1 files changed, 122 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_util/SpecializationConstant.cpp b/gfx/angle/checkout/src/compiler/translator/tree_util/SpecializationConstant.cpp
new file mode 100644
index 0000000000..6a7254802c
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_util/SpecializationConstant.cpp
@@ -0,0 +1,122 @@
+//
+// Copyright 2020 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.
+//
+// SpecializationConst.cpp: Add code to generate AST node for various specialization constants.
+//
+
+#include "compiler/translator/tree_util/SpecializationConstant.h"
+#include "common/PackedEnums.h"
+#include "common/angleutils.h"
+#include "compiler/translator/StaticType.h"
+#include "compiler/translator/SymbolTable.h"
+#include "compiler/translator/tree_util/IntermNode_util.h"
+
+namespace sh
+{
+
+namespace
+{
+// Specialization constant names
+constexpr ImmutableString kSurfaceRotationSpecConstVarName =
+    ImmutableString("ANGLESurfaceRotation");
+constexpr ImmutableString kDitherSpecConstVarName = ImmutableString("ANGLEDither");
+
+const TType *MakeSpecConst(const TType &type, vk::SpecializationConstantId id)
+{
+    // Create a new type with the EvqSpecConst qualifier
+    TType *specConstType = new TType(type);
+    specConstType->setQualifier(EvqSpecConst);
+
+    // Set the constant_id of the spec const
+    TLayoutQualifier layoutQualifier = TLayoutQualifier::Create();
+    layoutQualifier.location         = static_cast<int>(id);
+    specConstType->setLayoutQualifier(layoutQualifier);
+
+    return specConstType;
+}
+}  // anonymous namespace
+
+SpecConst::SpecConst(TSymbolTable *symbolTable,
+                     const ShCompileOptions &compileOptions,
+                     GLenum shaderType)
+    : mSymbolTable(symbolTable),
+      mCompileOptions(compileOptions),
+      mSurfaceRotationVar(nullptr),
+      mDitherVar(nullptr)
+{
+    if (shaderType == GL_FRAGMENT_SHADER || shaderType == GL_COMPUTE_SHADER)
+    {
+        return;
+    }
+
+    // Mark SpecConstUsage::Rotation unconditionally.  gl_Position is always rotated.
+    if (mCompileOptions.useSpecializationConstant)
+    {
+        mUsageBits.set(vk::SpecConstUsage::Rotation);
+    }
+}
+
+SpecConst::~SpecConst() {}
+
+void SpecConst::declareSpecConsts(TIntermBlock *root)
+{
+    // Add specialization constant declarations.  The default value of the specialization
+    // constant is irrelevant, as it will be set when creating the pipeline.
+    // Only emit specialized const declaration if it has been referenced.
+    if (mSurfaceRotationVar != nullptr)
+    {
+        TIntermDeclaration *decl = new TIntermDeclaration();
+        decl->appendDeclarator(
+            new TIntermBinary(EOpInitialize, getRotation(), CreateBoolNode(false)));
+
+        root->insertStatement(0, decl);
+    }
+
+    if (mDitherVar != nullptr)
+    {
+        TIntermDeclaration *decl = new TIntermDeclaration();
+        decl->appendDeclarator(new TIntermBinary(EOpInitialize, getDither(), CreateUIntNode(0)));
+
+        root->insertStatement(0, decl);
+    }
+}
+
+TIntermSymbol *SpecConst::getRotation()
+{
+    if (mSurfaceRotationVar == nullptr)
+    {
+        const TType *type = MakeSpecConst(*StaticType::GetBasic<EbtBool, EbpUndefined>(),
+                                          vk::SpecializationConstantId::SurfaceRotation);
+
+        mSurfaceRotationVar = new TVariable(mSymbolTable, kSurfaceRotationSpecConstVarName, type,
+                                            SymbolType::AngleInternal);
+    }
+    return new TIntermSymbol(mSurfaceRotationVar);
+}
+
+TIntermTyped *SpecConst::getSwapXY()
+{
+    if (!mCompileOptions.useSpecializationConstant)
+    {
+        return nullptr;
+    }
+    mUsageBits.set(vk::SpecConstUsage::Rotation);
+    return getRotation();
+}
+
+TIntermTyped *SpecConst::getDither()
+{
+    if (mDitherVar == nullptr)
+    {
+        const TType *type = MakeSpecConst(*StaticType::GetBasic<EbtUInt, EbpHigh>(),
+                                          vk::SpecializationConstantId::Dither);
+
+        mDitherVar =
+            new TVariable(mSymbolTable, kDitherSpecConstVarName, type, SymbolType::AngleInternal);
+        mUsageBits.set(vk::SpecConstUsage::Dither);
+    }
+    return new TIntermSymbol(mDitherVar);
+}
+}  // namespace sh