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

Reland 42c2dc4 which was reverted
in cb03b1b. The fix for the link
errors was to reintroduce one of the two occurences of 'Scalar'
under the LINK_COMPONENTS.

Differential Revision: https://reviews.llvm.org/D138654

Author: labrinea

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

@@ -40,10 +40,6 @@ 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

@@ -15,6 +15,8 @@
 #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>
@@ -173,6 +175,24 @@ 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

@@ -71,5 +71,4 @@ add_llvm_component_library(LLVMipo
   TransformUtils
   Vectorize
   Instrumentation
-  Scalar
   )

llvm/lib/Transforms/IPO/FunctionSpecialization.cpp

@@ -124,20 +124,6 @@ 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()) {