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

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• Author : Zhenyao Mo
  Date : 2014-07-16 17:40:36
  Hash : e40d1e9c
  Message : Fix style violations. BUG=angle:650 TEST=no behavior change Change-Id: I3096615a181b1ec2c18ce60566c3d6249975b84e Reviewed-on: https://chromium-review.googlesource.com/208569 Tested-by: Zhenyao Mo <zmo@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

• src/compiler/translator/LoopInfo.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.
  //
  
  #include "compiler/translator/LoopInfo.h"
  
  namespace
  {
  
  int EvaluateIntConstant(TIntermConstantUnion *node)
  {
      ASSERT(node && node->getUnionArrayPointer());
      return node->getIConst(0);
  }
  
  int GetLoopIntIncrement(TIntermLoop *node)
  {
      TIntermNode *expr = node->getExpression();
      // for expression has one of the following forms:
      //     loop_index++
      //     loop_index--
      //     loop_index += constant_expression
      //     loop_index -= constant_expression
      //     ++loop_index
      //     --loop_index
      // The last two forms are not specified in the spec, but I am assuming
      // its an oversight.
      TIntermUnary *unOp = expr->getAsUnaryNode();
      TIntermBinary *binOp = unOp ? NULL : expr->getAsBinaryNode();
  
      TOperator op = EOpNull;
      TIntermConstantUnion *incrementNode = NULL;
      if (unOp)
      {
          op = unOp->getOp();
      }
      else if (binOp)
      {
          op = binOp->getOp();
          ASSERT(binOp->getRight());
          incrementNode = binOp->getRight()->getAsConstantUnion();
          ASSERT(incrementNode);
      }
  
      int increment = 0;
      // The operator is one of: ++ -- += -=.
      switch (op)
      {
        case EOpPostIncrement:
        case EOpPreIncrement:
          ASSERT(unOp && !binOp);
          increment = 1;
          break;
        case EOpPostDecrement:
        case EOpPreDecrement:
          ASSERT(unOp && !binOp);
          increment = -1;
          break;
        case EOpAddAssign:
          ASSERT(!unOp && binOp);
          increment = EvaluateIntConstant(incrementNode);
          break;
        case EOpSubAssign:
          ASSERT(!unOp && binOp);
          increment = - EvaluateIntConstant(incrementNode);
          break;
        default:
          UNREACHABLE();
      }
  
      return increment;
  }
  
  }  // namespace anonymous
  
  TLoopIndexInfo::TLoopIndexInfo()
      : mId(-1),
        mType(EbtVoid),
        mInitValue(0),
        mStopValue(0),
        mIncrementValue(0),
        mOp(EOpNull),
        mCurrentValue(0)
  {
  }
  
  void TLoopIndexInfo::fillInfo(TIntermLoop *node)
  {
      if (node == NULL)
          return;
  
      // Here we assume all the operations are valid, because the loop node is
      // already validated in ValidateLimitations.
      TIntermSequence *declSeq =
          node->getInit()->getAsAggregate()->getSequence();
      TIntermBinary *declInit = (*declSeq)[0]->getAsBinaryNode();
      TIntermSymbol *symbol = declInit->getLeft()->getAsSymbolNode();
  
      mId = symbol->getId();
      mType = symbol->getBasicType();
  
      if (mType == EbtInt)
      {
          TIntermConstantUnion* initNode = declInit->getRight()->getAsConstantUnion();
          mInitValue = EvaluateIntConstant(initNode);
          mCurrentValue = mInitValue;
          mIncrementValue = GetLoopIntIncrement(node);
  
          TIntermBinary* binOp = node->getCondition()->getAsBinaryNode();
          mStopValue = EvaluateIntConstant(
              binOp->getRight()->getAsConstantUnion());
          mOp = binOp->getOp();
      }
  }
  
  bool TLoopIndexInfo::satisfiesLoopCondition() const
  {
      // Relational operator is one of: > >= < <= == or !=.
      switch (mOp)
      {
        case EOpEqual:
          return (mCurrentValue == mStopValue);
        case EOpNotEqual:
          return (mCurrentValue != mStopValue);
        case EOpLessThan:
          return (mCurrentValue < mStopValue);
        case EOpGreaterThan:
          return (mCurrentValue > mStopValue);
        case EOpLessThanEqual:
          return (mCurrentValue <= mStopValue);
        case EOpGreaterThanEqual:
          return (mCurrentValue >= mStopValue);
        default:
          UNREACHABLE();
          return false;
      }
  }
  
  TLoopInfo::TLoopInfo()
      : loop(NULL)
  {
  }
  
  TLoopInfo::TLoopInfo(TIntermLoop *node)
      : loop(node)
  {
      index.fillInfo(node);
  }
  
  TIntermLoop *TLoopStack::findLoop(TIntermSymbol *symbol)
  {
      if (!symbol)
          return NULL;
      for (iterator iter = begin(); iter != end(); ++iter)
      {
          if (iter->index.getId() == symbol->getId())
              return iter->loop;
      }
      return NULL;
  }
  
  TLoopIndexInfo *TLoopStack::getIndexInfo(TIntermSymbol *symbol)
  {
      if (!symbol)
          return NULL;
      for (iterator iter = begin(); iter != end(); ++iter)
      {
          if (iter->index.getId() == symbol->getId())
              return &(iter->index);
      }
      return NULL;
  }
  
  void TLoopStack::step()
  {
      ASSERT(!empty());
      rbegin()->index.step();
  }
  
  bool TLoopStack::satisfiesLoopCondition()
  {
      ASSERT(!empty());
      return rbegin()->index.satisfiesLoopCondition();
  }
  
  bool TLoopStack::needsToReplaceSymbolWithValue(TIntermSymbol *symbol)
  {
      TIntermLoop *loop = findLoop(symbol);
      return loop && loop->getUnrollFlag();
  }
  
  int TLoopStack::getLoopIndexValue(TIntermSymbol *symbol)
  {
      TLoopIndexInfo *info = getIndexInfo(symbol);
      ASSERT(info);
      return info->getCurrentValue();
  }
  
  void TLoopStack::push(TIntermLoop *loop)
  {
      TLoopInfo info(loop);
      push_back(info);
  }
  
  void TLoopStack::pop()
  {
      pop_back();
  }