stock perl 5.8.0 from CPAN

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;
+}
+