[LLVMdev] adde/addc

[Evan Cheng]

Legalizer will expand arithmetics using addc and adde. Is it not  
working for you? It works fine on x86, you can take a look how it's  
done.

Evan

On Sep 8, 2008, at 4:03 AM, Richard Pennington wrote:

> My target doesn't support 64 bit arithmetic, so I'd like to supply
> definitions for adde/addc. The problem is I can't seem to figure out  
> the
> magic. Here's an example of what I need to generate:
>
> # two i64s in r5/r6 and r7/r8
> # result in r1/r2, carry in r3
>
> # adde
>    add r2, r6, r8
>    cmpltu r3, r2, r6	# compute carry
>
> # addc
>     add r1, r5, r7
>     add r1, zero, r3
>
> Is this possible given the current code generation stuff? Is there
> another approach that I should consider?
>
> -Rich
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev