[llvm] r339069 - [LICM] Extract a helper function for readability [NFC]

[Philip Reames via llvm-commits]

Author: reames
Date: Mon Aug  6 15:07:37 2018
New Revision: 339069

URL: http://llvm.org/viewvc/llvm-project?rev=339069&view=rev
Log:
[LICM] Extract a helper function for readability [NFC]


Modified:
    llvm/trunk/lib/Transforms/Scalar/LICM.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=339069&r1=339068&r2=339069&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Mon Aug  6 15:07:37 2018
@@ -588,6 +588,16 @@ bool isHoistableAndSinkableInst(Instruct
           isa<ExtractElementInst>(I) || isa<ShuffleVectorInst>(I) ||
           isa<ExtractValueInst>(I) || isa<InsertValueInst>(I));
 }
+/// Return true if all of the alias sets within this AST are known not to
+/// contain a Mod.
+bool isReadOnly(AliasSetTracker *CurAST) {
+  for (AliasSet &AS : *CurAST) {
+    if (!AS.isForwardingAliasSet() && AS.isMod()) {
+      return false;
+    }
+  }
+  return true;
+}
 }
 
 bool llvm::canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
@@ -663,16 +673,10 @@ bool llvm::canSinkOrHoistInst(Instructio
             return false;
         return true;
       }
+
       // If this call only reads from memory and there are no writes to memory
       // in the loop, we can hoist or sink the call as appropriate.
-      bool FoundMod = false;
-      for (AliasSet &AS : *CurAST) {
-        if (!AS.isForwardingAliasSet() && AS.isMod()) {
-          FoundMod = true;
-          break;
-        }
-      }
-      if (!FoundMod)
+      if (isReadOnly(CurAST))
         return true;
     }