Re: [PATCH] lower-subreg: Decompose multiword shifts

[Rask Ingemann Lambertsen <rask@sygehus.dk>]

On Thu, Aug 02, 2007 at 09:21:40PM +0200, Andreas Krebbel wrote:
> Hello,
> 
> > > + typedef unsigned int u32;
> > > + typedef unsigned long long u64;
> > 
> >    Please use uint32_t and uint64_t from stdint.h (or some other reliable
> > means of getting types of the sizes you want).
> 
> Yes the names I've choosen aren't correct for any platform but I think the types are nevertheless a good choice

   For starters, some targets have 16 bits wide int so your testcase will
fail there with excess errors. Since your shift counts and constants in the
testcase assume 32 bits for u32 and 64 bits for u64, you should use the
stdint.h types because they work on all targets.

> considering that I need something as wide as register and something else with twice the size.

   Somewhat surpricingly, a fairly common 64-bit target such as x86_64 has a
long long with a width of only 64 bits rather than the expected 128 bits. If
you scanned the RTL dumps to check that the decomposition happened, x86_64
would fail the testcase.

-- 
Rask Ingemann Lambertsen