Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Tue, 17 Dec 2002 13:40:41 +0100

Bernd Schoeneburg wrote:

Hi all,
can anyone explain this:
~(~0UL << 32)        is 0xFFFFFFFF on a Motorola VME162 i.e., which is
correct
                                the same on a Pentium is 0, which is
false!
Ideas?
Bernd

The Pentium (and all Intel x86s, I think) does all shifts mod 32.
Thus (~0 << 32) is not shifted at all.
=> ~(~0 << 32) = ~~0 = 0
There may be other architectures that behave similar.
Dirk
--
Dr. Dirk Zimoch
Swiss Light Source
Paul Scherrer Institut
Computing and Controls
phone +41 56 310 5182
fax   +41 56 310 4413

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System