| //===---- llvm/Analysis/ScalarEvolutionExpander.h - SCEV Exprs --*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the classes used to generate code from scalar expressions. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H |
| #define LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H |
| |
| #include "llvm/Analysis/ScalarEvolutionExpressions.h" |
| #include "llvm/Support/IRBuilder.h" |
| #include "llvm/Support/TargetFolder.h" |
| #include <set> |
| |
| namespace llvm { |
| /// SCEVExpander - This class uses information about analyze scalars to |
| /// rewrite expressions in canonical form. |
| /// |
| /// Clients should create an instance of this class when rewriting is needed, |
| /// and destroy it when finished to allow the release of the associated |
| /// memory. |
| struct SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> { |
| ScalarEvolution &SE; |
| std::map<std::pair<const SCEV *, Instruction *>, AssertingVH<Value> > |
| InsertedExpressions; |
| std::set<Value*> InsertedValues; |
| |
| typedef IRBuilder<true, TargetFolder> BuilderType; |
| BuilderType Builder; |
| |
| friend struct SCEVVisitor<SCEVExpander, Value*>; |
| public: |
| explicit SCEVExpander(ScalarEvolution &se) |
| : SE(se), Builder(se.getContext(), |
| TargetFolder(se.TD, se.getContext())) {} |
| |
| /// clear - Erase the contents of the InsertedExpressions map so that users |
| /// trying to expand the same expression into multiple BasicBlocks or |
| /// different places within the same BasicBlock can do so. |
| void clear() { InsertedExpressions.clear(); } |
| |
| /// getOrInsertCanonicalInductionVariable - This method returns the |
| /// canonical induction variable of the specified type for the specified |
| /// loop (inserting one if there is none). A canonical induction variable |
| /// starts at zero and steps by one on each iteration. |
| Value *getOrInsertCanonicalInductionVariable(const Loop *L, const Type *Ty); |
| |
| /// expandCodeFor - Insert code to directly compute the specified SCEV |
| /// expression into the program. The inserted code is inserted into the |
| /// specified block. |
| Value *expandCodeFor(const SCEV *SH, const Type *Ty, Instruction *IP) { |
| Builder.SetInsertPoint(IP->getParent(), IP); |
| return expandCodeFor(SH, Ty); |
| } |
| |
| private: |
| LLVMContext &getContext() const { return SE.getContext(); } |
| |
| /// InsertBinop - Insert the specified binary operator, doing a small amount |
| /// of work to avoid inserting an obviously redundant operation. |
| Value *InsertBinop(Instruction::BinaryOps Opcode, Value *LHS, Value *RHS); |
| |
| /// InsertNoopCastOfTo - Insert a cast of V to the specified type, |
| /// which must be possible with a noop cast, doing what we can to |
| /// share the casts. |
| Value *InsertNoopCastOfTo(Value *V, const Type *Ty); |
| |
| /// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP |
| /// instead of using ptrtoint+arithmetic+inttoptr. |
| Value *expandAddToGEP(const SCEV *const *op_begin, |
| const SCEV *const *op_end, |
| const PointerType *PTy, const Type *Ty, Value *V); |
| |
| Value *expand(const SCEV *S); |
| |
| /// expandCodeFor - Insert code to directly compute the specified SCEV |
| /// expression into the program. The inserted code is inserted into the |
| /// SCEVExpander's current insertion point. If a type is specified, the |
| /// result will be expanded to have that type, with a cast if necessary. |
| Value *expandCodeFor(const SCEV *SH, const Type *Ty = 0); |
| |
| /// isInsertedInstruction - Return true if the specified instruction was |
| /// inserted by the code rewriter. If so, the client should not modify the |
| /// instruction. |
| bool isInsertedInstruction(Instruction *I) const { |
| return InsertedValues.count(I); |
| } |
| |
| Value *visitConstant(const SCEVConstant *S) { |
| return S->getValue(); |
| } |
| |
| Value *visitTruncateExpr(const SCEVTruncateExpr *S); |
| |
| Value *visitZeroExtendExpr(const SCEVZeroExtendExpr *S); |
| |
| Value *visitSignExtendExpr(const SCEVSignExtendExpr *S); |
| |
| Value *visitAddExpr(const SCEVAddExpr *S); |
| |
| Value *visitMulExpr(const SCEVMulExpr *S); |
| |
| Value *visitUDivExpr(const SCEVUDivExpr *S); |
| |
| Value *visitAddRecExpr(const SCEVAddRecExpr *S); |
| |
| Value *visitSMaxExpr(const SCEVSMaxExpr *S); |
| |
| Value *visitUMaxExpr(const SCEVUMaxExpr *S); |
| |
| Value *visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S); |
| |
| Value *visitAllocSizeExpr(const SCEVAllocSizeExpr *S); |
| |
| Value *visitUnknown(const SCEVUnknown *S) { |
| return S->getValue(); |
| } |
| }; |
| } |
| |
| #endif |