diff options
Diffstat (limited to 'numeric.c')
| -rw-r--r-- | numeric.c | 466 |
1 files changed, 307 insertions, 159 deletions
@@ -105,156 +105,161 @@ Perl_huge(void) } #endif -NV -Perl_scan_bin(pTHX_ char *start, STRLEN len, STRLEN *retlen) -{ - register char *s = start; - register NV rnv = 0.0; - register UV ruv = 0; - register bool seenb = FALSE; - register bool overflowed = FALSE; +/* +=for apidoc grok_bin - for (; len-- && *s; s++) { - if (!(*s == '0' || *s == '1')) { - if (*s == '_' && len && *retlen - && (s[1] == '0' || s[1] == '1')) - { - --len; - ++s; - } - else if (seenb == FALSE && *s == 'b' && ruv == 0) { - /* Disallow 0bbb0b0bbb... */ - seenb = TRUE; - continue; - } - else { - if (ckWARN(WARN_DIGIT)) - Perl_warner(aTHX_ WARN_DIGIT, - "Illegal binary digit '%c' ignored", *s); - break; - } +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 optinally be prefixed with "0b" or "b". If +C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> on entry 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; + + /* 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--; } - if (!overflowed) { - register UV xuv = ruv << 1; - - if ((xuv >> 1) != ruv) { - overflowed = TRUE; - rnv = (NV) ruv; - if (ckWARN_d(WARN_OVERFLOW)) - Perl_warner(aTHX_ WARN_OVERFLOW, - "Integer overflow in binary number"); - } - else - ruv = xuv | (*s - '0'); + else if (len >= 2 && s[0] == '0' && s[1] == 'b') { + s+=2; + len-=2; } - if (overflowed) { - rnv *= 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_ 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 an 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 rnv by the + * did we overflow and in the end just multiply value_nv by the * right amount. */ - rnv += (*s - '0'); - } - } - if (!overflowed) - rnv = (NV) ruv; - if ( ( overflowed && rnv > 4294967295.0) -#if UVSIZE > 4 - || (!overflowed && ruv > 0xffffffff ) -#endif - ) { - if (ckWARN(WARN_PORTABLE)) - Perl_warner(aTHX_ WARN_PORTABLE, - "Binary number > 0b11111111111111111111111111111111 non-portable"); - } - *retlen = s - start; - return rnv; -} - -NV -Perl_scan_oct(pTHX_ char *start, STRLEN len, STRLEN *retlen) -{ - register char *s = start; - register NV rnv = 0.0; - register UV ruv = 0; - register bool overflowed = FALSE; - - for (; len-- && *s; s++) { - if (!(*s >= '0' && *s <= '7')) { - if (*s == '_' && len && *retlen - && (s[1] >= '0' && s[1] <= '7')) + value_nv += (NV)(bit - '0'); + continue; + } + if (bit == '_' && len && allow_underscores && (bit = s[1]) + && (bit == '0' || bit == '1')) { --len; ++s; + goto redo; } - else { - /* 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 (*s == '8' || *s == '9') { - if (ckWARN(WARN_DIGIT)) - Perl_warner(aTHX_ WARN_DIGIT, - "Illegal octal digit '%c' ignored", *s); - } - break; - } - } - if (!overflowed) { - register UV xuv = ruv << 3; - - if ((xuv >> 3) != ruv) { - overflowed = TRUE; - rnv = (NV) ruv; - if (ckWARN_d(WARN_OVERFLOW)) - Perl_warner(aTHX_ WARN_OVERFLOW, - "Integer overflow in octal number"); - } - else - ruv = xuv | (*s - '0'); - } - if (overflowed) { - rnv *= 8.0; - /* If an NV has not enough bits in its mantissa to - * represent an 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 rnv by the - * right amount of 8-tuples. */ - rnv += (NV)(*s - '0'); - } + if (ckWARN(WARN_DIGIT)) + Perl_warner(aTHX_ WARN_DIGIT, + "Illegal binary digit '%c' ignored", *s); + break; } - if (!overflowed) - rnv = (NV) ruv; - if ( ( overflowed && rnv > 4294967295.0) + + if ( ( overflowed && value_nv > 4294967295.0) #if UVSIZE > 4 - || (!overflowed && ruv > 0xffffffff ) + || (!overflowed && value > 0xffffffff ) #endif ) { if (ckWARN(WARN_PORTABLE)) Perl_warner(aTHX_ WARN_PORTABLE, - "Octal number > 037777777777 non-portable"); + "Binary number > 0b11111111111111111111111111111111 non-portable"); } - *retlen = s - start; - return rnv; + *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; } -NV -Perl_scan_hex(pTHX_ char *start, STRLEN len, STRLEN *retlen) -{ - register char *s = start; - register NV rnv = 0.0; - register UV ruv = 0; - register bool overflowed = FALSE; - char *hexdigit; +/* +=for apidoc grok_hex - if (len > 2) { +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 optinally be prefixed with "0x" or "x". If +C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> on entry 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; + + /* 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 > 3 && s[0] == '0' && s[1] == 'x') { + else if (len >= 2 && s[0] == '0' && s[1] == 'x') { s+=2; len-=2; } @@ -262,57 +267,200 @@ Perl_scan_hex(pTHX_ char *start, STRLEN len, STRLEN *retlen) for (; len-- && *s; s++) { hexdigit = strchr((char *) PL_hexdigit, *s); - if (!hexdigit) { - if (*s == '_' && len && *retlen && s[1] + 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_ 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 an 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; } - else { - if (ckWARN(WARN_DIGIT)) - Perl_warner(aTHX_ WARN_DIGIT, - "Illegal hexadecimal digit '%c' ignored", *s); - break; - } - } - if (!overflowed) { - register UV xuv = ruv << 4; - - if ((xuv >> 4) != ruv) { - overflowed = TRUE; - rnv = (NV) ruv; - if (ckWARN_d(WARN_OVERFLOW)) - Perl_warner(aTHX_ WARN_OVERFLOW, - "Integer overflow in hexadecimal number"); - } - else - ruv = xuv | ((hexdigit - PL_hexdigit) & 15); - } - if (overflowed) { - rnv *= 16.0; + if (ckWARN(WARN_DIGIT)) + Perl_warner(aTHX_ 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_ 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_ 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 an 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 rnv by the - * right amount of 16-tuples. */ - rnv += (NV)((hexdigit - PL_hexdigit) & 15); - } + * 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_ WARN_DIGIT, + "Illegal octal digit '%c' ignored", *s); + } + break; } - if (!overflowed) - rnv = (NV) ruv; - if ( ( overflowed && rnv > 4294967295.0) + + if ( ( overflowed && value_nv > 4294967295.0) #if UVSIZE > 4 - || (!overflowed && ruv > 0xffffffff ) + || (!overflowed && value > 0xffffffff ) #endif ) { if (ckWARN(WARN_PORTABLE)) Perl_warner(aTHX_ WARN_PORTABLE, - "Hexadecimal number > 0xffffffff non-portable"); + "Octal number > 037777777777 non-portable"); + } + *len_p = s - start; + if (!overflowed) { + *flags = 0; + return value; } - *retlen = s - start; - return rnv; + *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; } /* |