/* 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;
}
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