[llvm] [InstCombine][foldPHIArgGEPIntoPHI] Early return for const vector index for gep inst. (PR #138661)

[Nikita Popov via llvm-commits]

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@@ -575,7 +575,9 @@ Instruction *InstCombinerImpl::foldPHIArgGEPIntoPHI(PHINode &PN) {
       // variable index could pessimize the path.  This also handles the case
       // for struct indices, which must always be constant.
       if (isa<ConstantInt>(FirstInst->getOperand(Op)) ||
-          isa<ConstantInt>(GEP->getOperand(Op)))
+          isa<ConstantInt>(GEP->getOperand(Op)) ||
+          isa<ConstantDataVector>(FirstInst->getOperand(Op)) ||
+          isa<ConstantDataVector>(GEP->getOperand(Op)))
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nikic wrote:

Can you change these to just check isa<Constant> instead?

https://github.com/llvm/llvm-project/pull/138661