On Sat, Sep 02, 2006 at 02:32:03PM +0200, Joerg Sonnenberger wrote:
> On Sat, Sep 02, 2006 at 01:40:01AM -0500, David Young wrote:
> > On Sat, Sep 02, 2006 at 12:09:19AM +0100, David Laight wrote:
> > > On Fri, Sep 01, 2006 at 09:01:06AM +0900, YAMAMOTO Takashi wrote:
> > > > > 
> > > > > Make the __BIT and __BITS macros "widthless," as best I can, by
> > > > > changing their type to uintmax_t from uint32_t.  XXX The manual
> > > > > page lags this change by a bit.
> > > > > 
> > > > > Define __PRIxBIT and __PRIxBITS printf(3) format strings.
> > > > 
> > > > is it ok to use typeof here?
> > > 
> > > Almost certainly not since the header files gets built into tools.
> > 
> > Please suggest an alternative.
> 
> Take a look at math.h, esp. __fpmacro_unary_floating.

__fpmacro_unary_floating copes with different-sized arguments, but that is
a different problem than the one I need to solve.  I want for the "return"
type of __BIT() and/or __SHIFTOUT()/__SHIFTIN() to change depending on
the width of the mask.  I've tried this macro, but it always evaluates
to a uintmax_t, which is about what I'd expect:

#define __CAST(__x, __v)                                                \
        ((sizeof(__x) < sizeof(uintmax_t))                              \
                ? ((sizeof(__x) < sizeof(uint64_t))                     \
                        ? ((sizeof(__x) < sizeof(uint32_t))             \
                                ? ((sizeof(__x) < sizeof(uint16_t))     \
                                        ? (uint8_t)(__v)                \
                                        : (uint16_t)(__v))              \
                                : (uint32_t)(__v))                      \
                        : (uint64_t)(__v))                              \
                : (uintmax_t)(__v))

Dave

-- 
David Young             OJC Technologies
dyoung@ojctech.com      Urbana, IL * (217) 278-3933