[PM] Port SimplifyCFG to the new pass manager.

This should be sufficient to replace the initial (minor) function pass
pipeline in Clang with the new pass manager. I'll probably add an (off
by default) flag to do that just to ensure we can get extra testing.

llvm-svn: 227726

1 files changed, 65 insertions, 44 deletions

diff --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 0a4bc871afe..bc2ae2423e1 100644
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -21,7 +21,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/SimplifyCFG.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -37,6 +37,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Scalar.h"
 using namespace llvm;
 
 #define DEBUG_TYPE "simplifycfg"
@@ -47,36 +48,6 @@ UserBonusInstThreshold("bonus-inst-threshold", cl::Hidden, cl::init(1),
 
 STATISTIC(NumSimpl, "Number of blocks simplified");
 
-namespace {
-struct CFGSimplifyPass : public FunctionPass {
-  static char ID; // Pass identification, replacement for typeid
-  unsigned BonusInstThreshold;
-  CFGSimplifyPass(int T = -1) : FunctionPass(ID) {
-    BonusInstThreshold = (T == -1) ? UserBonusInstThreshold : unsigned(T);
-    initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
-  }
-  bool runOnFunction(Function &F) override;
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<AssumptionCacheTracker>();
-    AU.addRequired<TargetTransformInfoWrapperPass>();
-  }
-};
-}
-
-char CFGSimplifyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
-                      false)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_END(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
-                    false)
-
-// Public interface to the CFGSimplification pass
-FunctionPass *llvm::createCFGSimplificationPass(int Threshold) {
-  return new CFGSimplifyPass(Threshold);
-}
-
 /// mergeEmptyReturnBlocks - If we have more than one empty (other than phi
 /// node) return blocks, merge them together to promote recursive block merging.
 static bool mergeEmptyReturnBlocks(Function &F) {
@@ -176,19 +147,9 @@ static bool iterativelySimplifyCFG(Function &F, const TargetTransformInfo &TTI,
   return Changed;
 }
 
-// It is possible that we may require multiple passes over the code to fully
-// simplify the CFG.
-//
-bool CFGSimplifyPass::runOnFunction(Function &F) {
-  if (skipOptnoneFunction(F))
-    return false;
-
-  AssumptionCache *AC =
-      &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
-  const TargetTransformInfo &TTI =
-      getAnalysis<TargetTransformInfoWrapperPass>().getTTI();
-  DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
+static bool simplifyFunctionCFG(Function &F, const TargetTransformInfo &TTI,
+                                const DataLayout *DL, AssumptionCache *AC,
+                                int BonusInstThreshold) {
   bool EverChanged = removeUnreachableBlocks(F);
   EverChanged |= mergeEmptyReturnBlocks(F);
   EverChanged |= iterativelySimplifyCFG(F, TTI, DL, AC, BonusInstThreshold);
@@ -211,3 +172,63 @@ bool CFGSimplifyPass::runOnFunction(Function &F) {
 
   return true;
 }
+
+SimplifyCFGPass::SimplifyCFGPass()
+    : BonusInstThreshold(UserBonusInstThreshold) {}
+
+SimplifyCFGPass::SimplifyCFGPass(int BonusInstThreshold)
+    : BonusInstThreshold(BonusInstThreshold) {}
+
+PreservedAnalyses SimplifyCFGPass::run(Function &F,
+                                       AnalysisManager<Function> *AM) {
+  auto *DL = F.getParent()->getDataLayout();
+  auto &TTI = AM->getResult<TargetIRAnalysis>(F);
+  auto &AC = AM->getResult<AssumptionAnalysis>(F);
+
+  if (!simplifyFunctionCFG(F, TTI, DL, &AC, BonusInstThreshold))
+    return PreservedAnalyses::none();
+
+  return PreservedAnalyses::all();
+}
+
+namespace {
+struct CFGSimplifyPass : public FunctionPass {
+  static char ID; // Pass identification, replacement for typeid
+  unsigned BonusInstThreshold;
+  CFGSimplifyPass(int T = -1) : FunctionPass(ID) {
+    BonusInstThreshold = (T == -1) ? UserBonusInstThreshold : unsigned(T);
+    initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
+  }
+  bool runOnFunction(Function &F) override {
+    if (skipOptnoneFunction(F))
+      return false;
+
+    AssumptionCache *AC =
+        &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+    const TargetTransformInfo &TTI =
+        getAnalysis<TargetTransformInfoWrapperPass>().getTTI();
+    DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+    const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
+    return simplifyFunctionCFG(F, TTI, DL, AC, BonusInstThreshold);
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<AssumptionCacheTracker>();
+    AU.addRequired<TargetTransformInfoWrapperPass>();
+  }
+};
+}
+
+char CFGSimplifyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
+                      false)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_END(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
+                    false)
+
+// Public interface to the CFGSimplification pass
+FunctionPass *llvm::createCFGSimplificationPass(int Threshold) {
+  return new CFGSimplifyPass(Threshold);
+}
+