[llvm-dev] Problem with "[SimplifyCFG] Handle tail-sinking of more than 2 incoming branches"

Krzysztof Parzyszek via llvm-dev llvm-dev at lists.llvm.org
Fri Sep 2 17:06:19 PDT 2016


On 9/2/2016 6:54 PM, Marcello Maggioni via llvm-dev wrote:
> It’s not about weird restrictions we are adding, it’s about the fact
> that for that specific address space we cannot dynamically index into
> the memory.
>
> The address needs to be a constant of some sort in the selection (it’s
> an hardware limitation, there’s nothing we can do about it) and the fact
> that it is transformed into a PHI makes it not constant anymore.

Could you use an intrinsic for the load?

An optimization could reasonably be expected not to replace a constant 
input to an intrinsic with a variable, so even if it fails at the 
moment, it could be addressed.

-Krzysztof



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