[llvm] 905623b - [NFC][LICM] Minor improvements to debug output

[Quentin Colombet via llvm-commits]

Author: Quentin Colombet
Date: 2021-01-11T18:02:49-08:00
New Revision: 905623b64df0c865d4dddc4a60aff9751fbaa0e0

URL: https://github.com/llvm/llvm-project/commit/905623b64df0c865d4dddc4a60aff9751fbaa0e0
DIFF: https://github.com/llvm/llvm-project/commit/905623b64df0c865d4dddc4a60aff9751fbaa0e0.diff

LOG: [NFC][LICM] Minor improvements to debug output

Added a utility function in Value class to print block name and use
block labels for unnamed blocks.
Changed LICM to call this function in its debug output.

Patch by Xiaoqing Wu <xiaoqing_wu at apple.com>

Differential Revision: https://reviews.llvm.org/D93577

Added: 
    

Modified: 
    llvm/include/llvm/IR/Value.h
    llvm/lib/IR/Value.cpp
    llvm/lib/Transforms/Scalar/LICM.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h
index 4f0336b44d28..e84840a30e96 100644
--- a/llvm/include/llvm/IR/Value.h
+++ b/llvm/include/llvm/IR/Value.h
@@ -281,6 +281,10 @@ class Value {
   /// \note It is an error to call V->takeName(V).
   void takeName(Value *V);
 
+#ifndef NDEBUG
+  std::string getNameOrAsOperand() const;
+#endif
+
   /// Change all uses of this to point to a new Value.
   ///
   /// Go through the uses list for this definition and make each use point to

diff  --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 51a84b6af241..572f37a32410 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -430,6 +430,18 @@ void Value::takeName(Value *V) {
     ST->reinsertValue(this);
 }
 
+#ifndef NDEBUG
+std::string Value::getNameOrAsOperand() const {
+  if (!getName().empty())
+    return std::string(getName());
+
+  std::string BBName;
+  raw_string_ostream OS(BBName);
+  printAsOperand(OS, false);
+  return OS.str();
+}
+#endif
+
 void Value::assertModuleIsMaterializedImpl() const {
 #ifndef NDEBUG
   const GlobalValue *GV = dyn_cast<GlobalValue>(this);

diff  --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index c26d588d9d45..d2b4ba296f41 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -221,6 +221,9 @@ struct LegacyLICMPass : public LoopPass {
     if (skipLoop(L))
       return false;
 
+    LLVM_DEBUG(dbgs() << "Perform LICM on Loop with header at block "
+                      << L->getHeader()->getNameOrAsOperand() << "\n");
+
     auto *SE = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>();
     MemorySSA *MSSA = EnableMSSALoopDependency
                           ? (&getAnalysis<MemorySSAWrapperPass>().getMSSA())
@@ -697,9 +700,10 @@ class ControlFlowHoister {
     // If not involved in a pending branch, hoist to preheader
     BasicBlock *InitialPreheader = CurLoop->getLoopPreheader();
     if (It == HoistableBranches.end()) {
-      LLVM_DEBUG(dbgs() << "LICM using " << InitialPreheader->getName()
-                        << " as hoist destination for " << BB->getName()
-                        << "\n");
+      LLVM_DEBUG(dbgs() << "LICM using "
+                        << InitialPreheader->getNameOrAsOperand()
+                        << " as hoist destination for "
+                        << BB->getNameOrAsOperand() << "\n");
       HoistDestinationMap[BB] = InitialPreheader;
       return InitialPreheader;
     }
@@ -978,7 +982,7 @@ bool llvm::hoistRegion(DomTreeNode *N, AAResults *AA, LoopInfo *LI,
           HoistPoint = Dominator->getTerminator();
         }
         LLVM_DEBUG(dbgs() << "LICM rehoisting to "
-                          << HoistPoint->getParent()->getName()
+                          << HoistPoint->getParent()->getNameOrAsOperand()
                           << ": " << *I << "\n");
         moveInstructionBefore(*I, *HoistPoint, *SafetyInfo, MSSAU, SE);
         HoistPoint = I;
@@ -1737,8 +1741,8 @@ static void hoist(Instruction &I, const DominatorTree *DT, const Loop *CurLoop,
                   BasicBlock *Dest, ICFLoopSafetyInfo *SafetyInfo,
                   MemorySSAUpdater *MSSAU, ScalarEvolution *SE,
                   OptimizationRemarkEmitter *ORE) {
-  LLVM_DEBUG(dbgs() << "LICM hoisting to " << Dest->getName() << ": " << I
-                    << "\n");
+  LLVM_DEBUG(dbgs() << "LICM hoisting to " << Dest->getNameOrAsOperand() << ": "
+                    << I << "\n");
   ORE->emit([&]() {
     return OptimizationRemark(DEBUG_TYPE, "Hoisted", &I) << "hoisting "
                                                          << ore::NV("Inst", &I);