implement the BlockHasNoFallThrough hook

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31264 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 6318846..9876e3c 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -259,6 +259,17 @@ void PPCInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
   BuildMI(&MBB, PPC::B, 1).addMBB(FBB);
 }
 
+bool PPCInstrInfo::BlockHasNoFallThrough(MachineBasicBlock &MBB) const {
+  if (MBB.empty()) return false;
+  
+  switch (MBB.back().getOpcode()) {
+  case PPC::B:     // Uncond branch.
+  case PPC::BCTR:  // Indirect branch.
+    return true;
+  default: return false;
+  }
+}
+
 bool PPCInstrInfo::
 ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
   assert(Cond.size() == 2 && "Invalid PPC branch opcode!");
diff --git a/lib/Target/PowerPC/PPCInstrInfo.h b/lib/Target/PowerPC/PPCInstrInfo.h
index dc16aed..769474b 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.h
+++ b/lib/Target/PowerPC/PPCInstrInfo.h
@@ -110,6 +110,7 @@ public:
   virtual void InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
                             MachineBasicBlock *FBB,
                             const std::vector<MachineOperand> &Cond) const;
+  virtual bool BlockHasNoFallThrough(MachineBasicBlock &MBB) const;
   virtual bool ReverseBranchCondition(std::vector<MachineOperand> &Cond) const;