Re: [PATCH][2/n] Always 64bit-HWI cleanups

[Richard Sandiford <rdsandiford at googlemail dot com>]

Richard Biener <rguenther@suse.de> writes:
> On Wed, 28 May 2014, Richard Sandiford wrote:
>
>> Richard Biener <rguenther@suse.de> writes:
>> > The following changes the configury to insist on [u]int64_t being
>> > available and removes the very old __int64 case.  Autoconf doesn't
>> > check for it, support came in via a big merge in Dec 2002, r60174,
>> > and it was never used on the libcpp side until I fixed that with
>> > the last patch of this series, so we couldn't have relied on it
>> > at least since libcpp was introduced.
>> >
>> > Both libcpp and vmsdbg.h now use [u]int64_t, switching HOST_WIDE_INT
>> > to literally use int64_t has to be done with the grand renaming of
>> > all users due to us using 'unsigned HOST_WIDE_INT'.
>> >
>> > Btw, I couldn't find any "standard" way of writing
>> > [u]int64_t literals (substitution for HOST_WIDE_INT_C) nor
>> > one for printf formats (substitutions for HOST_WIDE_INT_PRINT
>> > and friends).  I'll consider doing s/HOST_WIDE_INT/[U]INT64/
>> > there if nobody comes up with a better plan.
>> 
>> Not sure whether you meant that to apply to both groups, but as far as
>> the HOST_WIDE_INT_C replacement goes, how about just using int64_t (N)
>> instead of HOST_WIDE_INT_C (N) or INT64_C (N)?
>
> int64_t (N) would already be "taken", but yes, I considered [U]INT64_C 
> (N).

Not sure what you mean by "taken" though.  Isn't it just a C++-style cast?
The nice thing about [u]int64_t (N) is that it Just Works for both constant
and non-constant N.  We shouldn't really need a special macro that can only
handle constant N.

E.g.:

  #include <stdint.h>
  uint64_t x = uint64_t (1) << 48;

Thanks,
Richard