148 lines
5.5 KiB
C++
148 lines
5.5 KiB
C++
//===---- llvm/Analysis/ScalarEvolutionExpander.h - SCEV Exprs --*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the classes used to generate code from scalar expressions.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H
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#define LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H
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#include "llvm/Instructions.h"
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#include "llvm/Type.h"
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#include "llvm/Analysis/ScalarEvolution.h"
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#include "llvm/Analysis/ScalarEvolutionExpressions.h"
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namespace llvm {
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/// SCEVExpander - This class uses information about analyze scalars to
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/// rewrite expressions in canonical form.
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///
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/// Clients should create an instance of this class when rewriting is needed,
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/// and destroy it when finished to allow the release of the associated
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/// memory.
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struct SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> {
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ScalarEvolution &SE;
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std::map<SCEVHandle, AssertingVH<Value> > InsertedExpressions;
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std::set<Value*> InsertedValues;
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BasicBlock::iterator InsertPt;
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friend struct SCEVVisitor<SCEVExpander, Value*>;
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public:
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explicit SCEVExpander(ScalarEvolution &se)
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: SE(se) {}
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/// clear - Erase the contents of the InsertedExpressions map so that users
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/// trying to expand the same expression into multiple BasicBlocks or
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/// different places within the same BasicBlock can do so.
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void clear() { InsertedExpressions.clear(); }
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/// isInsertedInstruction - Return true if the specified instruction was
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/// inserted by the code rewriter. If so, the client should not modify the
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/// instruction.
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bool isInsertedInstruction(Instruction *I) const {
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return InsertedValues.count(I);
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}
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/// isInsertedExpression - Return true if the the code rewriter has a
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/// Value* recorded for the given expression.
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bool isInsertedExpression(const SCEV *S) const {
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return InsertedExpressions.count(S);
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}
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/// getOrInsertCanonicalInductionVariable - This method returns the
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/// canonical induction variable of the specified type for the specified
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/// loop (inserting one if there is none). A canonical induction variable
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/// starts at zero and steps by one on each iteration.
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Value *getOrInsertCanonicalInductionVariable(const Loop *L, const Type *Ty){
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assert(Ty->isInteger() && "Can only insert integer induction variables!");
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SCEVHandle H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty),
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SE.getIntegerSCEV(1, Ty), L);
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return expand(H);
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}
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/// addInsertedValue - Remember the specified instruction as being the
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/// canonical form for the specified SCEV.
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void addInsertedValue(Value *V, const SCEV *S) {
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InsertedExpressions[S] = V;
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InsertedValues.insert(V);
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}
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void setInsertionPoint(BasicBlock::iterator NewIP) { InsertPt = NewIP; }
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BasicBlock::iterator getInsertionPoint() const { return InsertPt; }
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/// expandCodeFor - Insert code to directly compute the specified SCEV
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/// expression into the program. The inserted code is inserted into the
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/// SCEVExpander's current insertion point. If a type is specified, the
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/// result will be expanded to have that type, with a cast if necessary.
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Value *expandCodeFor(SCEVHandle SH, const Type *Ty = 0);
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/// expandCodeFor - Insert code to directly compute the specified SCEV
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/// expression into the program. The inserted code is inserted into the
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/// specified block.
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Value *expandCodeFor(SCEVHandle SH, const Type *Ty,
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BasicBlock::iterator IP) {
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setInsertionPoint(IP);
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return expandCodeFor(SH, Ty);
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}
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/// InsertCastOfTo - Insert a cast of V to the specified type, doing what
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/// we can to share the casts.
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Value *InsertCastOfTo(Instruction::CastOps opcode, Value *V,
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const Type *Ty);
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/// InsertNoopCastOfTo - Insert a cast of V to the specified type,
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/// which must be possible with a noop cast.
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Value *InsertNoopCastOfTo(Value *V, const Type *Ty);
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/// InsertBinop - Insert the specified binary operator, doing a small amount
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/// of work to avoid inserting an obviously redundant operation.
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Value *InsertBinop(Instruction::BinaryOps Opcode, Value *LHS,
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Value *RHS, BasicBlock::iterator InsertPt);
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private:
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/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP
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/// instead of using ptrtoint+arithmetic+inttoptr.
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Value *expandAddToGEP(const SCEVHandle *op_begin, const SCEVHandle *op_end,
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const PointerType *PTy, const Type *Ty, Value *V);
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Value *expand(const SCEV *S);
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Value *visitConstant(const SCEVConstant *S) {
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return S->getValue();
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}
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Value *visitTruncateExpr(const SCEVTruncateExpr *S);
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Value *visitZeroExtendExpr(const SCEVZeroExtendExpr *S);
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Value *visitSignExtendExpr(const SCEVSignExtendExpr *S);
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Value *visitAddExpr(const SCEVAddExpr *S);
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Value *visitMulExpr(const SCEVMulExpr *S);
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Value *visitUDivExpr(const SCEVUDivExpr *S);
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Value *visitAddRecExpr(const SCEVAddRecExpr *S);
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Value *visitSMaxExpr(const SCEVSMaxExpr *S);
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Value *visitUMaxExpr(const SCEVUMaxExpr *S);
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Value *visitUnknown(const SCEVUnknown *S) {
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return S->getValue();
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}
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};
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}
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#endif
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