0xFFFFFFFF in a P14P int

[GilRoss]

I would like to load 0xFFFFFFFF into a P14P int. When I try this, I get a value error. It is fine if I use -1, but I don't want to represent these bit masks as negative numbers. This makes for poor reading. Is there any way I can load a P14P int with 0xFFFFFFFF and make the code readable?

Thanks,

Gil

[pir...@gmail.com]

0xFFFFFFFF Is ugly in C, and more in Python. It's way better to use
int mask = ~0x0

2013/4/2 GilRoss <gilber...@gmail.com>:

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[Marek Novák]

Is not ~0x0 evaluated runtime whereas 0xffffffff is a literal constant? 
But maybe Gil does not worry about the speed... 

2013/4/2 pir...@gmail.com <pir...@gmail.com>

[Dean Hall]

The nature of the problem is that PyMite uses C signed 32-bit integers to hold Python integers
AND
Python tries to make hex constants keep their sign. This means Python will attempt to turn 0xFFFFFFFF into 4294967295 which cannot be represented in a signed 32-bit value. Python tries to coerce the value into Python's Long type. PyMite gives you an error.

To answer Marek's question: It's easy to check what the CPython "compiler" does using Python's interactive prompt:

>>> import dis
>>> def foo():
... a = 0xFFFFFFFF
... b = ~0x0
...
>>> dis.disco(foo.__code__)
2 0 LOAD_CONST 1 (4294967295)
3 STORE_FAST 0 (a)

3 6 LOAD_CONST 3 (-1)
9 STORE_FAST 1 (b)
12 LOAD_CONST 0 (None)
15 RETURN_VALUE

As you can see the "compiler" turns "~0x0" into the constant "-1".
So there is no execution penalty.

!!Dean

[pir...@gmail.com]

Now I'm worried... Have I been doing wrong all the time or not?

Sent from my Android cell phone, please forgive the lack of format on the text, and my fat thumbs :-P