X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FScalarEvolutionExpander.h;h=9ee3a97bc70df3a138f85373e64a0723c3a81b15;hb=0b8c9a80f20772c3793201ab5b251d3520b9cea3;hp=4b02f82035fe3c056ed0ccc0b0f07345733d7567;hpb=ab28928fe276d20cf9533ae6b858497f835c7a53;p=oota-llvm.git diff --git a/include/llvm/Analysis/ScalarEvolutionExpander.h b/include/llvm/Analysis/ScalarEvolutionExpander.h index 4b02f82035f..9ee3a97bc70 100644 --- a/include/llvm/Analysis/ScalarEvolutionExpander.h +++ b/include/llvm/Analysis/ScalarEvolutionExpander.h @@ -16,12 +16,18 @@ #include "llvm/Analysis/ScalarEvolutionExpressions.h" #include "llvm/Analysis/ScalarEvolutionNormalization.h" -#include "llvm/Support/IRBuilder.h" +#include "llvm/IR/IRBuilder.h" #include "llvm/Support/TargetFolder.h" #include "llvm/Support/ValueHandle.h" #include namespace llvm { + class TargetLowering; + + /// Return true if the given expression is safe to expand in the sense that + /// all materialized values are safe to speculate. + bool isSafeToExpand(const SCEV *S); + /// SCEVExpander - This class uses information about analyze scalars to /// rewrite expressions in canonical form. /// @@ -30,11 +36,18 @@ namespace llvm { /// memory. class SCEVExpander : public SCEVVisitor { ScalarEvolution &SE; + + // New instructions receive a name to identifies them with the current pass. + const char* IVName; + std::map, AssertingVH > InsertedExpressions; std::set > InsertedValues; std::set > InsertedPostIncValues; + /// RelevantLoops - A memoization of the "relevant" loop for a given SCEV. + DenseMap RelevantLoops; + /// PostIncLoops - Addrecs referring to any of the given loops are expanded /// in post-inc mode. For example, expanding {1,+,1} in post-inc mode /// returns the add instruction that adds one to the phi for {0,+,1}, @@ -51,22 +64,43 @@ namespace llvm { /// insert the IV increment at this position. Instruction *IVIncInsertPos; + /// Phis that complete an IV chain. Reuse + std::set > ChainedPhis; + /// CanonicalMode - When true, expressions are expanded in "canonical" /// form. In particular, addrecs are expanded as arithmetic based on /// a canonical induction variable. When false, expression are expanded /// in a more literal form. bool CanonicalMode; + /// When invoked from LSR, the expander is in "strength reduction" mode. The + /// only difference is that phi's are only reused if they are already in + /// "expanded" form. + bool LSRMode; + typedef IRBuilder BuilderType; BuilderType Builder; +#ifndef NDEBUG + const char *DebugType; +#endif + friend struct SCEVVisitor; public: /// SCEVExpander - Construct a SCEVExpander in "canonical" mode. - explicit SCEVExpander(ScalarEvolution &se) - : SE(se), IVIncInsertLoop(0), CanonicalMode(true), - Builder(se.getContext(), TargetFolder(se.TD)) {} + explicit SCEVExpander(ScalarEvolution &se, const char *name) + : SE(se), IVName(name), IVIncInsertLoop(0), IVIncInsertPos(0), + CanonicalMode(true), LSRMode(false), + Builder(se.getContext(), TargetFolder(se.TD)) { +#ifndef NDEBUG + DebugType = ""; +#endif + } + +#ifndef NDEBUG + void setDebugType(const char* s) { DebugType = s; } +#endif /// clear - Erase the contents of the InsertedExpressions map so that users /// trying to expand the same expression into multiple BasicBlocks or @@ -75,19 +109,32 @@ namespace llvm { InsertedExpressions.clear(); InsertedValues.clear(); InsertedPostIncValues.clear(); + ChainedPhis.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. - PHINode *getOrInsertCanonicalInductionVariable(const Loop *L, - const Type *Ty); + PHINode *getOrInsertCanonicalInductionVariable(const Loop *L, Type *Ty); + + /// getIVIncOperand - Return the induction variable increment's IV operand. + Instruction *getIVIncOperand(Instruction *IncV, Instruction *InsertPos, + bool allowScale); + + /// hoistIVInc - Utility for hoisting an IV increment. + bool hoistIVInc(Instruction *IncV, Instruction *InsertPos); + + /// replaceCongruentIVs - replace congruent phis with their most canonical + /// representative. Return the number of phis eliminated. + unsigned replaceCongruentIVs(Loop *L, const DominatorTree *DT, + SmallVectorImpl &DeadInsts, + const TargetLowering *TLI = NULL); /// 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 *I); + Value *expandCodeFor(const SCEV *SH, Type *Ty, Instruction *I); /// setIVIncInsertPos - Set the current IV increment loop and position. void setIVIncInsertPos(const Loop *L, Instruction *Pos) { @@ -120,6 +167,8 @@ namespace llvm { /// is useful for late optimization passes. void disableCanonicalMode() { CanonicalMode = false; } + void enableLSRMode() { LSRMode = true; } + /// clearInsertPoint - Clear the current insertion point. This is useful /// if the instruction that had been serving as the insertion point may /// have been deleted. @@ -127,6 +176,15 @@ namespace llvm { Builder.ClearInsertionPoint(); } + /// 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) || InsertedPostIncValues.count(I); + } + + void setChainedPhi(PHINode *PN) { ChainedPhis.insert(PN); } + private: LLVMContext &getContext() const { return SE.getContext(); } @@ -138,20 +196,20 @@ namespace llvm { /// reusing an existing cast if a suitable one exists, moving an existing /// cast if a suitable one exists but isn't in the right place, or /// or creating a new one. - Value *ReuseOrCreateCast(Value *V, const Type *Ty, + Value *ReuseOrCreateCast(Value *V, Type *Ty, Instruction::CastOps Op, BasicBlock::iterator IP); /// 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); + Value *InsertNoopCastOfTo(Value *V, 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); + PointerType *PTy, Type *Ty, Value *V); Value *expand(const SCEV *S); @@ -159,14 +217,10 @@ namespace llvm { /// 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); + Value *expandCodeFor(const SCEV *SH, 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) || InsertedPostIncValues.count(I); - } + /// getRelevantLoop - Determine the most "relevant" loop for the given SCEV. + const Loop *getRelevantLoop(const SCEV *); Value *visitConstant(const SCEVConstant *S) { return S->getValue(); @@ -198,11 +252,17 @@ namespace llvm { void restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I); + bool isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, const Loop *L); + + bool isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, const Loop *L); + Value *expandAddRecExprLiterally(const SCEVAddRecExpr *); PHINode *getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized, const Loop *L, - const Type *ExpandTy, - const Type *IntTy); + Type *ExpandTy, + Type *IntTy); + Value *expandIVInc(PHINode *PN, Value *StepV, const Loop *L, + Type *ExpandTy, Type *IntTy, bool useSubtract); }; }