wnt_TupleLiteral.cpp

/*=====================================================================
wnt_TupleLiteral.cpp
--------------------
Copyright Glare Technologies Limited 2015 -
=====================================================================*/
#include "wnt_TupleLiteral.h"


#include "wnt_ASTNode.h"
#include "wnt_SourceBuffer.h"
#include "wnt_RefCounting.h"
#include "wnt_Variable.h"
#include "VMState.h"
#include "Value.h"
#include "Linker.h"
#include "BuiltInFunctionImpl.h"
#include "LLVMUtils.h"
#include "LLVMTypeUtils.h"
#include "ProofUtils.h"
#include "utils/StringUtils.h"
#include "maths/mathstypes.h"
#ifdef _MSC_VER // If compiling with Visual C++
#pragma warning(push, 0) // Disable warnings
#endif
#include "llvm/IR/Type.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/ExecutionEngine/Interpreter.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/Support/raw_ostream.h"
#include <llvm/IR/CallingConv.h>
#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/Intrinsics.h>
#ifdef _MSC_VER
#pragma warning(pop) // Re-enable warnings
#endif


using std::vector;
using std::string;


namespace Winter
{


TupleLiteral::TupleLiteral(const std::vector<ASTNodeRef>& elems, const SrcLocation& loc)
:	ASTNode(TupleLiteralType, loc),
	elements(elems)
{
	if(elems.empty())
		throw ExceptionWithPosition("Tuple literal can't be empty.", errorContext(*this));
}


TypeRef TupleLiteral::type() const
{
	vector<TypeVRef> component_types;
	component_types.reserve(elements.size());
	for(size_t i=0; i<elements.size(); ++i)
	{
		TypeRef t = elements[i]->type();
		if(t.isNull())
			return NULL;
		component_types.push_back(TypeVRef(t));
	}

	return new TupleType(component_types);
}


ValueRef TupleLiteral::exec(VMState& vmstate)
{
	vector<ValueRef> elem_values(elements.size());

	for(unsigned int i=0; i<this->elements.size(); ++i)
		elem_values[i] = this->elements[i]->exec(vmstate);

	return new TupleValue(elem_values);
}


void TupleLiteral::print(int depth, std::ostream& s) const
{
	printMargin(depth, s);
	s << "Tuple literal\n";

	for(unsigned int i=0; i<this->elements.size(); ++i)
	{
		this->elements[i]->print(depth + 1, s);
	}
}


std::string TupleLiteral::sourceString(int depth) const
{
	std::string s = "[";
	for(size_t i=0; i<elements.size(); ++i)
	{
		s += elements[i]->sourceString(depth);
		if(i + 1 < elements.size())
			s += ", ";
	}
	s += "]t";
	return s;
}


std::string TupleLiteral::emitOpenCLC(EmitOpenCLCodeParams& params) const
{
	const Reference<TupleType> t = this->type().downcast<TupleType>();

	params.tuple_types_used.insert(t);

	if(false)
	{
		// NOTE: Unforunately this code (using compound literals) crashes the AMD OpenCL C compiler, see
		// https://community.amd.com/message/2867567
		// So we can't use this approach for now.

		/*
		[1.0, 2.0, 3.0]t

		will be emitted as something like, using compound literals:

		(tuple_float_float_float) { 1.0, 2.0, 3.0 }

		*/
		std::string statements;
		std::string s = "(" + t->OpenCLCType(params) + "){";
		for(size_t i=0; i<elements.size(); ++i)
		{
			params.blocks.push_back("");
			const std::string elem_expression = this->elements[i]->emitOpenCLC(params);
			StringUtils::appendTabbed(statements, params.blocks.back(), 1);
			params.blocks.pop_back();

			s += elem_expression;
			if(i + 1 < elements.size())
				s += ", ";
		}
		s += "}";

		params.blocks.back() += statements;
		return s;
	}
	else
	{
		const std::string struct_var_name = "tuple_" + toString(params.uid++);
	
		std::string s = t->OpenCLCType(params) + " " + struct_var_name + ";\n";

		for(size_t i=0; i<elements.size(); ++i)
		{
			// Emit code for let variable
			params.blocks.push_back("");
			const std::string elem_expression = this->elements[i]->emitOpenCLC(params);
			StringUtils::appendTabbed(s, params.blocks.back(), 1);
			params.blocks.pop_back();

			const bool need_deref = (this->elements[i]->nodeType() == ASTNode::VariableASTNodeType) && 
				(this->elements[i].downcastToPtr<Variable>()->binding_type == Variable::BindingType_Argument) && this->elements[i]->type()->OpenCLPassByPointer();

			s += struct_var_name + ".field_" + toString(i) + " = " + (need_deref ? "*" : "") + elem_expression + ";\n";
		}
		params.blocks.back() += s;

		return struct_var_name;
	}
}


void TupleLiteral::traverse(TraversalPayload& payload, std::vector<ASTNode*>& stack)
{
	/*if(payload.operation == TraversalPayload::ConstantFolding)
	{
		for(size_t i=0; i<elements.size(); ++i)
			checkFoldExpression(elements[i], payload);
	}
	else */

	stack.push_back(this);
	for(unsigned int i=0; i<this->elements.size(); ++i)
	{
		this->elements[i]->traverse(payload, stack);
	}
	stack.pop_back();


	if(payload.operation == TraversalPayload::TypeCheck)
	{
		// Nothing in particular to do here
	}
	else if(payload.operation == TraversalPayload::ComputeCanConstantFold)
	{
		/*this->can_constant_fold = true;
		for(unsigned int i=0; i<elements.size(); ++i)
			if(!elements[i]->can_constant_fold)
			{
				this->can_constant_fold = false;
				break;
			}
		this->can_constant_fold = this->can_constant_fold && expressionIsWellTyped(*this, payload);*/
		this->can_maybe_constant_fold = true;
		for(size_t i=0; i<elements.size(); ++i)
		{
			const bool elem_is_literal = checkFoldExpression(elements[i], payload, stack);
			this->can_maybe_constant_fold = this->can_maybe_constant_fold && elem_is_literal;
		}
	}
}


void TupleLiteral::updateChild(const ASTNode* old_val, ASTNodeRef& new_val)
{
	for(size_t i=0; i<this->elements.size(); ++i)
		if(this->elements[i].ptr() == old_val)
		{
			this->elements[i] = new_val;
			return;
		}
	assert(0);
}


bool TupleLiteral::areAllElementsConstant() const
{
	for(size_t i=0; i<this->elements.size(); ++i)
		if(!this->elements[i]->isConstant())
			return false;
	return true;
}


llvm::Value* TupleLiteral::emitLLVMCode(EmitLLVMCodeParams& params, llvm::Value* ret_space_ptr) const
{
	TypeRef t_ = type();
	const TupleType* tuple_type = static_cast<const TupleType*>(t_.getPointer());


	llvm::Value* result_struct_val;
	if(ret_space_ptr)
		result_struct_val = ret_space_ptr;
	else
	{
		// Allocate space on stack for result structure/tuple
		
		// Emit the alloca in the entry block for better code-gen.
		// We will emit the alloca at the start of the block, so that it doesn't go after any terminator instructions already created which have to be at the end of the block.
		llvm::IRBuilder<> entry_block_builder(&params.currently_building_func->getEntryBlock(), params.currently_building_func->getEntryBlock().getFirstInsertionPt());

		result_struct_val = entry_block_builder.CreateAlloca(
			tuple_type->LLVMType(*params.module), // This type (tuple type)
			llvm::ConstantInt::get(*params.context, llvm::APInt(32, 1, true)), // num elems
			"Tuple literal space"
		);
	}

	// For each field in the structure
	for(unsigned int i=0; i<tuple_type->component_types.size(); ++i)
	{
		// Get the pointer to the structure field.
		llvm::Value* field_ptr = LLVMUtils::createStructGEP(params.builder, result_struct_val, i, tuple_type->LLVMType(*params.module));

		llvm::Value* arg_value_or_ptr = this->elements[i]->emitLLVMCode(params);

		if(tuple_type->component_types[i]->passByValue())
		{
			params.builder->CreateStore(
				arg_value_or_ptr, // value
				field_ptr // ptr
			);
		}
		else
		{
			LLVMUtils::createCollectionCopy(
				tuple_type->component_types[i], 
				field_ptr, // dest ptr
				arg_value_or_ptr, // src ptr
				params
			);
		}


		// If the field is a ref-counted type, we need to increment its reference count, since the newly constructed tuple now holds a reference to it.
		//tuple_type->component_types[i]->emitIncrRefCount(params, arg_value_or_ptr, "TupleLiteral::emitLLVMCode() for type " + tuple_type->toString());

		// If the field is of string type, we need to increment its reference count
		//if(tuple_type->component_types[i]->getType() == Type::StringType)
		//	RefCounting::emitIncrementStringRefCount(params, arg_value_or_ptr);
	}

	return result_struct_val;
}


Reference<ASTNode> TupleLiteral::clone(CloneMapType& clone_map)
{
	std::vector<ASTNodeRef> elems(this->elements.size());
	for(size_t i=0; i<elements.size(); ++i)
		elems[i] = this->elements[i]->clone(clone_map);

	TupleLiteral* res = new TupleLiteral(elems, srcLocation());
	clone_map.insert(std::make_pair(this, res));
	return res;
}


bool TupleLiteral::isConstant() const
{
	for(size_t i=0; i<elements.size(); ++i)
		if(!elements[i]->isConstant())
			return false;
	return true;
}


size_t TupleLiteral::getTimeBound(GetTimeBoundParams& params) const
{
	size_t sum = 0;
	for(size_t i=0; i<elements.size(); ++i)
		sum += elements[i]->getTimeBound(params);
	return sum;
}


GetSpaceBoundResults TupleLiteral::getSpaceBound(GetSpaceBoundParams& params) const
{
	// Compute space to compute the element values:
	GetSpaceBoundResults sum(0, 0);
	for(size_t i=0; i<elements.size(); ++i)
		sum += elements[i]->getSpaceBound(params);

	return sum;
}


size_t TupleLiteral::getSubtreeCodeComplexity() const
{
	size_t sum = 0;
	for(size_t i=0; i<elements.size(); ++i)
		sum += elements[i]->getSubtreeCodeComplexity();
	return 1 + sum;
}


} // end namespace Winter