Author: Carl Friedrich Bolz <[email protected]>
Branch:
Changeset: r73976:de1298e766a8
Date: 2014-10-16 16:47 +0200
http://bitbucket.org/pypy/pypy/changeset/de1298e766a8/
Log: make toint check early whether the conversion *can't* work
(for obscure reasons I have a context where I care about the
performance of the "toint is raising" case a lot)
diff --git a/rpython/rlib/rbigint.py b/rpython/rlib/rbigint.py
--- a/rpython/rlib/rbigint.py
+++ b/rpython/rlib/rbigint.py
@@ -71,7 +71,6 @@
FIVEARY_CUTOFF = 8
-
def _mask_digit(x):
return UDIGIT_MASK(x & MASK)
_mask_digit._annspecialcase_ = 'specialize:argtype(0)'
@@ -384,12 +383,17 @@
digits = ''.join([digits[i] for i in range(length-1, -1, -1)])
return digits
- @jit.elidable
def toint(self):
"""
Get an integer from a bigint object.
Raises OverflowError if overflow occurs.
"""
+ if self.numdigits() > MAX_DIGITS_THAT_CAN_FIT_IN_INT:
+ raise OverflowError
+ return self._toint_helper()
+
+ @jit.elidable
+ def _toint_helper(self):
x = self._touint_helper()
# Haven't lost any bits, but if the sign bit is set we're in
# trouble *unless* this is the min negative number. So,
@@ -422,8 +426,7 @@
prev = x
x = (x << SHIFT) + self.udigit(i)
if (x >> SHIFT) != prev:
- raise OverflowError(
- "long int too large to convert to unsigned int (%d,
%d)" % (x >> SHIFT, prev))
+ raise OverflowError("long int too large to convert to unsigned
int")
i -= 1
return x
@@ -1084,6 +1087,11 @@
(2 * SHIFT) % 5,
(1 * SHIFT) % 5]
+
+# if the bigint has more digits than this, it cannot fit into an int
+MAX_DIGITS_THAT_CAN_FIT_IN_INT = rbigint.fromint(-sys.maxint - 1).numdigits()
+
+
#_________________________________________________________________
# Helper Functions
_______________________________________________
pypy-commit mailing list
[email protected]
https://mail.python.org/mailman/listinfo/pypy-commit
