[llvm] [InstCombine] foldOpIntoPhi should apply to icmp with non-constant operand (PR #147676)

[Nikita Popov via llvm-commits]

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@@ -7699,6 +7695,10 @@ Instruction *InstCombinerImpl::visitICmpInst(ICmpInst &I) {
   if (Instruction *New = foldSignBitTest(I))
     return New;
 
+  if (auto *PN = dyn_cast<PHINode>(Op0))
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nikic wrote:

There is no guarantee that the phi node will be op0 if the other operand is not constant, so we should handle both. Can you please add a commuted test?

https://github.com/llvm/llvm-project/pull/147676