2004-04-02 20:23:17 +00:00
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//===- llvm/Analysis/ScalarEvolution.h - Scalar Evolution -------*- C++ -*-===//
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2005-04-21 20:19:05 +00:00
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//
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2004-04-02 20:23:17 +00:00
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// The LLVM Compiler Infrastructure
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//
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2007-12-29 19:59:42 +00:00
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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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2005-04-21 20:19:05 +00:00
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//
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2004-04-02 20:23:17 +00:00
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//===----------------------------------------------------------------------===//
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//
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// The ScalarEvolution class is an LLVM pass which can be used to analyze and
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// catagorize scalar expressions in loops. It specializes in recognizing
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// general induction variables, representing them with the abstract and opaque
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// SCEV class. Given this analysis, trip counts of loops and other important
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// properties can be obtained.
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//
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// This analysis is primarily useful for induction variable substitution and
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// strength reduction.
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2005-04-21 20:19:05 +00:00
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_H
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#define LLVM_ANALYSIS_SCALAREVOLUTION_H
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#include "llvm/Pass.h"
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2007-11-14 02:33:58 +00:00
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#include "llvm/Analysis/LoopInfo.h"
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2007-03-05 00:00:42 +00:00
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#include "llvm/Support/DataTypes.h"
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2009-05-04 22:30:44 +00:00
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#include "llvm/Support/ValueHandle.h"
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2009-06-14 22:55:07 +00:00
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#include "llvm/ADT/DenseMap.h"
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2008-05-29 19:52:31 +00:00
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#include <iosfwd>
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namespace llvm {
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class APInt;
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class ConstantInt;
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class Type;
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2007-10-22 18:31:58 +00:00
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class ScalarEvolution;
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class TargetData;
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2009-06-22 18:25:46 +00:00
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class SCEVConstant;
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class SCEVTruncateExpr;
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class SCEVZeroExtendExpr;
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class SCEVCommutativeExpr;
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class SCEVUDivExpr;
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class SCEVSignExtendExpr;
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class SCEVAddRecExpr;
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class SCEVUnknown;
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2009-05-24 23:45:28 +00:00
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/// SCEV - This class represents an analyzed expression in the program. These
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/// are reference-counted opaque objects that the client is not allowed to
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/// do much with directly.
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///
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class SCEV {
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const unsigned SCEVType; // The SCEV baseclass this node corresponds to
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SCEV(const SCEV &); // DO NOT IMPLEMENT
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void operator=(const SCEV &); // DO NOT IMPLEMENT
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protected:
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virtual ~SCEV();
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public:
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explicit SCEV(unsigned SCEVTy) :
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SCEVType(SCEVTy) {}
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unsigned getSCEVType() const { return SCEVType; }
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/// isLoopInvariant - Return true if the value of this SCEV is unchanging in
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/// the specified loop.
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virtual bool isLoopInvariant(const Loop *L) const = 0;
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/// hasComputableLoopEvolution - Return true if this SCEV changes value in a
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/// known way in the specified loop. This property being true implies that
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/// the value is variant in the loop AND that we can emit an expression to
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/// compute the value of the expression at any particular loop iteration.
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virtual bool hasComputableLoopEvolution(const Loop *L) const = 0;
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/// getType - Return the LLVM type of this SCEV expression.
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///
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virtual const Type *getType() const = 0;
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2008-06-18 16:23:07 +00:00
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/// isZero - Return true if the expression is a constant zero.
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///
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bool isZero() const;
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2009-05-18 15:22:39 +00:00
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/// isOne - Return true if the expression is a constant one.
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///
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bool isOne() const;
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2009-06-24 00:30:26 +00:00
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/// isAllOnesValue - Return true if the expression is a constant
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/// all-ones value.
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///
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bool isAllOnesValue() const;
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2005-02-13 04:34:51 +00:00
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/// replaceSymbolicValuesWithConcrete - If this SCEV internally references
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/// the symbolic value "Sym", construct and return a new SCEV that produces
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/// the same value, but which uses the concrete value Conc instead of the
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/// symbolic value. If this SCEV does not use the symbolic value, it
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/// returns itself.
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virtual const SCEV*
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replaceSymbolicValuesWithConcrete(const SCEV* Sym,
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const SCEV* Conc,
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ScalarEvolution &SE) const = 0;
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2005-02-13 04:34:51 +00:00
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2009-02-17 00:13:06 +00:00
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/// dominates - Return true if elements that makes up this SCEV dominates
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/// the specified basic block.
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virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const = 0;
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2004-04-02 20:23:17 +00:00
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/// print - Print out the internal representation of this scalar to the
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/// specified stream. This should really only be used for debugging
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/// purposes.
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2009-04-21 00:47:46 +00:00
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virtual void print(raw_ostream &OS) const = 0;
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void print(std::ostream &OS) const;
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2006-12-17 05:15:13 +00:00
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void print(std::ostream *OS) const { if (OS) print(*OS); }
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/// dump - This method is used for debugging.
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///
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void dump() const;
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};
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inline raw_ostream &operator<<(raw_ostream &OS, const SCEV &S) {
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S.print(OS);
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return OS;
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}
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inline std::ostream &operator<<(std::ostream &OS, const SCEV &S) {
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S.print(OS);
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return OS;
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}
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/// SCEVCouldNotCompute - An object of this class is returned by queries that
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/// could not be answered. For example, if you ask for the number of
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/// iterations of a linked-list traversal loop, you will get one of these.
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/// None of the standard SCEV operations are valid on this class, it is just a
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/// marker.
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struct SCEVCouldNotCompute : public SCEV {
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2009-06-22 21:57:23 +00:00
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SCEVCouldNotCompute();
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// None of these methods are valid for this object.
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virtual bool isLoopInvariant(const Loop *L) const;
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virtual const Type *getType() const;
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virtual bool hasComputableLoopEvolution(const Loop *L) const;
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virtual void print(raw_ostream &OS) const;
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virtual const SCEV*
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replaceSymbolicValuesWithConcrete(const SCEV* Sym,
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const SCEV* Conc,
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ScalarEvolution &SE) const;
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2009-02-17 00:13:06 +00:00
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virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const {
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return true;
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}
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2004-04-02 20:23:17 +00:00
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEVCouldNotCompute *S) { return true; }
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static bool classof(const SCEV *S);
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};
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/// ScalarEvolution - This class is the main scalar evolution driver. Because
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/// client code (intentionally) can't do much with the SCEV objects directly,
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/// they must ask this class for services.
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///
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class ScalarEvolution : public FunctionPass {
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2009-05-19 19:22:47 +00:00
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/// SCEVCallbackVH - A CallbackVH to arrange for ScalarEvolution to be
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/// notified whenever a Value is deleted.
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class SCEVCallbackVH : public CallbackVH {
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ScalarEvolution *SE;
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virtual void deleted();
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virtual void allUsesReplacedWith(Value *New);
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public:
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SCEVCallbackVH(Value *V, ScalarEvolution *SE = 0);
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};
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2009-05-04 22:30:44 +00:00
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friend class SCEVCallbackVH;
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2009-05-19 02:15:55 +00:00
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friend class SCEVExpander;
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2009-05-04 22:30:44 +00:00
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2009-04-21 23:15:49 +00:00
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/// F - The function we are analyzing.
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///
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Function *F;
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/// LI - The loop information for the function we are currently analyzing.
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///
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LoopInfo *LI;
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/// TD - The target data information for the target we are targetting.
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///
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TargetData *TD;
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2009-06-06 14:37:11 +00:00
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/// CouldNotCompute - This SCEV is used to represent unknown trip
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/// counts and things.
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const SCEV* CouldNotCompute;
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/// Scalars - This is a cache of the scalars we have analyzed so far.
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///
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2009-06-22 21:39:50 +00:00
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std::map<SCEVCallbackVH, const SCEV*> Scalars;
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2009-04-21 23:15:49 +00:00
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2009-04-30 20:47:05 +00:00
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/// BackedgeTakenInfo - Information about the backedge-taken count
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/// of a loop. This currently inclues an exact count and a maximum count.
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///
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struct BackedgeTakenInfo {
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/// Exact - An expression indicating the exact backedge-taken count of
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/// the loop if it is known, or a SCEVCouldNotCompute otherwise.
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const SCEV* Exact;
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2009-04-30 20:47:05 +00:00
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/// Exact - An expression indicating the least maximum backedge-taken
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/// count of the loop that is known, or a SCEVCouldNotCompute.
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const SCEV* Max;
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2009-06-22 21:39:50 +00:00
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/*implicit*/ BackedgeTakenInfo(const SCEV* exact) :
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Exact(exact), Max(exact) {}
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2009-06-22 21:39:50 +00:00
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BackedgeTakenInfo(const SCEV* exact, const SCEV* max) :
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Exact(exact), Max(max) {}
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/// hasAnyInfo - Test whether this BackedgeTakenInfo contains any
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/// computed information, or whether it's all SCEVCouldNotCompute
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/// values.
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bool hasAnyInfo() const {
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return !isa<SCEVCouldNotCompute>(Exact) ||
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!isa<SCEVCouldNotCompute>(Max);
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}
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};
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2009-04-21 23:15:49 +00:00
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/// BackedgeTakenCounts - Cache the backedge-taken count of the loops for
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/// this function as they are computed.
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2009-04-30 20:47:05 +00:00
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std::map<const Loop*, BackedgeTakenInfo> BackedgeTakenCounts;
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2009-04-21 23:15:49 +00:00
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/// ConstantEvolutionLoopExitValue - This map contains entries for all of
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/// the PHI instructions that we attempt to compute constant evolutions for.
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/// This allows us to avoid potentially expensive recomputation of these
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/// properties. An instruction maps to null if we are unable to compute its
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/// exit value.
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std::map<PHINode*, Constant*> ConstantEvolutionLoopExitValue;
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2009-05-08 20:47:27 +00:00
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/// ValuesAtScopes - This map contains entries for all the instructions
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/// that we attempt to compute getSCEVAtScope information for without
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/// using SCEV techniques, which can be expensive.
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std::map<Instruction *, std::map<const Loop *, Constant *> > ValuesAtScopes;
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2009-04-21 23:15:49 +00:00
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/// createSCEV - We know that there is no SCEV for the specified value.
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/// Analyze the expression.
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2009-06-22 21:39:50 +00:00
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const SCEV* createSCEV(Value *V);
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2009-04-21 23:15:49 +00:00
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/// createNodeForPHI - Provide the special handling we need to analyze PHI
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/// SCEVs.
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2009-06-22 21:39:50 +00:00
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const SCEV* createNodeForPHI(PHINode *PN);
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2009-04-21 23:15:49 +00:00
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2009-05-08 20:26:55 +00:00
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/// createNodeForGEP - Provide the special handling we need to analyze GEP
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/// SCEVs.
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2009-06-22 21:39:50 +00:00
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const SCEV* createNodeForGEP(User *GEP);
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2009-05-08 20:26:55 +00:00
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2009-04-21 23:15:49 +00:00
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/// ReplaceSymbolicValueWithConcrete - This looks up the computed SCEV value
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/// for the specified instruction and replaces any references to the
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/// symbolic value SymName with the specified value. This is used during
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/// PHI resolution.
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void ReplaceSymbolicValueWithConcrete(Instruction *I,
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const SCEV* SymName,
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const SCEV* NewVal);
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2009-04-21 23:15:49 +00:00
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2009-06-21 23:46:38 +00:00
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/// getBECount - Subtract the end and start values and divide by the step,
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/// rounding up, to get the number of times the backedge is executed. Return
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/// CouldNotCompute if an intermediate computation overflows.
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2009-06-22 21:39:50 +00:00
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const SCEV* getBECount(const SCEV* Start,
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const SCEV* End,
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const SCEV* Step);
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2009-06-21 23:46:38 +00:00
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2009-04-30 20:47:05 +00:00
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/// getBackedgeTakenInfo - Return the BackedgeTakenInfo for the given
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/// loop, lazily computing new values if the loop hasn't been analyzed
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/// yet.
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const BackedgeTakenInfo &getBackedgeTakenInfo(const Loop *L);
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2009-04-21 23:15:49 +00:00
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/// ComputeBackedgeTakenCount - Compute the number of times the specified
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/// loop will iterate.
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2009-04-30 20:47:05 +00:00
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BackedgeTakenInfo ComputeBackedgeTakenCount(const Loop *L);
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2009-04-21 23:15:49 +00:00
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2009-06-22 00:31:57 +00:00
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/// ComputeBackedgeTakenCountFromExit - Compute the number of times the
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/// backedge of the specified loop will execute if it exits via the
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/// specified block.
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BackedgeTakenInfo ComputeBackedgeTakenCountFromExit(const Loop *L,
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BasicBlock *ExitingBlock);
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/// ComputeBackedgeTakenCountFromExitCond - Compute the number of times the
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/// backedge of the specified loop will execute if its exit condition
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/// were a conditional branch of ExitCond, TBB, and FBB.
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BackedgeTakenInfo
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ComputeBackedgeTakenCountFromExitCond(const Loop *L,
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Value *ExitCond,
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BasicBlock *TBB,
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BasicBlock *FBB);
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/// ComputeBackedgeTakenCountFromExitCondICmp - Compute the number of
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/// times the backedge of the specified loop will execute if its exit
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/// condition were a conditional branch of the ICmpInst ExitCond, TBB,
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/// and FBB.
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BackedgeTakenInfo
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ComputeBackedgeTakenCountFromExitCondICmp(const Loop *L,
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ICmpInst *ExitCond,
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BasicBlock *TBB,
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BasicBlock *FBB);
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2009-04-21 23:15:49 +00:00
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/// ComputeLoadConstantCompareBackedgeTakenCount - Given an exit condition
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/// of 'icmp op load X, cst', try to see if we can compute the trip count.
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const SCEV*
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2009-04-21 23:15:49 +00:00
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|
|
ComputeLoadConstantCompareBackedgeTakenCount(LoadInst *LI,
|
|
|
|
Constant *RHS,
|
|
|
|
const Loop *L,
|
|
|
|
ICmpInst::Predicate p);
|
|
|
|
|
|
|
|
/// ComputeBackedgeTakenCountExhaustively - If the trip is known to execute
|
|
|
|
/// a constant number of times (the condition evolves only from constants),
|
|
|
|
/// try to evaluate a few iterations of the loop until we get the exit
|
|
|
|
/// condition gets a value of ExitWhen (true or false). If we cannot
|
2009-06-06 14:37:11 +00:00
|
|
|
/// evaluate the trip count of the loop, return CouldNotCompute.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* ComputeBackedgeTakenCountExhaustively(const Loop *L, Value *Cond,
|
2009-04-21 23:15:49 +00:00
|
|
|
bool ExitWhen);
|
|
|
|
|
|
|
|
/// HowFarToZero - Return the number of times a backedge comparing the
|
|
|
|
/// specified value to zero will execute. If not computable, return
|
2009-06-06 14:37:11 +00:00
|
|
|
/// CouldNotCompute.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* HowFarToZero(const SCEV *V, const Loop *L);
|
2009-04-21 23:15:49 +00:00
|
|
|
|
|
|
|
/// HowFarToNonZero - Return the number of times a backedge checking the
|
|
|
|
/// specified value for nonzero will execute. If not computable, return
|
2009-06-06 14:37:11 +00:00
|
|
|
/// CouldNotCompute.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* HowFarToNonZero(const SCEV *V, const Loop *L);
|
2009-04-21 23:15:49 +00:00
|
|
|
|
|
|
|
/// HowManyLessThans - Return the number of times a backedge containing the
|
|
|
|
/// specified less-than comparison will execute. If not computable, return
|
2009-06-06 14:37:11 +00:00
|
|
|
/// CouldNotCompute. isSigned specifies whether the less-than is signed.
|
2009-05-04 22:30:44 +00:00
|
|
|
BackedgeTakenInfo HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
|
|
|
|
const Loop *L, bool isSigned);
|
2009-04-21 23:15:49 +00:00
|
|
|
|
2009-05-18 15:36:09 +00:00
|
|
|
/// getLoopPredecessor - If the given loop's header has exactly one unique
|
|
|
|
/// predecessor outside the loop, return it. Otherwise return null.
|
|
|
|
BasicBlock *getLoopPredecessor(const Loop *L);
|
|
|
|
|
2009-04-21 23:15:49 +00:00
|
|
|
/// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB
|
|
|
|
/// (which may not be an immediate predecessor) which has exactly one
|
|
|
|
/// successor from which BB is reachable, or null if no such block is
|
|
|
|
/// found.
|
|
|
|
BasicBlock* getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB);
|
|
|
|
|
|
|
|
/// getConstantEvolutionLoopExitValue - If we know that the specified Phi is
|
|
|
|
/// in the header of its containing loop, we know the loop executes a
|
|
|
|
/// constant number of times, and the PHI node is just a recurrence
|
|
|
|
/// involving constants, fold it.
|
|
|
|
Constant *getConstantEvolutionLoopExitValue(PHINode *PN, const APInt& BEs,
|
|
|
|
const Loop *L);
|
|
|
|
|
2009-05-02 17:43:35 +00:00
|
|
|
/// forgetLoopPHIs - Delete the memoized SCEVs associated with the
|
|
|
|
/// PHI nodes in the given loop. This is used when the trip count of
|
|
|
|
/// the loop may have changed.
|
|
|
|
void forgetLoopPHIs(const Loop *L);
|
|
|
|
|
2004-04-02 20:23:17 +00:00
|
|
|
public:
|
2007-05-06 13:37:16 +00:00
|
|
|
static char ID; // Pass identification, replacement for typeid
|
2009-04-21 23:15:49 +00:00
|
|
|
ScalarEvolution();
|
2005-04-21 20:19:05 +00:00
|
|
|
|
2009-04-21 01:07:12 +00:00
|
|
|
/// isSCEVable - Test if values of the given type are analyzable within
|
|
|
|
/// the SCEV framework. This primarily includes integer types, and it
|
|
|
|
/// can optionally include pointer types if the ScalarEvolution class
|
|
|
|
/// has access to target-specific information.
|
|
|
|
bool isSCEVable(const Type *Ty) const;
|
|
|
|
|
|
|
|
/// getTypeSizeInBits - Return the size in bits of the specified type,
|
|
|
|
/// for which isSCEVable must return true.
|
|
|
|
uint64_t getTypeSizeInBits(const Type *Ty) const;
|
|
|
|
|
|
|
|
/// getEffectiveSCEVType - Return a type with the same bitwidth as
|
|
|
|
/// the given type and which represents how SCEV will treat the given
|
|
|
|
/// type, for which isSCEVable must return true. For pointer types,
|
|
|
|
/// this is the pointer-sized integer type.
|
|
|
|
const Type *getEffectiveSCEVType(const Type *Ty) const;
|
2009-04-16 03:18:22 +00:00
|
|
|
|
2004-04-02 20:23:17 +00:00
|
|
|
/// getSCEV - Return a SCEV expression handle for the full generality of the
|
|
|
|
/// specified expression.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getSCEV(Value *V);
|
|
|
|
|
|
|
|
const SCEV* getConstant(ConstantInt *V);
|
|
|
|
const SCEV* getConstant(const APInt& Val);
|
|
|
|
const SCEV* getConstant(const Type *Ty, uint64_t V, bool isSigned = false);
|
|
|
|
const SCEV* getTruncateExpr(const SCEV* Op, const Type *Ty);
|
|
|
|
const SCEV* getZeroExtendExpr(const SCEV* Op, const Type *Ty);
|
|
|
|
const SCEV* getSignExtendExpr(const SCEV* Op, const Type *Ty);
|
|
|
|
const SCEV* getAnyExtendExpr(const SCEV* Op, const Type *Ty);
|
|
|
|
const SCEV* getAddExpr(SmallVectorImpl<const SCEV*> &Ops);
|
|
|
|
const SCEV* getAddExpr(const SCEV* LHS, const SCEV* RHS) {
|
|
|
|
SmallVector<const SCEV*, 2> Ops;
|
2007-10-22 18:31:58 +00:00
|
|
|
Ops.push_back(LHS);
|
|
|
|
Ops.push_back(RHS);
|
|
|
|
return getAddExpr(Ops);
|
|
|
|
}
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getAddExpr(const SCEV* Op0, const SCEV* Op1,
|
|
|
|
const SCEV* Op2) {
|
|
|
|
SmallVector<const SCEV*, 3> Ops;
|
2007-10-22 18:31:58 +00:00
|
|
|
Ops.push_back(Op0);
|
|
|
|
Ops.push_back(Op1);
|
|
|
|
Ops.push_back(Op2);
|
|
|
|
return getAddExpr(Ops);
|
|
|
|
}
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getMulExpr(SmallVectorImpl<const SCEV*> &Ops);
|
|
|
|
const SCEV* getMulExpr(const SCEV* LHS, const SCEV* RHS) {
|
|
|
|
SmallVector<const SCEV*, 2> Ops;
|
2007-10-22 18:31:58 +00:00
|
|
|
Ops.push_back(LHS);
|
|
|
|
Ops.push_back(RHS);
|
|
|
|
return getMulExpr(Ops);
|
|
|
|
}
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getUDivExpr(const SCEV* LHS, const SCEV* RHS);
|
|
|
|
const SCEV* getAddRecExpr(const SCEV* Start, const SCEV* Step,
|
2007-10-22 18:31:58 +00:00
|
|
|
const Loop *L);
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getAddRecExpr(SmallVectorImpl<const SCEV*> &Operands,
|
2007-10-22 18:31:58 +00:00
|
|
|
const Loop *L);
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getAddRecExpr(const SmallVectorImpl<const SCEV*> &Operands,
|
2007-10-22 18:31:58 +00:00
|
|
|
const Loop *L) {
|
2009-06-22 21:39:50 +00:00
|
|
|
SmallVector<const SCEV*, 4> NewOp(Operands.begin(), Operands.end());
|
2007-10-22 18:31:58 +00:00
|
|
|
return getAddRecExpr(NewOp, L);
|
|
|
|
}
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getSMaxExpr(const SCEV* LHS, const SCEV* RHS);
|
|
|
|
const SCEV* getSMaxExpr(SmallVectorImpl<const SCEV*> &Operands);
|
|
|
|
const SCEV* getUMaxExpr(const SCEV* LHS, const SCEV* RHS);
|
|
|
|
const SCEV* getUMaxExpr(SmallVectorImpl<const SCEV*> &Operands);
|
|
|
|
const SCEV* getSMinExpr(const SCEV* LHS, const SCEV* RHS);
|
|
|
|
const SCEV* getUMinExpr(const SCEV* LHS, const SCEV* RHS);
|
|
|
|
const SCEV* getUnknown(Value *V);
|
|
|
|
const SCEV* getCouldNotCompute();
|
2007-10-22 18:31:58 +00:00
|
|
|
|
|
|
|
/// getNegativeSCEV - Return the SCEV object corresponding to -V.
|
|
|
|
///
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getNegativeSCEV(const SCEV* V);
|
2007-10-22 18:31:58 +00:00
|
|
|
|
2008-02-20 06:48:22 +00:00
|
|
|
/// getNotSCEV - Return the SCEV object corresponding to ~V.
|
|
|
|
///
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getNotSCEV(const SCEV* V);
|
2008-02-20 06:48:22 +00:00
|
|
|
|
2007-10-22 18:31:58 +00:00
|
|
|
/// getMinusSCEV - Return LHS-RHS.
|
|
|
|
///
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getMinusSCEV(const SCEV* LHS,
|
|
|
|
const SCEV* RHS);
|
2007-10-22 18:31:58 +00:00
|
|
|
|
2008-06-13 04:38:55 +00:00
|
|
|
/// getTruncateOrZeroExtend - Return a SCEV corresponding to a conversion
|
|
|
|
/// of the input value to the specified type. If the type must be
|
|
|
|
/// extended, it is zero extended.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getTruncateOrZeroExtend(const SCEV* V, const Type *Ty);
|
2008-06-13 04:38:55 +00:00
|
|
|
|
2009-02-18 17:22:41 +00:00
|
|
|
/// getTruncateOrSignExtend - Return a SCEV corresponding to a conversion
|
|
|
|
/// of the input value to the specified type. If the type must be
|
|
|
|
/// extended, it is sign extended.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getTruncateOrSignExtend(const SCEV* V, const Type *Ty);
|
2009-02-18 17:22:41 +00:00
|
|
|
|
2009-05-13 03:46:30 +00:00
|
|
|
/// getNoopOrZeroExtend - Return a SCEV corresponding to a conversion of
|
|
|
|
/// the input value to the specified type. If the type must be extended,
|
|
|
|
/// it is zero extended. The conversion must not be narrowing.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getNoopOrZeroExtend(const SCEV* V, const Type *Ty);
|
2009-05-13 03:46:30 +00:00
|
|
|
|
|
|
|
/// getNoopOrSignExtend - Return a SCEV corresponding to a conversion of
|
|
|
|
/// the input value to the specified type. If the type must be extended,
|
|
|
|
/// it is sign extended. The conversion must not be narrowing.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getNoopOrSignExtend(const SCEV* V, const Type *Ty);
|
2009-05-13 03:46:30 +00:00
|
|
|
|
2009-06-13 15:56:47 +00:00
|
|
|
/// getNoopOrAnyExtend - Return a SCEV corresponding to a conversion of
|
|
|
|
/// the input value to the specified type. If the type must be extended,
|
|
|
|
/// it is extended with unspecified bits. The conversion must not be
|
|
|
|
/// narrowing.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getNoopOrAnyExtend(const SCEV* V, const Type *Ty);
|
2009-06-13 15:56:47 +00:00
|
|
|
|
2009-05-13 03:46:30 +00:00
|
|
|
/// getTruncateOrNoop - Return a SCEV corresponding to a conversion of the
|
|
|
|
/// input value to the specified type. The conversion must not be
|
|
|
|
/// widening.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getTruncateOrNoop(const SCEV* V, const Type *Ty);
|
2009-05-13 03:46:30 +00:00
|
|
|
|
2009-06-24 00:54:57 +00:00
|
|
|
/// getIntegerSCEV - Given a SCEVable type, create a constant for the
|
2007-10-22 18:31:58 +00:00
|
|
|
/// specified signed integer value and return a SCEV for the constant.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getIntegerSCEV(int Val, const Type *Ty);
|
2007-10-22 18:31:58 +00:00
|
|
|
|
2009-06-22 00:31:57 +00:00
|
|
|
/// getUMaxFromMismatchedTypes - Promote the operands to the wider of
|
|
|
|
/// the types using zero-extension, and then perform a umax operation
|
|
|
|
/// with them.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getUMaxFromMismatchedTypes(const SCEV* LHS,
|
|
|
|
const SCEV* RHS);
|
2009-06-22 00:31:57 +00:00
|
|
|
|
2009-06-22 15:03:27 +00:00
|
|
|
/// getUMinFromMismatchedTypes - Promote the operands to the wider of
|
|
|
|
/// the types using zero-extension, and then perform a umin operation
|
|
|
|
/// with them.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getUMinFromMismatchedTypes(const SCEV* LHS,
|
|
|
|
const SCEV* RHS);
|
2009-06-22 15:03:27 +00:00
|
|
|
|
2005-08-09 23:36:18 +00:00
|
|
|
/// hasSCEV - Return true if the SCEV for this value has already been
|
|
|
|
/// computed.
|
|
|
|
bool hasSCEV(Value *V) const;
|
|
|
|
|
|
|
|
/// setSCEV - Insert the specified SCEV into the map of current SCEVs for
|
|
|
|
/// the specified value.
|
2009-06-22 21:39:50 +00:00
|
|
|
void setSCEV(Value *V, const SCEV* H);
|
2005-08-09 23:36:18 +00:00
|
|
|
|
2004-04-02 20:23:17 +00:00
|
|
|
/// getSCEVAtScope - Return a SCEV expression handle for the specified value
|
|
|
|
/// at the specified scope in the program. The L value specifies a loop
|
|
|
|
/// nest to evaluate the expression at, where null is the top-level or a
|
|
|
|
/// specified loop is immediately inside of the loop.
|
|
|
|
///
|
|
|
|
/// This method can be used to compute the exit value for a variable defined
|
|
|
|
/// in a loop by querying what the value will hold in the parent loop.
|
|
|
|
///
|
2009-05-24 23:25:42 +00:00
|
|
|
/// In the case that a relevant loop exit value cannot be computed, the
|
|
|
|
/// original value V is returned.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getSCEVAtScope(const SCEV *S, const Loop *L);
|
2009-05-08 20:38:54 +00:00
|
|
|
|
|
|
|
/// getSCEVAtScope - This is a convenience function which does
|
|
|
|
/// getSCEVAtScope(getSCEV(V), L).
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getSCEVAtScope(Value *V, const Loop *L);
|
2004-04-02 20:23:17 +00:00
|
|
|
|
2009-02-12 22:19:27 +00:00
|
|
|
/// isLoopGuardedByCond - Test whether entry to the loop is protected by
|
2009-04-30 20:48:53 +00:00
|
|
|
/// a conditional between LHS and RHS. This is used to help avoid max
|
|
|
|
/// expressions in loop trip counts.
|
2009-02-12 22:19:27 +00:00
|
|
|
bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
|
2009-05-04 22:30:44 +00:00
|
|
|
const SCEV *LHS, const SCEV *RHS);
|
2009-02-12 22:19:27 +00:00
|
|
|
|
2009-02-24 18:55:53 +00:00
|
|
|
/// getBackedgeTakenCount - If the specified loop has a predictable
|
|
|
|
/// backedge-taken count, return it, otherwise return a SCEVCouldNotCompute
|
|
|
|
/// object. The backedge-taken count is the number of times the loop header
|
|
|
|
/// will be branched to from within the loop. This is one less than the
|
|
|
|
/// trip count of the loop, since it doesn't count the first iteration,
|
|
|
|
/// when the header is branched to from outside the loop.
|
|
|
|
///
|
|
|
|
/// Note that it is not valid to call this method on a loop without a
|
|
|
|
/// loop-invariant backedge-taken count (see
|
|
|
|
/// hasLoopInvariantBackedgeTakenCount).
|
|
|
|
///
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getBackedgeTakenCount(const Loop *L);
|
2004-04-02 20:23:17 +00:00
|
|
|
|
2009-04-30 20:47:05 +00:00
|
|
|
/// getMaxBackedgeTakenCount - Similar to getBackedgeTakenCount, except
|
|
|
|
/// return the least SCEV value that is known never to be less than the
|
|
|
|
/// actual backedge taken count.
|
2009-06-22 21:39:50 +00:00
|
|
|
const SCEV* getMaxBackedgeTakenCount(const Loop *L);
|
2009-04-30 20:47:05 +00:00
|
|
|
|
2009-02-24 18:55:53 +00:00
|
|
|
/// hasLoopInvariantBackedgeTakenCount - Return true if the specified loop
|
|
|
|
/// has an analyzable loop-invariant backedge-taken count.
|
2009-04-21 23:15:49 +00:00
|
|
|
bool hasLoopInvariantBackedgeTakenCount(const Loop *L);
|
2004-04-02 20:23:17 +00:00
|
|
|
|
2009-02-24 18:55:53 +00:00
|
|
|
/// forgetLoopBackedgeTakenCount - This method should be called by the
|
2009-02-17 20:49:49 +00:00
|
|
|
/// client when it has changed a loop in a way that may effect
|
2009-02-24 18:55:53 +00:00
|
|
|
/// ScalarEvolution's ability to compute a trip count, or if the loop
|
|
|
|
/// is deleted.
|
|
|
|
void forgetLoopBackedgeTakenCount(const Loop *L);
|
2009-02-17 20:49:49 +00:00
|
|
|
|
2009-06-19 23:29:04 +00:00
|
|
|
/// GetMinTrailingZeros - Determine the minimum number of zero bits that S is
|
|
|
|
/// guaranteed to end in (at every loop iteration). It is, at the same time,
|
|
|
|
/// the minimum number of times S is divisible by 2. For example, given {4,+,8}
|
|
|
|
/// it returns 2. If S is guaranteed to be 0, it returns the bitwidth of S.
|
2009-06-22 21:39:50 +00:00
|
|
|
uint32_t GetMinTrailingZeros(const SCEV* S);
|
2009-06-19 23:29:04 +00:00
|
|
|
|
|
|
|
/// GetMinLeadingZeros - Determine the minimum number of zero bits that S is
|
|
|
|
/// guaranteed to begin with (at every loop iteration).
|
2009-06-22 21:39:50 +00:00
|
|
|
uint32_t GetMinLeadingZeros(const SCEV* S);
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2009-06-19 23:29:04 +00:00
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/// GetMinSignBits - Determine the minimum number of sign bits that S is
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/// guaranteed to begin with.
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2009-06-22 21:39:50 +00:00
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uint32_t GetMinSignBits(const SCEV* S);
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2009-06-19 23:29:04 +00:00
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2004-04-02 20:23:17 +00:00
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virtual bool runOnFunction(Function &F);
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virtual void releaseMemory();
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virtual void getAnalysisUsage(AnalysisUsage &AU) const;
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2009-04-21 00:47:46 +00:00
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void print(raw_ostream &OS, const Module* = 0) const;
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2004-12-07 04:03:45 +00:00
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virtual void print(std::ostream &OS, const Module* = 0) const;
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2006-12-17 05:15:13 +00:00
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void print(std::ostream *OS, const Module* M = 0) const {
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if (OS) print(*OS, M);
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}
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2009-06-22 18:25:46 +00:00
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private:
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// Uniquing tables.
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std::map<ConstantInt*, SCEVConstant*> SCEVConstants;
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std::map<std::pair<const SCEV*, const Type*>,
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SCEVTruncateExpr*> SCEVTruncates;
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std::map<std::pair<const SCEV*, const Type*>,
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SCEVZeroExtendExpr*> SCEVZeroExtends;
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std::map<std::pair<unsigned, std::vector<const SCEV*> >,
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SCEVCommutativeExpr*> SCEVCommExprs;
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std::map<std::pair<const SCEV*, const SCEV*>,
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SCEVUDivExpr*> SCEVUDivs;
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std::map<std::pair<const SCEV*, const Type*>,
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SCEVSignExtendExpr*> SCEVSignExtends;
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std::map<std::pair<const Loop *, std::vector<const SCEV*> >,
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SCEVAddRecExpr*> SCEVAddRecExprs;
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std::map<Value*, SCEVUnknown*> SCEVUnknowns;
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2004-04-02 20:23:17 +00:00
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};
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}
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#endif
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