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5401ba7099
This is to be consistent with StringSet and ultimately with the standard library's associative container insert function. This lead to updating SmallSet::insert to return pair<iterator, bool>, and then to update SmallPtrSet::insert to return pair<iterator, bool>, and then to update all the existing users of those functions... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
835 lines
30 KiB
C++
835 lines
30 KiB
C++
//===- llvm/Analysis/ScalarEvolutionExpressions.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 represent and build scalar expressions.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_SCALAREVOLUTIONEXPRESSIONS_H
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#define LLVM_ANALYSIS_SCALAREVOLUTIONEXPRESSIONS_H
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#include "llvm/ADT/iterator_range.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/Analysis/ScalarEvolution.h"
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#include "llvm/Support/ErrorHandling.h"
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namespace llvm {
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class ConstantInt;
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class ConstantRange;
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class DominatorTree;
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enum SCEVTypes {
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// These should be ordered in terms of increasing complexity to make the
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// folders simpler.
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scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr,
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scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr,
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scUnknown, scCouldNotCompute
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};
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//===--------------------------------------------------------------------===//
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/// SCEVConstant - This class represents a constant integer value.
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///
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class SCEVConstant : public SCEV {
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friend class ScalarEvolution;
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ConstantInt *V;
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SCEVConstant(const FoldingSetNodeIDRef ID, ConstantInt *v) :
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SCEV(ID, scConstant), V(v) {}
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public:
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ConstantInt *getValue() const { return V; }
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Type *getType() const { return V->getType(); }
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scConstant;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVCastExpr - This is the base class for unary cast operator classes.
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///
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class SCEVCastExpr : public SCEV {
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protected:
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const SCEV *Op;
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Type *Ty;
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SCEVCastExpr(const FoldingSetNodeIDRef ID,
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unsigned SCEVTy, const SCEV *op, Type *ty);
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public:
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const SCEV *getOperand() const { return Op; }
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Type *getType() const { return Ty; }
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scTruncate ||
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S->getSCEVType() == scZeroExtend ||
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S->getSCEVType() == scSignExtend;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVTruncateExpr - This class represents a truncation of an integer value
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/// to a smaller integer value.
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///
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class SCEVTruncateExpr : public SCEVCastExpr {
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friend class ScalarEvolution;
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SCEVTruncateExpr(const FoldingSetNodeIDRef ID,
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const SCEV *op, Type *ty);
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scTruncate;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVZeroExtendExpr - This class represents a zero extension of a small
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/// integer value to a larger integer value.
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///
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class SCEVZeroExtendExpr : public SCEVCastExpr {
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friend class ScalarEvolution;
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SCEVZeroExtendExpr(const FoldingSetNodeIDRef ID,
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const SCEV *op, Type *ty);
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scZeroExtend;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVSignExtendExpr - This class represents a sign extension of a small
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/// integer value to a larger integer value.
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///
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class SCEVSignExtendExpr : public SCEVCastExpr {
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friend class ScalarEvolution;
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SCEVSignExtendExpr(const FoldingSetNodeIDRef ID,
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const SCEV *op, Type *ty);
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scSignExtend;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVNAryExpr - This node is a base class providing common
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/// functionality for n'ary operators.
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///
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class SCEVNAryExpr : public SCEV {
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protected:
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// Since SCEVs are immutable, ScalarEvolution allocates operand
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// arrays with its SCEVAllocator, so this class just needs a simple
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// pointer rather than a more elaborate vector-like data structure.
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// This also avoids the need for a non-trivial destructor.
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const SCEV *const *Operands;
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size_t NumOperands;
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SCEVNAryExpr(const FoldingSetNodeIDRef ID,
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enum SCEVTypes T, const SCEV *const *O, size_t N)
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: SCEV(ID, T), Operands(O), NumOperands(N) {}
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public:
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size_t getNumOperands() const { return NumOperands; }
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const SCEV *getOperand(unsigned i) const {
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assert(i < NumOperands && "Operand index out of range!");
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return Operands[i];
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}
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typedef const SCEV *const *op_iterator;
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typedef iterator_range<op_iterator> op_range;
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op_iterator op_begin() const { return Operands; }
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op_iterator op_end() const { return Operands + NumOperands; }
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op_range operands() const {
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return make_range(op_begin(), op_end());
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}
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Type *getType() const { return getOperand(0)->getType(); }
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NoWrapFlags getNoWrapFlags(NoWrapFlags Mask = NoWrapMask) const {
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return (NoWrapFlags)(SubclassData & Mask);
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}
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scAddExpr ||
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S->getSCEVType() == scMulExpr ||
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S->getSCEVType() == scSMaxExpr ||
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S->getSCEVType() == scUMaxExpr ||
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S->getSCEVType() == scAddRecExpr;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVCommutativeExpr - This node is the base class for n'ary commutative
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/// operators.
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///
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class SCEVCommutativeExpr : public SCEVNAryExpr {
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protected:
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SCEVCommutativeExpr(const FoldingSetNodeIDRef ID,
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enum SCEVTypes T, const SCEV *const *O, size_t N)
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: SCEVNAryExpr(ID, T, O, N) {}
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scAddExpr ||
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S->getSCEVType() == scMulExpr ||
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S->getSCEVType() == scSMaxExpr ||
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S->getSCEVType() == scUMaxExpr;
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}
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/// Set flags for a non-recurrence without clearing previously set flags.
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void setNoWrapFlags(NoWrapFlags Flags) {
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SubclassData |= Flags;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVAddExpr - This node represents an addition of some number of SCEVs.
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///
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class SCEVAddExpr : public SCEVCommutativeExpr {
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friend class ScalarEvolution;
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SCEVAddExpr(const FoldingSetNodeIDRef ID,
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const SCEV *const *O, size_t N)
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: SCEVCommutativeExpr(ID, scAddExpr, O, N) {
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}
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public:
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Type *getType() const {
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// Use the type of the last operand, which is likely to be a pointer
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// type, if there is one. This doesn't usually matter, but it can help
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// reduce casts when the expressions are expanded.
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return getOperand(getNumOperands() - 1)->getType();
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}
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scAddExpr;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVMulExpr - This node represents multiplication of some number of SCEVs.
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///
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class SCEVMulExpr : public SCEVCommutativeExpr {
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friend class ScalarEvolution;
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SCEVMulExpr(const FoldingSetNodeIDRef ID,
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const SCEV *const *O, size_t N)
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: SCEVCommutativeExpr(ID, scMulExpr, O, N) {
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}
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scMulExpr;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVUDivExpr - This class represents a binary unsigned division operation.
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///
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class SCEVUDivExpr : public SCEV {
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friend class ScalarEvolution;
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const SCEV *LHS;
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const SCEV *RHS;
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SCEVUDivExpr(const FoldingSetNodeIDRef ID, const SCEV *lhs, const SCEV *rhs)
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: SCEV(ID, scUDivExpr), LHS(lhs), RHS(rhs) {}
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public:
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const SCEV *getLHS() const { return LHS; }
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const SCEV *getRHS() const { return RHS; }
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Type *getType() const {
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// In most cases the types of LHS and RHS will be the same, but in some
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// crazy cases one or the other may be a pointer. ScalarEvolution doesn't
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// depend on the type for correctness, but handling types carefully can
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// avoid extra casts in the SCEVExpander. The LHS is more likely to be
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// a pointer type than the RHS, so use the RHS' type here.
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return getRHS()->getType();
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}
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scUDivExpr;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
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/// count of the specified loop. This is the primary focus of the
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/// ScalarEvolution framework; all the other SCEV subclasses are mostly just
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/// supporting infrastructure to allow SCEVAddRecExpr expressions to be
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/// created and analyzed.
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///
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/// All operands of an AddRec are required to be loop invariant.
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///
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class SCEVAddRecExpr : public SCEVNAryExpr {
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friend class ScalarEvolution;
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const Loop *L;
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SCEVAddRecExpr(const FoldingSetNodeIDRef ID,
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const SCEV *const *O, size_t N, const Loop *l)
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: SCEVNAryExpr(ID, scAddRecExpr, O, N), L(l) {}
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public:
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const SCEV *getStart() const { return Operands[0]; }
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const Loop *getLoop() const { return L; }
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/// getStepRecurrence - This method constructs and returns the recurrence
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/// indicating how much this expression steps by. If this is a polynomial
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/// of degree N, it returns a chrec of degree N-1.
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/// We cannot determine whether the step recurrence has self-wraparound.
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const SCEV *getStepRecurrence(ScalarEvolution &SE) const {
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if (isAffine()) return getOperand(1);
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return SE.getAddRecExpr(SmallVector<const SCEV *, 3>(op_begin()+1,
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op_end()),
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getLoop(), FlagAnyWrap);
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}
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/// isAffine - Return true if this represents an expression
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/// A + B*x where A and B are loop invariant values.
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bool isAffine() const {
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// We know that the start value is invariant. This expression is thus
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// affine iff the step is also invariant.
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return getNumOperands() == 2;
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}
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/// isQuadratic - Return true if this represents an expression
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/// A + B*x + C*x^2 where A, B and C are loop invariant values.
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/// This corresponds to an addrec of the form {L,+,M,+,N}
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bool isQuadratic() const {
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return getNumOperands() == 3;
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}
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/// Set flags for a recurrence without clearing any previously set flags.
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/// For AddRec, either NUW or NSW implies NW. Keep track of this fact here
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/// to make it easier to propagate flags.
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void setNoWrapFlags(NoWrapFlags Flags) {
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if (Flags & (FlagNUW | FlagNSW))
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Flags = ScalarEvolution::setFlags(Flags, FlagNW);
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SubclassData |= Flags;
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}
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/// evaluateAtIteration - Return the value of this chain of recurrences at
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/// the specified iteration number.
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const SCEV *evaluateAtIteration(const SCEV *It, ScalarEvolution &SE) const;
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/// getNumIterationsInRange - Return the number of iterations of this loop
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/// that produce values in the specified constant range. Another way of
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/// looking at this is that it returns the first iteration number where the
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/// value is not in the condition, thus computing the exit count. If the
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/// iteration count can't be computed, an instance of SCEVCouldNotCompute is
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/// returned.
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const SCEV *getNumIterationsInRange(ConstantRange Range,
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ScalarEvolution &SE) const;
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/// getPostIncExpr - Return an expression representing the value of
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/// this expression one iteration of the loop ahead.
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const SCEVAddRecExpr *getPostIncExpr(ScalarEvolution &SE) const {
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return cast<SCEVAddRecExpr>(SE.getAddExpr(this, getStepRecurrence(SE)));
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}
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scAddRecExpr;
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}
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/// Collect parametric terms occurring in step expressions.
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void collectParametricTerms(ScalarEvolution &SE,
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SmallVectorImpl<const SCEV *> &Terms) const;
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/// Return in Subscripts the access functions for each dimension in Sizes.
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void computeAccessFunctions(ScalarEvolution &SE,
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SmallVectorImpl<const SCEV *> &Subscripts,
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SmallVectorImpl<const SCEV *> &Sizes) const;
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/// Split this SCEVAddRecExpr into two vectors of SCEVs representing the
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/// subscripts and sizes of an array access.
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///
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/// The delinearization is a 3 step process: the first two steps compute the
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/// sizes of each subscript and the third step computes the access functions
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/// for the delinearized array:
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///
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/// 1. Find the terms in the step functions
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/// 2. Compute the array size
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/// 3. Compute the access function: divide the SCEV by the array size
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/// starting with the innermost dimensions found in step 2. The Quotient
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/// is the SCEV to be divided in the next step of the recursion. The
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/// Remainder is the subscript of the innermost dimension. Loop over all
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/// array dimensions computed in step 2.
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///
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/// To compute a uniform array size for several memory accesses to the same
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/// object, one can collect in step 1 all the step terms for all the memory
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/// accesses, and compute in step 2 a unique array shape. This guarantees
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/// that the array shape will be the same across all memory accesses.
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///
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/// FIXME: We could derive the result of steps 1 and 2 from a description of
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/// the array shape given in metadata.
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///
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/// Example:
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///
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/// A[][n][m]
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///
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/// for i
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/// for j
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/// for k
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/// A[j+k][2i][5i] =
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///
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/// The initial SCEV:
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///
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/// A[{{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k]
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///
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/// 1. Find the different terms in the step functions:
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/// -> [2*m, 5, n*m, n*m]
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///
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/// 2. Compute the array size: sort and unique them
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/// -> [n*m, 2*m, 5]
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/// find the GCD of all the terms = 1
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/// divide by the GCD and erase constant terms
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/// -> [n*m, 2*m]
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/// GCD = m
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/// divide by GCD -> [n, 2]
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/// remove constant terms
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/// -> [n]
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/// size of the array is A[unknown][n][m]
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///
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/// 3. Compute the access function
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/// a. Divide {{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k by the innermost size m
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/// Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k
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/// Remainder: {{{0,+,5}_i, +, 0}_j, +, 0}_k
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/// The remainder is the subscript of the innermost array dimension: [5i].
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///
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/// b. Divide Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k by next outer size n
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/// Quotient: {{{0,+,0}_i, +, 1}_j, +, 1}_k
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/// Remainder: {{{0,+,2}_i, +, 0}_j, +, 0}_k
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/// The Remainder is the subscript of the next array dimension: [2i].
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///
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/// The subscript of the outermost dimension is the Quotient: [j+k].
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///
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/// Overall, we have: A[][n][m], and the access function: A[j+k][2i][5i].
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void delinearize(ScalarEvolution &SE,
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SmallVectorImpl<const SCEV *> &Subscripts,
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SmallVectorImpl<const SCEV *> &Sizes,
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const SCEV *ElementSize) const;
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};
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//===--------------------------------------------------------------------===//
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/// SCEVSMaxExpr - This class represents a signed maximum selection.
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///
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class SCEVSMaxExpr : public SCEVCommutativeExpr {
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friend class ScalarEvolution;
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SCEVSMaxExpr(const FoldingSetNodeIDRef ID,
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const SCEV *const *O, size_t N)
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: SCEVCommutativeExpr(ID, scSMaxExpr, O, N) {
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// Max never overflows.
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setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
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}
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public:
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/// Methods for support type inquiry through isa, cast, and dyn_cast:
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static inline bool classof(const SCEV *S) {
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return S->getSCEVType() == scSMaxExpr;
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}
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};
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//===--------------------------------------------------------------------===//
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/// SCEVUMaxExpr - This class represents an unsigned maximum selection.
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///
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class SCEVUMaxExpr : public SCEVCommutativeExpr {
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friend class ScalarEvolution;
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SCEVUMaxExpr(const FoldingSetNodeIDRef ID,
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const SCEV *const *O, size_t N)
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: SCEVCommutativeExpr(ID, scUMaxExpr, O, N) {
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// Max never overflows.
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setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
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|
}
|
|
|
|
public:
|
|
/// Methods for support type inquiry through isa, cast, and dyn_cast:
|
|
static inline bool classof(const SCEV *S) {
|
|
return S->getSCEVType() == scUMaxExpr;
|
|
}
|
|
};
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
/// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
|
|
/// value, and only represent it as its LLVM Value. This is the "bottom"
|
|
/// value for the analysis.
|
|
///
|
|
class SCEVUnknown : public SCEV, private CallbackVH {
|
|
friend class ScalarEvolution;
|
|
|
|
// Implement CallbackVH.
|
|
void deleted() override;
|
|
void allUsesReplacedWith(Value *New) override;
|
|
|
|
/// SE - The parent ScalarEvolution value. This is used to update
|
|
/// the parent's maps when the value associated with a SCEVUnknown
|
|
/// is deleted or RAUW'd.
|
|
ScalarEvolution *SE;
|
|
|
|
/// Next - The next pointer in the linked list of all
|
|
/// SCEVUnknown instances owned by a ScalarEvolution.
|
|
SCEVUnknown *Next;
|
|
|
|
SCEVUnknown(const FoldingSetNodeIDRef ID, Value *V,
|
|
ScalarEvolution *se, SCEVUnknown *next) :
|
|
SCEV(ID, scUnknown), CallbackVH(V), SE(se), Next(next) {}
|
|
|
|
public:
|
|
Value *getValue() const { return getValPtr(); }
|
|
|
|
/// isSizeOf, isAlignOf, isOffsetOf - Test whether this is a special
|
|
/// constant representing a type size, alignment, or field offset in
|
|
/// a target-independent manner, and hasn't happened to have been
|
|
/// folded with other operations into something unrecognizable. This
|
|
/// is mainly only useful for pretty-printing and other situations
|
|
/// where it isn't absolutely required for these to succeed.
|
|
bool isSizeOf(Type *&AllocTy) const;
|
|
bool isAlignOf(Type *&AllocTy) const;
|
|
bool isOffsetOf(Type *&STy, Constant *&FieldNo) const;
|
|
|
|
Type *getType() const { return getValPtr()->getType(); }
|
|
|
|
/// Methods for support type inquiry through isa, cast, and dyn_cast:
|
|
static inline bool classof(const SCEV *S) {
|
|
return S->getSCEVType() == scUnknown;
|
|
}
|
|
};
|
|
|
|
/// SCEVVisitor - This class defines a simple visitor class that may be used
|
|
/// for various SCEV analysis purposes.
|
|
template<typename SC, typename RetVal=void>
|
|
struct SCEVVisitor {
|
|
RetVal visit(const SCEV *S) {
|
|
switch (S->getSCEVType()) {
|
|
case scConstant:
|
|
return ((SC*)this)->visitConstant((const SCEVConstant*)S);
|
|
case scTruncate:
|
|
return ((SC*)this)->visitTruncateExpr((const SCEVTruncateExpr*)S);
|
|
case scZeroExtend:
|
|
return ((SC*)this)->visitZeroExtendExpr((const SCEVZeroExtendExpr*)S);
|
|
case scSignExtend:
|
|
return ((SC*)this)->visitSignExtendExpr((const SCEVSignExtendExpr*)S);
|
|
case scAddExpr:
|
|
return ((SC*)this)->visitAddExpr((const SCEVAddExpr*)S);
|
|
case scMulExpr:
|
|
return ((SC*)this)->visitMulExpr((const SCEVMulExpr*)S);
|
|
case scUDivExpr:
|
|
return ((SC*)this)->visitUDivExpr((const SCEVUDivExpr*)S);
|
|
case scAddRecExpr:
|
|
return ((SC*)this)->visitAddRecExpr((const SCEVAddRecExpr*)S);
|
|
case scSMaxExpr:
|
|
return ((SC*)this)->visitSMaxExpr((const SCEVSMaxExpr*)S);
|
|
case scUMaxExpr:
|
|
return ((SC*)this)->visitUMaxExpr((const SCEVUMaxExpr*)S);
|
|
case scUnknown:
|
|
return ((SC*)this)->visitUnknown((const SCEVUnknown*)S);
|
|
case scCouldNotCompute:
|
|
return ((SC*)this)->visitCouldNotCompute((const SCEVCouldNotCompute*)S);
|
|
default:
|
|
llvm_unreachable("Unknown SCEV type!");
|
|
}
|
|
}
|
|
|
|
RetVal visitCouldNotCompute(const SCEVCouldNotCompute *S) {
|
|
llvm_unreachable("Invalid use of SCEVCouldNotCompute!");
|
|
}
|
|
};
|
|
|
|
/// Visit all nodes in the expression tree using worklist traversal.
|
|
///
|
|
/// Visitor implements:
|
|
/// // return true to follow this node.
|
|
/// bool follow(const SCEV *S);
|
|
/// // return true to terminate the search.
|
|
/// bool isDone();
|
|
template<typename SV>
|
|
class SCEVTraversal {
|
|
SV &Visitor;
|
|
SmallVector<const SCEV *, 8> Worklist;
|
|
SmallPtrSet<const SCEV *, 8> Visited;
|
|
|
|
void push(const SCEV *S) {
|
|
if (Visited.insert(S).second && Visitor.follow(S))
|
|
Worklist.push_back(S);
|
|
}
|
|
public:
|
|
SCEVTraversal(SV& V): Visitor(V) {}
|
|
|
|
void visitAll(const SCEV *Root) {
|
|
push(Root);
|
|
while (!Worklist.empty() && !Visitor.isDone()) {
|
|
const SCEV *S = Worklist.pop_back_val();
|
|
|
|
switch (S->getSCEVType()) {
|
|
case scConstant:
|
|
case scUnknown:
|
|
break;
|
|
case scTruncate:
|
|
case scZeroExtend:
|
|
case scSignExtend:
|
|
push(cast<SCEVCastExpr>(S)->getOperand());
|
|
break;
|
|
case scAddExpr:
|
|
case scMulExpr:
|
|
case scSMaxExpr:
|
|
case scUMaxExpr:
|
|
case scAddRecExpr: {
|
|
const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(S);
|
|
for (SCEVNAryExpr::op_iterator I = NAry->op_begin(),
|
|
E = NAry->op_end(); I != E; ++I) {
|
|
push(*I);
|
|
}
|
|
break;
|
|
}
|
|
case scUDivExpr: {
|
|
const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
|
|
push(UDiv->getLHS());
|
|
push(UDiv->getRHS());
|
|
break;
|
|
}
|
|
case scCouldNotCompute:
|
|
llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
|
|
default:
|
|
llvm_unreachable("Unknown SCEV kind!");
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
/// Use SCEVTraversal to visit all nodes in the given expression tree.
|
|
template<typename SV>
|
|
void visitAll(const SCEV *Root, SV& Visitor) {
|
|
SCEVTraversal<SV> T(Visitor);
|
|
T.visitAll(Root);
|
|
}
|
|
|
|
typedef DenseMap<const Value*, Value*> ValueToValueMap;
|
|
|
|
/// The SCEVParameterRewriter takes a scalar evolution expression and updates
|
|
/// the SCEVUnknown components following the Map (Value -> Value).
|
|
struct SCEVParameterRewriter
|
|
: public SCEVVisitor<SCEVParameterRewriter, const SCEV*> {
|
|
public:
|
|
static const SCEV *rewrite(const SCEV *Scev, ScalarEvolution &SE,
|
|
ValueToValueMap &Map,
|
|
bool InterpretConsts = false) {
|
|
SCEVParameterRewriter Rewriter(SE, Map, InterpretConsts);
|
|
return Rewriter.visit(Scev);
|
|
}
|
|
|
|
SCEVParameterRewriter(ScalarEvolution &S, ValueToValueMap &M, bool C)
|
|
: SE(S), Map(M), InterpretConsts(C) {}
|
|
|
|
const SCEV *visitConstant(const SCEVConstant *Constant) {
|
|
return Constant;
|
|
}
|
|
|
|
const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getTruncateExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getZeroExtendExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getSignExtendExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitAddExpr(const SCEVAddExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getAddExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitMulExpr(const SCEVMulExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getMulExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) {
|
|
return SE.getUDivExpr(visit(Expr->getLHS()), visit(Expr->getRHS()));
|
|
}
|
|
|
|
const SCEV *visitAddRecExpr(const SCEVAddRecExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getAddRecExpr(Operands, Expr->getLoop(),
|
|
Expr->getNoWrapFlags());
|
|
}
|
|
|
|
const SCEV *visitSMaxExpr(const SCEVSMaxExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getSMaxExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUMaxExpr(const SCEVUMaxExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getUMaxExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUnknown(const SCEVUnknown *Expr) {
|
|
Value *V = Expr->getValue();
|
|
if (Map.count(V)) {
|
|
Value *NV = Map[V];
|
|
if (InterpretConsts && isa<ConstantInt>(NV))
|
|
return SE.getConstant(cast<ConstantInt>(NV));
|
|
return SE.getUnknown(NV);
|
|
}
|
|
return Expr;
|
|
}
|
|
|
|
const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) {
|
|
return Expr;
|
|
}
|
|
|
|
private:
|
|
ScalarEvolution &SE;
|
|
ValueToValueMap ⤅
|
|
bool InterpretConsts;
|
|
};
|
|
|
|
typedef DenseMap<const Loop*, const SCEV*> LoopToScevMapT;
|
|
|
|
/// The SCEVApplyRewriter takes a scalar evolution expression and applies
|
|
/// the Map (Loop -> SCEV) to all AddRecExprs.
|
|
struct SCEVApplyRewriter
|
|
: public SCEVVisitor<SCEVApplyRewriter, const SCEV*> {
|
|
public:
|
|
static const SCEV *rewrite(const SCEV *Scev, LoopToScevMapT &Map,
|
|
ScalarEvolution &SE) {
|
|
SCEVApplyRewriter Rewriter(SE, Map);
|
|
return Rewriter.visit(Scev);
|
|
}
|
|
|
|
SCEVApplyRewriter(ScalarEvolution &S, LoopToScevMapT &M)
|
|
: SE(S), Map(M) {}
|
|
|
|
const SCEV *visitConstant(const SCEVConstant *Constant) {
|
|
return Constant;
|
|
}
|
|
|
|
const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getTruncateExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getZeroExtendExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) {
|
|
const SCEV *Operand = visit(Expr->getOperand());
|
|
return SE.getSignExtendExpr(Operand, Expr->getType());
|
|
}
|
|
|
|
const SCEV *visitAddExpr(const SCEVAddExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getAddExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitMulExpr(const SCEVMulExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getMulExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) {
|
|
return SE.getUDivExpr(visit(Expr->getLHS()), visit(Expr->getRHS()));
|
|
}
|
|
|
|
const SCEV *visitAddRecExpr(const SCEVAddRecExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
|
|
const Loop *L = Expr->getLoop();
|
|
const SCEV *Res = SE.getAddRecExpr(Operands, L, Expr->getNoWrapFlags());
|
|
|
|
if (0 == Map.count(L))
|
|
return Res;
|
|
|
|
const SCEVAddRecExpr *Rec = (const SCEVAddRecExpr *) Res;
|
|
return Rec->evaluateAtIteration(Map[L], SE);
|
|
}
|
|
|
|
const SCEV *visitSMaxExpr(const SCEVSMaxExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getSMaxExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUMaxExpr(const SCEVUMaxExpr *Expr) {
|
|
SmallVector<const SCEV *, 2> Operands;
|
|
for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
|
|
Operands.push_back(visit(Expr->getOperand(i)));
|
|
return SE.getUMaxExpr(Operands);
|
|
}
|
|
|
|
const SCEV *visitUnknown(const SCEVUnknown *Expr) {
|
|
return Expr;
|
|
}
|
|
|
|
const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) {
|
|
return Expr;
|
|
}
|
|
|
|
private:
|
|
ScalarEvolution &SE;
|
|
LoopToScevMapT ⤅
|
|
};
|
|
|
|
/// Applies the Map (Loop -> SCEV) to the given Scev.
|
|
static inline const SCEV *apply(const SCEV *Scev, LoopToScevMapT &Map,
|
|
ScalarEvolution &SE) {
|
|
return SCEVApplyRewriter::rewrite(Scev, Map, SE);
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|