[PATCH] D143422: [LV] Update logic for calculating register usage due to invariants

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added inline comments.


================
Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:6122
+      }
     }
 
----------------
sdesmalen wrote:
> I think you can write the algorithm above a bit shorter using a lambda:
> 
>   bool IsScalar = all_of(cast<Instruction>(Inst)->users(), [&](User *U) {
>     auto *I = dyn_cast<Instruction>(U);
>     return !I || TheLoop != LI->getLoopFor(I->getParent()) ||
>            isScalarAfterVectorization(I, VFs[i]);
>   });      
>   
>   ElementCount VF = IsScalar ? ElementCount::getFixed(1) : VFs[i];
>   unsigned  ClassID = TTI.getRegisterClassForType(VF.isVector(), Inst->getType());
>   Invariant[ClassID] += GetRegusage(Inst->getType(), VF);;
> 
> I think you can write the algorithm above a bit shorter using a lambda:
> 
>   bool IsScalar = all_of(cast<Instruction>(Inst)->users(), [&](User *U) {
>     auto *I = dyn_cast<Instruction>(U);
>     return !I || TheLoop != LI->getLoopFor(I->getParent()) ||
>            isScalarAfterVectorization(I, VFs[i]);
>   });      
>   
>   ElementCount VF = IsScalar ? ElementCount::getFixed(1) : VFs[i];
>   unsigned  ClassID = TTI.getRegisterClassForType(VF.isVector(), Inst->getType());
>   Invariant[ClassID] += GetRegusage(Inst->getType(), VF);;
> 
@sushgokh did you try the above suggestion?

When I try it locally, all the tests in your patch still pass.


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  https://reviews.llvm.org/D143422/new/

https://reviews.llvm.org/D143422