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 (defined in perl.h). If the value
-of the number can fit an in UV, it is returned in the *valuep.
+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 + '0';
- int numtype = 0;
- int sawinf = 0;
+ 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++;
- while (isSPACE(*s))
- s++;
- 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. */
- int digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- digit = *++s - '0';
- if (digit >= 0 && digit <= 9) {
- value = value * 10 + digit;
- /* 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
- && *s <= max_mod_10))) {
- value = value * 10 + digit;
- digit = *++s - '0';
- }
- if (digit >= 0 && digit <= 9) {
- /* value overflowed.
- skip the remaining digits, don't
- worry about setting *valuep. */
- do {
- s++;
- } while (isDIGIT(*s));
- numtype |=
- IS_NUMBER_GREATER_THAN_UV_MAX;
- goto skip_value;
- }
- }
+ /* 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 (isDIGIT(*s)) /* optional digits after the radix */
- s++;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
}
+ }
}
- else if (GROK_NUMERIC_RADIX(&s, send)) {
- numtype |= IS_NUMBER_NOT_INT;
- /* no digits before the radix means we need digits after it */
- if (isDIGIT(*s)) {
- do {
- s++;
- } while (isDIGIT(*s));
- numtype |= IS_NUMBER_IN_UV;
- if (valuep) {
- /* integer approximation is valid - it's 0. */
- *valuep = 0;
- }
- }
- else
- return 0;
+ 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 (*s == 'I' || *s == 'i') {
- s++; if (*s != 'N' && *s != 'n') return 0;
- s++; if (*s != 'F' && *s != 'f') return 0;
- s++; if (*s == 'I' || *s == 'i') {
- s++; if (*s != 'N' && *s != 'n') return 0;
- s++; if (*s != 'I' && *s != 'i') return 0;
- s++; if (*s != 'T' && *s != 't') return 0;
- s++; if (*s != 'Y' && *s != 'y') return 0;
- s++;
- }
- sawinf = 1;
- }
- else /* Add test for NaN here. */
- return 0;
-
- if (sawinf) {
- numtype &= IS_NUMBER_NEG; /* Keep track of sign */
- numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT;
- } else {
- /* 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 == '-' || *s == '+')
- s++;
- if (isDIGIT(*s)) {
- do {
- s++;
- } while (isDIGIT(*s));
- }
- else
- return 0;
- }
+ }
+ 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;
+ }
}
- while (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;
+ 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
negative = 1;
exponent = -exponent;
}
+
+ /* 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. */
+#if defined(VMS) && !defined(__IEEE_FP) && defined(NV_MAX_10_EXP)
+ if (!negative &&
+ (log10(value) + exponent) >= (NV_MAX_10_EXP))
+ return 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.
+ * 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(_UNICOS) && defined(NV_MAX_10_EXP)
+ if (!negative &&
+ (log10(value) + exponent) >= NV_MAX_10_EXP)
+ return NV_MAX;
+#endif
+
for (bit = 1; exponent; bit <<= 1) {
if (exponent & bit) {
exponent ^= bit;
result *= power;
}
+ /* Floating point exceptions are supposed to be turned off. */
power *= power;
}
return negative ? value / result : value * result;
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 '-':
https://perl5.git.perl.org / perl5.git / blobdiff