initial checkin of SkSL compiler

src/sksl/SkSLSPIRVCodeGenerator.h

Index: src/sksl/SkSLSPIRVCodeGenerator.h
diff --git a/src/sksl/SkSLSPIRVCodeGenerator.h b/src/sksl/SkSLSPIRVCodeGenerator.h
new file mode 100644
index 0000000000000000000000000000000000000000..23e5a340289af47800295cce2f98655e2400532b
--- /dev/null
+++ b/src/sksl/SkSLSPIRVCodeGenerator.h
@@ -0,0 +1,240 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+ 
+#ifndef SKSL_SPIRVCODEGENERATOR
+#define SKSL_SPIRVCODEGENERATOR
+
+#include <sstream>
+#include <stack>
+#include <tuple>
+#include <unordered_map>
+
+#include "SkSLCodeGenerator.h"
+#include "ir/SkSLBinaryExpression.h"
+#include "ir/SkSLBoolLiteral.h"
+#include "ir/SkSLConstructor.h"
+#include "ir/SkSLFloatLiteral.h"
+#include "ir/SkSLIfStatement.h"
+#include "ir/SkSLIndexExpression.h"
+#include "ir/SkSLInterfaceBlock.h"
+#include "ir/SkSLIntLiteral.h"
+#include "ir/SkSLFieldAccess.h"
+#include "ir/SkSLForStatement.h"
+#include "ir/SkSLFunctionCall.h"
+#include "ir/SkSLFunctionDeclaration.h"
+#include "ir/SkSLFunctionDefinition.h"
+#include "ir/SkSLPrefixExpression.h"
+#include "ir/SkSLPostfixExpression.h"
+#include "ir/SkSLProgramElement.h"
+#include "ir/SkSLReturnStatement.h"
+#include "ir/SkSLStatement.h"
+#include "ir/SkSLSwizzle.h"
+#include "ir/SkSLTernaryExpression.h"
+#include "ir/SkSLVarDeclaration.h"
+#include "ir/SkSLVarDeclarationStatement.h"
+#include "ir/SkSLVariableReference.h"
+#include "spirv.h"
+
+namespace SkSL {
+
+#define kLast_Capability SpvCapabilityMultiViewport
+
+/**
+ * Converts a Program into a SPIR-V binary.
+ */
+class SPIRVCodeGenerator : public CodeGenerator {
+public:
+    SPIRVCodeGenerator()
+    : fCapabilities(1 << SpvCapabilityShader)
+    , fIdCount(1)
+    , fBoolTrue(0)
+    , fBoolFalse(0)
+    , fCurrentBlock(0) {
+        this->setupIntrinsics();
+    }
+
+    void generateCode(Program& program, std::ostream& out) override;
+
+private:
+    enum IntrinsicKind {
+        kGLSL_STD_450_IntrinsicKind,
+        kSPIRV_IntrinsicKind,
+        kSpecial_IntrinsicKind
+    };
+
+    enum SpecialIntrinsic {
+        kAtan_SpecialIntrinsic,
+        kTexture_SpecialIntrinsic,
+        kTexture2D_SpecialIntrinsic,
+        kTextureProj_SpecialIntrinsic
+    };
+
+    void setupIntrinsics();
+
+    SpvId nextId();
+
+    SpvId getType(std::shared_ptr<Type> type);
+
+    SpvId getFunctionType(std::shared_ptr<FunctionDeclaration> function);
+
+    SpvId getPointerType(std::shared_ptr<Type> type, SpvStorageClass_ storageClass);
+
+    std::vector<SpvId> getAccessChain(Expression& expr, std::ostream& out);
+
+    void writeLayout(const Layout& layout, SpvId target);
+
+    void writeLayout(const Layout& layout, SpvId target, int member);
+
+    void writeStruct(std::shared_ptr<Type> type, SpvId resultId);
+
+    void writeProgramElement(ProgramElement& pe, std::ostream& out);
+
+    SpvId writeInterfaceBlock(InterfaceBlock& intf);
+
+    SpvId writeFunctionStart(std::shared_ptr<FunctionDeclaration> f, std::ostream& out);
+    
+    SpvId writeFunctionDeclaration(std::shared_ptr<FunctionDeclaration> f, std::ostream& out);
+
+    SpvId writeFunction(FunctionDefinition& f, std::ostream& out);
+
+    void writeGlobalVars(VarDeclaration& v, std::ostream& out);
+
+    void writeVarDeclaration(VarDeclaration& decl, std::ostream& out);
+
+    SpvId writeVariableReference(VariableReference& ref, std::ostream& out);
+
+    SpvId getLValue(Expression& value, std::ostream& out);
+
+    void storeToLValue(Expression& lvalue, SpvId value, std::ostream& out);
+
+    SpvId writeExpression(Expression& expr, std::ostream& out);
+    
+    SpvId writeIntrinsicCall(FunctionCall& c, std::ostream& out);
+
+    SpvId writeFunctionCall(FunctionCall& c, std::ostream& out);
+
+    SpvId writeSpecialIntrinsic(FunctionCall& c, SpecialIntrinsic kind, std::ostream& out);
+
+    SpvId writeConstructor(Constructor& c, std::ostream& out);
+
+    SpvId writeFieldAccess(FieldAccess& f, std::ostream& out);
+
+    SpvId writeSwizzle(Swizzle& swizzle, std::ostream& out);
+
+    SpvId writeBinaryOperation(std::shared_ptr<Type> resultType, std::shared_ptr<Type> operandType, 
+                               SpvId lhs, SpvId rhs, SpvOp_ ifFloat, SpvOp_ ifInt, SpvOp_ ifUInt, 
+                               SpvOp_ ifBool, std::ostream& out);
+
+    SpvId writeBinaryOperation(BinaryExpression& expr, SpvOp_ ifFloat, SpvOp_ ifInt, SpvOp_ ifUInt,
+                               std::ostream& out);
+
+    SpvId writeBinaryExpression(BinaryExpression& b, std::ostream& out);
+
+    SpvId writeTernaryExpression(TernaryExpression& t, std::ostream& out);
+
+    SpvId writeIndexExpression(IndexExpression& expr, std::ostream& out);
+
+    SpvId writeLogicalAnd(BinaryExpression& b, std::ostream& out);
+
+    SpvId writeLogicalOr(BinaryExpression& o, std::ostream& out);
+
+    SpvId writePrefixExpression(PrefixExpression& p, std::ostream& out);
+
+    SpvId writePostfixExpression(PostfixExpression& p, std::ostream& out);
+
+    SpvId writeBoolLiteral(BoolLiteral& b);
+
+    SpvId writeIntLiteral(IntLiteral& i);
+
+    SpvId writeFloatLiteral(FloatLiteral& f);
+
+    void writeStatement(Statement& s, std::ostream& out);
+
+    void writeBlock(Block& b, std::ostream& out);
+
+    void writeIfStatement(IfStatement& stmt, std::ostream& out);
+
+    void writeForStatement(ForStatement& f, std::ostream& out);
+
+    void writeReturnStatement(ReturnStatement& r, std::ostream& out);
+
+    void writeCapabilities(std::ostream& out);
+
+    void writeInstructions(Program& program, std::ostream& out);
+
+    void writeOpCode(SpvOp_ opCode, int length, std::ostream& out);
+
+    void writeWord(int32_t word, std::ostream& out);
+
+    void writeString(const char* string, std::ostream& out);
+
+    void writeLabel(SpvId id, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, const char* string, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, const char* string, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, const char* string,
+                          std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, 
+                          std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, int32_t word4,
+                          std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, int32_t word4,
+                          int32_t word5, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, int32_t word4,
+                          int32_t word5, int32_t word6, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, int32_t word4,
+                          int32_t word5, int32_t word6, int32_t word7, std::ostream& out);
+
+    void writeInstruction(SpvOp_ opCode, int32_t word1, int32_t word2, int32_t word3, int32_t word4,
+                          int32_t word5, int32_t word6, int32_t word7, int32_t word8, 
+                          std::ostream& out);
+
+    uint64_t fCapabilities;
+    SpvId fIdCount;
+    SpvId fGLSLExtendedInstructions;
+    typedef std::tuple<IntrinsicKind, int32_t, int32_t, int32_t, int32_t> Intrinsic;

[dogben, 2016/06/24 17:05:29]

nit: define a struct?

+    std::unordered_map<std::string, Intrinsic> fIntrinsicMap;
+    std::unordered_map<std::shared_ptr<FunctionDeclaration>, SpvId> fFunctionMap;

[dogben, 2016/06/24 17:05:29]

nit: Seems like fFunctionMap, fVariableMap, and fInterfaceBlockMap should use
raw pointer rather than shared_ptr.

+    std::unordered_map<std::shared_ptr<Variable>, SpvId> fVariableMap;
+    std::unordered_map<std::shared_ptr<Variable>, int32_t> fInterfaceBlockMap;
+    std::unordered_map<std::string, SpvId> fTypeMap;

[dogben, 2016/06/24 17:05:29]

nit: Seems like it would be better to have fTypeMap keyed by Type*,
fFunctionTypeMap keyed by FuctionDeclaration*, and fPointerTypeMap keyed by
pair<Type*,SpvStorageClass_>. Hashing pointers is much faster than hashing
strings.

+    std::stringstream fCapabilitiesBuffer;
+    std::stringstream fGlobalInitializersBuffer;
+    std::stringstream fConstantBuffer;
+    std::stringstream fExternalFunctionsBuffer;
+    std::stringstream fVariableBuffer;
+    std::stringstream fNameBuffer;
+    std::stringstream fDecorationBuffer;
+
+    SpvId fBoolTrue;
+    SpvId fBoolFalse;
+    std::unordered_map<int64_t, SpvId> fIntConstants;
+    std::unordered_map<uint64_t, SpvId> fUIntConstants;
+    std::unordered_map<float, SpvId> fFloatConstants;
+    std::unordered_map<double, SpvId> fDoubleConstants;
+    // label of the current block, or 0 if we are not in a block
+    SpvId fCurrentBlock;
+    std::stack<SpvId> fBreakTarget;
+    std::stack<SpvId> fContinueTarget;
+};
+
+}
+
+#endif