Move the utility function UpdateTerminator() from CodePlacementOpt() into

MachineBasicBlock so other passes can utilize it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86947 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 63 insertions, 62 deletions

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index 95fd6a4..b11adfe 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -225,7 +225,13 @@ public:
   /// potential fall-throughs at the end of the block.
   void moveBefore(MachineBasicBlock *NewAfter);
   void moveAfter(MachineBasicBlock *NewBefore);
-  
+
+  /// updateTerminator - Update the terminator instructions in block to account
+  /// for changes to the layout. If the block previously used a fallthrough,
+  /// it may now need a branch, and if it previously used branching it may now
+  /// be able to use a fallthrough.
+  void updateTerminator();
+
   // Machine-CFG mutators
   
   /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
diff --git a/lib/CodeGen/CodePlacementOpt.cpp b/lib/CodeGen/CodePlacementOpt.cpp
index 6fff12c..e9844d8 100644
--- a/lib/CodeGen/CodePlacementOpt.cpp
+++ b/lib/CodeGen/CodePlacementOpt.cpp
@@ -56,7 +56,6 @@ namespace {
                 MachineFunction::iterator InsertPt,
                 MachineFunction::iterator Begin,
                 MachineFunction::iterator End);
-    void UpdateTerminator(MachineBasicBlock *MBB);
     bool EliminateUnconditionalJumpsToTop(MachineFunction &MF,
                                           MachineLoop *L);
     bool MoveDiscontiguousLoopBlocks(MachineFunction &MF,
@@ -141,66 +140,9 @@ void CodePlacementOpt::Splice(MachineFunction &MF,
 
   MF.splice(InsertPt, Begin, End);
 
-  UpdateTerminator(prior(Begin));
-  UpdateTerminator(OldBeginPrior);
-  UpdateTerminator(OldEndPrior);
-}
-
-/// UpdateTerminator - Update the terminator instructions in MBB to account
-/// for changes to the layout. If the block previously used a fallthrough,
-/// it may now need a branch, and if it previously used branching it may now
-/// be able to use a fallthrough.
-///
-void CodePlacementOpt::UpdateTerminator(MachineBasicBlock *MBB) {
-  // A block with no successors has no concerns with fall-through edges.
-  if (MBB->succ_empty()) return;
-
-  MachineBasicBlock *TBB = 0, *FBB = 0;
-  SmallVector<MachineOperand, 4> Cond;
-  bool B = TII->AnalyzeBranch(*MBB, TBB, FBB, Cond);
-  (void) B;
-  assert(!B && "UpdateTerminators requires analyzable predecessors!");
-  if (Cond.empty()) {
-    if (TBB) {
-      // The block has an unconditional branch. If its successor is now
-      // its layout successor, delete the branch.
-      if (MBB->isLayoutSuccessor(TBB))
-        TII->RemoveBranch(*MBB);
-    } else {
-      // The block has an unconditional fallthrough. If its successor is not
-      // its layout successor, insert a branch.
-      TBB = *MBB->succ_begin();
-      if (!MBB->isLayoutSuccessor(TBB))
-        TII->InsertBranch(*MBB, TBB, 0, Cond);
-    }
-  } else {
-    if (FBB) {
-      // The block has a non-fallthrough conditional branch. If one of its
-      // successors is its layout successor, rewrite it to a fallthrough
-      // conditional branch.
-      if (MBB->isLayoutSuccessor(TBB)) {
-        TII->RemoveBranch(*MBB);
-        TII->ReverseBranchCondition(Cond);
-        TII->InsertBranch(*MBB, FBB, 0, Cond);
-      } else if (MBB->isLayoutSuccessor(FBB)) {
-        TII->RemoveBranch(*MBB);
-        TII->InsertBranch(*MBB, TBB, 0, Cond);
-      }
-    } else {
-      // The block has a fallthrough conditional branch.
-      MachineBasicBlock *MBBA = *MBB->succ_begin();
-      MachineBasicBlock *MBBB = *next(MBB->succ_begin());
-      if (MBBA == TBB) std::swap(MBBB, MBBA);
-      if (MBB->isLayoutSuccessor(TBB)) {
-        TII->RemoveBranch(*MBB);
-        TII->ReverseBranchCondition(Cond);
-        TII->InsertBranch(*MBB, MBBA, 0, Cond);
-      } else if (!MBB->isLayoutSuccessor(MBBA)) {
-        TII->RemoveBranch(*MBB);
-        TII->InsertBranch(*MBB, TBB, MBBA, Cond);
-      }
-    }
-  }
+  prior(Begin)->updateTerminator();
+  OldBeginPrior->updateTerminator();
+  OldEndPrior->updateTerminator();
 }
 
 /// EliminateUnconditionalJumpsToTop - Move blocks which unconditionally jump
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 14d6682..7b14a4c 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetInstrDesc.h"
+#include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Support/LeakDetector.h"
 #include "llvm/Support/raw_ostream.h"
@@ -242,6 +243,58 @@ void MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) {
   getParent()->splice(++BBI, this);
 }
 
+void MachineBasicBlock::updateTerminator() {
+  const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
+  // A block with no successors has no concerns with fall-through edges.
+  if (this->succ_empty()) return;
+
+  MachineBasicBlock *TBB = 0, *FBB = 0;
+  SmallVector<MachineOperand, 4> Cond;
+  bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond);
+  (void) B;
+  assert(!B && "UpdateTerminators requires analyzable predecessors!");
+  if (Cond.empty()) {
+    if (TBB) {
+      // The block has an unconditional branch. If its successor is now
+      // its layout successor, delete the branch.
+      if (isLayoutSuccessor(TBB))
+        TII->RemoveBranch(*this);
+    } else {
+      // The block has an unconditional fallthrough. If its successor is not
+      // its layout successor, insert a branch.
+      TBB = *succ_begin();
+      if (!isLayoutSuccessor(TBB))
+        TII->InsertBranch(*this, TBB, 0, Cond);
+    }
+  } else {
+    if (FBB) {
+      // The block has a non-fallthrough conditional branch. If one of its
+      // successors is its layout successor, rewrite it to a fallthrough
+      // conditional branch.
+      if (isLayoutSuccessor(TBB)) {
+        TII->RemoveBranch(*this);
+        TII->ReverseBranchCondition(Cond);
+        TII->InsertBranch(*this, FBB, 0, Cond);
+      } else if (isLayoutSuccessor(FBB)) {
+        TII->RemoveBranch(*this);
+        TII->InsertBranch(*this, TBB, 0, Cond);
+      }
+    } else {
+      // The block has a fallthrough conditional branch.
+      MachineBasicBlock *MBBA = *succ_begin();
+      MachineBasicBlock *MBBB = *next(succ_begin());
+      if (MBBA == TBB) std::swap(MBBB, MBBA);
+      if (isLayoutSuccessor(TBB)) {
+        TII->RemoveBranch(*this);
+        TII->ReverseBranchCondition(Cond);
+        TII->InsertBranch(*this, MBBA, 0, Cond);
+      } else if (!isLayoutSuccessor(MBBA)) {
+        TII->RemoveBranch(*this);
+        TII->InsertBranch(*this, TBB, MBBA, Cond);
+      }
+    }
+  }
+}
 
 void MachineBasicBlock::addSuccessor(MachineBasicBlock *succ) {
   Successors.push_back(succ);