diff options
Diffstat (limited to 'lib/CodeGen/PHIElimination.h')
| -rw-r--r-- | lib/CodeGen/PHIElimination.h | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/lib/CodeGen/PHIElimination.h b/lib/CodeGen/PHIElimination.h index 3d02dfd..94716ee 100644 --- a/lib/CodeGen/PHIElimination.h +++ b/lib/CodeGen/PHIElimination.h @@ -89,11 +89,33 @@ namespace llvm { /// void analyzePHINodes(const MachineFunction& Fn); - // FindCopyInsertPoint - Find a safe place in MBB to insert a copy from - // SrcReg. This needs to be after any def or uses of SrcReg, but before - // any subsequent point where control flow might jump out of the basic - // block. + /// Split critical edges where necessary for good coalescer performance. + bool SplitPHIEdges(MachineFunction &MF, MachineBasicBlock &MBB); + + /// isLiveOut - Determine if Reg is live out from MBB, when not + /// considering PHI nodes. This means that Reg is either killed by + /// a successor block or passed through one. + bool isLiveOut(unsigned Reg, const MachineBasicBlock &MBB, + LiveVariables &LV); + + /// isLiveIn - Determine if Reg is live in to MBB, not considering PHI + /// source registers. This means that Reg is either killed by MBB or passes + /// through it. + bool isLiveIn(unsigned Reg, const MachineBasicBlock &MBB, + LiveVariables &LV); + + /// SplitCriticalEdge - Split a critical edge from A to B by + /// inserting a new MBB. Update branches in A and PHI instructions + /// in B. Return the new block. + MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *A, + MachineBasicBlock *B); + + /// FindCopyInsertPoint - Find a safe place in MBB to insert a copy from + /// SrcReg when following the CFG edge to SuccMBB. This needs to be after + /// any def of SrcReg, but before any subsequent point where control flow + /// might jump out of the basic block. MachineBasicBlock::iterator FindCopyInsertPoint(MachineBasicBlock &MBB, + MachineBasicBlock &SuccMBB, unsigned SrcReg); // SkipPHIsAndLabels - Copies need to be inserted after phi nodes and |
