/* numeric.c
*
- * Copyright (c) 2001-2002, Larry Wall
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ * 2000, 2001, 2002, 2003, 2005 by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
/*
=head1 Numeric functions
+
+This file contains all the stuff needed by perl for manipulating numeric
+values, including such things as replacements for the OS's atof() function
+
+=cut
+
*/
#include "EXTERN.h"
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.
+Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
+invalid character will also trigger a warning.
+On return I<*len> is set to the length of the 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,
+If the value is <= C<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
+The binary 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.
*/
UV
-Perl_grok_bin(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+Perl_grok_bin(pTHX_ const 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;
+ const bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES;
bool overflowed = FALSE;
+ char bit;
if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) {
/* strip off leading b or 0b.
}
}
- for (; len-- && *s; s++) {
- char bit = *s;
+ for (; len-- && (bit = *s); 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.
++s;
goto redo;
}
- if (ckWARN(WARN_DIGIT))
+ if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal binary digit '%c' ignored", *s);
break;
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.
+The scan stops at the end of the string, or the first invalid character.
+Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
+invalid character will also trigger a warning.
+On return I<*len> is set to the length of the 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>
*/
UV
-Perl_grok_hex(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) {
+ dVAR;
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;
+ const 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 (; len-- && *s; s++) {
- hexdigit = strchr((char *) PL_hexdigit, *s);
+ const char *hexdigit = strchr(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.
continue;
}
if (*s == '_' && len && allow_underscores && s[1]
- && (hexdigit = strchr((char *) PL_hexdigit, s[1])))
+ && (hexdigit = strchr(PL_hexdigit, s[1])))
{
--len;
++s;
goto redo;
}
- if (ckWARN(WARN_DIGIT))
+ if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal hexadecimal digit '%c' ignored", *s);
break;
/*
=for apidoc grok_oct
+converts a string representing an octal 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.
+Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
+invalid character will also trigger a warning.
+On return I<*len> is set to the length of the 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_oct>
+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).
+
+If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the octal
+number may use '_' characters to separate digits.
=cut
*/
UV
-Perl_grok_oct(pTHX_ char *start, STRLEN *len_p, I32 *flags, NV *result) {
+Perl_grok_oct(pTHX_ const 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;
+ const bool allow_underscores = *flags & PERL_SCAN_ALLOW_UNDERSCORES;
bool overflowed = FALSE;
for (; len-- && *s; 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
+ * as soon as non-octal characters are seen, complain only if
* someone seems to want to use the digits eight and nine). */
if (digit == 8 || digit == 9) {
- if (ckWARN(WARN_DIGIT))
+ if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT) && ckWARN(WARN_DIGIT))
Perl_warner(aTHX_ packWARN(WARN_DIGIT),
"Illegal octal digit '%c' ignored", *s);
}
*/
NV
-Perl_scan_bin(pTHX_ char *start, STRLEN len, STRLEN *retlen)
+Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
- UV ruv = grok_bin (start, &len, &flags, &rnv);
+ const 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)
+Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
- UV ruv = grok_oct (start, &len, &flags, &rnv);
+ const 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)
+Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen)
{
NV rnv;
I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0;
- UV ruv = grok_hex (start, &len, &flags, &rnv);
+ const UV ruv = grok_hex (start, &len, &flags, &rnv);
*retlen = len;
return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv;
#ifdef USE_LOCALE_NUMERIC
if (PL_numeric_radix_sv && IN_LOCALE) {
STRLEN len;
- char* radix = SvPV(PL_numeric_radix_sv, len);
+ const char* radix = SvPV(PL_numeric_radix_sv, len);
if (*sp + len <= send && memEQ(*sp, radix, len)) {
*sp += len;
return TRUE;
return 0;
}
-NV
+STATIC NV
S_mulexp10(NV value, I32 exponent)
{
NV result = 1.0;
if (exponent == 0)
return value;
- else if (exponent < 0) {
- negative = 1;
- exponent = -exponent;
- }
+ if (value == 0)
+ return (NV)0;
/* On OpenVMS VAX we by default use the D_FLOAT double format,
* and that format does not have *easy* capabilities [1] for
*
* [1] Trying to establish a condition handler to trap floating point
* exceptions is not a good idea. */
-#if defined(VMS) && !defined(__IEEE_FP) && defined(NV_MAX_10_EXP)
- if ((log10(value) + exponent) >= (NV_MAX_10_EXP))
- return negative ? 0.0 : NV_MAX;
-#endif
/* 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.
* 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(_UNICOS) && defined(NV_MAX_10_EXP)
- if (!negative &&
- (log10(value) + exponent) >= NV_MAX_10_EXP)
- return NV_MAX;
+
+#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;
char*
Perl_my_atof2(pTHX_ const char* orig, NV* value)
{
- NV result = 0.0;
- char* s = (char*)orig;
+ NV result[3] = {0.0, 0.0, 0.0};
+ const char* s = orig;
#ifdef USE_PERL_ATOF
+ UV accumulator[2] = {0,0}; /* before/after dp */
bool negative = 0;
- char* send = s + strlen(orig) - 1;
- bool seendigit = 0;
- I32 expextra = 0;
+ const char* send = s + strlen(orig) - 1;
+ bool seen_digit = 0;
+ I32 exp_adjust[2] = {0,0};
+ I32 exp_acc[2] = {-1, -1};
+ /* the current exponent adjust for the accumulators */
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 */
+ I32 seen_dp = 0;
+ I32 digit = 0;
+ I32 old_digit = 0;
+ I32 sig_digits = 0; /* noof significant digits seen so far */
+
+/* There is no point in processing more significant digits
+ * than the NV can hold. Note that NV_DIG is a lower-bound value,
+ * while we need an upper-bound value. We add 2 to account for this;
+ * since it will have been conservative on both the first and last digit.
+ * For example a 32-bit mantissa with an exponent of 4 would have
+ * exact values in the set
+ * 4
+ * 8
+ * ..
+ * 17179869172
+ * 17179869176
+ * 17179869180
+ *
+ * where for the purposes of calculating NV_DIG we would have to discount
+ * both the first and last digit, since neither can hold all values from
+ * 0..9; but for calculating the value we must examine those two digits.
+ */
+#define MAX_SIG_DIGITS (NV_DIG+2)
+
+/* the max number we can accumulate in a UV, and still safely do 10*N+9 */
+#define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10))
/* leading whitespace */
while (isSPACE(*s))
++s;
}
- part[0] = offcount = 0;
- if (isDIGIT(*s)) {
- seendigit = 1; /* get this over with */
-
- /* skip leading zeros */
- while (*s == '0')
- ++s;
+ /* punt to strtod for NaN/Inf; if no support for it there, tough luck */
+
+#ifdef HAS_STRTOD
+ if (*s == 'n' || *s == 'N' || *s == 'i' || *s == 'I') {
+ const char *p = negative ? s - 1 : s;
+ char *endp;
+ NV rslt;
+ rslt = strtod(p, &endp);
+ if (endp != p) {
+ *value = rslt;
+ return (char *)endp;
+ }
}
+#endif
- /* integer digits */
- while (isDIGIT(*s)) {
- if (++offcount > PARTSIZE) {
- if (++ipart < PARTLIM) {
- part[ipart] = 0;
- offcount = 1; /* ++0 */
- }
- else {
+ /* we accumulate digits into an integer; when this becomes too
+ * large, we add the total to NV and start again */
+
+ while (1) {
+ if (isDIGIT(*s)) {
+ seen_digit = 1;
+ old_digit = digit;
+ digit = *s++ - '0';
+ if (seen_dp)
+ exp_adjust[1]++;
+
+ /* don't start counting until we see the first significant
+ * digit, eg the 5 in 0.00005... */
+ if (!sig_digits && digit == 0)
+ continue;
+
+ if (++sig_digits > MAX_SIG_DIGITS) {
/* limits of precision reached */
- --ipart;
- --offcount;
- if (*s >= '5')
- ++part[ipart];
+ if (digit > 5) {
+ ++accumulator[seen_dp];
+ } else if (digit == 5) {
+ if (old_digit % 2) { /* round to even - Allen */
+ ++accumulator[seen_dp];
+ }
+ }
+ if (seen_dp) {
+ exp_adjust[1]--;
+ } else {
+ exp_adjust[0]++;
+ }
+ /* skip remaining digits */
while (isDIGIT(*s)) {
- ++expextra;
++s;
+ if (! seen_dp) {
+ exp_adjust[0]++;
+ }
}
/* 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 {
+ if (accumulator[seen_dp] > MAX_ACCUMULATE) {
+ /* add accumulator to result and start again */
+ result[seen_dp] = S_mulexp10(result[seen_dp],
+ exp_acc[seen_dp])
+ + (NV)accumulator[seen_dp];
+ accumulator[seen_dp] = 0;
+ exp_acc[seen_dp] = 0;
}
- else {
- /* limits of precision reached */
- --ipart;
- --offcount;
- if (*s >= '5')
- ++part[ipart];
- while (isDIGIT(*s))
- ++s;
- /* warn of loss of precision? */
- break;
+ accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit;
+ ++exp_acc[seen_dp];
+ }
+ }
+ else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) {
+ seen_dp = 1;
+ if (sig_digits > MAX_SIG_DIGITS) {
+ ++s;
+ while (isDIGIT(*s)) {
+ ++s;
}
+ break;
}
- --expextra;
- part[ipart] = part[ipart] * 10 + (*s++ - '0');
+ }
+ else {
+ break;
}
}
- /* combine components of mantissa */
- for (i = 0; i <= ipart; ++i)
- result += S_mulexp10((NV)part[ipart - i],
- i ? offcount + (i - 1) * PARTSIZE : 0);
+ result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0];
+ if (seen_dp) {
+ result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1];
+ }
- if (seendigit && (*s == 'e' || *s == 'E')) {
+ if (seen_digit && (*s == 'e' || *s == 'E')) {
bool expnegative = 0;
++s;
exponent = -exponent;
}
+
+
/* now apply the exponent */
- exponent += expextra;
- result = S_mulexp10(result, exponent);
+
+ if (seen_dp) {
+ result[2] = S_mulexp10(result[0],exponent+exp_adjust[0])
+ + S_mulexp10(result[1],exponent-exp_adjust[1]);
+ } else {
+ result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]);
+ }
/* now apply the sign */
if (negative)
- result = -result;
+ result[2] = -result[2];
#endif /* USE_PERL_ATOF */
- *value = result;
- return s;
+ *value = result[2];
+ return (char *)s;
+}
+
+#if ! defined(HAS_MODFL) && defined(HAS_AINTL) && defined(HAS_COPYSIGNL)
+long double
+Perl_my_modfl(long double x, long double *ip)
+{
+ *ip = aintl(x);
+ return (x == *ip ? copysignl(0.0L, x) : x - *ip);
}
+#endif
+#if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL)
+long double
+Perl_my_frexpl(long double x, int *e) {
+ *e = x == 0.0L ? 0 : ilogbl(x) + 1;
+ return (scalbnl(x, -*e));
+}
+#endif
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */