diff options
Diffstat (limited to 'lib/CodeGen/CodePlacementOpt.cpp')
| -rw-r--r-- | lib/CodeGen/CodePlacementOpt.cpp | 64 | 
1 files changed, 3 insertions, 61 deletions
diff --git a/lib/CodeGen/CodePlacementOpt.cpp b/lib/CodeGen/CodePlacementOpt.cpp index 6fff12c0b0d5..e9844d84c17f 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  | 
