Author: stian
Branch: improve-rbigint
Changeset: r56336:e8c1863ac3e4
Date: 2012-06-26 02:45 +0200
http://bitbucket.org/pypy/pypy/changeset/e8c1863ac3e4/
Log: Some not working code for checking for int128 support. Also add
support for non-int128 platforms as soon as we can detect them.
diff --git a/pypy/rlib/rbigint.py b/pypy/rlib/rbigint.py
--- a/pypy/rlib/rbigint.py
+++ b/pypy/rlib/rbigint.py
@@ -7,17 +7,35 @@
from pypy.rlib import jit
from pypy.rpython.lltypesystem import lltype, rffi
from pypy.rpython import extregistry
+from pypy.rpython.tool import rffi_platform
+from pypy.translator.tool.cbuild import ExternalCompilationInfo
import math, sys
+# Check for int128 support. Is this right? It sure doesn't work.
+"""class CConfig:
+ _compilation_info_ = ExternalCompilationInfo()
+
+ __INT128 = rffi_platform.SimpleType("__int128", rffi.__INT128)
+
+cConfig = rffi_platform.configure(CConfig)"""
+
+SUPPORT_INT128 = True
+
# note about digit sizes:
# In division, the native integer type must be able to hold
# a sign bit plus two digits plus 1 overflow bit.
#SHIFT = (LONG_BIT // 2) - 1
-SHIFT = 63
-
-MASK = long((1 << SHIFT) - 1)
+if SUPPORT_INT128:
+ SHIFT = 63
+ MASK = long((1 << SHIFT) - 1)
+ UDIGIT_TYPE = r_ulonglong
+else:
+ SHIFT = 31
+ MASK = int((1 << SHIFT) - 1)
+ UDIGIT_TYPE = r_uint
+
FLOAT_MULTIPLIER = float(1 << LONG_BIT) # Because it works.
CACHE_INTS = 1024 # CPython do 256
@@ -34,7 +52,12 @@
# Karatsuba is O(N**1.585)
USE_KARATSUBA = True # set to False for comparison
-KARATSUBA_CUTOFF = 19 #38
+
+if SHIFT > 31:
+ KARATSUBA_CUTOFF = 19
+else:
+ KARATSUBA_CUTOFF = 38
+
KARATSUBA_SQUARE_CUTOFF = 2 * KARATSUBA_CUTOFF
USE_TOOMCOCK = False # WIP
@@ -48,8 +71,13 @@
FIVEARY_CUTOFF = 8
-def _mask_digit(x):
- return longlongmask(x & MASK) #intmask(x & MASK)
+if SHIFT <= 31:
+ def _mask_digit(x):
+ return intmask(x & MASK)
+else:
+ def _mask_digit(x):
+ return longlongmask(x & MASK)
+
_mask_digit._annspecialcase_ = 'specialize:argtype(0)'
def _widen_digit(x):
@@ -95,7 +123,10 @@
def _check_digits(l):
for x in l:
assert type(x) is type(NULLDIGIT)
- assert longlongmask(x) & MASK == longlongmask(x)
+ if SHIFT <= 31:
+ assert intmask(x) & MASK == intmask(x)
+ else:
+ assert longlongmask(x) & MASK == longlongmask(x)
class Entry(extregistry.ExtRegistryEntry):
_about_ = _check_digits
@@ -882,7 +913,7 @@
size_a, size_b = size_b, size_a
z = rbigint([NULLDIGIT] * (size_a + 1), 1)
i = 0
- carry = r_ulonglong(0)
+ carry = UDIGIT_TYPE(0)
while i < size_b:
carry += a.udigit(i) + b.udigit(i)
z.setdigit(i, carry)
@@ -926,7 +957,7 @@
size_a = size_b = i+1
z = rbigint([NULLDIGIT] * size_a, sign)
- borrow = r_ulonglong(0)
+ borrow = UDIGIT_TYPE(0)
i = 0
while i < size_b:
# The following assumes unsigned arithmetic
@@ -1430,7 +1461,7 @@
def _x_divrem(v1, w1):
""" Unsigned bigint division with remainder -- the algorithm """
size_w = w1.numdigits()
- d = (r_ulonglong(MASK)+1) // (w1.udigit(size_w-1) + 1)
+ d = (UDIGIT_TYPE(MASK)+1) // (w1.udigit(size_w-1) + 1)
assert d <= MASK # because the first digit of w1 is not zero
d = longlongmask(d)
v = _muladd1(v1, d)
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