ExpressionGraph.cpp

#include "test/Modules.h"
#include "common/ExprGraph.h"

#include "spvgentwo/Templates.h"

using namespace spvgentwo;

namespace {

	enum class Op
	{
		Nop,
		Var,
		Const,
		Add,
		Sub,
		Mul,
		Div
	};

	struct MyExpr
	{
		const char* name = nullptr;
		BasicBlock& bb;
		Op op = Op::Nop;
		Instruction* result = nullptr;

		void operator()( const List<MyExpr*>& _inputs, [[maybe_unused]] const List<MyExpr*>& _outputs )
		{
			Instruction* lhs = _inputs.empty() ? nullptr : _inputs.front()->result;
			Instruction* rhs = _inputs.size() == 2u ? _inputs.back()->result : nullptr;

			switch( op )
			{
			case Op::Nop:
				bb->opNop();
				break;
			case Op::Var:
				break;
			case Op::Const:
				// nothing to do
				break;
			case Op::Add:
				result = bb->Add( lhs, rhs );
				break;
			case Op::Sub:
				result = bb->Sub( lhs, rhs );
				break;
			case Op::Mul:
				result = bb->Mul( lhs, rhs );
				break;
			case Op::Div:
				result = bb->Div( lhs, rhs );
				break;
			default:
				break;
			}
		};
	};
}

spvgentwo::Module test::expressionGraph(spvgentwo::IAllocator* _pAllocator, spvgentwo::ILogger* _pLogger)
{
	Module module(_pAllocator, _pLogger);
	module.addCapability(spv::Capability::Shader);
	Function& main = module.addEntryPoint<void>(spv::ExecutionModel::Vertex, u8"mainÜmlautß"); //test utf-8
	BasicBlock& bb = *main;

	ExprGraph<MyExpr> exprgraph(_pAllocator);

	auto* c1 = exprgraph.emplace(MyExpr{ "c1",bb, Op::Const, module.constant(1337) });
	auto* c2 = exprgraph.emplace(MyExpr{ "c1",bb, Op::Const, module.constant(42) });

	auto* add = exprgraph.emplace(MyExpr{ "add",bb, Op::Add });
	auto* sub = exprgraph.emplace(MyExpr{ "sub",bb, Op::Sub });
	auto* mul = exprgraph.emplace(MyExpr{ "mul",bb, Op::Mul });
	auto* div = exprgraph.emplace(MyExpr{ "div",bb, Op::Div });

	// c1 + c1 = add
	c1->connect(add);
	c2->connect(add);

	// c2 - add = sub
	c2->connect(sub);
	add->connect(sub);

	// sub * add = mul
	sub->connect(mul);
	add->connect(mul);

	// c1 / mul = div
	c1->connect(div);
	mul->connect(div);

	ExprGraph<MyExpr>::evaluateRecursive<ExprArgs::FunctionPtrLists>(div);

	bb.returnValue();

	return module;
}