[llvm] [AMDGPU] LRO: allow same-BB non-lookthrough users for PHI (PR #160909)

[via llvm-commits]

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@@ -150,7 +150,10 @@ class LiveRegOptimizer {
       if (!CVisited.insert(CII).second)
         continue;
 
-      if (CII->getParent() == II->getParent() && !IsLookThru(II))
+      // Same-BB filter must look at the *user*; and allow non-lookthrough
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michaelselehov wrote:

Added a minimal IR test (lro-phi-samebb-nonlookthrough-store.ll) that checks the same-BB filter looks at the user and allows non-lookthrough when the def is a PHI

https://github.com/llvm/llvm-project/pull/160909