[IndVarSimplify] Extract the logic of `-indvars` out into a class; NFC

This will be used later to port IndVarSimplify to the new pass manager.

llvm-svn: 271190

llvm/include/llvm/InitializePasses.h

@@ -152,7 +152,7 @@ void initializeIPSCCPLegacyPassPass(PassRegistry &);
 void initializeIVUsersPass(PassRegistry&);
 void initializeIfConverterPass(PassRegistry&);
 void initializeInductiveRangeCheckEliminationPass(PassRegistry&);
-void initializeIndVarSimplifyPass(PassRegistry&);
+void initializeIndVarSimplifyLegacyPassPass(PassRegistry&);
 void initializeInferFunctionAttrsLegacyPassPass(PassRegistry&);
 void initializeInlineCostAnalysisPass(PassRegistry&);
 void initializeInstructionCombiningPassPass(PassRegistry&);

llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -86,34 +86,16 @@ static cl::opt<ReplaceExitVal> ReplaceExitValue(
 namespace {
 struct RewritePhi;
 
-class IndVarSimplify : public LoopPass {
-  LoopInfo                  *LI;
-  ScalarEvolution           *SE;
-  DominatorTree             *DT;
-  TargetLibraryInfo         *TLI;
+class IndVarSimplify {
+  LoopInfo *LI;
+  ScalarEvolution *SE;
+  DominatorTree *DT;
+  const DataLayout &DL;
+  TargetLibraryInfo *TLI;
   const TargetTransformInfo *TTI;
 
   SmallVector<WeakVH, 16> DeadInsts;
-  bool Changed;
-public:
-
-  static char ID; // Pass identification, replacement for typeid
-  IndVarSimplify()
-    : LoopPass(ID), LI(nullptr), SE(nullptr), DT(nullptr), Changed(false) {
-    initializeIndVarSimplifyPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnLoop(Loop *L, LPPassManager &LPM) override;
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-    getLoopAnalysisUsage(AU);
-  }
-
-private:
-  void releaseMemory() override {
-    DeadInsts.clear();
-  }
+  bool Changed = false;
 
   bool isValidRewrite(Value *FromVal, Value *ToVal);
 
@@ -133,20 +115,17 @@ private:
 
   Value *expandSCEVIfNeeded(SCEVExpander &Rewriter, const SCEV *S, Loop *L,
                             Instruction *InsertPt, Type *Ty);
+
+public:
+  IndVarSimplify(LoopInfo *LI, ScalarEvolution *SE, DominatorTree *DT,
+                 const DataLayout &DL, TargetLibraryInfo *TLI,
+                 TargetTransformInfo *TTI)
+      : LI(LI), SE(SE), DT(DT), DL(DL), TLI(TLI), TTI(TTI) {}
+
+  bool run(Loop *L);
 };
 }
 
-char IndVarSimplify::ID = 0;
-INITIALIZE_PASS_BEGIN(IndVarSimplify, "indvars",
-                "Induction Variable Simplification", false, false)
-INITIALIZE_PASS_DEPENDENCY(LoopPass)
-INITIALIZE_PASS_END(IndVarSimplify, "indvars",
-                "Induction Variable Simplification", false, false)
-
-Pass *llvm::createIndVarSimplifyPass() {
-  return new IndVarSimplify();
-}
-
 /// Return true if the SCEV expansion generated by the rewriter can replace the
 /// original value. SCEV guarantees that it produces the same value, but the way
 /// it is produced may be illegal IR.  Ideally, this function will only be
@@ -2121,10 +2100,7 @@ void IndVarSimplify::sinkUnusedInvariants(Loop *L) {
 //  IndVarSimplify driver. Manage several subpasses of IV simplification.
 //===----------------------------------------------------------------------===//
 
-bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
-  if (skipLoop(L))
-    return false;
-
+bool IndVarSimplify::run(Loop *L) {
   // If LoopSimplify form is not available, stay out of trouble. Some notes:
   //  - LSR currently only supports LoopSimplify-form loops. Indvars'
   //    canonicalization can be a pessimization without LSR to "clean up"
@@ -2136,18 +2112,6 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
   if (!L->isLoopSimplifyForm())
     return false;
 
-  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
-  SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
-  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
-  TLI = TLIP ? &TLIP->getTLI() : nullptr;
-  auto *TTIP = getAnalysisIfAvailable<TargetTransformInfoWrapperPass>();
-  TTI = TTIP ? &TTIP->getTTI(*L->getHeader()->getParent()) : nullptr;
-  const DataLayout &DL = L->getHeader()->getModule()->getDataLayout();
-
-  DeadInsts.clear();
-  Changed = false;
-
   // If there are any floating-point recurrences, attempt to
   // transform them to use integer recurrences.
   rewriteNonIntegerIVs(L);
@@ -2249,3 +2213,45 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
 
   return Changed;
 }
+
+namespace {
+struct IndVarSimplifyLegacyPass : public LoopPass {
+  static char ID; // Pass identification, replacement for typeid
+  IndVarSimplifyLegacyPass() : LoopPass(ID) {
+    initializeIndVarSimplifyLegacyPassPass(*PassRegistry::getPassRegistry());
+  }
+
+  bool runOnLoop(Loop *L, LPPassManager &LPM) override {
+    if (skipLoop(L))
+      return false;
+
+    auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+    auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+    auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+    auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
+    auto *TLI = TLIP ? &TLIP->getTLI() : nullptr;
+    auto *TTIP = getAnalysisIfAvailable<TargetTransformInfoWrapperPass>();
+    auto *TTI = TTIP ? &TTIP->getTTI(*L->getHeader()->getParent()) : nullptr;
+    const DataLayout &DL = L->getHeader()->getModule()->getDataLayout();
+
+    IndVarSimplify IVS(LI, SE, DT, DL, TLI, TTI);
+    return IVS.run(L);
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+    getLoopAnalysisUsage(AU);
+  }
+};
+}
+
+char IndVarSimplifyLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(IndVarSimplifyLegacyPass, "indvars",
+                      "Induction Variable Simplification", false, false)
+INITIALIZE_PASS_DEPENDENCY(LoopPass)
+INITIALIZE_PASS_END(IndVarSimplifyLegacyPass, "indvars",
+                    "Induction Variable Simplification", false, false)
+
+Pass *llvm::createIndVarSimplifyPass() {
+  return new IndVarSimplifyLegacyPass();
+}

llvm/lib/Transforms/Scalar/Scalar.cpp

@@ -46,7 +46,7 @@ void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeEarlyCSELegacyPassPass(Registry);
   initializeFlattenCFGPassPass(Registry);
   initializeInductiveRangeCheckEliminationPass(Registry);
-  initializeIndVarSimplifyPass(Registry);
+  initializeIndVarSimplifyLegacyPassPass(Registry);
   initializeJumpThreadingPass(Registry);
   initializeLICMPass(Registry);
   initializeLoopDataPrefetchPass(Registry);