[PATCH] D87490: [MachineInstr] return mayAlias for not mayLoadOrStore instructions.

[ChenZheng via Phabricator via llvm-commits]

shchenz updated this revision to Diff 291125.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87490/new/

https://reviews.llvm.org/D87490

Files:
  llvm/lib/CodeGen/MachineInstr.cpp


Index: llvm/lib/CodeGen/MachineInstr.cpp
===================================================================
--- llvm/lib/CodeGen/MachineInstr.cpp
+++ llvm/lib/CodeGen/MachineInstr.cpp
@@ -1234,14 +1234,14 @@
   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
   const MachineFrameInfo &MFI = MF->getFrameInfo();
 
-  // If neither instruction stores to memory, they can't alias in any
-  // meaningful way, even if they read from the same address.
-  if (!mayStore() && !Other.mayStore())
+  // If both instructions are loads, they can't alias in any meaningful way,
+  // even if they read from the same address.
+  if (mayLoad() && !mayStore() && Other.mayLoad() && !Other.mayStore())
     return false;
 
   // Both instructions must be memory operations to be able to alias.
   if (!mayLoadOrStore() || !Other.mayLoadOrStore())
-    return false;
+    return true;
 
   // Let the target decide if memory accesses cannot possibly overlap.
   if (TII->areMemAccessesTriviallyDisjoint(*this, Other))


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