kc3-lang/angle/src/compiler/translator/tree_ops/RemoveInactiveInterfaceVariables.cpp

• Show log

  Commit

• Hash : 6f80f0f0
  Author :
  Date : 2022-08-06T02:29:19
  

  Translator: Clean up the compile flag passing interface
  
  Historically, compile flags were sent to the translator as a bitmask.
  Recently, we were getting close to running out of bits.  Additionally,
  direct-to-metal work had started to introduce constants to be passed to
  the translator, which were misplaced in ShBuiltInResources and Caps.
  Recent work on Pixel Local Storage adds even more constants, aggravating
  the situation.
  
  In this change, the interface to passing compile flags is reworked.  A
  struct is passed (instead of a bitmask) that has one bit for each flag.
  This can be indefinitely extended.  Additionally, the constants needed
  by metal and PLS are also placed in this struct.  In turn, the backends
  can set these options directly, and don't have to hack them into Caps to
  further get hacked into ShBuiltInResources.
  
  Bug: angleproject:7559
  Change-Id: If93f1e1b8818ad3a0ac708ab04ab93b4b397d114
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3812562
  Reviewed-by: Geoff Lang <geofflang@chromium.org>
  Reviewed-by: Amirali Abdolrashidi <abdolrashidi@google.com>
  Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com>
  Auto-Submit: Shahbaz Youssefi <syoussefi@chromium.org>
  

Download

• src/compiler/translator/tree_ops/RemoveInactiveInterfaceVariables.cpp

• //
  // Copyright 2019 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.
  //
  // RemoveInactiveInterfaceVariables.h:
  //  Drop shader interface variable declarations for those that are inactive.
  //
  
  #include "compiler/translator/tree_ops/RemoveInactiveInterfaceVariables.h"
  
  #include "compiler/translator/SymbolTable.h"
  #include "compiler/translator/tree_util/IntermTraverse.h"
  #include "compiler/translator/util.h"
  
  namespace sh
  {
  
  namespace
  {
  
  // Traverser that removes all declarations that correspond to inactive variables.
  class RemoveInactiveInterfaceVariablesTraverser : public TIntermTraverser
  {
    public:
      RemoveInactiveInterfaceVariablesTraverser(
          TSymbolTable *symbolTable,
          const std::vector<sh::ShaderVariable> &attributes,
          const std::vector<sh::ShaderVariable> &inputVaryings,
          const std::vector<sh::ShaderVariable> &outputVariables,
          const std::vector<sh::ShaderVariable> &uniforms,
          const std::vector<sh::InterfaceBlock> &interfaceBlocks,
          bool removeFragmentOutputs);
  
      bool visitDeclaration(Visit visit, TIntermDeclaration *node) override;
      bool visitBinary(Visit visit, TIntermBinary *node) override;
  
    private:
      const std::vector<sh::ShaderVariable> &mAttributes;
      const std::vector<sh::ShaderVariable> &mInputVaryings;
      const std::vector<sh::ShaderVariable> &mOutputVariables;
      const std::vector<sh::ShaderVariable> &mUniforms;
      const std::vector<sh::InterfaceBlock> &mInterfaceBlocks;
      bool mRemoveFragmentOutputs;
  };
  
  RemoveInactiveInterfaceVariablesTraverser::RemoveInactiveInterfaceVariablesTraverser(
      TSymbolTable *symbolTable,
      const std::vector<sh::ShaderVariable> &attributes,
      const std::vector<sh::ShaderVariable> &inputVaryings,
      const std::vector<sh::ShaderVariable> &outputVariables,
      const std::vector<sh::ShaderVariable> &uniforms,
      const std::vector<sh::InterfaceBlock> &interfaceBlocks,
      bool removeFragmentOutputs)
      : TIntermTraverser(true, false, false, symbolTable),
        mAttributes(attributes),
        mInputVaryings(inputVaryings),
        mOutputVariables(outputVariables),
        mUniforms(uniforms),
        mInterfaceBlocks(interfaceBlocks),
        mRemoveFragmentOutputs(removeFragmentOutputs)
  {}
  
  template <typename Variable>
  bool IsVariableActive(const std::vector<Variable> &mVars, const ImmutableString &name)
  {
      for (const Variable &var : mVars)
      {
          if (name == var.name)
          {
              return var.active;
          }
      }
      UNREACHABLE();
      return true;
  }
  
  bool RemoveInactiveInterfaceVariablesTraverser::visitDeclaration(Visit visit,
                                                                   TIntermDeclaration *node)
  {
      // SeparateDeclarations should have already been run.
      ASSERT(node->getSequence()->size() == 1u);
  
      TIntermTyped *declarator = node->getSequence()->front()->getAsTyped();
      ASSERT(declarator);
  
      TIntermSymbol *asSymbol = declarator->getAsSymbolNode();
      if (!asSymbol)
      {
          return false;
      }
  
      const TType &type = declarator->getType();
  
      // Remove all shader interface variables except outputs, i.e. uniforms, interface blocks and
      // inputs.
      //
      // Imagine a situation where the VS doesn't write to a varying but the FS reads from it.  This
      // is allowed, though the value of the varying is undefined.  If the varying is removed here,
      // the situation is changed to VS not declaring the varying, but the FS reading from it, which
      // is not allowed.  That's why inactive shader outputs are not removed.
      //
      // Inactive fragment shader outputs can be removed though, as there is no next stage.
      bool removeDeclaration     = false;
      const TQualifier qualifier = type.getQualifier();
  
      if (type.isInterfaceBlock())
      {
          // When a member has an explicit location, interface block should not be removed.
          // If the member or interface would be removed, GetProgramResource could not return the
          // location.
          if (!IsShaderIoBlock(type.getQualifier()) && type.getQualifier() != EvqPatchIn &&
              type.getQualifier() != EvqPatchOut)
          {
              removeDeclaration =
                  !IsVariableActive(mInterfaceBlocks, type.getInterfaceBlock()->name());
          }
      }
      else if (qualifier == EvqUniform)
      {
          removeDeclaration = !IsVariableActive(mUniforms, asSymbol->getName());
      }
      else if (qualifier == EvqAttribute || qualifier == EvqVertexIn)
      {
          removeDeclaration = !IsVariableActive(mAttributes, asSymbol->getName());
      }
      else if (IsShaderIn(qualifier))
      {
          removeDeclaration = !IsVariableActive(mInputVaryings, asSymbol->getName());
      }
      else if (qualifier == EvqFragmentOut)
      {
          removeDeclaration =
              !IsVariableActive(mOutputVariables, asSymbol->getName()) && mRemoveFragmentOutputs;
      }
  
      if (removeDeclaration)
      {
          TIntermSequence replacement;
  
          // If the declaration was of a struct, keep the struct declaration itself.
          if (type.isStructSpecifier())
          {
              TType *structSpecifierType      = new TType(type.getStruct(), true);
              TVariable *emptyVariable        = new TVariable(mSymbolTable, kEmptyImmutableString,
                                                              structSpecifierType, SymbolType::Empty);
              TIntermDeclaration *declaration = new TIntermDeclaration();
              declaration->appendDeclarator(new TIntermSymbol(emptyVariable));
              replacement.push_back(declaration);
          }
  
          mMultiReplacements.emplace_back(getParentNode()->getAsBlock(), node,
                                          std::move(replacement));
      }
  
      return false;
  }
  
  bool RemoveInactiveInterfaceVariablesTraverser::visitBinary(Visit visit, TIntermBinary *node)
  {
      // Remove any code that initOutputVariables might have added corresponding to inactive
      // output variables.  This code is always in the form of `variable = ...;`.
      if (node->getOp() != EOpAssign)
      {
          // Don't recurse, won't find the initialization nested in another expression.
          return false;
      }
  
      // Get the symbol being initialized, and check if it's an inactive output.  If it is, this must
      // necessarily be initialization code that ANGLE has added (and wasn't there in the original
      // shader; if it was, the symbol wouldn't have been inactive).
      TIntermSymbol *symbol = node->getLeft()->getAsSymbolNode();
      if (symbol == nullptr)
      {
          return false;
      }
  
      const TQualifier qualifier = symbol->getType().getQualifier();
      if (qualifier != EvqFragmentOut || IsVariableActive(mOutputVariables, symbol->getName()))
      {
          return false;
      }
  
      // Drop the initialization code.
      TIntermSequence replacement;
      mMultiReplacements.emplace_back(getParentNode()->getAsBlock(), node, std::move(replacement));
      return false;
  }
  
  }  // namespace
  
  bool RemoveInactiveInterfaceVariables(TCompiler *compiler,
                                        TIntermBlock *root,
                                        TSymbolTable *symbolTable,
                                        const std::vector<sh::ShaderVariable> &attributes,
                                        const std::vector<sh::ShaderVariable> &inputVaryings,
                                        const std::vector<sh::ShaderVariable> &outputVariables,
                                        const std::vector<sh::ShaderVariable> &uniforms,
                                        const std::vector<sh::InterfaceBlock> &interfaceBlocks,
                                        bool removeFragmentOutputs)
  {
      RemoveInactiveInterfaceVariablesTraverser traverser(symbolTable, attributes, inputVaryings,
                                                          outputVariables, uniforms, interfaceBlocks,
                                                          removeFragmentOutputs);
      root->traverse(&traverser);
      return traverser.updateTree(compiler, root);
  }
  
  }  // namespace sh
  

Download