src/compiler/intermediate.h

//
// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

//
// Definition of the in-memory high-level intermediate representation
// of shaders.  This is a tree that parser creates.
//
// Nodes in the tree are defined as a hierarchy of classes derived from 
// TIntermNode. Each is a node in a tree.  There is no preset branching factor;
// each node can have it's own type of list of children.
//

#ifndef __INTERMEDIATE_H
#define __INTERMEDIATE_H

#include "Common.h"
#include "Types.h"
#include "ConstantUnion.h"

//
// Operators used by the high-level (parse tree) representation.
//
enum TOperator {
	EOpNull,            // if in a node, should only mean a node is still being built
	EOpSequence,        // denotes a list of statements, or parameters, etc.
	EOpFunctionCall,    
	EOpFunction,        // For function definition
	EOpParameters,      // an aggregate listing the parameters to a function
	EOpDeclaration,

	//
	// Unary operators
	//
	
	EOpNegative,
	EOpLogicalNot,
	EOpVectorLogicalNot,

	EOpPostIncrement,
	EOpPostDecrement,
	EOpPreIncrement,
	EOpPreDecrement,

	EOpConvIntToBool,
	EOpConvFloatToBool,
	EOpConvBoolToFloat,
	EOpConvIntToFloat,
	EOpConvFloatToInt,
	EOpConvBoolToInt,

	//
	// binary operations
	//

	EOpAdd,
	EOpSub,
	EOpMul,
	EOpDiv,
	EOpEqual,
	EOpNotEqual,
	EOpVectorEqual,
	EOpVectorNotEqual,
	EOpLessThan,
	EOpGreaterThan,
	EOpLessThanEqual,
	EOpGreaterThanEqual,
	EOpComma,

	EOpVectorTimesScalar,
	EOpVectorTimesMatrix,
	EOpMatrixTimesVector,
	EOpMatrixTimesScalar,

	EOpLogicalOr,
	EOpLogicalXor,
	EOpLogicalAnd,

	EOpIndexDirect,
	EOpIndexIndirect,
	EOpIndexDirectStruct,

	EOpVectorSwizzle,

	//
	// Built-in functions potentially mapped to operators
	//

	EOpRadians,
	EOpDegrees,
	EOpSin,
	EOpCos,
	EOpTan,
	EOpAsin,
	EOpAcos,
	EOpAtan,

	EOpPow,
	EOpExp,
	EOpLog,
	EOpExp2,
	EOpLog2,
	EOpSqrt,
	EOpInverseSqrt,

	EOpAbs,
	EOpSign,
	EOpFloor,
	EOpCeil,
	EOpFract,
	EOpMod,
	EOpMin,
	EOpMax,
	EOpClamp,
	EOpMix,
	EOpStep,
	EOpSmoothStep,

	EOpLength,
	EOpDistance,
	EOpDot,
	EOpCross,
	EOpNormalize,
	EOpFaceForward,
	EOpReflect,
	EOpRefract,

//	EOpDPdx,            // Fragment only, OES_standard_derivatives extension
//	EOpDPdy,            // Fragment only, OES_standard_derivatives extension
//	EOpFwidth,          // Fragment only, OES_standard_derivatives extension

	EOpMatrixTimesMatrix,

	EOpAny,
	EOpAll,
	
	//
	// Branch
	//

	EOpKill,            // Fragment only
	EOpReturn,
	EOpBreak,
	EOpContinue,

	//
	// Constructors
	//

	EOpConstructInt,
	EOpConstructBool,
	EOpConstructFloat,
	EOpConstructVec2,
	EOpConstructVec3,
	EOpConstructVec4,
	EOpConstructBVec2,
	EOpConstructBVec3,
	EOpConstructBVec4,
	EOpConstructIVec2,
	EOpConstructIVec3,
	EOpConstructIVec4,
	EOpConstructMat2,
	EOpConstructMat3,
	EOpConstructMat4,
	EOpConstructStruct,

	//
	// moves
	//

	EOpAssign,
	EOpInitialize,
	EOpAddAssign,
	EOpSubAssign,
	EOpMulAssign,
	EOpVectorTimesMatrixAssign,
	EOpVectorTimesScalarAssign,
	EOpMatrixTimesScalarAssign,
	EOpMatrixTimesMatrixAssign,
	EOpDivAssign,
};

class TIntermTraverser;
class TIntermAggregate;
class TIntermBinary;
class TIntermConstantUnion;
class TIntermSelection;
class TIntermTyped;
class TIntermSymbol;
class TInfoSink;

//
// Base class for the tree nodes
//
class TIntermNode {
public:
	POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)

	TIntermNode() : line(0) {}
	virtual TSourceLoc getLine() const { return line; }
	virtual void setLine(TSourceLoc l) { line = l; }
	virtual void traverse(TIntermTraverser*) = 0;
	virtual TIntermTyped*     getAsTyped()         { return 0; }
	virtual TIntermConstantUnion*     getAsConstantUnion()         { return 0; }
	virtual TIntermAggregate* getAsAggregate()     { return 0; }
	virtual TIntermBinary*    getAsBinaryNode()    { return 0; }
	virtual TIntermSelection* getAsSelectionNode() { return 0; }
	virtual TIntermSymbol*    getAsSymbolNode()    { return 0; }
	virtual ~TIntermNode() { }
protected:
	TSourceLoc line;
};

//
// This is just to help yacc.
//
struct TIntermNodePair {
	TIntermNode* node1;
	TIntermNode* node2;
};

class TIntermSymbol;
class TIntermBinary;

//
// Intermediate class for nodes that have a type.
//
class TIntermTyped : public TIntermNode {
public:
	TIntermTyped(const TType& t) : type(t)  { }
	virtual TIntermTyped* getAsTyped()         { return this; }
	virtual void setType(const TType& t) { type = t; }
	virtual const TType& getType() const { return type; }
	virtual TType* getTypePointer() { return &type; }

	virtual TBasicType getBasicType() const { return type.getBasicType(); }
	virtual TQualifier getQualifier() const { return type.getQualifier(); }
	virtual int getNominalSize() const { return type.getNominalSize(); }
	virtual int getSize() const { return type.getInstanceSize(); }
	virtual bool isMatrix() const { return type.isMatrix(); }
	virtual bool isArray()  const { return type.isArray(); }
	virtual bool isVector() const { return type.isVector(); }
	const char* getBasicString()      const { return type.getBasicString(); }
	const char* getQualifierString()  const { return type.getQualifierString(); }
	TString getCompleteString() const { return type.getCompleteString(); }

protected:
	TType type;
};

//
// Handle for, do-while, and while loops.
//
class TIntermLoop : public TIntermNode {
public:
	TIntermLoop(TIntermNode *init, TIntermNode* aBody, TIntermTyped* aTest, TIntermTyped* aTerminal, bool testFirst) : 
	    init(init),
		body(aBody),
		test(aTest),
		terminal(aTerminal),
		first(testFirst) { }
	virtual void traverse(TIntermTraverser*);
	TIntermNode *getInit() { return init; }
	TIntermNode *getBody() { return body; }
	TIntermTyped *getTest() { return test; }
	TIntermTyped *getTerminal() { return terminal; }
	bool testFirst() { return first; }
protected:
	TIntermNode *init;
	TIntermNode *body;       // code to loop over
	TIntermTyped *test;      // exit condition associated with loop, could be 0 for 'for' loops
	TIntermTyped *terminal;  // exists for for-loops
	bool first;              // true for while and for, not for do-while
};

//
// Handle break, continue, return, and kill.
//
class TIntermBranch : public TIntermNode {
public:
	TIntermBranch(TOperator op, TIntermTyped* e) :
		flowOp(op),
		expression(e) { }
	virtual void traverse(TIntermTraverser*);
	TOperator getFlowOp() { return flowOp; }
	TIntermTyped* getExpression() { return expression; }
protected:
	TOperator flowOp;
	TIntermTyped* expression;  // non-zero except for "return exp;" statements
};

//
// Nodes that correspond to symbols or constants in the source code.
//
class TIntermSymbol : public TIntermTyped {
public:
	// if symbol is initialized as symbol(sym), the memory comes from the poolallocator of sym. If sym comes from
	// per process globalpoolallocator, then it causes increased memory usage per compile
	// it is essential to use "symbol = sym" to assign to symbol
	TIntermSymbol(int i, const TString& sym, const TType& t) : 
		TIntermTyped(t), id(i)  { symbol = sym;} 
	virtual int getId() const { return id; }
	virtual const TString& getSymbol() const { return symbol;  }
	virtual void traverse(TIntermTraverser*);
	virtual TIntermSymbol* getAsSymbolNode() { return this; }
protected:
	int id;
	TString symbol;
};

class TIntermConstantUnion : public TIntermTyped {
public:
	TIntermConstantUnion(constUnion *unionPointer, const TType& t) : TIntermTyped(t), unionArrayPointer(unionPointer) { }
	constUnion* getUnionArrayPointer() const { return unionArrayPointer; }
	void setUnionArrayPointer(constUnion *c) { unionArrayPointer = c; }
	virtual TIntermConstantUnion* getAsConstantUnion()  { return this; }
	virtual void traverse(TIntermTraverser* );
	virtual TIntermTyped* fold(TOperator, TIntermTyped*, TInfoSink&);
protected:
	constUnion *unionArrayPointer;
};

//
// Intermediate class for node types that hold operators.
//
class TIntermOperator : public TIntermTyped {
public:
	TOperator getOp() const { return op; }
	bool modifiesState() const;
	bool isConstructor() const;
	virtual bool promote(TInfoSink&) { return true; }
protected:
	TIntermOperator(TOperator o) : TIntermTyped(TType(EbtFloat)), op(o) {}
	TIntermOperator(TOperator o, TType& t) : TIntermTyped(t), op(o) {}   
	TOperator op;
};

//
// Nodes for all the basic binary math operators.
//
class TIntermBinary : public TIntermOperator {
public:
	TIntermBinary(TOperator o) : TIntermOperator(o) {}
	virtual void traverse(TIntermTraverser*);
	virtual void setLeft(TIntermTyped* n) { left = n; }
	virtual void setRight(TIntermTyped* n) { right = n; }
	virtual TIntermTyped* getLeft() const { return left; }
	virtual TIntermTyped* getRight() const { return right; }
	virtual TIntermBinary* getAsBinaryNode() { return this; }
	virtual bool promote(TInfoSink&);
protected:
	TIntermTyped* left;
	TIntermTyped* right;
};

//
// Nodes for unary math operators.
//
class TIntermUnary : public TIntermOperator {
public:
	TIntermUnary(TOperator o, TType& t) : TIntermOperator(o, t), operand(0) {}
	TIntermUnary(TOperator o) : TIntermOperator(o), operand(0) {}
	virtual void traverse(TIntermTraverser*);
	virtual void setOperand(TIntermTyped* o) { operand = o; }
	virtual TIntermTyped* getOperand() { return operand; }
	virtual bool promote(TInfoSink&);
protected:
	TIntermTyped* operand;
};

typedef TVector<TIntermNode*> TIntermSequence;
typedef TVector<int> TQualifierList;
//
// Nodes that operate on an arbitrary sized set of children.
//
class TIntermAggregate : public TIntermOperator {
public:
	TIntermAggregate() : TIntermOperator(EOpNull), userDefined(false), pragmaTable(0) { }
	TIntermAggregate(TOperator o) : TIntermOperator(o), pragmaTable(0) { }
	~TIntermAggregate() { delete pragmaTable; }
	virtual TIntermAggregate* getAsAggregate() { return this; }
	virtual void setOperator(TOperator o) { op = o; }
	virtual TIntermSequence& getSequence() { return sequence; }
	virtual void setName(const TString& n) { name = n; }
	virtual const TString& getName() const { return name; }
	virtual void traverse(TIntermTraverser*);
	virtual void setUserDefined() { userDefined = true; }
	virtual bool isUserDefined() { return userDefined; }
	virtual TQualifierList& getQualifier() { return qualifier; }
	void setOptimize(bool o) { optimize = o; }
	void setDebug(bool d) { debug = d; }
	bool getOptimize() { return optimize; }
	bool getDebug() { return debug; }
	void addToPragmaTable(const TPragmaTable& pTable);
	const TPragmaTable& getPragmaTable() const { return *pragmaTable; }
protected:
	TIntermAggregate(const TIntermAggregate&); // disallow copy constructor
	TIntermAggregate& operator=(const TIntermAggregate&); // disallow assignment operator
	TIntermSequence sequence;
	TQualifierList qualifier;
	TString name;
	bool userDefined; // used for user defined function names
	bool optimize;
	bool debug;
	TPragmaTable *pragmaTable;
};

//
// For if tests.  Simplified since there is no switch statement.
//
class TIntermSelection : public TIntermTyped {
public:
	TIntermSelection(TIntermTyped* cond, TIntermNode* trueB, TIntermNode* falseB) :
		TIntermTyped(TType(EbtVoid)), condition(cond), trueBlock(trueB), falseBlock(falseB) {}
	TIntermSelection(TIntermTyped* cond, TIntermNode* trueB, TIntermNode* falseB, const TType& type) :
		TIntermTyped(type), condition(cond), trueBlock(trueB), falseBlock(falseB) {}
	virtual void traverse(TIntermTraverser*);
        bool usesTernaryOperator() const { return getBasicType() != EbtVoid; }
	virtual TIntermNode* getCondition() const { return condition; }
	virtual TIntermNode* getTrueBlock() const { return trueBlock; }
	virtual TIntermNode* getFalseBlock() const { return falseBlock; }
	virtual TIntermSelection* getAsSelectionNode() { return this; }
protected:
	TIntermTyped* condition;
	TIntermNode* trueBlock;
	TIntermNode* falseBlock;
};

enum Visit
{
	PreVisit,
	InVisit,
	PostVisit
};

//
// For traversing the tree.  User should derive from this, 
// put their traversal specific data in it, and then pass
// it to a Traverse method.
//
// When using this, just fill in the methods for nodes you want visited.
// Return false from a pre-visit to skip visiting that node's subtree.
//
class TIntermTraverser
{
public:
	POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)

	TIntermTraverser(bool preVisit = true, bool inVisit = false, bool postVisit = false, bool rightToLeft = false) : 
		preVisit(preVisit),
		inVisit(inVisit),
		postVisit(postVisit),
		rightToLeft(rightToLeft)
	{
		depth = 0;
	}

	virtual void visitSymbol(TIntermSymbol*) {}
	virtual void visitConstantUnion(TIntermConstantUnion*) {}
	virtual bool visitBinary(Visit visit, TIntermBinary*) {return true;}
	virtual bool visitUnary(Visit visit, TIntermUnary*) {return true;}
	virtual bool visitSelection(Visit visit, TIntermSelection*) {return true;}
	virtual bool visitAggregate(Visit visit, TIntermAggregate*) {return true;}
	virtual bool visitLoop(Visit visit, TIntermLoop*) {return true;}
	virtual bool visitBranch(Visit visit, TIntermBranch*) {return true;}

	void incrementDepth() {depth++;}
	void decrementDepth() {depth--;}

	const bool preVisit;
	const bool inVisit;
	const bool postVisit;
	const bool rightToLeft;

protected:
	int depth;
};

#endif // __INTERMEDIATE_H