llvm dev - Mar 2010 - [LLVMdev] Smaller than 32-bit?

Does LLVM support any target platforms on which the natural integer
size/pointer size is smaller than 32 bits? For example, I noticed
mention of PIC16, is that such a platform?

If so, does the usual rule about the largest supported integer being
the size of two pointers still apply? So that on that platform you
can't use 64-bit integers, but you can use 32-bit integers?

Hi Russell-

The PIC16 is an 8-bit target, and the msp430 is a 16-bit target. The rules about
the largest supported integer no longer apply as much- for most operations,
codegen can now handle arbitrary precision (exceptions: mul, udiv, urem, sdiv,
srem). For those five, library calls should be emitted for big integers - best
way to check if they're supported is to just try them :)

Alastair

On 11 Mar 2010, at 18:27, Russell Wallace wrote:
> Does LLVM support any target platforms on which the natural integer
> size/pointer size is smaller than 32 bits? For example, I noticed
> mention of PIC16, is that such a platform?
> 
> If so, does the usual rule about the largest supported integer being
> the size of two pointers still apply? So that on that platform you
> can't use 64-bit integers, but you can use 32-bit integers?
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

I tried 128 bit integers on both of those, and msp430 crashes (in llc
2.6), but pic16 does indeed generate correct looking in-line code for
addition, and library calls for multiplication. Thanks!

On Fri, Mar 12, 2010 at 12:51 AM, Alastair Lynn <arplynn at gmail.com>
wrote:
> Hi Russell-
>
> The PIC16 is an 8-bit target, and the msp430 is a 16-bit target. The rules
about the largest supported integer no longer apply as much- for most
operations, codegen can now handle arbitrary precision (exceptions: mul, udiv,
urem, sdiv, srem). For those five, library calls should be emitted for big
integers - best way to check if they're supported is to just try them :)
>
> Alastair
>
> On 11 Mar 2010, at 18:27, Russell Wallace wrote:
>
>> Does LLVM support any target platforms on which the natural integer
>> size/pointer size is smaller than 32 bits? For example, I noticed
>> mention of PIC16, is that such a platform?
>>
>> If so, does the usual rule about the largest supported integer being
>> the size of two pointers still apply? So that on that platform you
>> can't use 64-bit integers, but you can use 32-bit integers?
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>