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

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• Author : Olli Etuaho
  Date : 2015-12-10 20:25:12
  Hash : 8a76dcc7
  Message : Don't try to apply ForLoopUnroll to loops it can't handle ForLoopUnroll should only mark loops that fit the limitations in ESSL 1.00 Appendix A. BUG=angleproject:1253 TEST=angle_unittests, WebGL conformance tests Change-Id: I00b0a7d29cd42efea9611d020aa1f873ac04773f Reviewed-on: https://chromium-review.googlesource.com/317551 Tested-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Zhenyao Mo <zmo@chromium.org>

• src/compiler/translator/ForLoopUnroll.cpp

• //
  // Copyright (c) 2002-2013 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/ForLoopUnroll.h"
  
  #include "compiler/translator/ValidateLimitations.h"
  #include "angle_gl.h"
  
  bool ForLoopUnrollMarker::visitBinary(Visit, TIntermBinary *node)
  {
      if (mUnrollCondition != kSamplerArrayIndex)
          return true;
  
      // If a sampler array index is also the loop index,
      //   1) if the index type is integer, mark the loop for unrolling;
      //   2) if the index type if float, set a flag to later fail compile.
      switch (node->getOp())
      {
        case EOpIndexIndirect:
          if (node->getLeft() != NULL && node->getRight() != NULL && node->getLeft()->getAsSymbolNode())
          {
              TIntermSymbol *symbol = node->getLeft()->getAsSymbolNode();
              if (IsSampler(symbol->getBasicType()) && symbol->isArray() && !mLoopStack.empty())
              {
                  mVisitSamplerArrayIndexNodeInsideLoop = true;
                  node->getRight()->traverse(this);
                  mVisitSamplerArrayIndexNodeInsideLoop = false;
                  // We have already visited all the children.
                  return false;
              }
          }
          break;
        default:
          break;
      }
      return true;
  }
  
  bool ForLoopUnrollMarker::visitLoop(Visit, TIntermLoop *node)
  {
      bool canBeUnrolled = mHasRunLoopValidation;
      if (!mHasRunLoopValidation)
      {
          canBeUnrolled = ValidateLimitations::IsLimitedForLoop(node);
      }
      if (mUnrollCondition == kIntegerIndex && canBeUnrolled)
      {
          // Check if loop index type is integer.
          // This is called after ValidateLimitations pass, so the loop has the limited form specified
          // in ESSL 1.00 appendix A.
          TIntermSequence *declSeq = node->getInit()->getAsAggregate()->getSequence();
          TIntermSymbol *symbol = (*declSeq)[0]->getAsBinaryNode()->getLeft()->getAsSymbolNode();
          if (symbol->getBasicType() == EbtInt)
              node->setUnrollFlag(true);
      }
  
      TIntermNode *body = node->getBody();
      if (body != nullptr)
      {
          if (canBeUnrolled)
          {
              mLoopStack.push(node);
              body->traverse(this);
              mLoopStack.pop();
          }
          else
          {
              body->traverse(this);
          }
      }
      // The loop is fully processed - no need to visit children.
      return false;
  }
  
  void ForLoopUnrollMarker::visitSymbol(TIntermSymbol* symbol)
  {
      if (!mVisitSamplerArrayIndexNodeInsideLoop)
          return;
      TIntermLoop *loop = mLoopStack.findLoop(symbol);
      if (loop)
      {
          switch (symbol->getBasicType())
          {
            case EbtFloat:
              mSamplerArrayIndexIsFloatLoopIndex = true;
              break;
            case EbtInt:
              loop->setUnrollFlag(true);
              break;
            default:
              UNREACHABLE();
          }
      }
  }