * 2) #endif #if defined(_STRTOD_RESTRICT_DIGITS) || defined(_STRTOD_ENDPTR) || defined(_STRTOD_HEXADECIMAL_FLOATS) #undef _STRTOD_NEED_NUM_DIGITS #define _STRTOD_NEED_NUM_DIGITS 1 #endif /**********************************************************************/ #if defined(L___strtofpmax) || defined(L___strtofpmax_l) || defined(L___wcstofpmax) || defined(L___wcstofpmax_l) #if defined(L___wcstofpmax) || defined(L___wcstofpmax_l) #define __strtofpmax __wcstofpmax #define __strtofpmax_l __wcstofpmax_l #define Wchar wchar_t #ifdef __UCLIBC_DO_XLOCALE #define ISSPACE(C) iswspace_l((C), locale_arg) #else #define ISSPACE(C) iswspace((C)) #endif #else /* defined(L___wcstofpmax) || defined(L___wcstofpmax) */ #define Wchar char #ifdef __UCLIBC_DO_XLOCALE #define ISSPACE(C) isspace_l((C), locale_arg) #else #define ISSPACE(C) isspace((C)) #endif #endif /* defined(L___wcstofpmax) || defined(L___wcstofpmax) */ #if defined(__UCLIBC_HAS_XLOCALE__) && !defined(__UCLIBC_DO_XLOCALE) __fpmax_t __strtofpmax(const Wchar *str, Wchar **endptr, int exponent_power) { return __strtofpmax_l(str, endptr, exponent_power, __UCLIBC_CURLOCALE); } #else /* defined(__UCLIBC_HAS_XLOCALE__) && !defined(__UCLIBC_DO_XLOCALE) */ __fpmax_t __XL_NPP(__strtofpmax)(const Wchar *str, Wchar **endptr, int exponent_power __LOCALE_PARAM ) { __fpmax_t number; __fpmax_t p_base = 10; /* Adjusted to 16 in the hex case. */ Wchar *pos0; #ifdef _STRTOD_ENDPTR Wchar *pos1; #endif Wchar *pos = (Wchar *) str; int exponent_temp; int negative; /* A flag for the number, a multiplier for the exponent. */ #ifdef _STRTOD_NEED_NUM_DIGITS int num_digits; #endif #ifdef __UCLIBC_HAS_LOCALE__ const char *decpt = __LOCALE_PTR->decimal_point; #if defined(L___wcstofpmax) || defined(L___wcstofpmax) wchar_t decpt_wc = __LOCALE_PTR->decimal_point; #else int decpt_len = __LOCALE_PTR->decimal_point_len; #endif #endif #ifdef _STRTOD_HEXADECIMAL_FLOATS Wchar expchar = 'e'; Wchar *poshex = NULL; __uint16_t is_mask = _ISdigit; #define EXPCHAR expchar #define IS_X_DIGIT(C) __isctype((C), is_mask) #else /* _STRTOD_HEXADECIMAL_FLOATS */ #define EXPCHAR 'e' #define IS_X_DIGIT(C) isdigit((C)) #endif /* _STRTOD_HEXADECIMAL_FLOATS */ while (ISSPACE(*pos)) { /* Skip leading whitespace. */ ++pos; } negative = 0; switch(*pos) { /* Handle optional sign. */ case '-': negative = 1; /* Fall through to increment position. */ case '+': ++pos; } #ifdef _STRTOD_HEXADECIMAL_FLOATS if ((*pos == '0') && (((pos[1])|0x20) == 'x')) { poshex = ++pos; /* Save position of 'x' in case no digits */ ++pos; /* and advance past it. */ is_mask = _ISxdigit; /* Used by IS_X_DIGIT. */ expchar = 'p'; /* Adjust exponent char. */ p_base = 16; /* Adjust base multiplier. */ } #endif number = 0.; #ifdef _STRTOD_NEED_NUM_DIGITS num_digits = -1; #endif /* exponent_power = 0; */ pos0 = NULL; LOOP: while (IS_X_DIGIT(*pos)) { /* Process string of (hex) digits. */ #ifdef _STRTOD_RESTRICT_DIGITS if (num_digits < 0) { /* First time through? */ ++num_digits; /* We've now seen a digit. */ } if (num_digits || (*pos != '0')) { /* Had/have nonzero. */ ++num_digits; if (num_digits <= DECIMAL_DIG) { /* Is digit significant? */ #ifdef _STRTOD_HEXADECIMAL_FLOATS number = number * p_base + (isdigit(*pos) ? (*pos - '0') : (((*pos)|0x20) - ('a' - 10))); #else /* _STRTOD_HEXADECIMAL_FLOATS */ number = number * p_base + (*pos - '0'); #endif /* _STRTOD_HEXADECIMAL_FLOATS */ } } #else /* _STRTOD_RESTRICT_DIGITS */ #ifdef _STRTOD_NEED_NUM_DIGITS ++num_digits; #endif #ifdef _STRTOD_HEXADECIMAL_FLOATS number = number * p_base + (isdigit(*pos) ? (*pos - '0') : (((*pos)|0x20) - ('a' - 10))); #else /* _STRTOD_HEXADECIMAL_FLOATS */ number = number * p_base + (*pos - '0'); #endif /* _STRTOD_HEXADECIMAL_FLOATS */ #endif /* _STRTOD_RESTRICT_DIGITS */ ++pos; } #ifdef __UCLIBC_HAS_LOCALE__ #if defined(L___wcstofpmax) || defined(L___wcstofpmax) if (!pos0 && (*pos == decpt_wc)) { /* First decimal point? */ pos0 = ++pos; goto LOOP; } #else if (!pos0 && !memcmp(pos, decpt, decpt_len)) { /* First decimal point? */ pos0 = (pos += decpt_len); goto LOOP; } #endif #else /* __UCLIBC_HAS_LOCALE__ */ if ((*pos == '.') && !pos0) { /* First decimal point? */ pos0 = ++pos; /* Save position of decimal point */ goto LOOP; /* and process rest of digits. */ } #endif /* __UCLIBC_HAS_LOCALE__ */ #ifdef _STRTOD_NEED_NUM_DIGITS if (num_digits<0) { /* Must have at least one digit. */ #ifdef _STRTOD_HEXADECIMAL_FLOATS if (poshex) { /* Back up to '0' in '0x' prefix. */ pos = poshex; goto DONE; } #endif /* _STRTOD_HEXADECIMAL_FLOATS */ #ifdef _STRTOD_NAN_INF_STRINGS if (!pos0) { /* No decimal point, so check for inf/nan. */ /* Note: nan is the first string so 'number = i/0.;' works. */ static const char nan_inf_str[] = "\05nan\0\012infinity\0\05inf\0"; int i = 0; #ifdef __UCLIBC_HAS_LOCALE__ /* Avoid tolower problems for INFINITY in the tr_TR locale. (yuk)*/ #undef _tolower #define _tolower(C) ((C)|0x20) #endif /* __UCLIBC_HAS_LOCALE__ */ do { /* Unfortunately, we have no memcasecmp(). */ int j = 0; while (_tolower(pos[j]) == nan_inf_str[i+1+j]) { ++j; if (!nan_inf_str[i+1+j]) { number = i / 0.; if (negative) { /* Correct for sign. */ number = -number; } pos += nan_inf_str[i] - 2; goto DONE; } } i += nan_inf_str[i]; } while (nan_inf_str[i]); } #endif /* STRTOD_NAN_INF_STRINGS */ #ifdef _STRTOD_ENDPTR pos = (Wchar *) str; #endif goto DONE; } #endif /* _STRTOD_NEED_NUM_DIGITS */ #ifdef _STRTOD_RESTRICT_DIGITS if (num_digits > DECIMAL_DIG) { /* Adjust exponent for skipped digits. */ exponent_power += num_digits - DECIMAL_DIG; } #endif if (pos0) { exponent_power += pos0 - pos; /* Adjust exponent for decimal point. */ } #ifdef _STRTOD_HEXADECIMAL_FLOATS if (poshex) { exponent_power *= 4; /* Above is 2**4, but below is 2. */ p_base = 2; } #endif /* _STRTOD_HEXADECIMAL_FLOATS */ if (negative) { /* Correct for sign. */ number = -number; } /* process an exponent string */ if (((*pos)|0x20) == EXPCHAR) { #ifdef _STRTOD_ENDPTR pos1 = pos; #endif negative = 1; switch(*++pos) { /* Handle optional sign. */ case '-': negative = -1; /* Fall through to increment pos. */ case '+': ++pos; } pos0 = pos; exponent_temp = 0; while (isdigit(*pos)) { /* Process string of digits. */ #ifdef _STRTOD_RESTRICT_EXP if (exponent_temp < MAX_ALLOWED_EXP) { /* Avoid overflow. */ exponent_temp = exponent_temp * 10 + (*pos - '0'); } #else exponent_temp = exponent_temp * 10 + (*pos - '0'); #endif ++pos; } #ifdef _STRTOD_ENDPTR if (pos == pos0) { /* No digits? */ pos = pos1; /* Back up to {e|E}/{p|P}. */ } /* else */ #endif exponent_power += negative * exponent_temp; } #ifdef _STRTOD_ZERO_CHECK if (number == 0.) { goto DONE; } #endif /* scale the result */ #ifdef _STRTOD_LOG_SCALING exponent_temp = exponent_power; if (exponent_temp < 0) { exponent_temp = -exponent_temp; } while (exponent_temp) { if (exponent_temp & 1) { if (exponent_power < 0) { /* Warning... caluclating a factor for the exponent and * then dividing could easily be faster. But doing so * might cause problems when dealing with denormals. */ number /= p_base; } else { number *= p_base; } } exponent_temp >>= 1; p_base *= p_base; } #else /* _STRTOD_LOG_SCALING */ while (exponent_power) { if (exponent_power < 0) { number /= p_base; exponent_power++; } else { number *= p_base; exponent_power--; } } #endif /* _STRTOD_LOG_SCALING */ #ifdef _STRTOD_ERRNO if (__FPMAX_ZERO_OR_INF_CHECK(number)) { __set_errno(ERANGE); } #endif DONE: #ifdef _STRTOD_ENDPTR if (endptr) { *endptr = pos; } #endif return number; } #endif /* defined(__UCLIBC_HAS_XLOCALE__) && !defined(__UCLIBC_DO_XLOCALE) */ #endif /**********************************************************************/ #ifdef L___fp_range_check #if defined(NEED_STRTOF_WRAPPER) || defined(NEED_STRTOD_WRAPPER) extern void __fp_range_check(__fpmax_t y, __fpmax_t x) { if (__FPMAX_ZERO_OR_INF_CHECK(y) /* y is 0 or +/- infinity */ && (y != 0) /* y is not 0 (could have x>0, y==0 if underflow) */ && !__FPMAX_ZERO_OR_INF_CHECK(x) /* x is not 0 or +/- infinity */ ) { __set_errno(ERANGE); /* Then x is not in y's range. */ } } #endif #endif /**********************************************************************/ #if defined(L_strtof) || defined(L_strtof_l) || defined(L_wcstof) || defined(L_wcstof_l) #if defined(NEED_STRTOF_WRAPPER) #if defined(L_wcstof) || defined(L_wcstof_l) #define strtof wcstof #define strtof_l wcstof_l #define __strtof __wcstof #define __strtof_l __wcstof_l #define __strtofpmax __wcstofpmax #define __strtofpmax_l __wcstofpmax_l #define Wchar wchar_t #else #define Wchar char #endif float __XL(strtof)(const Wchar *str, Wchar **endptr __LOCALE_PARAM ) { #if FPMAX_TYPE == 1 return __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); #else __fpmax_t x; float y; x = __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); y = (float) x; __fp_range_check(y, x); return y; #endif } __XL_ALIAS(strtof) #endif #endif /**********************************************************************/ #if defined(L_strtod) || defined(L_strtod_l) || defined(L_wcstod) || defined(L_wcstod_l) #if defined(NEED_STRTOD_WRAPPER) #if defined(L_wcstod) || defined(L_wcstod_l) #define strtod wcstod #define strtod_l wcstod_l #define __strtod __wcstod #define __strtod_l __wcstod_l #define __strtofpmax __wcstofpmax #define __strtofpmax_l __wcstofpmax_l #define Wchar wchar_t #else #define Wchar char #endif double __XL(strtod)(const Wchar *__restrict str, Wchar **__restrict endptr __LOCALE_PARAM ) { #if FPMAX_TYPE == 2 return __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); #else __fpmax_t x; double y; x = __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); y = (double) x; __fp_range_check(y, x); return y; #endif } __XL_ALIAS(strtod) #endif #endif /**********************************************************************/ #if defined(L_strtold) || defined(L_strtold_l) || defined(L_wcstold) || defined(L_wcstold_l) #if defined(NEED_STRTOLD_WRAPPER) #if defined(L_wcstold) || defined(L_wcstold_l) #define strtold wcstold #define strtold_l wcstold_l #define __strtold __wcstold #define __strtold_l __wcstold_l #define __strtofpmax __wcstofpmax #define __strtofpmax_l __wcstofpmax_l #define Wchar wchar_t #else #define Wchar char #endif long double __XL(strtold)(const Wchar *str, Wchar **endptr __LOCALE_PARAM ) { #if FPMAX_TYPE == 3 return __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); #else __fpmax_t x; long double y; x = __XL_NPP(__strtofpmax)(str, endptr, 0 __LOCALE_ARG ); y = (long double) x; __fp_range_check(y, x); return y; #endif } __XL_ALIAS(strtold) #endif #endif /**********************************************************************/