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

[Andreas Krebbel <Andreas.Krebbel@de.ibm.com>]

Hello,

> Why isn't the same magic happening on s390?

Your target does not seem to provide shift instructions dealing with
register pairs. So I would guess that optab already decomposes such
shifts for you - right?!  At least I don't see an SI mode shift in the
RTL pieces you've sent. Certainly that optimization only makes sense if
your back end provides such an instruction.

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

Looks like an ideal place for using __attribute__((mode(word))) ;)

Bye,

-Andreas-