Revert "[IPSCCP] Move the IPSCCP run function under the IPO directory."

This reverts commit 42c2dc4.

This broke some buildbots:

 undefined reference to `llvm::createBitTrackingDCEPass()'
 undefined reference to `llvm::createAlignmentFromAssumptionsPass()'
 undefined reference to `llvm::createLoopUnrollPass(int, bool, bool, int, int, int, int, int, int)'
 undefined reference to `llvm::createLICMPass(unsigned int, unsigned int, bool)'
 undefined reference to `llvm::createWarnMissedTransformationsPass()'
 undefined reference to `llvm::createAlignmentFromAssumptionsPass()'
 undefined reference to `llvm::createCallSiteSplittingPass()'
 undefined reference to `llvm::createCFGSimplificationPass(llvm::SimplifyCFGOptions, std::function<bool (llvm::Function const&)>)'
 undefined reference to `llvm::createFloat2IntPass()'
 undefined reference to `llvm::createLowerConstantIntrinsicsPass()'
 undefined reference to `llvm::createLoopRotatePass(int, bool)'
 undefined reference to `llvm::createLoopDistributePass()'
 undefined reference to `llvm::createLoopSinkPass()'
 undefined reference to `llvm::createInstSimplifyLegacyPass()'
 undefined reference to `llvm::createDivRemPairsPass()'
 undefined reference to `llvm::createCFGSimplificationPass(llvm::SimplifyCFGOptions, std::function<bool (llvm::Function const&)>)'
 undefined reference to `llvm::SetLicmMssaOptCap'
 undefined reference to `llvm::SetLicmMssaNoAccForPromotionCap'
 undefined reference to `llvm::ForgetSCEVInLoopUnroll'

llvm/include/llvm/Transforms/Scalar/SCCP.h

@@ -40,6 +40,10 @@ class SCCPPass : public PassInfoMixin<SCCPPass> {
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
 };
 
+bool runIPSCCP(Module &M, const DataLayout &DL,
+               std::function<const TargetLibraryInfo &(Function &)> GetTLI,
+               function_ref<AnalysisResultsForFn(Function &)> getAnalysis);
+
 bool runFunctionSpecialization(
     Module &M, FunctionAnalysisManager *FAM, const DataLayout &DL,
     std::function<TargetLibraryInfo &(Function &)> GetTLI,

llvm/include/llvm/Transforms/Utils/SCCPSolver.h

@@ -15,8 +15,6 @@
 #define LLVM_TRANSFORMS_UTILS_SCCPSOLVER_H
 
 #include "llvm/ADT/MapVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/DomTreeUpdater.h"
 #include "llvm/Transforms/Utils/PredicateInfo.h"
 #include <vector>
@@ -175,24 +173,6 @@ class SCCPSolver {
   void visitCall(CallInst &I);
 };
 
-//===----------------------------------------------------------------------===//
-//
-/// Helper functions used by the SCCP and IPSCCP passes.
-//
-bool isConstant(const ValueLatticeElement &LV);
-
-bool isOverdefined(const ValueLatticeElement &LV);
-
-bool simplifyInstsInBlock(SCCPSolver &Solver, BasicBlock &BB,
-                          SmallPtrSetImpl<Value *> &InsertedValues,
-                          Statistic &InstRemovedStat,
-                          Statistic &InstReplacedStat);
-
-bool tryToReplaceWithConstant(SCCPSolver &Solver, Value *V);
-
-bool removeNonFeasibleEdges(const llvm::SCCPSolver &Solver, BasicBlock *BB,
-                            DomTreeUpdater &DTU,
-                            BasicBlock *&NewUnreachableBB);
 } // namespace llvm
 
 #endif // LLVM_TRANSFORMS_UTILS_SCCPSOLVER_H

llvm/lib/Transforms/IPO/CMakeLists.txt

@@ -66,8 +66,10 @@ add_llvm_component_library(LLVMipo
   Linker
   Object
   ProfileData
+  Scalar
   Support
   TransformUtils
   Vectorize
   Instrumentation
+  Scalar
   )

llvm/lib/Transforms/IPO/FunctionSpecialization.cpp

@@ -124,6 +124,20 @@ using CallSpecBinding = std::pair<CallBase *, SpecializationInfo>;
 // order across executions.
 using SpecializationMap = SmallMapVector<CallBase *, SpecializationInfo, 8>;
 
+// Helper to check if \p LV is either a constant or a constant
+// range with a single element. This should cover exactly the same cases as the
+// old ValueLatticeElement::isConstant() and is intended to be used in the
+// transition to ValueLatticeElement.
+static bool isConstant(const ValueLatticeElement &LV) {
+  return LV.isConstant() ||
+         (LV.isConstantRange() && LV.getConstantRange().isSingleElement());
+}
+
+// Helper to check if \p LV is either overdefined or a constant int.
+static bool isOverdefined(const ValueLatticeElement &LV) {
+  return !LV.isUnknownOrUndef() && !isConstant(LV);
+}
+
 static Constant *getPromotableAlloca(AllocaInst *Alloca, CallInst *Call) {
   Value *StoreValue = nullptr;
   for (auto *User : Alloca->users()) {