[PATCH] D82061: [IR] Prefer scalar type for struct indexes in GEP constant expressions.

[Eli Friedman via Phabricator via llvm-commits]

efriedma marked an inline comment as done.
efriedma added inline comments.


================
Comment at: llvm/lib/IR/Constants.cpp:2192
+               !Idx->getType()->isVectorTy()) {
       Idx = ConstantVector::getSplat(EltCount, Idx);
+    }
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sdesmalen wrote:
> What is the reason for not always using a scalar index value?
In my thinking, there are two reasons:

1. I wanted to be conservative; arbitrary constant expressions are legal in this position anyway, so the harm from code failing to understand a vector splat is much smaller.
2. We don't want to accidentally change the result type of a GEP if every operand is a splat.


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  https://reviews.llvm.org/D82061/new/

https://reviews.llvm.org/D82061