#define LLVM_ANALYSIS_SCALAREVOLUTION_EXPANDER_H
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/ScalarEvolutionNormalization.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/Support/TargetFolder.h"
+#include "llvm/Support/ValueHandle.h"
#include <set>
namespace llvm {
/// 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;
std::map<std::pair<const SCEV *, Instruction *>, AssertingVH<Value> >
InsertedExpressions;
- std::set<Value*> InsertedValues;
+ std::set<AssertingVH<Value> > InsertedValues;
+ std::set<AssertingVH<Value> > InsertedPostIncValues;
+
+ /// RelevantLoops - A memoization of the "relevant" loop for a given SCEV.
+ DenseMap<const SCEV *, const Loop *> RelevantLoops;
+
+ /// PostIncLoops - Addrecs referring to any of the given loops are 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.
+ PostIncLoopSet PostIncLoops;
+
+ /// 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;
typedef IRBuilder<true, TargetFolder> BuilderType;
BuilderType Builder;
friend struct SCEVVisitor<SCEVExpander, Value*>;
+
public:
+ /// SCEVExpander - Construct a SCEVExpander in "canonical" mode.
explicit SCEVExpander(ScalarEvolution &se)
- : SE(se), Builder(se.getContext(),
- TargetFolder(se.TD, se.getContext())) {}
+ : SE(se), 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(); }
+ void clear() {
+ InsertedExpressions.clear();
+ InsertedValues.clear();
+ InsertedPostIncValues.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);
+ PHINode *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);
+ Value *expandCodeFor(const SCEV *SH, const Type *Ty, Instruction *I);
+
+ /// 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 - Enable post-inc expansion for addrecs referring to the
+ /// given loops. Post-inc expansion is only supported in non-canonical
+ /// mode.
+ void setPostInc(const PostIncLoopSet &L) {
+ assert(!CanonicalMode &&
+ "Post-inc expansion is not supported in CanonicalMode");
+ PostIncLoops = L;
+ }
+
+ /// clearPostInc - Disable all post-inc expansion.
+ void clearPostInc() {
+ PostIncLoops.clear();
+
+ // When we change the post-inc loop set, cached expansions may no
+ // longer be valid.
+ InsertedPostIncValues.clear();
+ }
+
+ /// 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; }
+
+ /// clearInsertPoint - Clear the current insertion point. This is useful
+ /// if the instruction that had been serving as the insertion point may
+ /// have been deleted.
+ void clearInsertPoint() {
+ Builder.ClearInsertionPoint();
}
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);
+ /// ReuseOrCreateCast - Arange for there to be a cast of V to Ty at IP,
+ /// 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,
+ 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.
/// inserted by the code rewriter. If so, the client should not modify the
/// instruction.
bool isInsertedInstruction(Instruction *I) const {
- return InsertedValues.count(I);
+ 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();
}
Value *visitUnknown(const SCEVUnknown *S) {
return S->getValue();
}
+
+ void rememberInstruction(Value *I);
+
+ void restoreInsertPoint(BasicBlock *BB, BasicBlock::iterator I);
+
+ Value *expandAddRecExprLiterally(const SCEVAddRecExpr *);
+ PHINode *getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
+ const Loop *L,
+ const Type *ExpandTy,
+ const Type *IntTy);
};
}
#endif
-