Author: David Schneider <david.schnei...@picle.org>
Branch:
Changeset: r64940:fcd5bdf14412
Date: 2013-06-19 13:10 -0500
http://bitbucket.org/pypy/pypy/changeset/fcd5bdf14412/
Log: fix for the bitmask calculation of bitfields in _rawffi and ctypes
On 32 bit systems longlong bitfields need a bitmask that is larger
than a word
diff --git a/pypy/module/_rawffi/structure.py b/pypy/module/_rawffi/structure.py
--- a/pypy/module/_rawffi/structure.py
+++ b/pypy/module/_rawffi/structure.py
@@ -15,7 +15,8 @@
from pypy.module._rawffi.interp_rawffi import size_alignment, LL_TYPEMAP
from pypy.module._rawffi.interp_rawffi import unroll_letters_for_numbers
from rpython.rlib import clibffi
-from rpython.rlib.rarithmetic import intmask, r_uint, signedtype, widen
+from rpython.rlib.rarithmetic import intmask, signedtype, widen
+from rpython.rlib.rarithmetic import r_uint, r_ulonglong, r_longlong
def unpack_fields(space, w_fields):
fields_w = space.unpackiterable(w_fields)
@@ -260,10 +261,17 @@
def LOW_BIT(x):
return x & 0xFFFF
+
def NUM_BITS(x):
return x >> 16
-def BIT_MASK(x):
- return (1 << x) - 1
+
+def BIT_MASK(x, ll_t):
+ if ll_t is lltype.SignedLongLong:
+ return (r_longlong(1) << x) - 1
+ elif ll_t is lltype.UnsignedLongLong:
+ return (r_ulonglong(1) << x) - 1
+ return (1 << x) -1
+BIT_MASK._annspecialcase_ = 'specialize:arg(1)'
def push_field(self, num, value):
ptr = rffi.ptradd(self.ll_buffer, self.shape.ll_positions[num])
@@ -279,8 +287,9 @@
lowbit = LOW_BIT(bitsize)
if numbits:
value = widen(value)
+ bitmask = BIT_MASK(numbits, TP)
+ #
current = widen(rffi.cast(T, ptr)[0])
- bitmask = BIT_MASK(numbits)
current &= ~ (bitmask << lowbit)
current |= (value & bitmask) << lowbit
value = rffi.cast(TP, current)
@@ -301,13 +310,16 @@
numbits = NUM_BITS(bitsize)
lowbit = LOW_BIT(bitsize)
if numbits:
- value = widen(value)
+ value = widen(rffi.cast(ll_t, value))
+ bitmask = BIT_MASK(numbits, ll_t)
+ #
value >>= lowbit
- value &= BIT_MASK(numbits)
+ value &= bitmask
if ll_t is lltype.Bool or signedtype(ll_t._type):
sign = (value >> (numbits - 1)) & 1
if sign:
- value = value - (1 << numbits)
+ one = r_longlong(1) if ll_t is lltype.SignedLongLong
else 1
+ value = value - (one << numbits)
value = rffi.cast(ll_t, value)
break
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