Remove unnecessary gotos to fall-thru successors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85257 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 26 insertions, 1 deletions

diff --git a/lib/Target/PIC16/PIC16InstrInfo.cpp b/lib/Target/PIC16/PIC16InstrInfo.cpp
index 87bd3d9c7e..2fb405e947 100644
--- a/lib/Target/PIC16/PIC16InstrInfo.cpp
+++ b/lib/Target/PIC16/PIC16InstrInfo.cpp
@@ -214,3 +214,25 @@ InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
   // returning NULL.
   return 0;
 }
+
+bool PIC16InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
+                                   MachineBasicBlock *&TBB,
+                                   MachineBasicBlock *&FBB,
+                                   SmallVectorImpl<MachineOperand> &Cond,
+                                   bool AllowModify) const {
+  MachineBasicBlock::iterator I = MBB.end();
+  if (I == MBB.begin())
+    return true;
+
+  // Get the terminator instruction.
+  --I;
+  // Handle unconditional branches. If the unconditional branch's target is
+  // successor basic block then remove the unconditional branch. 
+  if (I->getOpcode() == PIC16::br_uncond  && AllowModify) {
+    if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
+      TBB = 0;
+      I->eraseFromParent();
+    }
+  }
+  return true;
+}
diff --git a/lib/Target/PIC16/PIC16InstrInfo.h b/lib/Target/PIC16/PIC16InstrInfo.h
index 85c098428c..56f51f00dd 100644
--- a/lib/Target/PIC16/PIC16InstrInfo.h
+++ b/lib/Target/PIC16/PIC16InstrInfo.h
@@ -68,7 +68,10 @@ public:
   unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
                         MachineBasicBlock *FBB,
                         const SmallVectorImpl<MachineOperand> &Cond) const; 
-
+  virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
+                             MachineBasicBlock *&FBB,
+                             SmallVectorImpl<MachineOperand> &Cond,
+                             bool AllowModify) const;
   };
 } // namespace llvm