[llvm] [InstCombine] Pull extract through broadcast (PR #143380)

[via llvm-commits]

================
@@ -542,6 +542,12 @@ Instruction *InstCombinerImpl::visitExtractElementInst(ExtractElementInst &EI) {
         }
       }
     } else if (auto *SVI = dyn_cast<ShuffleVectorInst>(I)) {
+      // extractelt (shufflevector %v1, %v2, zeroinitializer) ->
+      // extractelt %v1, 0
+      if (isa<FixedVectorType>(SVI->getType()))
----------------
agorenstein-nvidia wrote:

Thanks for taking such a quick look. To disambiguate, you're requesting I relax this constraint to include scalable vectors too? I'd be happy to do so and add the appropriate test.

https://github.com/llvm/llvm-project/pull/143380