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Diffstat (limited to 'gnu/usr.bin/perl/numeric.c')
| -rw-r--r-- | gnu/usr.bin/perl/numeric.c | 944 |
1 files changed, 944 insertions, 0 deletions
diff --git a/gnu/usr.bin/perl/numeric.c b/gnu/usr.bin/perl/numeric.c new file mode 100644 index 00000000000..b193e0c2e4a --- /dev/null +++ b/gnu/usr.bin/perl/numeric.c @@ -0,0 +1,944 @@ +/* numeric.c + * + * Copyright (c) 2001-2002, Larry Wall + * + * You may distribute under the terms of either the GNU General Public + * License or the Artistic License, as specified in the README file. + * + */ + +/* + * "That only makes eleven (plus one mislaid) and not fourteen, unless + * wizards count differently to other people." + */ + +/* +=head1 Numeric functions +*/ + +#include "EXTERN.h" +#define PERL_IN_NUMERIC_C +#include "perl.h" + +U32 +Perl_cast_ulong(pTHX_ NV f) +{ + if (f < 0.0) + return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f; + if (f < U32_MAX_P1) { +#if CASTFLAGS & 2 + if (f < U32_MAX_P1_HALF) + return (U32) f; + f -= U32_MAX_P1_HALF; + return ((U32) f) | (1 + U32_MAX >> 1); +#else + return (U32) f; +#endif + } + return f > 0 ? U32_MAX : 0 /* NaN */; +} + +I32 +Perl_cast_i32(pTHX_ NV f) +{ + if (f < I32_MAX_P1) + return f < I32_MIN ? I32_MIN : (I32) f; + if (f < U32_MAX_P1) { +#if CASTFLAGS & 2 + if (f < U32_MAX_P1_HALF) + return (I32)(U32) f; + f -= U32_MAX_P1_HALF; + return (I32)(((U32) f) | (1 + U32_MAX >> 1)); +#else + return (I32)(U32) f; +#endif + } + return f > 0 ? (I32)U32_MAX : 0 /* NaN */; +} + +IV +Perl_cast_iv(pTHX_ NV f) +{ + if (f < IV_MAX_P1) + return f < IV_MIN ? IV_MIN : (IV) f; + if (f < UV_MAX_P1) { +#if CASTFLAGS & 2 + /* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */ + if (f < UV_MAX_P1_HALF) + return (IV)(UV) f; + f -= UV_MAX_P1_HALF; + return (IV)(((UV) f) | (1 + UV_MAX >> 1)); +#else + return (IV)(UV) f; +#endif + } + return f > 0 ? (IV)UV_MAX : 0 /* NaN */; +} + +UV +Perl_cast_uv(pTHX_ NV f) +{ + if (f < 0.0) + return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f; + if (f < UV_MAX_P1) { +#if CASTFLAGS & 2 + if (f < UV_MAX_P1_HALF) + return (UV) f; + f -= UV_MAX_P1_HALF; + return ((UV) f) | (1 + UV_MAX >> 1); +#else + return (UV) f; +#endif + } + return f > 0 ? UV_MAX : 0 /* NaN */; +} + +#if defined(HUGE_VAL) || (defined(USE_LONG_DOUBLE) && defined(HUGE_VALL)) +/* + * This hack is to force load of "huge" support from libm.a + * So it is in perl for (say) POSIX to use. + * Needed for SunOS with Sun's 'acc' for example. + */ +NV +Perl_huge(void) +{ +# if defined(USE_LONG_DOUBLE) && defined(HUGE_VALL) + return HUGE_VALL; +# endif + return HUGE_VAL; +} +#endif + +/* +=for apidoc grok_bin + +converts a string representing a binary number to numeric form. + +On entry I<start> and I<*len> give the string to scan, I<*flags> gives +conversion flags, and I<result> should be NULL or a pointer to an NV. +The scan stops at the end of the string, or the first invalid character. +On return I<*len> is set to the length scanned string, and I<*flags> gives +output flags. + +If the value is <= UV_MAX it is returned as a UV, the output flags are clear, +and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin> +returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags, +and writes the value to I<*result> (or the value is discarded if I<result> +is NULL). + +The hex number may optionally be prefixed with "0b" or "b" unless +C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If +C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary +number may use '_' characters to separate digits. + +=cut + */ + +UV +Perl_grok_bin(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) { + const char *s = start; + STRLEN len = *len_p; + UV value = 0; + NV value_nv = 0; + + const UV max_div_2 = UV_MAX / 2; + bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES; + bool overflowed = FALSE; + + if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) { + /* strip off leading b or 0b. + for compatibility silently suffer "b" and "0b" as valid binary + numbers. */ + if (len >= 1) { + if (s[0] == 'b') { + s++; + len--; + } + else if (len >= 2 && s[0] == '0' && s[1] == 'b') { + s+=2; + len-=2; + } + } + } + + for (; len-- && *s; s++) { + char bit = *s; + if (bit == '0' || bit == '1') { + /* Write it in this wonky order with a goto to attempt to get the + compiler to make the common case integer-only loop pretty tight. + With gcc seems to be much straighter code than old scan_bin. */ + redo: + if (!overflowed) { + if (value <= max_div_2) { + value = (value << 1) | (bit - '0'); + continue; + } + /* Bah. We're just overflowed. */ + if (ckWARN_d(WARN_OVERFLOW)) + Perl_warner(aTHX_ packWARN(WARN_OVERFLOW), + "Integer overflow in binary number"); + overflowed = TRUE; + value_nv = (NV) value; + } + value_nv *= 2.0; + /* If an NV has not enough bits in its mantissa to + * represent a UV this summing of small low-order numbers + * is a waste of time (because the NV cannot preserve + * the low-order bits anyway): we could just remember when + * did we overflow and in the end just multiply value_nv by the + * right amount. */ + value_nv += (NV)(bit - '0'); + continue; + } + if (bit == '_' && len && allow_underscores && (bit = s[1]) + && (bit == '0' || bit == '1')) + { + --len; + ++s; + goto redo; + } + if (ckWARN(WARN_DIGIT)) + Perl_warner(aTHX_ packWARN(WARN_DIGIT), + "Illegal binary digit '%c' ignored", *s); + break; + } + + if ( ( overflowed && value_nv > 4294967295.0) +#if UVSIZE > 4 + || (!overflowed && value > 0xffffffff ) +#endif + ) { + if (ckWARN(WARN_PORTABLE)) + Perl_warner(aTHX_ packWARN(WARN_PORTABLE), + "Binary number > 0b11111111111111111111111111111111 non-portable"); + } + *len_p = s - start; + if (!overflowed) { + *flags = 0; + return value; + } + *flags = PERL_SCAN_GREATER_THAN_UV_MAX; + if (result) + *result = value_nv; + return UV_MAX; +} + +/* +=for apidoc grok_hex + +converts a string representing a hex number to numeric form. + +On entry I<start> and I<*len> give the string to scan, I<*flags> gives +conversion flags, and I<result> should be NULL or a pointer to an NV. +The scan stops at the end of the string, or the first non-hex-digit character. +On return I<*len> is set to the length scanned string, and I<*flags> gives +output flags. + +If the value is <= UV_MAX it is returned as a UV, the output flags are clear, +and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex> +returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags, +and writes the value to I<*result> (or the value is discarded if I<result> +is NULL). + +The hex number may optionally be prefixed with "0x" or "x" unless +C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If +C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the hex +number may use '_' characters to separate digits. + +=cut + */ + +UV +Perl_grok_hex(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) { + const char *s = start; + STRLEN len = *len_p; + UV value = 0; + NV value_nv = 0; + + const UV max_div_16 = UV_MAX / 16; + bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES; + bool overflowed = FALSE; + const char *hexdigit; + + if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) { + /* strip off leading x or 0x. + for compatibility silently suffer "x" and "0x" as valid hex numbers. + */ + if (len >= 1) { + if (s[0] == 'x') { + s++; + len--; + } + else if (len >= 2 && s[0] == '0' && s[1] == 'x') { + s+=2; + len-=2; + } + } + } + + for (; len-- && *s; s++) { + hexdigit = strchr((char *) PL_hexdigit, *s); + if (hexdigit) { + /* Write it in this wonky order with a goto to attempt to get the + compiler to make the common case integer-only loop pretty tight. + With gcc seems to be much straighter code than old scan_hex. */ + redo: + if (!overflowed) { + if (value <= max_div_16) { + value = (value << 4) | ((hexdigit - PL_hexdigit) & 15); + continue; + } + /* Bah. We're just overflowed. */ + if (ckWARN_d(WARN_OVERFLOW)) + Perl_warner(aTHX_ packWARN(WARN_OVERFLOW), + "Integer overflow in hexadecimal number"); + overflowed = TRUE; + value_nv = (NV) value; + } + value_nv *= 16.0; + /* If an NV has not enough bits in its mantissa to + * represent a UV this summing of small low-order numbers + * is a waste of time (because the NV cannot preserve + * the low-order bits anyway): we could just remember when + * did we overflow and in the end just multiply value_nv by the + * right amount of 16-tuples. */ + value_nv += (NV)((hexdigit - PL_hexdigit) & 15); + continue; + } + if (*s == '_' && len && allow_underscores && s[1] + && (hexdigit = strchr((char *) PL_hexdigit, s[1]))) + { + --len; + ++s; + goto redo; + } + if (ckWARN(WARN_DIGIT)) + Perl_warner(aTHX_ packWARN(WARN_DIGIT), + "Illegal hexadecimal digit '%c' ignored", *s); + break; + } + + if ( ( overflowed && value_nv > 4294967295.0) +#if UVSIZE > 4 + || (!overflowed && value > 0xffffffff ) +#endif + ) { + if (ckWARN(WARN_PORTABLE)) + Perl_warner(aTHX_ packWARN(WARN_PORTABLE), + "Hexadecimal number > 0xffffffff non-portable"); + } + *len_p = s - start; + if (!overflowed) { + *flags = 0; + return value; + } + *flags = PERL_SCAN_GREATER_THAN_UV_MAX; + if (result) + *result = value_nv; + return UV_MAX; +} + +/* +=for apidoc grok_oct + + +=cut + */ + +UV +Perl_grok_oct(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) { + const char *s = start; + STRLEN len = *len_p; + UV value = 0; + NV value_nv = 0; + + const UV max_div_8 = UV_MAX / 8; + bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES; + bool overflowed = FALSE; + + for (; len-- && *s; s++) { + /* gcc 2.95 optimiser not smart enough to figure that this subtraction + out front allows slicker code. */ + int digit = *s - '0'; + if (digit >= 0 && digit <= 7) { + /* Write it in this wonky order with a goto to attempt to get the + compiler to make the common case integer-only loop pretty tight. + */ + redo: + if (!overflowed) { + if (value <= max_div_8) { + value = (value << 3) | digit; + continue; + } + /* Bah. We're just overflowed. */ + if (ckWARN_d(WARN_OVERFLOW)) + Perl_warner(aTHX_ packWARN(WARN_OVERFLOW), + "Integer overflow in octal number"); + overflowed = TRUE; + value_nv = (NV) value; + } + value_nv *= 8.0; + /* If an NV has not enough bits in its mantissa to + * represent a UV this summing of small low-order numbers + * is a waste of time (because the NV cannot preserve + * the low-order bits anyway): we could just remember when + * did we overflow and in the end just multiply value_nv by the + * right amount of 8-tuples. */ + value_nv += (NV)digit; + continue; + } + if (digit == ('_' - '0') && len && allow_underscores + && (digit = s[1] - '0') && (digit >= 0 && digit <= 7)) + { + --len; + ++s; + goto redo; + } + /* Allow \octal to work the DWIM way (that is, stop scanning + * as soon as non-octal characters are seen, complain only iff + * someone seems to want to use the digits eight and nine). */ + if (digit == 8 || digit == 9) { + if (ckWARN(WARN_DIGIT)) + Perl_warner(aTHX_ packWARN(WARN_DIGIT), + "Illegal octal digit '%c' ignored", *s); + } + break; + } + + if ( ( overflowed && value_nv > 4294967295.0) +#if UVSIZE > 4 + || (!overflowed && value > 0xffffffff ) +#endif + ) { + if (ckWARN(WARN_PORTABLE)) + Perl_warner(aTHX_ packWARN(WARN_PORTABLE), + "Octal number > 037777777777 non-portable"); + } + *len_p = s - start; + if (!overflowed) { + *flags = 0; + return value; + } + *flags = PERL_SCAN_GREATER_THAN_UV_MAX; + if (result) + *result = value_nv; + return UV_MAX; +} + +/* +=for apidoc scan_bin + +For backwards compatibility. Use C<grok_bin> instead. + +=for apidoc scan_hex + +For backwards compatibility. Use C<grok_hex> instead. + +=for apidoc scan_oct + +For backwards compatibility. Use C<grok_oct> instead. + +=cut + */ + +NV +Perl_scan_bin(pTHX_ char *start, STRLEN len, STRLEN *retlen) +{ + NV rnv; + I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; + UV ruv = grok_bin (start, &len, &flags, &rnv); + + *retlen = len; + return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; +} + +NV +Perl_scan_oct(pTHX_ char *start, STRLEN len, STRLEN *retlen) +{ + NV rnv; + I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; + UV ruv = grok_oct (start, &len, &flags, &rnv); + + *retlen = len; + return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; +} + +NV +Perl_scan_hex(pTHX_ char *start, STRLEN len, STRLEN *retlen) +{ + NV rnv; + I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; + UV ruv = grok_hex (start, &len, &flags, &rnv); + + *retlen = len; + return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; +} + +/* +=for apidoc grok_numeric_radix + +Scan and skip for a numeric decimal separator (radix). + +=cut + */ +bool +Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send) +{ +#ifdef USE_LOCALE_NUMERIC + if (PL_numeric_radix_sv && IN_LOCALE) { + STRLEN len; + char* radix = SvPV(PL_numeric_radix_sv, len); + if (*sp + len <= send && memEQ(*sp, radix, len)) { + *sp += len; + return TRUE; + } + } + /* always try "." if numeric radix didn't match because + * we may have data from different locales mixed */ +#endif + if (*sp < send && **sp == '.') { + ++*sp; + return TRUE; + } + return FALSE; +} + +/* +=for apidoc grok_number + +Recognise (or not) a number. The type of the number is returned +(0 if unrecognised), otherwise it is a bit-ORed combination of +IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT, +IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h). + +If the value of the number can fit an in UV, it is returned in the *valuep +IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV +will never be set unless *valuep is valid, but *valuep may have been assigned +to during processing even though IS_NUMBER_IN_UV is not set on return. +If valuep is NULL, IS_NUMBER_IN_UV will be set for the same cases as when +valuep is non-NULL, but no actual assignment (or SEGV) will occur. + +IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were +seen (in which case *valuep gives the true value truncated to an integer), and +IS_NUMBER_NEG if the number is negative (in which case *valuep holds the +absolute value). IS_NUMBER_IN_UV is not set if e notation was used or the +number is larger than a UV. + +=cut + */ +int +Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep) +{ + const char *s = pv; + const char *send = pv + len; + const UV max_div_10 = UV_MAX / 10; + const char max_mod_10 = UV_MAX % 10; + int numtype = 0; + int sawinf = 0; + int sawnan = 0; + + while (s < send && isSPACE(*s)) + s++; + if (s == send) { + return 0; + } else if (*s == '-') { + s++; + numtype = IS_NUMBER_NEG; + } + else if (*s == '+') + s++; + + if (s == send) + return 0; + + /* next must be digit or the radix separator or beginning of infinity */ + if (isDIGIT(*s)) { + /* UVs are at least 32 bits, so the first 9 decimal digits cannot + overflow. */ + UV value = *s - '0'; + /* This construction seems to be more optimiser friendly. + (without it gcc does the isDIGIT test and the *s - '0' separately) + With it gcc on arm is managing 6 instructions (6 cycles) per digit. + In theory the optimiser could deduce how far to unroll the loop + before checking for overflow. */ + if (++s < send) { + int digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + digit = *s - '0'; + if (digit >= 0 && digit <= 9) { + value = value * 10 + digit; + if (++s < send) { + /* Now got 9 digits, so need to check + each time for overflow. */ + digit = *s - '0'; + while (digit >= 0 && digit <= 9 + && (value < max_div_10 + || (value == max_div_10 + && digit <= max_mod_10))) { + value = value * 10 + digit; + if (++s < send) + digit = *s - '0'; + else + break; + } + if (digit >= 0 && digit <= 9 + && (s < send)) { + /* value overflowed. + skip the remaining digits, don't + worry about setting *valuep. */ + do { + s++; + } while (s < send && isDIGIT(*s)); + numtype |= + IS_NUMBER_GREATER_THAN_UV_MAX; + goto skip_value; + } + } + } + } + } + } + } + } + } + } + } + } + } + } + } + } + } + } + numtype |= IS_NUMBER_IN_UV; + if (valuep) + *valuep = value; + + skip_value: + if (GROK_NUMERIC_RADIX(&s, send)) { + numtype |= IS_NUMBER_NOT_INT; + while (s < send && isDIGIT(*s)) /* optional digits after the radix */ + s++; + } + } + else if (GROK_NUMERIC_RADIX(&s, send)) { + numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */ + /* no digits before the radix means we need digits after it */ + if (s < send && isDIGIT(*s)) { + do { + s++; + } while (s < send && isDIGIT(*s)); + if (valuep) { + /* integer approximation is valid - it's 0. */ + *valuep = 0; + } + } + else + return 0; + } else if (*s == 'I' || *s == 'i') { + s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; + s++; if (s == send || (*s != 'F' && *s != 'f')) return 0; + s++; if (s < send && (*s == 'I' || *s == 'i')) { + s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; + s++; if (s == send || (*s != 'I' && *s != 'i')) return 0; + s++; if (s == send || (*s != 'T' && *s != 't')) return 0; + s++; if (s == send || (*s != 'Y' && *s != 'y')) return 0; + s++; + } + sawinf = 1; + } else if (*s == 'N' || *s == 'n') { + /* XXX TODO: There are signaling NaNs and quiet NaNs. */ + s++; if (s == send || (*s != 'A' && *s != 'a')) return 0; + s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; + s++; + sawnan = 1; + } else + return 0; + + if (sawinf) { + numtype &= IS_NUMBER_NEG; /* Keep track of sign */ + numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT; + } else if (sawnan) { + numtype &= IS_NUMBER_NEG; /* Keep track of sign */ + numtype |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT; + } else if (s < send) { + /* we can have an optional exponent part */ + if (*s == 'e' || *s == 'E') { + /* The only flag we keep is sign. Blow away any "it's UV" */ + numtype &= IS_NUMBER_NEG; + numtype |= IS_NUMBER_NOT_INT; + s++; + if (s < send && (*s == '-' || *s == '+')) + s++; + if (s < send && isDIGIT(*s)) { + do { + s++; + } while (s < send && isDIGIT(*s)); + } + else + return 0; + } + } + while (s < send && isSPACE(*s)) + s++; + if (s >= send) + return numtype; + if (len == 10 && memEQ(pv, "0 but true", 10)) { + if (valuep) + *valuep = 0; + return IS_NUMBER_IN_UV; + } + return 0; +} + +NV +S_mulexp10(NV value, I32 exponent) +{ + NV result = 1.0; + NV power = 10.0; + bool negative = 0; + I32 bit; + + if (exponent == 0) + return value; + + /* On OpenVMS VAX we by default use the D_FLOAT double format, + * and that format does not have *easy* capabilities [1] for + * overflowing doubles 'silently' as IEEE fp does. We also need + * to support G_FLOAT on both VAX and Alpha, and though the exponent + * range is much larger than D_FLOAT it still doesn't do silent + * overflow. Therefore we need to detect early whether we would + * overflow (this is the behaviour of the native string-to-float + * conversion routines, and therefore of native applications, too). + * + * [1] Trying to establish a condition handler to trap floating point + * exceptions is not a good idea. */ + + /* In UNICOS and in certain Cray models (such as T90) there is no + * IEEE fp, and no way at all from C to catch fp overflows gracefully. + * There is something you can do if you are willing to use some + * inline assembler: the instruction is called DFI-- but that will + * disable *all* floating point interrupts, a little bit too large + * a hammer. Therefore we need to catch potential overflows before + * it's too late. */ + +#if ((defined(VMS) && !defined(__IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP) + STMT_START { + NV exp_v = log10(value); + if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP) + return NV_MAX; + if (exponent < 0) { + if (-(exponent + exp_v) >= NV_MAX_10_EXP) + return 0.0; + while (-exponent >= NV_MAX_10_EXP) { + /* combination does not overflow, but 10^(-exponent) does */ + value /= 10; + ++exponent; + } + } + } STMT_END; +#endif + + if (exponent < 0) { + negative = 1; + exponent = -exponent; + } + for (bit = 1; exponent; bit <<= 1) { + if (exponent & bit) { + exponent ^= bit; + result *= power; + /* Floating point exceptions are supposed to be turned off, + * but if we're obviously done, don't risk another iteration. + */ + if (exponent == 0) break; + } + power *= power; + } + return negative ? value / result : value * result; +} + +NV +Perl_my_atof(pTHX_ const char* s) +{ + NV x = 0.0; +#ifdef USE_LOCALE_NUMERIC + if (PL_numeric_local && IN_LOCALE) { + NV y; + + /* Scan the number twice; once using locale and once without; + * choose the larger result (in absolute value). */ + Perl_atof2(s, x); + SET_NUMERIC_STANDARD(); + Perl_atof2(s, y); + SET_NUMERIC_LOCAL(); + if ((y < 0.0 && y < x) || (y > 0.0 && y > x)) + return y; + } + else + Perl_atof2(s, x); +#else + Perl_atof2(s, x); +#endif + return x; +} + +char* +Perl_my_atof2(pTHX_ const char* orig, NV* value) +{ + NV result = 0.0; + char* s = (char*)orig; +#ifdef USE_PERL_ATOF + bool negative = 0; + char* send = s + strlen(orig) - 1; + bool seendigit = 0; + I32 expextra = 0; + I32 exponent = 0; + I32 i; +/* this is arbitrary */ +#define PARTLIM 6 +/* we want the largest integers we can usefully use */ +#if defined(HAS_QUAD) && defined(USE_64_BIT_INT) +# define PARTSIZE ((int)TYPE_DIGITS(U64)-1) + U64 part[PARTLIM]; +#else +# define PARTSIZE ((int)TYPE_DIGITS(U32)-1) + U32 part[PARTLIM]; +#endif + I32 ipart = 0; /* index into part[] */ + I32 offcount; /* number of digits in least significant part */ + + /* leading whitespace */ + while (isSPACE(*s)) + ++s; + + /* sign */ + switch (*s) { + case '-': + negative = 1; + /* fall through */ + case '+': + ++s; + } + + part[0] = offcount = 0; + if (isDIGIT(*s)) { + seendigit = 1; /* get this over with */ + + /* skip leading zeros */ + while (*s == '0') + ++s; + } + + /* integer digits */ + while (isDIGIT(*s)) { + if (++offcount > PARTSIZE) { + if (++ipart < PARTLIM) { + part[ipart] = 0; + offcount = 1; /* ++0 */ + } + else { + /* limits of precision reached */ + --ipart; + --offcount; + if (*s >= '5') + ++part[ipart]; + while (isDIGIT(*s)) { + ++expextra; + ++s; + } + /* warn of loss of precision? */ + break; + } + } + part[ipart] = part[ipart] * 10 + (*s++ - '0'); + } + + /* decimal point */ + if (GROK_NUMERIC_RADIX((const char **)&s, send)) { + if (isDIGIT(*s)) + seendigit = 1; /* get this over with */ + + /* decimal digits */ + while (isDIGIT(*s)) { + if (++offcount > PARTSIZE) { + if (++ipart < PARTLIM) { + part[ipart] = 0; + offcount = 1; /* ++0 */ + } + else { + /* limits of precision reached */ + --ipart; + --offcount; + if (*s >= '5') + ++part[ipart]; + while (isDIGIT(*s)) + ++s; + /* warn of loss of precision? */ + break; + } + } + --expextra; + part[ipart] = part[ipart] * 10 + (*s++ - '0'); + } + } + + /* combine components of mantissa */ + for (i = 0; i <= ipart; ++i) + result += S_mulexp10((NV)part[ipart - i], + i ? offcount + (i - 1) * PARTSIZE : 0); + + if (seendigit && (*s == 'e' || *s == 'E')) { + bool expnegative = 0; + + ++s; + switch (*s) { + case '-': + expnegative = 1; + /* fall through */ + case '+': + ++s; + } + while (isDIGIT(*s)) + exponent = exponent * 10 + (*s++ - '0'); + if (expnegative) + exponent = -exponent; + } + + /* now apply the exponent */ + exponent += expextra; + result = S_mulexp10(result, exponent); + + /* now apply the sign */ + if (negative) + result = -result; +#endif /* USE_PERL_ATOF */ + *value = result; + return s; +} + |