michael@0: //
michael@0: // Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: //
michael@0: // Contains analysis utilities for dealing with HLSL's lack of support for
michael@0: // the use of intrinsic functions which (implicitly or explicitly) compute
michael@0: // gradients of functions with discontinuities. 
michael@0: //
michael@0: 
michael@0: #include "compiler/DetectDiscontinuity.h"
michael@0: 
michael@0: #include "compiler/ParseHelper.h"
michael@0: 
michael@0: namespace sh
michael@0: {
michael@0: bool DetectLoopDiscontinuity::traverse(TIntermNode *node)
michael@0: {
michael@0:     mLoopDepth = 0;
michael@0:     mLoopDiscontinuity = false;
michael@0:     node->traverse(this);
michael@0:     return mLoopDiscontinuity;
michael@0: }
michael@0: 
michael@0: bool DetectLoopDiscontinuity::visitLoop(Visit visit, TIntermLoop *loop)
michael@0: {
michael@0:     if (visit == PreVisit)
michael@0:     {
michael@0:         ++mLoopDepth;
michael@0:     }
michael@0:     else if (visit == PostVisit)
michael@0:     {
michael@0:         --mLoopDepth;
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool DetectLoopDiscontinuity::visitBranch(Visit visit, TIntermBranch *node)
michael@0: {
michael@0:     if (mLoopDiscontinuity)
michael@0:     {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     if (!mLoopDepth)
michael@0:     {
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     switch (node->getFlowOp())
michael@0:     {
michael@0:       case EOpKill:
michael@0:         break;
michael@0:       case EOpBreak:
michael@0:       case EOpContinue:
michael@0:       case EOpReturn:
michael@0:         mLoopDiscontinuity = true;
michael@0:         break;
michael@0:       default: UNREACHABLE();
michael@0:     }
michael@0: 
michael@0:     return !mLoopDiscontinuity;
michael@0: }
michael@0: 
michael@0: bool DetectLoopDiscontinuity::visitAggregate(Visit visit, TIntermAggregate *node)
michael@0: {
michael@0:     return !mLoopDiscontinuity;
michael@0: }
michael@0: 
michael@0: bool containsLoopDiscontinuity(TIntermNode *node)
michael@0: {
michael@0:     DetectLoopDiscontinuity detectLoopDiscontinuity;
michael@0:     return detectLoopDiscontinuity.traverse(node);
michael@0: }
michael@0: 
michael@0: bool DetectGradientOperation::traverse(TIntermNode *node)
michael@0: {
michael@0:     mGradientOperation = false;
michael@0:     node->traverse(this);
michael@0:     return mGradientOperation;
michael@0: }
michael@0: 
michael@0: bool DetectGradientOperation::visitUnary(Visit visit, TIntermUnary *node)
michael@0: {
michael@0:     if (mGradientOperation)
michael@0:     {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     switch (node->getOp())
michael@0:     {
michael@0:       case EOpDFdx:
michael@0:       case EOpDFdy:
michael@0:         mGradientOperation = true;
michael@0:       default:
michael@0:         break;
michael@0:     }
michael@0: 
michael@0:     return !mGradientOperation;
michael@0: }
michael@0: 
michael@0: bool DetectGradientOperation::visitAggregate(Visit visit, TIntermAggregate *node)
michael@0: {
michael@0:     if (mGradientOperation)
michael@0:     {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     if (node->getOp() == EOpFunctionCall)
michael@0:     {
michael@0:         if (!node->isUserDefined())
michael@0:         {
michael@0:             TString name = TFunction::unmangleName(node->getName());
michael@0: 
michael@0:             if (name == "texture2D" ||
michael@0:                 name == "texture2DProj" ||
michael@0:                 name == "textureCube")
michael@0:             {
michael@0:                 mGradientOperation = true;
michael@0:             }
michael@0:         }
michael@0:         else
michael@0:         {
michael@0:             // When a user defined function is called, we have to
michael@0:             // conservatively assume it to contain gradient operations
michael@0:             mGradientOperation = true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return !mGradientOperation;
michael@0: }
michael@0: 
michael@0: bool containsGradientOperation(TIntermNode *node)
michael@0: {
michael@0:     DetectGradientOperation detectGradientOperation;
michael@0:     return detectGradientOperation.traverse(node);
michael@0: }
michael@0: }