diff options
Diffstat (limited to 'stdlib/strtod.c')
| -rw-r--r-- | stdlib/strtod.c | 163 |
1 files changed, 135 insertions, 28 deletions
diff --git a/stdlib/strtod.c b/stdlib/strtod.c index ed24c08f2b..316adec5ff 100644 --- a/stdlib/strtod.c +++ b/stdlib/strtod.c @@ -40,6 +40,8 @@ # define CHAR_TYPE wint_t # define L_(Ch) L##Ch # define ISSPACE(Ch) iswspace (Ch) +# define ISDIGIT(Ch) iswdigit (Ch) +# define ISXDIGIT(Ch) iswxdigit (Ch) # define TOLOWER(Ch) towlower (Ch) # define STRNCASECMP(S1, S2, N) __wcsncasecmp ((S1), (S2), (N)) #else @@ -47,6 +49,8 @@ # 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 STRNCASECMP(S1, S2, N) __strncasecmp ((S1), (S2), (N)) #endif @@ -125,6 +129,7 @@ static const mp_limb_t _tens_in_limb[MAX_DIG_PER_LIMB + 1] = #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) \ @@ -239,7 +244,7 @@ str_to_mpn (const STRING_TYPE *str, int digcnt, mp_limb_t *n, mp_size_t *nsize, /* Number of digits for actual limb. */ int cnt = 0; mp_limb_t low = 0; - mp_limb_t base; + mp_limb_t start; *nsize = 0; assert (digcnt > 0); @@ -262,9 +267,10 @@ str_to_mpn (const STRING_TYPE *str, int digcnt, mp_limb_t *n, mp_size_t *nsize, 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. */ + /* 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. */ while (*str < L_('0') || *str > L_('9')) ++str; low = low * 10 + *str++ - L_('0'); @@ -275,11 +281,11 @@ str_to_mpn (const STRING_TYPE *str, int digcnt, mp_limb_t *n, mp_size_t *nsize, if (*exponent > 0 && cnt + *exponent <= MAX_DIG_PER_LIMB) { low *= _tens_in_limb[*exponent]; - base = _tens_in_limb[cnt + *exponent]; + start = _tens_in_limb[cnt + *exponent]; *exponent = 0; } else - base = _tens_in_limb[cnt]; + start = _tens_in_limb[cnt]; if (*nsize == 0) { @@ -289,11 +295,12 @@ str_to_mpn (const STRING_TYPE *str, int digcnt, mp_limb_t *n, mp_size_t *nsize, else { mp_limb_t cy; - cy = __mpn_mul_1 (n, n, *nsize, base); + cy = __mpn_mul_1 (n, n, *nsize, start); cy += __mpn_add_1 (n, n, *nsize, low); if (cy != 0) n[(*nsize)++] = cy; } + return str; } @@ -346,6 +353,9 @@ INTERNAL (STRTOF) (nptr, endptr, group) 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). */ @@ -485,6 +495,18 @@ INTERNAL (STRTOF) (nptr, endptr, group) 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; @@ -494,25 +516,29 @@ INTERNAL (STRTOF) (nptr, endptr, group) /* If no other digit but a '0' is found the result is 0.0. Return current read pointer. */ - if ((c < L_('0') || c > L_('9')) && (wint_t) c != decimal - && TOLOWER (c) != L_('e')) + if ((c < L_('0') || c > L_('9')) && + (base == 16 && (c < TOLOWER (L_('a')) || c > TOLOWER (L_('f')))) && + (wint_t) c != decimal && + (base == 16 && (cp == start_of_digits || TOLOWER (c) != L_('p'))) && + (base != 16 && TOLOWER (c) != L_('e'))) { tp = correctly_grouped_prefix (start_of_digits, cp, thousands, grouping); /* If TP is at the start of the digits, there was no correctly grouped prefix of the string; so no number found. */ - RETURN (0.0, tp == start_of_digits ? nptr : tp); + RETURN (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 (dig_no < NDIG || + while (dig_no < (base == 16 ? HEXNDIG : NDIG) || /* If parsing grouping info, keep going past useful digits so we can check all the grouping separators. */ grouping) { - if (c >= L_('0') && c <= L_('9')) + if ((c >= L_('0') && c <= L_('9')) + || (base == 16 && TOLOWER (c) >= L_('a') && TOLOWER (c) <= L_('f'))) ++dig_no; else if (thousands == L'\0' || (wint_t) c != thousands) /* Not a digit or separator: end of the integer part. */ @@ -552,7 +578,7 @@ INTERNAL (STRTOF) (nptr, endptr, group) } } - if (dig_no >= NDIG) + if (dig_no >= (base == 16 ? HEXNDIG : NDIG)) /* Too many digits to be representable. Assigning this to EXPONENT allows us to read the full number but return HUGE_VAL after parsing. */ exponent = MAX_10_EXP; @@ -567,7 +593,8 @@ INTERNAL (STRTOF) (nptr, endptr, group) if ((wint_t) c == decimal) { c = *++cp; - while (c >= L_('0') && c <= L_('9')) + while (c >= L_('0') && c <= L_('9') || + (base == 16 && TOLOWER (c) >= L_('a') && TOLOWER (c) <= L_('f'))) { if (c != L_('0') && lead_zero == -1) lead_zero = dig_no - int_no; @@ -580,7 +607,7 @@ INTERNAL (STRTOF) (nptr, endptr, group) expp = cp; /* Read exponent. */ - if (TOLOWER (c) == L_('e')) + if (TOLOWER (c) == (base == 16 ? L_('p') : L_('e'))) { int exp_negative = 0; @@ -598,9 +625,14 @@ INTERNAL (STRTOF) (nptr, endptr, group) int exp_limit; /* Get the exponent limit. */ - exp_limit = exp_negative ? - -MIN_10_EXP + MANT_DIG - int_no : - MAX_10_EXP - int_no + lead_zero; + if (base == 16) + exp_limit = (exp_negative ? + -MIN_EXP + MANT_DIG - 4 * int_no : + MAX_EXP - 4 * int_no + lead_zero); + else + exp_limit = (exp_negative ? + -MIN_10_EXP + MANT_DIG - int_no : + MAX_10_EXP - int_no + lead_zero); do { @@ -610,11 +642,11 @@ INTERNAL (STRTOF) (nptr, endptr, group) /* The exponent is too large/small to represent a valid number. */ { - FLOAT retval; + FLOAT result; /* Overflow or underflow. */ __set_errno (ERANGE); - retval = (exp_negative ? 0.0 : + result = (exp_negative ? 0.0 : negative ? -FLOAT_HUGE_VAL : FLOAT_HUGE_VAL); /* Accept all following digits as part of the exponent. */ @@ -622,7 +654,7 @@ INTERNAL (STRTOF) (nptr, endptr, group) ++cp; while (*cp >= L_('0') && *cp <= L_('9')); - RETURN (retval, cp); + RETURN (result, cp); /* NOTREACHED */ } @@ -664,17 +696,89 @@ INTERNAL (STRTOF) (nptr, endptr, group) while ((wint_t) *startp != decimal) ++startp; startp += lead_zero + 1; - exponent -= lead_zero; + 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; + if (ISDIGIT (*startp)) + val = *startp++ - L_('0'); + else + val = 10 + TOLOWER (*startp++) - L_('a'); + bits = nbits[val]; + + if (pos + 1 >= 4) + { + /* We don't have to care for wrapping. This is the normal + case so we add this optimization. */ + retval[idx] = val << (pos - bits + 1); + pos -= bits; + } + else + { + if (pos + 1 >= bits) + { + 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); + } + } + + while (--dig_no > 0 && idx >= 0) + { + while (!ISXDIGIT (*startp)) + ++startp; + 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); + register int incr = (exponent < 0 ? MAX (-int_no, exponent) + : MIN (dig_no - int_no, exponent)); int_no += incr; exponent -= incr; } @@ -711,9 +815,10 @@ INTERNAL (STRTOF) (nptr, endptr, group) 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. */ + /* 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, &ttab->array[_FPIO_CONST_OFFSET], @@ -848,7 +953,7 @@ INTERNAL (STRTOF) (nptr, endptr, group) assert (dig_no > int_no && exponent <= 0); - /* For the fractional part we need not process too much digits. One + /* 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 @@ -1126,7 +1231,9 @@ INTERNAL (STRTOF) (nptr, endptr, group) for (i = RETURN_LIMB_SIZE; i > empty; --i) retval[i] = retval[i - empty]; #endif +#if RETURN_LIMB_SIZE > 1 retval[1] = 0; +#endif for (i = numsize; i > 0; --i) num[i + empty] = num[i - 1]; MPN_ZERO (num, empty + 1); |