vendor/llvm/llvm-trunk-r338150

1 files changed, 36 insertions, 23 deletions

diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp
index df1eebf43b2b..25cd7802264e 100644
--- a/lib/CodeGen/TailDuplication.cpp
+++ b/lib/CodeGen/TailDuplication.cpp
@@ -7,8 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This pass duplicates basic blocks ending in unconditional branches into
-// the tails of their predecessors, using the TailDuplicator utility class.
+/// \file This pass duplicates basic blocks ending in unconditional branches
+/// into the tails of their predecessors, using the TailDuplicator utility
+/// class.
 //
 //===----------------------------------------------------------------------===//
 
@@ -26,38 +27,55 @@ using namespace llvm;
 
 namespace {
 
-/// Perform tail duplication. Delegates to TailDuplicator
-class TailDuplicatePass : public MachineFunctionPass {
+class TailDuplicateBase : public MachineFunctionPass {
   TailDuplicator Duplicator;
-
+  bool PreRegAlloc;
 public:
-  static char ID;
-
-  explicit TailDuplicatePass() : MachineFunctionPass(ID) {}
+  TailDuplicateBase(char &PassID, bool PreRegAlloc)
+    : MachineFunctionPass(PassID), PreRegAlloc(PreRegAlloc) {}
 
   bool runOnMachineFunction(MachineFunction &MF) override;
 
-  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<MachineBranchProbabilityInfo>();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+};
+
+class TailDuplicate : public TailDuplicateBase {
+public:
+  static char ID;
+  TailDuplicate() : TailDuplicateBase(ID, false) {
+    initializeTailDuplicatePass(*PassRegistry::getPassRegistry());
+  }
+};
+
+class EarlyTailDuplicate : public TailDuplicateBase {
+public:
+  static char ID;
+  EarlyTailDuplicate() : TailDuplicateBase(ID, true) {
+    initializeEarlyTailDuplicatePass(*PassRegistry::getPassRegistry());
+  }
 };
 
 } // end anonymous namespace
 
-char TailDuplicatePass::ID = 0;
+char TailDuplicate::ID;
+char EarlyTailDuplicate::ID;
 
-char &llvm::TailDuplicateID = TailDuplicatePass::ID;
+char &llvm::TailDuplicateID = TailDuplicate::ID;
+char &llvm::EarlyTailDuplicateID = EarlyTailDuplicate::ID;
 
-INITIALIZE_PASS(TailDuplicatePass, DEBUG_TYPE, "Tail Duplication", false, false)
+INITIALIZE_PASS(TailDuplicate, DEBUG_TYPE, "Tail Duplication", false, false)
+INITIALIZE_PASS(EarlyTailDuplicate, "early-tailduplication",
+                "Early Tail Duplication", false, false)
 
-bool TailDuplicatePass::runOnMachineFunction(MachineFunction &MF) {
+bool TailDuplicateBase::runOnMachineFunction(MachineFunction &MF) {
   if (skipFunction(MF.getFunction()))
     return false;
 
   auto MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
-
-  // TODO: Querying isSSA() to determine pre-/post-regalloc is fragile, better
-  // split this into two passes instead.
-  bool PreRegAlloc = MF.getRegInfo().isSSA();
-  Duplicator.initMF(MF, PreRegAlloc, MBPI, /* LayoutMode */ false);
+  Duplicator.initMF(MF, PreRegAlloc, MBPI, /*LayoutMode=*/false);
 
   bool MadeChange = false;
   while (Duplicator.tailDuplicateBlocks())
@@ -65,8 +83,3 @@ bool TailDuplicatePass::runOnMachineFunction(MachineFunction &MF) {
 
   return MadeChange;
 }
-
-void TailDuplicatePass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<MachineBranchProbabilityInfo>();
-  MachineFunctionPass::getAnalysisUsage(AU);
-}