diff options
Diffstat (limited to 'include/llvm/Transforms/Utils/BasicBlockUtils.h')
| -rw-r--r-- | include/llvm/Transforms/Utils/BasicBlockUtils.h | 142 |
1 files changed, 66 insertions, 76 deletions
diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h index 13c856dfdc9a..37fd20925cba 100644 --- a/include/llvm/Transforms/Utils/BasicBlockUtils.h +++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h @@ -22,7 +22,7 @@ namespace llvm { -class MemoryDependenceAnalysis; +class MemoryDependenceResults; class DominatorTree; class LoopInfo; class Instruction; @@ -31,51 +31,45 @@ class ReturnInst; class TargetLibraryInfo; class TerminatorInst; -/// DeleteDeadBlock - Delete the specified block, which must have no -/// predecessors. +/// Delete the specified block, which must have no predecessors. void DeleteDeadBlock(BasicBlock *BB); -/// FoldSingleEntryPHINodes - We know that BB has one predecessor. If there are -/// any single-entry PHI nodes in it, fold them away. This handles the case -/// when all entries to the PHI nodes in a block are guaranteed equal, such as -/// when the block has exactly one predecessor. +/// We know that BB has one predecessor. If there are any single-entry PHI nodes +/// in it, fold them away. This handles the case when all entries to the PHI +/// nodes in a block are guaranteed equal, such as when the block has exactly +/// one predecessor. void FoldSingleEntryPHINodes(BasicBlock *BB, - MemoryDependenceAnalysis *MemDep = nullptr); + MemoryDependenceResults *MemDep = nullptr); -/// DeleteDeadPHIs - Examine each PHI in the given block and delete it if it -/// is dead. Also recursively delete any operands that become dead as -/// a result. This includes tracing the def-use list from the PHI to see if -/// it is ultimately unused or if it reaches an unused cycle. Return true -/// if any PHIs were deleted. +/// Examine each PHI in the given block and delete it if it is dead. Also +/// recursively delete any operands that become dead as a result. This includes +/// tracing the def-use list from the PHI to see if it is ultimately unused or +/// if it reaches an unused cycle. Return true if any PHIs were deleted. bool DeleteDeadPHIs(BasicBlock *BB, const TargetLibraryInfo *TLI = nullptr); -/// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor, -/// if possible. The return value indicates success or failure. +/// Attempts to merge a block into its predecessor, if possible. The return +/// value indicates success or failure. bool MergeBlockIntoPredecessor(BasicBlock *BB, DominatorTree *DT = nullptr, LoopInfo *LI = nullptr, - MemoryDependenceAnalysis *MemDep = nullptr); + MemoryDependenceResults *MemDep = nullptr); -// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI) -// with a value, then remove and delete the original instruction. -// +/// 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. Copies DebugLoc from BI to I, if I doesn't -// already have a DebugLoc. The original instruction is deleted and BI is -// updated to point to the new instruction. -// +/// Replace the instruction specified by BI with the instruction specified by I. +/// Copies DebugLoc from BI to I, if I doesn't already have a DebugLoc. 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. Copies DebugLoc from BI to I, if I doesn't -// already have a DebugLoc. -// +/// Replace the instruction specified by From with the instruction specified by +/// To. Copies DebugLoc from BI to I, if I doesn't already have a DebugLoc. void ReplaceInstWithInst(Instruction *From, Instruction *To); -/// \brief Option class for critical edge splitting. +/// Option class for critical edge splitting. /// /// This provides a builder interface for overriding the default options used /// during critical edge splitting. @@ -107,10 +101,9 @@ struct CriticalEdgeSplittingOptions { } }; -/// SplitCriticalEdge - If this edge is a critical edge, insert a new node to -/// split the critical edge. This will update the analyses passed in through -/// the option struct. This returns the new block if the edge was split, null -/// otherwise. +/// If this edge is a critical edge, insert a new node to split the critical +/// edge. This will update the analyses passed in through the option struct. +/// This returns the new block if the edge was split, null otherwise. /// /// If MergeIdenticalEdges in the options struct is true (not the default), /// *all* edges from TI to the specified successor will be merged into the same @@ -137,11 +130,10 @@ SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Options); } -/// 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. If P is specified, it updates the analyses -/// described above. +/// 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. If P is specified, it +/// updates the analyses described above. inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, const CriticalEdgeSplittingOptions &Options = CriticalEdgeSplittingOptions()) { @@ -153,10 +145,9 @@ inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, return MadeChange; } -/// SplitCriticalEdge - If an edge from Src to Dst is critical, split the edge -/// and return true, otherwise return false. This method requires that there be -/// an edge between the two blocks. It updates the analyses -/// passed in the options struct +/// If an edge from Src to Dst is critical, split the edge and return true, +/// otherwise return false. This method requires that there be an edge between +/// the two blocks. It updates the analyses passed in the options struct inline BasicBlock * SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, const CriticalEdgeSplittingOptions &Options = @@ -171,30 +162,28 @@ SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, } } -// SplitAllCriticalEdges - Loop over all of the edges in the CFG, -// breaking critical edges as they are found. -// Returns the number of broken edges. +/// Loop over all of the edges in the CFG, breaking critical edges as they are +/// found. Returns the number of broken edges. unsigned SplitAllCriticalEdges(Function &F, const CriticalEdgeSplittingOptions &Options = CriticalEdgeSplittingOptions()); -/// SplitEdge - Split the edge connecting specified block. +/// Split the edge connecting specified block. BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To, DominatorTree *DT = nullptr, LoopInfo *LI = nullptr); -/// SplitBlock - Split the specified block at the specified instruction - every -/// thing before SplitPt stays in Old and everything starting with SplitPt moves -/// to a new block. The two blocks are joined by an unconditional branch and -/// the loop info is updated. -/// +/// Split the specified block at the specified instruction - everything before +/// SplitPt stays in Old and everything starting with SplitPt moves to a new +/// block. The two blocks are joined by an unconditional branch and the loop +/// info is updated. BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt, DominatorTree *DT = nullptr, LoopInfo *LI = nullptr); -/// SplitBlockPredecessors - This method introduces at least one new basic block -/// into the function and moves some of the predecessors of BB to be -/// predecessors of the new block. The new predecessors are indicated by the -/// Preds array. The new block is given a suffix of 'Suffix'. Returns new basic -/// block to which predecessors from Preds are now pointing. +/// This method introduces at least one new basic block into the function and +/// moves some of the predecessors of BB to be predecessors of the new block. +/// The new predecessors are indicated by the Preds array. The new block is +/// given a suffix of 'Suffix'. Returns new basic block to which predecessors +/// from Preds are now pointing. /// /// If BB is a landingpad block then additional basicblock might be introduced. /// It will have Suffix+".split_lp". See SplitLandingPadPredecessors for more @@ -211,12 +200,12 @@ BasicBlock *SplitBlockPredecessors(BasicBlock *BB, ArrayRef<BasicBlock *> Preds, LoopInfo *LI = nullptr, bool PreserveLCSSA = false); -/// SplitLandingPadPredecessors - This method transforms the landing pad, -/// OrigBB, by introducing two new basic blocks into the function. One of those -/// new basic blocks gets the predecessors listed in Preds. The other basic -/// block gets the remaining predecessors of OrigBB. The landingpad instruction -/// OrigBB is clone into both of the new basic blocks. The new blocks are given -/// the suffixes 'Suffix1' and 'Suffix2', and are returned in the NewBBs vector. +/// This method transforms the landing pad, OrigBB, by introducing two new basic +/// blocks into the function. One of those new basic blocks gets the +/// predecessors listed in Preds. The other basic block gets the remaining +/// predecessors of OrigBB. The landingpad instruction OrigBB is clone into both +/// of the new basic blocks. The new blocks are given the suffixes 'Suffix1' and +/// 'Suffix2', and are returned in the NewBBs vector. /// /// This currently updates the LLVM IR, DominatorTree, LoopInfo, and LCCSA but /// no other analyses. In particular, it does not preserve LoopSimplify @@ -231,19 +220,17 @@ void SplitLandingPadPredecessors(BasicBlock *OrigBB, LoopInfo *LI = nullptr, bool PreserveLCSSA = false); -/// FoldReturnIntoUncondBranch - This method duplicates the specified return -/// instruction into a predecessor which ends in an unconditional branch. If -/// the return instruction returns a value defined by a PHI, propagate the -/// right value into the return. It returns the new return instruction in the -/// predecessor. +/// This method duplicates the specified return instruction into a predecessor +/// which ends in an unconditional branch. If the return instruction returns a +/// value defined by a PHI, propagate the right value into the return. It +/// returns the new return instruction in the predecessor. ReturnInst *FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB, BasicBlock *Pred); -/// SplitBlockAndInsertIfThen - Split the containing block at the -/// specified instruction - everything before and including SplitBefore stays -/// in the old basic block, and everything after SplitBefore is moved to a -/// new block. The two blocks are connected by a conditional branch -/// (with value of Cmp being the condition). +/// Split the containing block at the specified instruction - everything before +/// and including SplitBefore stays in the old basic block, and everything after +/// SplitBefore is moved to a new block. The two blocks are connected by a +/// conditional branch (with value of Cmp being the condition). /// Before: /// Head /// SplitBefore @@ -259,11 +246,12 @@ ReturnInst *FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB, /// UnreachableInst, otherwise it branches to Tail. /// Returns the NewBasicBlock's terminator. /// -/// Updates DT if given. +/// Updates DT and LI if given. TerminatorInst *SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights = nullptr, - DominatorTree *DT = nullptr); + DominatorTree *DT = nullptr, + LoopInfo *LI = nullptr); /// SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, /// but also creates the ElseBlock. @@ -284,12 +272,14 @@ void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore, TerminatorInst **ElseTerm, MDNode *BranchWeights = nullptr); -/// -/// GetIfCondition - Check whether BB is the merge point of a if-region. +/// Check whether BB is the merge point of a if-region. /// If so, return the boolean condition that determines which entry into /// BB will be taken. Also, return by references the block that will be /// entered from if the condition is true, and the block that will be /// entered if the condition is false. +/// +/// This does no checking to see if the true/false blocks have large or unsavory +/// instructions in them. Value *GetIfCondition(BasicBlock *BB, BasicBlock *&IfTrue, BasicBlock *&IfFalse); } // End llvm namespace |