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kc3-lang/angle/src/compiler/translator/Intermediate.cpp

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  • Author : Arun Patole
    Date : 2015-05-05 13:33:30
    Hash : 274f0709
    Message : Add constant folding support for min,max and clamp This change adds necessary mechanism to support constant folding of built-ins that take more than one parameter and also adds constant folding support for min, max and clamp built-ins. BUG=angleproject:913 TESTS=dEQP tests (126 tests started passing with this change) dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.min_* dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.max_* dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.clamp_* Change-Id: Iccc9bf503a536f2e3c144627e64572f2f95db9db Reviewed-on: https://chromium-review.googlesource.com/271251 Reviewed-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Olli Etuaho <oetuaho@nvidia.com>

  • src/compiler/translator/Intermediate.cpp
  • //
    // Copyright (c) 2002-2014 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.
    //
    
    //
    // Build the intermediate representation.
    //
    
    #include <float.h>
    #include <limits.h>
    #include <algorithm>
    
    #include "compiler/translator/Intermediate.h"
    #include "compiler/translator/SymbolTable.h"
    
    ////////////////////////////////////////////////////////////////////////////
    //
    // First set of functions are to help build the intermediate representation.
    // These functions are not member functions of the nodes.
    // They are called from parser productions.
    //
    /////////////////////////////////////////////////////////////////////////////
    
    //
    // Add a terminal node for an identifier in an expression.
    //
    // Returns the added node.
    //
    TIntermSymbol *TIntermediate::addSymbol(
        int id, const TString &name, const TType &type, const TSourceLoc &line)
    {
        TIntermSymbol *node = new TIntermSymbol(id, name, type);
        node->setLine(line);
    
        return node;
    }
    
    //
    // Connect two nodes with a new parent that does a binary operation on the nodes.
    //
    // Returns the added node.
    //
    TIntermTyped *TIntermediate::addBinaryMath(
        TOperator op, TIntermTyped *left, TIntermTyped *right, const TSourceLoc &line)
    {
        //
        // Need a new node holding things together then.  Make
        // one and promote it to the right type.
        //
        TIntermBinary *node = new TIntermBinary(op);
        node->setLine(line);
    
        node->setLeft(left);
        node->setRight(right);
        if (!node->promote(mInfoSink))
            return NULL;
    
        //
        // See if we can fold constants.
        //
        TIntermConstantUnion *leftTempConstant = left->getAsConstantUnion();
        TIntermConstantUnion *rightTempConstant = right->getAsConstantUnion();
        if (leftTempConstant && rightTempConstant)
        {
            TIntermTyped *typedReturnNode =
                leftTempConstant->fold(node->getOp(), rightTempConstant, mInfoSink);
    
            if (typedReturnNode)
                return typedReturnNode;
        }
    
        return node;
    }
    
    //
    // Connect two nodes through an assignment.
    //
    // Returns the added node.
    //
    TIntermTyped *TIntermediate::addAssign(
        TOperator op, TIntermTyped *left, TIntermTyped *right, const TSourceLoc &line)
    {
        if (left->getType().getStruct() || right->getType().getStruct())
        {
            if (left->getType() != right->getType())
            {
                return NULL;
            }
        }
    
        TIntermBinary *node = new TIntermBinary(op);
        node->setLine(line);
    
        node->setLeft(left);
        node->setRight(right);
        if (!node->promote(mInfoSink))
            return NULL;
    
        return node;
    }
    
    //
    // Connect two nodes through an index operator, where the left node is the base
    // of an array or struct, and the right node is a direct or indirect offset.
    //
    // Returns the added node.
    // The caller should set the type of the returned node.
    //
    TIntermTyped *TIntermediate::addIndex(
        TOperator op, TIntermTyped *base, TIntermTyped *index, const TSourceLoc &line)
    {
        TIntermBinary *node = new TIntermBinary(op);
        node->setLine(line);
        node->setLeft(base);
        node->setRight(index);
    
        // caller should set the type
    
        return node;
    }
    
    //
    // Add one node as the parent of another that it operates on.
    //
    // Returns the added node.
    //
    TIntermTyped *TIntermediate::addUnaryMath(
        TOperator op, TIntermTyped *child, const TSourceLoc &line, const TType *funcReturnType)
    {
        TIntermConstantUnion *childTempConstant = 0;
        if (child->getAsConstantUnion())
            childTempConstant = child->getAsConstantUnion();
    
        //
        // Make a new node for the operator.
        //
        TIntermUnary *node = new TIntermUnary(op);
        node->setLine(line);
        node->setOperand(child);
        node->promote(funcReturnType);
    
        if (childTempConstant)
        {
            TIntermTyped *newChild = childTempConstant->fold(op, nullptr, mInfoSink);
    
            if (newChild)
                return newChild;
        }
    
        return node;
    }
    
    //
    // This is the safe way to change the operator on an aggregate, as it
    // does lots of error checking and fixing.  Especially for establishing
    // a function call's operation on it's set of parameters.  Sequences
    // of instructions are also aggregates, but they just direnctly set
    // their operator to EOpSequence.
    //
    // Returns an aggregate node, which could be the one passed in if
    // it was already an aggregate but no operator was set.
    //
    TIntermAggregate *TIntermediate::setAggregateOperator(
        TIntermNode *node, TOperator op, const TSourceLoc &line)
    {
        TIntermAggregate *aggNode;
    
        //
        // Make sure we have an aggregate.  If not turn it into one.
        //
        if (node)
        {
            aggNode = node->getAsAggregate();
            if (aggNode == NULL || aggNode->getOp() != EOpNull)
            {
                //
                // Make an aggregate containing this node.
                //
                aggNode = new TIntermAggregate();
                aggNode->getSequence()->push_back(node);
            }
        }
        else
        {
            aggNode = new TIntermAggregate();
        }
    
        //
        // Set the operator.
        //
        aggNode->setOp(op);
        aggNode->setLine(line);
    
        return aggNode;
    }
    
    //
    // Safe way to combine two nodes into an aggregate.  Works with null pointers,
    // a node that's not a aggregate yet, etc.
    //
    // Returns the resulting aggregate, unless 0 was passed in for
    // both existing nodes.
    //
    TIntermAggregate *TIntermediate::growAggregate(
        TIntermNode *left, TIntermNode *right, const TSourceLoc &line)
    {
        if (left == NULL && right == NULL)
            return NULL;
    
        TIntermAggregate *aggNode = NULL;
        if (left)
            aggNode = left->getAsAggregate();
        if (!aggNode || aggNode->getOp() != EOpNull)
        {
            aggNode = new TIntermAggregate;
            if (left)
                aggNode->getSequence()->push_back(left);
        }
    
        if (right)
            aggNode->getSequence()->push_back(right);
    
        aggNode->setLine(line);
    
        return aggNode;
    }
    
    //
    // Turn an existing node into an aggregate.
    //
    // Returns an aggregate, unless NULL was passed in for the existing node.
    //
    TIntermAggregate *TIntermediate::makeAggregate(
        TIntermNode *node, const TSourceLoc &line)
    {
        if (node == NULL)
            return NULL;
    
        TIntermAggregate *aggNode = new TIntermAggregate;
        aggNode->getSequence()->push_back(node);
    
        aggNode->setLine(line);
    
        return aggNode;
    }
    
    //
    // For "if" test nodes.  There are three children; a condition,
    // a true path, and a false path.  The two paths are in the
    // nodePair.
    //
    // Returns the selection node created.
    //
    TIntermNode *TIntermediate::addSelection(
        TIntermTyped *cond, TIntermNodePair nodePair, const TSourceLoc &line)
    {
        //
        // For compile time constant selections, prune the code and
        // test now.
        //
    
        if (cond->getAsTyped() && cond->getAsTyped()->getAsConstantUnion())
        {
            if (cond->getAsConstantUnion()->getBConst(0) == true)
            {
                return nodePair.node1 ? setAggregateOperator(
                    nodePair.node1, EOpSequence, nodePair.node1->getLine()) : NULL;
            }
            else
            {
                return nodePair.node2 ? setAggregateOperator(
                    nodePair.node2, EOpSequence, nodePair.node2->getLine()) : NULL;
            }
        }
    
        TIntermSelection *node = new TIntermSelection(
            cond, nodePair.node1, nodePair.node2);
        node->setLine(line);
    
        return node;
    }
    
    TIntermTyped *TIntermediate::addComma(
        TIntermTyped *left, TIntermTyped *right, const TSourceLoc &line)
    {
        if (left->getType().getQualifier() == EvqConst &&
            right->getType().getQualifier() == EvqConst)
        {
            return right;
        }
        else
        {
            TIntermTyped *commaAggregate = growAggregate(left, right, line);
            commaAggregate->getAsAggregate()->setOp(EOpComma);
            commaAggregate->setType(right->getType());
            commaAggregate->getTypePointer()->setQualifier(EvqTemporary);
            return commaAggregate;
        }
    }
    
    //
    // For "?:" test nodes.  There are three children; a condition,
    // a true path, and a false path.  The two paths are specified
    // as separate parameters.
    //
    // Returns the selection node created, or one of trueBlock and falseBlock if the expression could be folded.
    //
    TIntermTyped *TIntermediate::addSelection(TIntermTyped *cond, TIntermTyped *trueBlock, TIntermTyped *falseBlock,
                                              const TSourceLoc &line)
    {
        // Right now it's safe to fold ternary operators only when all operands
        // are constant. If only the condition is constant, it's theoretically
        // possible to fold the ternary operator, but that requires making sure
        // that the node returned from here won't be treated as a constant
        // expression in case the node that gets eliminated was not a constant
        // expression.
        if (cond->getAsConstantUnion() &&
            trueBlock->getAsConstantUnion() &&
            falseBlock->getAsConstantUnion())
        {
            if (cond->getAsConstantUnion()->getBConst(0))
                return trueBlock;
            else
                return falseBlock;
        }
    
        //
        // Make a selection node.
        //
        TIntermSelection *node = new TIntermSelection(cond, trueBlock, falseBlock, trueBlock->getType());
        node->getTypePointer()->setQualifier(EvqTemporary);
        node->setLine(line);
    
        return node;
    }
    
    TIntermSwitch *TIntermediate::addSwitch(
        TIntermTyped *init, TIntermAggregate *statementList, const TSourceLoc &line)
    {
        TIntermSwitch *node = new TIntermSwitch(init, statementList);
        node->setLine(line);
    
        return node;
    }
    
    TIntermCase *TIntermediate::addCase(
        TIntermTyped *condition, const TSourceLoc &line)
    {
        TIntermCase *node = new TIntermCase(condition);
        node->setLine(line);
    
        return node;
    }
    
    //
    // Constant terminal nodes.  Has a union that contains bool, float or int constants
    //
    // Returns the constant union node created.
    //
    
    TIntermConstantUnion *TIntermediate::addConstantUnion(
        TConstantUnion *constantUnion, const TType &type, const TSourceLoc &line)
    {
        TIntermConstantUnion *node = new TIntermConstantUnion(constantUnion, type);
        node->setLine(line);
    
        return node;
    }
    
    TIntermTyped *TIntermediate::addSwizzle(
        TVectorFields &fields, const TSourceLoc &line)
    {
    
        TIntermAggregate *node = new TIntermAggregate(EOpSequence);
    
        node->setLine(line);
        TIntermConstantUnion *constIntNode;
        TIntermSequence *sequenceVector = node->getSequence();
        TConstantUnion *unionArray;
    
        for (int i = 0; i < fields.num; i++)
        {
            unionArray = new TConstantUnion[1];
            unionArray->setIConst(fields.offsets[i]);
            constIntNode = addConstantUnion(
                unionArray, TType(EbtInt, EbpUndefined, EvqConst), line);
            sequenceVector->push_back(constIntNode);
        }
    
        return node;
    }
    
    //
    // Create loop nodes.
    //
    TIntermNode *TIntermediate::addLoop(
        TLoopType type, TIntermNode *init, TIntermTyped *cond, TIntermTyped *expr,
        TIntermNode *body, const TSourceLoc &line)
    {
        TIntermNode *node = new TIntermLoop(type, init, cond, expr, body);
        node->setLine(line);
    
        return node;
    }
    
    //
    // Add branches.
    //
    TIntermBranch* TIntermediate::addBranch(
        TOperator branchOp, const TSourceLoc &line)
    {
        return addBranch(branchOp, 0, line);
    }
    
    TIntermBranch* TIntermediate::addBranch(
        TOperator branchOp, TIntermTyped *expression, const TSourceLoc &line)
    {
        TIntermBranch *node = new TIntermBranch(branchOp, expression);
        node->setLine(line);
    
        return node;
    }
    
    //
    // This is to be executed once the final root is put on top by the parsing
    // process.
    //
    bool TIntermediate::postProcess(TIntermNode *root)
    {
        if (root == NULL)
            return true;
    
        //
        // First, finish off the top level sequence, if any
        //
        TIntermAggregate *aggRoot = root->getAsAggregate();
        if (aggRoot && aggRoot->getOp() == EOpNull)
            aggRoot->setOp(EOpSequence);
    
        return true;
    }
    
    TIntermTyped *TIntermediate::foldAggregateBuiltIn(TOperator op, TIntermAggregate *aggregate)
    {
        switch (op)
        {
          case EOpMin:
          case EOpMax:
          case EOpClamp:
            return TIntermConstantUnion::FoldAggregateBuiltIn(op, aggregate);
          default:
            // Constant folding not supported for the built-in.
            return nullptr;
        }
    
        return nullptr;
    }