#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H
#define LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H
-#include "llvm/Instructions.h"
-#include "llvm/Type.h"
-#include "llvm/Analysis/ScalarEvolution.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
+ /// and destroy it when finished to allow the release of the associated
/// memory.
- struct SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> {
+ class SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> {
ScalarEvolution &SE;
- LoopInfo &LI;
- std::map<SCEVHandle, Value*> InsertedExpressions;
- std::set<Instruction*> InsertedInstructions;
+ std::map<std::pair<const SCEV *, Instruction *>, AssertingVH<Value> >
+ InsertedExpressions;
+ std::set<Value*> InsertedValues;
+
+ /// PostIncLoop - When non-null, expanded addrecs referring to the given
+ /// loop expanded in post-inc mode. For example, expanding {1,+,1}<L> in
+ /// post-inc mode returns the add instruction that adds one to the phi
+ /// for {0,+,1}<L>, as opposed to a new phi starting at 1. This is only
+ /// supported in non-canonical mode.
+ const Loop *PostIncLoop;
+
+ /// IVIncInsertPos - When this is non-null, addrecs expanded in the
+ /// loop it indicates should be inserted with increments at
+ /// IVIncInsertPos.
+ const Loop *IVIncInsertLoop;
+
+ /// IVIncInsertPos - When expanding addrecs in the IVIncInsertLoop loop,
+ /// insert the IV increment at this position.
+ Instruction *IVIncInsertPos;
+
+ /// 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;
- Instruction *InsertPt;
+ protected:
+ typedef IRBuilder<true, TargetFolder> BuilderType;
+ BuilderType Builder;
friend struct SCEVVisitor<SCEVExpander, Value*>;
public:
- SCEVExpander(ScalarEvolution &se, LoopInfo &li) : SE(se), LI(li) {}
-
- LoopInfo &getLoopInfo() const { return LI; }
+ /// SCEVExpander - Construct a SCEVExpander in "canonical" mode.
+ explicit SCEVExpander(ScalarEvolution &se)
+ : SE(se), PostIncLoop(0), IVIncInsertLoop(0), CanonicalMode(true),
+ Builder(se.getContext(), TargetFolder(se.TD)) {}
/// 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(); }
- /// 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 InsertedInstructions.count(I);
- }
-
/// 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){
- assert(Ty->isInteger() && "Can only insert integer induction variables!");
- SCEVHandle H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty),
- SE.getIntegerSCEV(1, Ty), L);
- return expand(H);
- }
-
- /// addInsertedValue - Remember the specified instruction as being the
- /// canonical form for the specified SCEV.
- void addInsertedValue(Instruction *I, SCEV *S) {
- InsertedExpressions[S] = (Value*)I;
- InsertedInstructions.insert(I);
- }
+ Value *getOrInsertCanonicalInductionVariable(const Loop *L, const Type *Ty);
- Instruction *getInsertionPoint() const { return InsertPt; }
-
/// expandCodeFor - Insert code to directly compute the specified SCEV
/// expression into the program. The inserted code is inserted into the
/// specified block.
- Value *expandCodeFor(SCEVHandle SH, Instruction *IP);
+ Value *expandCodeFor(const SCEV *SH, const Type *Ty, Instruction *I) {
+ BasicBlock::iterator IP = I;
+ while (isInsertedInstruction(IP)) ++IP;
+ Builder.SetInsertPoint(IP->getParent(), IP);
+ return expandCodeFor(SH, Ty);
+ }
+
+ /// setIVIncInsertPos - Set the current IV increment loop and position.
+ void setIVIncInsertPos(const Loop *L, Instruction *Pos) {
+ assert(!CanonicalMode &&
+ "IV increment positions are not supported in CanonicalMode");
+ IVIncInsertLoop = L;
+ IVIncInsertPos = Pos;
+ }
+
+ /// setPostInc - If L is non-null, enable post-inc expansion for addrecs
+ /// referring to the given loop. If L is null, disable post-inc expansion
+ /// completely. Post-inc expansion is only supported in non-canonical
+ /// mode.
+ void setPostInc(const Loop *L) {
+ assert(!CanonicalMode &&
+ "Post-inc expansion is not supported in CanonicalMode");
+ PostIncLoop = L;
+ }
+
+ /// disableCanonicalMode - Disable the behavior of expanding expressions in
+ /// canonical form rather than in a more literal form. Non-canonical mode
+ /// is useful for late optimization passes.
+ void disableCanonicalMode() { CanonicalMode = false; }
+
+ private:
+ LLVMContext &getContext() const { return SE.getContext(); }
- /// InsertCastOfTo - Insert a cast of V to the specified type, doing what
- /// we can to share the casts.
- static Value *InsertCastOfTo(Instruction::CastOps opcode, Value *V,
- const Type *Ty);
/// InsertBinop - Insert the specified binary operator, doing a small amount
/// of work to avoid inserting an obviously redundant operation.
- static Value *InsertBinop(Instruction::BinaryOps Opcode, Value *LHS,
- Value *RHS, Instruction *InsertPt);
- protected:
- Value *expand(SCEV *S);
-
- Value *visitConstant(SCEVConstant *S) {
+ 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(SCEVTruncateExpr *S);
+ Value *visitTruncateExpr(const SCEVTruncateExpr *S);
- Value *visitZeroExtendExpr(SCEVZeroExtendExpr *S);
+ Value *visitZeroExtendExpr(const SCEVZeroExtendExpr *S);
- Value *visitSignExtendExpr(SCEVSignExtendExpr *S);
+ Value *visitSignExtendExpr(const SCEVSignExtendExpr *S);
- Value *visitAddExpr(SCEVAddExpr *S);
+ Value *visitAddExpr(const SCEVAddExpr *S);
- Value *visitMulExpr(SCEVMulExpr *S);
+ Value *visitMulExpr(const SCEVMulExpr *S);
- Value *visitUDivExpr(SCEVUDivExpr *S) {
- Value *LHS = expand(S->getLHS());
- Value *RHS = expand(S->getRHS());
- return InsertBinop(Instruction::UDiv, LHS, RHS, InsertPt);
- }
+ Value *visitUDivExpr(const SCEVUDivExpr *S);
+
+ Value *visitAddRecExpr(const SCEVAddRecExpr *S);
+
+ Value *visitSMaxExpr(const SCEVSMaxExpr *S);
- Value *visitAddRecExpr(SCEVAddRecExpr *S);
+ Value *visitUMaxExpr(const SCEVUMaxExpr *S);
- Value *visitSMaxExpr(SCEVSMaxExpr *S);
+ Value *visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S);
- Value *visitUMaxExpr(SCEVUMaxExpr *S);
+ Value *visitAllocSizeExpr(const SCEVAllocSizeExpr *S);
- Value *visitUnknown(SCEVUnknown *S) {
+ Value *visitUnknown(const SCEVUnknown *S) {
return S->getValue();
}
+
+ void rememberInstruction(Value *I) {
+ if (!PostIncLoop) InsertedValues.insert(I);
+ }
+
+ Value *expandAddRecExprLiterally(const SCEVAddRecExpr *);
+ PHINode *getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
+ const Loop *L,
+ const Type *ExpandTy,
+ const Type *IntTy);
};
}
#endif
-
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