Revert "[ConstraintElimination] Change debug output to display variab…

…le names."

This reverts commit 869c87a.

`dumpWithNames` function should be removed

llvm/include/llvm/Analysis/ConstraintSystem.h

@@ -36,17 +36,13 @@ class ConstraintSystem {
   // Eliminate constraints from the system using Fourier–Motzkin elimination.
   bool eliminateUsingFM();
 
+  /// Print the constraints in the system, using x0...xn as variable names.
+  void dump() const;
+
   /// Returns true if there may be a solution for the constraints in the system.
   bool mayHaveSolutionImpl();
 
-  /// Get list of variable names from the Value2Index map.
-  SmallVector<std::string> getVarNamesList() const;
-
 public:
-  ConstraintSystem() {}
-  ConstraintSystem(const DenseMap<Value *, unsigned> &Value2Index)
-      : Value2Index(Value2Index) {}
-
   bool addVariableRow(ArrayRef<int64_t> R) {
     assert(Constraints.empty() || R.size() == Constraints.back().size());
     // If all variable coefficients are 0, the constraint does not provide any
@@ -107,8 +103,8 @@ class ConstraintSystem {
   /// Returns the number of rows in the constraint system.
   unsigned size() const { return Constraints.size(); }
 
-  /// Print the constraints in the system.
-  void dump() const;
+  /// Print the constraints in the system, using \p Names as variable names.
+  void dump(ArrayRef<std::string> Names) const;
 };
 } // namespace llvm
 

llvm/lib/Analysis/ConstraintSystem.cpp

@@ -111,23 +111,10 @@ bool ConstraintSystem::mayHaveSolutionImpl() {
   return all_of(Constraints, [](auto &R) { return R[0] >= 0; });
 }
 
-SmallVector<std::string> ConstraintSystem::getVarNamesList() const {
-  SmallVector<std::string> Names(Value2Index.size(), "");
-  for (auto &[V, Index] : Value2Index) {
-    std::string OperandName;
-    if (V->getName().empty())
-      OperandName = V->getNameOrAsOperand();
-    else
-      OperandName = std::string("%") + V->getName().str();
-    Names[Index - 1] = OperandName;
-  }
-  return Names;
-}
-
-void ConstraintSystem::dump() const {
+void ConstraintSystem::dump(ArrayRef<std::string> Names) const {
   if (Constraints.empty())
     return;
-  SmallVector<std::string> Names = getVarNamesList();
+
   for (const auto &Row : Constraints) {
     SmallVector<std::string, 16> Parts;
     for (unsigned I = 1, S = Row.size(); I < S; ++I) {
@@ -144,6 +131,14 @@ void ConstraintSystem::dump() const {
   }
 }
 
+void ConstraintSystem::dump() const {
+  SmallVector<std::string, 16> Names;
+  for (unsigned i = 1; i < Constraints.back().size(); ++i)
+    Names.push_back("x" + std::to_string(i));
+  LLVM_DEBUG(dbgs() << "---\n");
+  dump(Names);
+}
+
 bool ConstraintSystem::mayHaveSolution() {
   LLVM_DEBUG(dump());
   bool HasSolution = mayHaveSolutionImpl();

llvm/lib/Transforms/Scalar/ConstraintElimination.cpp

@@ -644,12 +644,20 @@ struct State {
 } // namespace
 
 #ifndef NDEBUG
+static void dumpWithNames(const ConstraintSystem &CS,
+                          DenseMap<Value *, unsigned> &Value2Index) {
+  SmallVector<std::string> Names(Value2Index.size(), "");
+  for (auto &KV : Value2Index) {
+    Names[KV.second - 1] = std::string("%") + KV.first->getName().str();
+  }
+  CS.dump(Names);
+}
 
-static void dumpConstraint(ArrayRef<int64_t> C,
-                           const DenseMap<Value *, unsigned> &Value2Index) {
-  ConstraintSystem CS(Value2Index);
+static void dumpWithNames(ArrayRef<int64_t> C,
+                          DenseMap<Value *, unsigned> &Value2Index) {
+  ConstraintSystem CS;
   CS.addVariableRowFill(C);
-  CS.dump();
+  dumpWithNames(CS, Value2Index);
 }
 #endif
 
@@ -997,7 +1005,7 @@ void ConstraintInfo::addFact(CmpInst::Predicate Pred, Value *A, Value *B,
 
     LLVM_DEBUG({
       dbgs() << "  constraint: ";
-      dumpConstraint(R.Coefficients, getValue2Index(R.IsSigned));
+      dumpWithNames(R.Coefficients, getValue2Index(R.IsSigned));
       dbgs() << "\n";
     });
 
@@ -1142,8 +1150,8 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT,
         break;
       LLVM_DEBUG({
         dbgs() << "Removing ";
-        dumpConstraint(Info.getCS(E.IsSigned).getLastConstraint(),
-                       Info.getValue2Index(E.IsSigned));
+        dumpWithNames(Info.getCS(E.IsSigned).getLastConstraint(),
+                      Info.getValue2Index(E.IsSigned));
         dbgs() << "\n";
       });