[PATCH] D24168: Refactor LICM pass in preparation for LoopSink pass.

[Dehao Chen via llvm-commits]

danielcdh created this revision.
danielcdh added reviewers: chandlerc, davidxl.
danielcdh added a subscriber: llvm-commits.

LoopSink pass uses some common function in LICM. This patch refactor the LICM code to make it usable by LoopSink pass (https://reviews.llvm.org/D22778).

https://reviews.llvm.org/D24168

Files:
  lib/Transforms/Scalar/LICM.cpp

Index: lib/Transforms/Scalar/LICM.cpp
===================================================================
--- lib/Transforms/Scalar/LICM.cpp
+++ lib/Transforms/Scalar/LICM.cpp
@@ -101,7 +101,7 @@
                             const LoopInfo *LI,
                             const LoopSafetyInfo *SafetyInfo);
 static bool canSinkOrHoistInst(Instruction &I, AliasAnalysis *AA,
-                               DominatorTree *DT, TargetLibraryInfo *TLI,
+                               DominatorTree *DT,
                                Loop *CurLoop, AliasSetTracker *CurAST,
                                LoopSafetyInfo *SafetyInfo);
 
@@ -337,7 +337,7 @@
     // operands of the instruction are loop invariant.
     //
     if (isNotUsedInLoop(I, CurLoop, SafetyInfo) &&
-        canSinkOrHoistInst(I, AA, DT, TLI, CurLoop, CurAST, SafetyInfo)) {
+        canSinkOrHoistInst(I, AA, DT, CurLoop, CurAST, SafetyInfo)) {
       ++II;
       Changed |= sink(I, LI, DT, CurLoop, CurAST, SafetyInfo);
     }
@@ -390,7 +390,7 @@
       // is safe to hoist the instruction.
       //
       if (CurLoop->hasLoopInvariantOperands(&I) &&
-          canSinkOrHoistInst(I, AA, DT, TLI, CurLoop, CurAST, SafetyInfo) &&
+          canSinkOrHoistInst(I, AA, DT, CurLoop, CurAST, SafetyInfo) &&
           isSafeToExecuteUnconditionally(
               I, DT, CurLoop, SafetyInfo,
               CurLoop->getLoopPreheader()->getTerminator()))
@@ -439,9 +439,17 @@
 /// canSinkOrHoistInst - Return true if the hoister and sinker can handle this
 /// instruction.
 ///
-bool canSinkOrHoistInst(Instruction &I, AliasAnalysis *AA, DominatorTree *DT,
-                        TargetLibraryInfo *TLI, Loop *CurLoop,
-                        AliasSetTracker *CurAST, LoopSafetyInfo *SafetyInfo) {
+bool canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
+                        Loop *CurLoop, AliasSetTracker *CurAST,
+                        LoopSafetyInfo *SafetyInfo) {
+  if (!isa<LoadInst>(I) && !isa<CallInst>(I) &&
+      !isa<BinaryOperator>(I) && !isa<CastInst>(I) && !isa<SelectInst>(I) &&
+      !isa<GetElementPtrInst>(I) && !isa<CmpInst>(I) &&
+      !isa<InsertElementInst>(I) && !isa<ExtractElementInst>(I) &&
+      !isa<ShuffleVectorInst>(I) && !isa<ExtractValueInst>(I) &&
+      !isa<InsertValueInst>(I))
+    return false;
+
   // Loads have extra constraints we have to verify before we can hoist them.
   if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
     if (!LI->isUnordered())
@@ -457,15 +465,15 @@
     // Don't hoist loads which have may-aliased stores in loop.
     uint64_t Size = 0;
     if (LI->getType()->isSized())
-      Size = I.getModule()->getDataLayout().getTypeStoreSize(LI->getType());
+      Size = LI->getModule()->getDataLayout().getTypeStoreSize(LI->getType());
 
     AAMDNodes AAInfo;
     LI->getAAMetadata(AAInfo);
 
     return !pointerInvalidatedByLoop(LI->getOperand(0), Size, AAInfo, CurAST);
   } else if (CallInst *CI = dyn_cast<CallInst>(&I)) {
     // Don't sink or hoist dbg info; it's legal, but not useful.
-    if (isa<DbgInfoIntrinsic>(I))
+    if (isa<DbgInfoIntrinsic>(*CI))
       return false;
 
     // Don't sink calls which can throw.
@@ -503,22 +511,16 @@
 
     // FIXME: This should use mod/ref information to see if we can hoist or
     // sink the call.
-
     return false;
   }
 
-  // Only these instructions are hoistable/sinkable.
-  if (!isa<BinaryOperator>(I) && !isa<CastInst>(I) && !isa<SelectInst>(I) &&
-      !isa<GetElementPtrInst>(I) && !isa<CmpInst>(I) &&
-      !isa<InsertElementInst>(I) && !isa<ExtractElementInst>(I) &&
-      !isa<ShuffleVectorInst>(I) && !isa<ExtractValueInst>(I) &&
-      !isa<InsertValueInst>(I))
-    return false;
-
-  // TODO: Plumb the context instruction through to make hoisting and sinking
-  // more powerful. Hoisting of loads already works due to the special casing
-  // above.
-  return isSafeToExecuteUnconditionally(I, DT, CurLoop, SafetyInfo, nullptr);
+  if (SafetyInfo)
+    // TODO: Plumb the context instruction through to make hoisting and sinking
+    // more powerful. Hoisting of loads already works due to the special casing
+    // above.
+    return isSafeToExecuteUnconditionally(I, DT, CurLoop, SafetyInfo, nullptr);
+  else
+    return true;
 }
 
 /// Returns true if a PHINode is a trivially replaceable with an


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