[llvm-branch-commits] [llvm] [CodeGen][LSR][NPM] Make LoopStrengthReduce pass preserve LCSSA (PR #176692)

[Aiden Grossman via llvm-branch-commits]

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@@ -7135,6 +7135,10 @@ PreservedAnalyses LoopStrengthReducePass::run(Loop &L, LoopAnalysisManager &AM,
   if (!ReduceLoopStrength(&L, AM.getResult<IVUsersAnalysis>(L, AR), AR.SE,
                           AR.DT, AR.LI, AR.TTI, AR.AC, AR.TLI, AR.MSSA))
     return PreservedAnalyses::all();
+  
+  // TODO: Remove this once the LSR handles LCSSA preservation completely.
+  if (auto *OuterLoop = L.getOutermostLoop())
+    formLCSSARecursively(*OuterLoop, AR.DT, &AR.LI, &AR.SE);
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boomanaiden154 wrote:

This looks like it might be somewhat expensive compile time wise?

https://github.com/llvm/llvm-project/pull/176692