Add getTopBlock and getBottomBlock member functions to MachineLoopInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84596 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/MachineLoopInfo.h b/include/llvm/CodeGen/MachineLoopInfo.h
index 65ad4e4..d3df805 100644
--- a/include/llvm/CodeGen/MachineLoopInfo.h
+++ b/include/llvm/CodeGen/MachineLoopInfo.h
@@ -38,6 +38,17 @@
class MachineLoop : public LoopBase<MachineBasicBlock, MachineLoop> {
public:
MachineLoop();
+
+ /// getTopBlock - Return the "top" block in the loop, which is the first
+ /// block in the linear layout, ignoring any parts of the loop not
+ /// contiguous with the part the contains the header.
+ MachineBasicBlock *getTopBlock();
+
+ /// getBottomBlock - Return the "bottom" block in the loop, which is the last
+ /// block in the linear layout, ignoring any parts of the loop not
+ /// contiguous with the part the contains the header.
+ MachineBasicBlock *getBottomBlock();
+
private:
friend class LoopInfoBase<MachineBasicBlock, MachineLoop>;
explicit MachineLoop(MachineBasicBlock *MBB)
diff --git a/lib/CodeGen/MachineLoopInfo.cpp b/lib/CodeGen/MachineLoopInfo.cpp
index 2da8e37..db77d19 100644
--- a/lib/CodeGen/MachineLoopInfo.cpp
+++ b/lib/CodeGen/MachineLoopInfo.cpp
@@ -43,3 +43,31 @@
AU.addRequired<MachineDominatorTree>();
MachineFunctionPass::getAnalysisUsage(AU);
}
+
+MachineBasicBlock *MachineLoop::getTopBlock() {
+ MachineBasicBlock *TopMBB = getHeader();
+ MachineFunction::iterator Begin = TopMBB->getParent()->begin();
+ if (TopMBB != Begin) {
+ MachineBasicBlock *PriorMBB = prior(MachineFunction::iterator(TopMBB));
+ while (contains(PriorMBB)) {
+ TopMBB = PriorMBB;
+ if (TopMBB == Begin) break;
+ PriorMBB = prior(MachineFunction::iterator(TopMBB));
+ }
+ }
+ return TopMBB;
+}
+
+MachineBasicBlock *MachineLoop::getBottomBlock() {
+ MachineBasicBlock *BotMBB = getHeader();
+ MachineFunction::iterator End = BotMBB->getParent()->end();
+ if (BotMBB != prior(End)) {
+ MachineBasicBlock *NextMBB = next(MachineFunction::iterator(BotMBB));
+ while (contains(NextMBB)) {
+ BotMBB = NextMBB;
+ if (BotMBB == next(MachineFunction::iterator(BotMBB))) break;
+ NextMBB = next(MachineFunction::iterator(BotMBB));
+ }
+ }
+ return BotMBB;
+}