| //===-- Transform/Utils/BasicBlockUtils.h - BasicBlock Utils ----*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This family of functions perform manipulations on basic blocks, and |
| // instructions contained within basic blocks. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_TRANSFORMS_UTILS_BASICBLOCK_H |
| #define LLVM_TRANSFORMS_UTILS_BASICBLOCK_H |
| |
| // FIXME: Move to this file: BasicBlock::removePredecessor, BB::splitBasicBlock |
| |
| #include "llvm/BasicBlock.h" |
| #include "llvm/Support/CFG.h" |
| |
| namespace llvm { |
| |
| class Instruction; |
| class Pass; |
| |
| // ReplaceInstWithValue - Replace all uses of an instruction (specified by BI) |
| // with a value, then remove and delete the original instruction. |
| // |
| void ReplaceInstWithValue(BasicBlock::InstListType &BIL, |
| BasicBlock::iterator &BI, Value *V); |
| |
| // ReplaceInstWithInst - Replace the instruction specified by BI with the |
| // instruction specified by I. The original instruction is deleted and BI is |
| // updated to point to the new instruction. |
| // |
| void ReplaceInstWithInst(BasicBlock::InstListType &BIL, |
| BasicBlock::iterator &BI, Instruction *I); |
| |
| // ReplaceInstWithInst - Replace the instruction specified by From with the |
| // instruction specified by To. |
| // |
| void ReplaceInstWithInst(Instruction *From, Instruction *To); |
| |
| |
| // RemoveSuccessor - Change the specified terminator instruction such that its |
| // successor #SuccNum no longer exists. Because this reduces the outgoing |
| // degree of the current basic block, the actual terminator instruction itself |
| // may have to be changed. In the case where the last successor of the block is |
| // deleted, a return instruction is inserted in its place which can cause a |
| // suprising change in program behavior if it is not expected. |
| // |
| void RemoveSuccessor(TerminatorInst *TI, unsigned SuccNum); |
| |
| /// isCriticalEdge - Return true if the specified edge is a critical edge. |
| /// Critical edges are edges from a block with multiple successors to a block |
| /// with multiple predecessors. |
| /// |
| bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum); |
| |
| /// SplitCriticalEdge - If this edge is a critical edge, insert a new node to |
| /// split the critical edge. This will update DominatorSet, ImmediateDominator, |
| /// DominatorTree, and DominatorFrontier information if it is available, thus |
| /// calling this pass will not invalidate either of them. This returns true if |
| /// the edge was split, false otherwise. |
| /// |
| bool SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0); |
| |
| inline bool SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) { |
| return SplitCriticalEdge(BB->getTerminator(), SI.getSuccessorIndex(), P); |
| } |
| |
| /// SplitCriticalEdge - If the edge from *PI to BB is not critical, return |
| /// false. Otherwise, split all edges between the two blocks and return true. |
| /// This updates all of the same analyses as the other SplitCriticalEdge |
| /// function. |
| inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, Pass *P = 0) { |
| BasicBlock *Pred = *PI; |
| bool MadeChange = false; |
| for (succ_iterator SI = succ_begin(Pred), E = succ_end(Pred); SI != E; ++SI) |
| if (*SI == Succ) |
| MadeChange |= SplitCriticalEdge(Pred, SI, P); |
| return MadeChange; |
| } |
| |
| inline bool SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, Pass *P = 0) { |
| for (succ_iterator SI = succ_begin(Src); ; ++SI) { |
| assert(SI != succ_end(Src) && "Edge doesn't exist"); |
| if (*SI == Dst) |
| return SplitCriticalEdge(Src, SI, P); |
| } |
| } |
| } // End llvm namespace |
| |
| #endif |