Re: [PATCH -mm] timer: parenthesis fix in tbase_get_deferrable() etc.

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On 5/10/07, Satyam Sharma <[email protected]> wrote:
> [...]
> On a 64 bit system, converting pointer to int causes unnecessary
> compiler
> warning, and intermediate long conversion was to avoid that. I will have

Whoa! Hello, hold on, just wait a second there. Do you _really_ want
an unsigned int return out of tbase_get_deferrable() or will an
unsigned long do? If the rest of your code is fine with unsigned long,
then I'd suggest something like:

static inline unsigned long tbase_get_deferrable(tvec_base_t *base)
{
        return ((unsigned long)base & TBASE_DEFERRABLE_FLAG);
}

I don't really know your code (so I could be horribly incorrect here),
but personally I would prefer *heeding* to that warning than _hiding_
it -- it's not unnecessary, it's telling you that you're *losing* data
by converting a pointer (which is always unsigned long) to unsigned
int for 64-bit platforms where sizeof(void *) == sizeof(unsigned long)
== 8 bytes, but sizeof(unsigned int) == 4.

Oh well, pardon my obtuseness (I _really_ ought to be at least looking
around in the code before jumping in like this :-) ...
TBASE_DEFERRABLE_FLAG only {ab}uses the lowest bit of tvec_base_t *,
so clearly no pointer truncation issues here (you could still prefer
the unsigned long version for simplicity & style, though).

*embarrassed, goes for a cup of coffee*
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