Revert "[LAA] Support pointer phis in loop by analyzing each incoming pointer."

This reverts commit 1ed7f8ede564c3b11da4fdca30c36ccbff422576.

This change can cause loop-distribute to crash in some cases. Revert
until I have more time to wrap up a fix.

See  PR50296, PR5028 and D102266.

1 files changed, 2 insertions, 23 deletions

diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 3535058..3248b2a 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1938,18 +1938,7 @@ void LoopAccessInfo::analyzeLoop(AAResults *AA, LoopInfo *LI,
       if (blockNeedsPredication(ST->getParent(), TheLoop, DT))
         Loc.AATags.TBAA = nullptr;
 
-      // SCEV does not look through non-header PHIs inside the loop. Such phis
-      // can be analyzed by adding separate accesses for each incoming pointer
-      // value.
-      auto *PN = dyn_cast<PHINode>(Loc.Ptr);
-      if (PN && TheLoop->contains(PN->getParent()) &&
-          PN->getParent() != TheLoop->getHeader()) {
-        for (const Use &Inc : PN->incoming_values()) {
-          MemoryLocation NewLoc = Loc.getWithNewPtr(Inc);
-          Accesses.addStore(NewLoc);
-        }
-      } else
-        Accesses.addStore(Loc);
+      Accesses.addStore(Loc);
     }
   }
 
@@ -1993,17 +1982,7 @@ void LoopAccessInfo::analyzeLoop(AAResults *AA, LoopInfo *LI,
     if (blockNeedsPredication(LD->getParent(), TheLoop, DT))
       Loc.AATags.TBAA = nullptr;
 
-    // SCEV does not look through non-header PHIs inside the loop. Such phis can
-    // be analyzed by adding separate accesses for each incoming pointer value.
-    auto *PN = dyn_cast<PHINode>(Loc.Ptr);
-    if (PN && TheLoop->contains(PN->getParent()) &&
-        PN->getParent() != TheLoop->getHeader()) {
-      for (const Use &Inc : PN->incoming_values()) {
-        MemoryLocation NewLoc = Loc.getWithNewPtr(Inc);
-        Accesses.addLoad(NewLoc, IsReadOnlyPtr);
-      }
-    } else
-      Accesses.addLoad(Loc, IsReadOnlyPtr);
+    Accesses.addLoad(Loc, IsReadOnlyPtr);
   }
 
   // If we write (or read-write) to a single destination and there are no