[llvm-dev] multiprecision add/sub

Bagel via llvm-dev llvm-dev at lists.llvm.org
Thu Feb 16 09:12:36 PST 2017

It takes two "llvm.uadd.with.overflow" instances to model the add-with-carry
when there is a carry-in.  Look at the IR generated by the example.

I figured that the optimization of this would bedifficult (else it would have
already been done :-)).  And would this optimization have to be done for every

On 02/15/2017 04:28 PM, Stephen Canon wrote:
> Why do you think this requires new intrinsics instead of teaching the optimizer what to do with the existing intrinsics?
> – Steve

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