Aarch64 JIT compiler wip: partial struct support

examples/jit_test.psl

@@ -15,8 +15,6 @@ foreign func putchar(c: i32) -> i32
 func print(c: u8):
 	putchar(c as i32)
 
-let x = 0
-
 func test1():
 	print('H')
 	print('e')
@@ -44,20 +42,28 @@ func test() -> i32:
 	else:
 		return b()
 
-struct interval:
+struct vec2:
-	min: f32
+	x : f32
-	max: f32
+	y : f32
 
-struct box2f:
+struct vecX:
-	x: interval
+	a: f32
-	y: interval
+	b: f32
+	c: f64
 
-struct weird:
+func test2():
-	a: i32
+	//let v = vec2(1.0, 2.0)
-	b: u8
+	vec2(1.0, 2.0)
-	c: f32 -> f32
+
-	d: f64
+//test2()
-	e: f16
+
+mut v = vecX(6.0, 9.0, 4.0l)
+v = vecX(1.0, 2.0, 5.0l)
+v.a = 1.0
+//v.b = 2.0
+v.c = 5.0l
+print('0' + (v.b as u8))
+print('\n')
 
 //func test1():
 //	let str = ['H', 'e', 'l', 'l', 'o', ',', ' ', 'w', 'o', 'r', 'l', 'd', '!', '\n']

libs/ast/source/type_check.cpp

@@ -63,12 +63,12 @@ namespace pslang::ast
 
 			size_and_alignment apply(types::unit_type const &)
 			{
-				return {.size = 1, .alignment = 1};
+				return {.size = 0, .alignment = 1};
 			}
 
 			size_and_alignment apply(types::primitive_type const & type)
 			{
-				auto size = types::builtin_type_size(type);
+				auto size = types::type_size(type);
 				return {.size = size, .alignment = size};
 			}
 
@@ -561,7 +561,7 @@ namespace pslang::ast
 						os << "Cannot create built-in type ";
 						types::print(os, *type);
 						os << ": expected 0 arguments, but got " << node.arguments.size();
-						throw std::runtime_error(os.str());
+						throw type_error(os.str(), node.location);
 					}
 					else if (auto named_type = std::get_if<types::named_type>(type.get()))
 					{
@@ -702,6 +702,17 @@ namespace pslang::ast
 			{
 				apply(node.lhs);
 				apply(node.rhs);
+
+				if (auto lvalue = classify_lvalue(node.lhs))
+				{
+					if (*lvalue != ast::value_category::_mutable)
+						throw type_error("Cannot assign to a non-mutable object", node.location);
+				}
+				else
+				{
+					throw type_error("Cannot assign to a non-lvalue", node.location);
+				}
+
 				auto ltype = get_type(*node.lhs);
 				auto rtype = get_type(*node.rhs);
 				// TODO: check lvalue
@@ -863,6 +874,30 @@ namespace pslang::ast
 				for (auto & struct_data : scopes.back().structs)
 					compute_layout(struct_data.second, scopes);
 			}
+
+		private:
+			std::optional<ast::value_category> classify_lvalue(expression_ptr const & node)
+			{
+				if (auto identifier = std::get_if<ast::identifier>(node.get()))
+				{
+					auto const & scope = scopes[identifier->level];
+					if (scope.functions.contains(identifier->name))
+						return ast::value_category::constant;
+					if (auto it = scope.variables.find(identifier->name); it != scope.variables.end())
+						return it->second.category;
+					return std::nullopt;
+				}
+				else if (auto field_access = std::get_if<ast::field_access>(node.get()))
+				{
+					return classify_lvalue(field_access->object);
+				}
+				else if (auto array_access = std::get_if<ast::array_access>(node.get()))
+				{
+					return classify_lvalue(array_access->array);
+				}
+
+				return std::nullopt;
+			}
 		};
 
 	}

libs/jit/include/pslang/jit/arch/aarch64/instruction_builder.hpp

@@ -20,7 +20,7 @@ namespace pslang::jit::aarch64
 		// @shift must be 0, 1, 2 or 3
 		void movk(std::uint8_t reg, std::uint16_t val, std::uint8_t shift = 0);
 
-		// Load the value of the register @reg_src at the address specified by the value of
+		// Store the value of the register @reg_src at the address specified by the value of
 		// register @reg_addr plus an unsigned 12-bit offset multiplied by 8.
 		void str(std::uint8_t reg_src, std::uint8_t reg_addr, std::uint16_t offset);
 
@@ -28,6 +28,22 @@ namespace pslang::jit::aarch64
 		// plus a signed 9-bit offset. Store the new address value in @reg_addr
 		void str_pre(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset);
 
+		// Store the value of the register @reg_src at the address specified by the value of
+		// register @reg_addr plus an signed 9-bit offset.
+		void stur(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Store the lowest 32 bits of the value of the register @reg_src at the address specified by the value of
+		// register @reg_addr plus an signed 9-bit offset.
+		void sturw(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Store the lowest 16 bits of the value of the register @reg_src at the address specified by the value of
+		// register @reg_addr plus an signed 9-bit offset.
+		void sturh(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Store the lowest 9 bits of the value of the register @reg_src at the address specified by the value of
+		// register @reg_addr plus an signed 9-bit offset.
+		void sturb(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset);
+
 		// Load the value at address specified by the value of register @reg_addr
 		// plus an unsigned 12-bit offset multiplied by 8 and store it in the register @reg_dst.
 		void ldr(std::uint8_t reg_dst, std::uint8_t reg_addr, std::uint16_t offset);
@@ -42,6 +58,22 @@ namespace pslang::jit::aarch64
 		// Store the address plus a signed 9-bit offset in @reg_addr
 		void ldr_post(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset);
 
+		// Load the value at address specified by the value of register @reg_addr
+		// plus an signed 9-bit offset and store it in the register @reg_dst.
+		void ldur(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Load the lowest 32 bits of the value at address specified by the value of register @reg_addr
+		// plus an signed 9-bit offset and store it in the register @reg_dst.
+		void ldurw(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Load the lowest 16 bits of the value at address specified by the value of register @reg_addr
+		// plus an signed 9-bit offset and store it in the register @reg_dst.
+		void ldurh(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset);
+
+		// Load the lowest 8 bits of the value at address specified by the value of register @reg_addr
+		// plus an signed 9-bit offset and store it in the register @reg_dst.
+		void ldurb(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset);
+
 		// Load the value at address specified by the value of the program counter (PC)
 		// plus a signed 19-bit @offset multiplied by 4, and store it into register @reg_dst
 		void ldr_pc(std::uint8_t reg_dst, std::int32_t offset);
@@ -135,15 +167,25 @@ namespace pslang::jit::aarch64
 		void ldr_fp_pc(std::uint8_t reg_dst, std::uint8_t mode, std::int32_t offset);
 
 		// Load a floating-point value from the address stored in @reg_addr plus a
-		// 12-bit unsigned @offset multiplied by 4, and store it in floating-point
+		// 12-bit unsigned @offset multiplied by sizeof the type (2, 4 or 8), and store it in floating-point
 		// register @reg_dst. @mode should be 1 for 16-bit values, 2 for 32-bit, 3 for 64-bit
 		void ldr_fp(std::uint8_t reg_dst, std::uint8_t mode, std::uint8_t reg_addr, std::uint16_t offset);
 
+		// Load a floating-point value from the address stored in @reg_addr plus a
+		// 9-bit signed @offset, and store it in floating-point
+		// register @reg_dst. @mode should be 1 for 16-bit values, 2 for 32-bit, 3 for 64-bit
+		void ldur_fp(std::uint8_t reg_dst, std::uint8_t mode, std::uint8_t reg_addr, std::uint16_t offset);
+
 		// Store a floating-point value from @reg_src into the address stored in 
-		// @reg_addr plus a 12-bit unsigned @offset multiplied by 4.
+		// @reg_addr plus a 12-bit unsigned @offset multiplied by sizeof the type (2, 4 or 8).
 		// @mode should be 1 for 16-bit values, 2 for 32-bit, 3 for 64-bit
 		void str_fp(std::uint8_t reg_src, std::uint8_t mode, std::uint8_t reg_addr, std::uint16_t offset);
 
+		// Store a floating-point value from @reg_src into the address stored in 
+		// @reg_addr plus a 9-bit signed @offset.
+		// @mode should be 1 for 16-bit values, 2 for 32-bit, 3 for 64-bit
+		void stur_fp(std::uint8_t reg_src, std::uint8_t mode, std::uint8_t reg_addr, std::int16_t offset);
+
 		// Convert a floating-point value from @reg_src stored in format @mode_src
 		// into a floating-point value in @reg_dst in format @mode_dst
 		// Modes are the same as for ldr_fp/str_fp
@@ -161,7 +203,6 @@ namespace pslang::jit::aarch64
 
 		// If @op is 0, move the value of a floating-point register @reg_src in format @mode into a general register @reg_dst
 		// If @op is 1, move the value of a general register @reg_src into a floating-point register @reg_dst in format @mode
-		// NB: mode = 2 (single precision) isn't supported
 		void fmov(std::uint8_t reg_src, std::uint8_t reg_dst, std::uint8_t mode, std::uint8_t op);
 
 		// Convert signed integer in floating-point register @reg_src into floating-point format @mode and

libs/jit/source/arch/aarch64/compiler.cpp

@@ -18,6 +18,14 @@ namespace pslang::jit::aarch64
 	namespace
 	{
 
+		// Homogeneous floating-point aggregate: up to 4 floating-point members
+		// of the same type (after struct flattening)
+		struct hfa_data
+		{
+			types::type_ptr type;
+			std::size_t count;
+		};
+
 		struct local_context
 		{
 			std::unordered_map<float, std::int32_t> f16_constants;
@@ -28,10 +36,18 @@ namespace pslang::jit::aarch64
 
 			std::unordered_map<ast::function_definition const *, std::int32_t> functions;
 
+			struct struct_data
+			{
+				std::optional<hfa_data> hfa = {};
+			};
+
+			std::unordered_map<ast::struct_definition const *, struct_data> structs;
+
 			struct scope
 			{
 				std::unordered_set<std::string> foreign_functions;
 				std::unordered_map<std::string, ast::function_definition const *> functions;
+				std::unordered_map<std::string, ast::struct_definition const *> structs;
 			};
 
 			std::vector<scope> scopes;
@@ -54,6 +70,9 @@ namespace pslang::jit::aarch64
 
 					if (it->functions.contains(name))
 						return false;
+
+					if (it->structs.contains(name))
+						return false;
 				}
 				return false;
 			}
@@ -62,11 +81,30 @@ namespace pslang::jit::aarch64
 			{
 				for (auto it = scopes.rbegin(); it != scopes.rend(); ++it)
 				{
+					if (auto jt = it->functions.find(name); jt != it->functions.end())
+						return jt->second;
+
 					if (it->foreign_functions.contains(name))
 						return nullptr;
 
-					if (auto jt = it->functions.find(name); jt != it->functions.end())
+					if (it->structs.contains(name))
+						return nullptr;
+				}
+				return nullptr;
+			}
+
+			ast::struct_definition const * is_struct(std::string const & name)
+			{
+				for (auto it = scopes.rbegin(); it != scopes.rend(); ++it)
+				{
+					if (auto jt = it->structs.find(name); jt != it->structs.end())
 						return jt->second;
+
+					if (it->foreign_functions.contains(name))
+						return nullptr;
+
+					if (it->functions.contains(name))
+						return nullptr;
 				}
 				return nullptr;
 			}
@@ -158,6 +196,7 @@ namespace pslang::jit::aarch64
 
 			void apply(ast::function_call const & node)
 			{
+				if (node.function)
 					apply(*node.function);
 				for (auto const & argument : node.arguments)
 					apply(*argument);
@@ -258,6 +297,56 @@ namespace pslang::jit::aarch64
 			}
 		};
 
+		std::optional<hfa_data> get_hfa_data(ast::struct_definition const & node, local_context & lcontext)
+		{
+			if (auto it = lcontext.structs.find(&node); it != lcontext.structs.end())
+				return it->second.hfa;
+
+			types::type_ptr type = nullptr;
+			std::size_t count = 0;
+
+			for (auto const & field : node.fields)
+			{
+				if (types::is_builtin_type(*field.inferred_type))
+				{
+					if (!types::is_floating_point_type(*field.inferred_type))
+						return std::nullopt;
+
+					if (type && !types::equal(*type, *field.inferred_type))
+						return std::nullopt;
+
+					type = field.inferred_type;
+					++count;
+				}
+				else if (auto named_type = std::get_if<types::named_type>(field.inferred_type.get()))
+				{
+					// NB: recursion must be impossible due to prior checks in type checker
+					if (auto struct_node = lcontext.is_struct(named_type->name))
+					{
+						if (auto subdata = get_hfa_data(*struct_node, lcontext))
+						{
+							if (type && !types::equal(*type, *subdata->type))
+								return std::nullopt;
+
+							type = subdata->type;
+							count += subdata->count;
+						}
+						else
+							return std::nullopt;
+					}
+					else
+						throw std::runtime_error("Unknown named type: \"" + named_type->name + "\"");
+				}
+				else
+					return std::nullopt;
+			}
+
+			if (count <= 4)
+				return hfa_data{type, count};
+
+			return std::nullopt;
+		}
+
 		// Iterate over a single scope (i.e. not visiting subscopes recursively)
 		// and add all defined functions & foreign functions to the current scope
 		struct populate_symbols_visitor
@@ -297,7 +386,16 @@ namespace pslang::jit::aarch64
 
 			void apply(ast::field_definition const &) {}
 
-			void apply(ast::struct_definition const &) {}
+			void apply(ast::struct_definition const & node)
+			{
+				lcontext.scopes.back().structs[node.name] = &node;
+				if (!lcontext.structs.contains(&node))
+				{
+					// NB: make sure not to add struct to lcontext.structs before computing hfa data
+					auto hfa = get_hfa_data(node, lcontext);
+					lcontext.structs[&node].hfa = hfa;
+				}
+			}
 		};
 
 		struct reg_extend_visitor
@@ -363,9 +461,9 @@ namespace pslang::jit::aarch64
 
 			struct variable_data
 			{
-				// Difference between initial stack pointer at scope enter
+				// Difference between initial stack pointer at function enter
 				// and the variable address
-				// Must be a multiple of 8
+				// Must be a multiple of 16
 				std::uint32_t frame_offset;
 			};
 
@@ -450,8 +548,30 @@ namespace pslang::jit::aarch64
 				{
 					if (auto jt = it->variables.find(node.name); jt != it->variables.end())
 					{
-						if (types::is_floating_point_type(*node.inferred_type))
+						if (auto named_type = std::get_if<types::named_type>(node.inferred_type.get()))
-							builder.ldr_fp(0, fp_mode_for(*node.inferred_type), 31, (stack_offset - jt->second.frame_offset) / builtin_type_size(*node.inferred_type));
+						{
+							if (auto struct_node = lcontext.is_struct(named_type->name))
+							{
+								std::size_t stack_size = ((struct_node->layout.size + 15) / 16) * 16;
+								builder.sub_imm(31, 31, stack_size);
+								stack_offset += stack_size;
+								scopes.back().stack_offset += stack_size;
+								std::size_t variable_offset = stack_offset - jt->second.frame_offset;
+								for (std::size_t offset = 0; offset < stack_size; offset += 16)
+								{
+									builder.ldr(0, 31, (variable_offset + offset) / 8);
+									builder.ldr(1, 31, (variable_offset + offset) / 8 + 1);
+									builder.str(0, 31, offset / 8);
+									builder.str(1, 31, offset / 8 + 1);
+								}
+							}
+							else
+								throw std::runtime_error("Unknown type \"" + named_type->name + "\"");
+						}
+						else if (types::is_unit_type(*node.inferred_type))
+						{}
+						else if (types::is_floating_point_type(*node.inferred_type))
+							builder.ldr_fp(0, fp_mode_for(*node.inferred_type), 31, (stack_offset - jt->second.frame_offset) / type_size(*node.inferred_type));
 						else
 							builder.ldr(0, 31, (stack_offset - jt->second.frame_offset) / 8);
 						return;
@@ -766,6 +886,8 @@ namespace pslang::jit::aarch64
 			}
 
 			void apply(ast::function_call const & node)
+			{
+				if (node.function)
 				{
 					apply(*node.function);
 					push(0);
@@ -807,31 +929,186 @@ namespace pslang::jit::aarch64
 					builder.b_reg(reg);
 					pop(30);
 				}
+				else // if (node.type)
+				{
+					if (types::is_unit_type(*node.inferred_type))
+					{
+						// Do nothing
+					}
+					else if (types::is_bool_type(*node.inferred_type) || types::is_integer_type(*node.inferred_type) || types::is_function_type(*node.inferred_type))
+					{
+						builder.xor_reg(0, 0, 0);
+					}
+					else if (types::is_floating_point_type(*node.inferred_type))
+					{
+						builder.xor_reg(0, 0, 0);
+						builder.fmov(0, 0, fp_mode_for(*node.inferred_type), 1);
+					}
+					else if (auto named_type = std::get_if<types::named_type>(node.inferred_type.get()))
+					{
+						if (auto struct_node = lcontext.is_struct(named_type->name))
+						{
+							// Allocate stack space for the struct
+							std::size_t stack_size = ((struct_node->layout.size + 15) / 16) * 16;
+							auto offset = stack_offset;
+							stack_offset += stack_size;
+							scopes.back().stack_offset += stack_size;
+							builder.sub_imm(31, 31, stack_size);
+
+							// Evaluate each field of the struct (i.e. each constructor argument)
+							// and copy it to the corresponding place in the struct
+							for (std::size_t i = 0; i < node.arguments.size(); ++i)
+							{
+								auto type = ast::get_type(*node.arguments[i]);
+								apply(*node.arguments[i]);
+
+								if (std::get_if<types::named_type>(type.get()))
+								{
+									// TODO: struct field
+									throw std::runtime_error("Not implemented");
+								}
+								else if (types::is_floating_point_type(*type))
+								{
+									builder.stur_fp(0, fp_mode_for(*type), 31, struct_node->fields[i].layout.offset);
+								}
+								else
+								{
+									auto size = types::type_size(*type);
+
+									if (size == 1)
+										builder.sturb(0, 31, struct_node->fields[i].layout.offset);
+									else if (size == 2)
+										builder.sturh(0, 31, struct_node->fields[i].layout.offset);
+									else if (size == 4)
+										builder.sturw(0, 31, struct_node->fields[i].layout.offset);
+									else if (size == 8)
+										builder.stur(0, 31, struct_node->fields[i].layout.offset);
+								}
+							}
+						}
+						else
+							throw std::runtime_error("Unknown type \"" + named_type->name + "\"");
+					}
+				}
+			}
+
+			void apply(ast::field_access const & node)
+			{
+				auto struct_type = get_type(*node.object);
+				if (auto named_type = std::get_if<types::named_type>(struct_type.get()))
+				{
+					if (auto struct_node = lcontext.is_struct(named_type->name))
+					{
+						std::size_t field_id = -1;
+						for (std::size_t i = 0; i < struct_node->fields.size(); ++i)
+						{
+							if (struct_node->fields[i].name == node.field_name)
+							{
+								field_id = i;
+								break;
+							}
+						}
+
+						if (field_id == -1)
+							throw std::runtime_error("Unknown field \"" + node.field_name + "\" in struct \"" + named_type->name + "\"");
+
+						apply(*node.object);
+
+						auto stack_size = ((struct_node->layout.size + 15) / 16) * 16;
+
+						auto const & field = struct_node->fields[field_id];
+						if (types::is_unit_type(*field.inferred_type))
+						{}
+						else if (types::is_floating_point_type(*field.inferred_type))
+						{
+							builder.ldur_fp(0, fp_mode_for(*field.inferred_type), 31, field.layout.offset);
+
+							builder.add_imm(31, 31, stack_size);
+							stack_offset -= stack_size;
+							scopes.back().stack_offset -= stack_size;
+						}
+						else if (types::is_bool_type(*field.inferred_type) || types::is_integer_type(*field.inferred_type) || types::is_function_type(*field.inferred_type))
+						{
+							auto size = types::type_size(*field.inferred_type);
+							if (size == 1)
+								builder.ldurb(0, 31, field.layout.offset);
+							else if (size == 2)
+								builder.ldurh(0, 31, field.layout.offset);
+							else if (size == 4)
+								builder.ldurw(0, 31, field.layout.offset);
+							else if (size == 8)
+								builder.ldur(0, 31, field.layout.offset);
+
+							builder.add_imm(31, 31, stack_size);
+							stack_offset -= stack_size;
+							scopes.back().stack_offset -= stack_size;
+						}
+						else if (auto named_type = std::get_if<types::named_type>(field.inferred_type.get()))
+						{
+							if (auto field_struct_node = lcontext.is_struct(named_type->name))
+							{
+								// TODO: copy the struct-typed field on stack, overriding
+								// the struct itself, and update the stack offset
+								throw std::runtime_error("Not implemented");
+							}
+							else
+								throw std::runtime_error("Unknown type \"" + named_type->name + "\"");
+						}
+
+						return;
+					}
+				}
+
+				throw std::runtime_error("Unknown object in field access");
+			}
 
 			void apply(ast::expression_ptr const & node)
 			{
+				auto stack_offset_before = stack_offset;
 				apply(*node);
+
+				// Restore stack offset in case the expression evaluated to a struct
+				// (in which case the struct would be placed on the stack)
+				auto stack_delta = stack_offset - stack_offset_before;
+				if (stack_delta > 0)
+				{
+					builder.add_imm(31, 31, stack_delta);
+					stack_offset -= stack_delta;
+					scopes.back().stack_offset -= stack_delta;
+				}
 			}
 
 			void apply(ast::assignment const & node)
 			{
-				auto identifier = std::get_if<ast::identifier>(node.lhs.get());
+				auto frame_offset = lvalue_offset(node.lhs);
-				if (!identifier)
-					throw std::runtime_error("assignment for non-identifier lhs is not implemented");
 
 				apply(*node.rhs);
-
-				for (auto it = scopes.rbegin(); it != scopes.rend(); ++it)
-				{
-					if (auto jt = it->variables.find(identifier->name); jt != it->variables.end())
-					{
 				auto type = ast::get_type(*node.rhs);
-						if (types::is_floating_point_type(*type))
+				if (types::is_unit_type(*type))
-							builder.str_fp(0, fp_mode_for(*type), 31, (stack_offset - jt->second.frame_offset) / builtin_type_size(*type));
+				{}
-						else
+				else if (types::is_floating_point_type(*type))
-							builder.str(0, 31, (stack_offset - jt->second.frame_offset) / 8);
+					builder.str_fp(0, fp_mode_for(*type), 31, (stack_offset - frame_offset) / type_size(*type));
-						break;
+				else if (types::is_bool_type(*type) || types::is_integer_type(*type) || types::is_function_type(*type))
+				{
+					auto size = types::type_size(*type);
+					if (size == 1)
+						builder.sturb(0, 31, stack_offset - frame_offset);
+					else if (size == 2)
+						builder.sturh(0, 31, stack_offset - frame_offset);
+					else if (size == 4)
+						builder.sturw(0, 31, stack_offset - frame_offset);
+					else if (size == 8)
+						builder.stur(0, 31, stack_offset - frame_offset);
 				}
+				else if (auto named_type = std::get_if<types::named_type>(type.get()))
+				{
+					if (auto struct_node = lcontext.is_struct(named_type->name))
+					{
+						// TODO: whole-struct assignment
+						throw std::runtime_error("Not implemented");
+					}
+					else
+						throw std::runtime_error("Unknown type \"" + named_type->name + "\"");
 				}
 			}
 
@@ -839,8 +1116,18 @@ namespace pslang::jit::aarch64
 			{
 				apply(*node.initializer);
 				auto type = ast::get_type(*node.initializer);
-				if (types::is_floating_point_type(*type))
+				if (std::get_if<types::named_type>(type.get()))
+				{
+					// Nothing to be done: the struct is already on the stack
+					// Just record the stack offset as variable location
+				}
+				else if (types::is_floating_point_type(*type))
 					push_fp(0, fp_mode_for(*type));
+				else if (types::is_unit_type(*type))
+				{
+					// Nothing to be done: unit type has zero size
+					// Its stack position is recorded but de facto unused
+				}
 				else
 					push(0);
 				scopes.back().variables[node.name] = {.frame_offset = stack_offset};
@@ -909,6 +1196,7 @@ namespace pslang::jit::aarch64
 
 			void apply(ast::return_statement const & node)
 			{
+				// TODO: struct return value
 				if (node.value)
 					apply(*node.value);
 				do_return();
@@ -924,6 +1212,11 @@ namespace pslang::jit::aarch64
 				// Must be handled prior to that in populate_symbols_visitor
 			}
 
+			void apply(ast::struct_definition const &)
+			{
+				// Must be handled prior to that in populate_symbols_visitor
+			}
+
 			void apply(ast::statement_list const & node)
 			{
 				lcontext.scopes.emplace_back();
@@ -1036,6 +1329,51 @@ namespace pslang::jit::aarch64
 					stack_offset -= scopes.back().stack_offset;
 				}
 			}
+
+			// Returns offset from function entry stack frame
+			std::size_t lvalue_offset(ast::expression_ptr const & node)
+			{
+				if (auto identifier = std::get_if<ast::identifier>(node.get()))
+				{
+					auto const & scope = scopes[identifier->level];
+					if (auto it = scope.variables.find(identifier->name); it != scope.variables.end())
+						return it->second.frame_offset;
+					throw std::runtime_error("Non-lvalue identifier: \"" + identifier->name + "\"");
+				}
+				else if (auto field_access = std::get_if<ast::field_access>(node.get()))
+				{
+					auto base_offset = lvalue_offset(field_access->object);
+					auto type = ast::get_type(*field_access->object);
+					if (auto named_type = std::get_if<types::named_type>(type.get()))
+					{
+						if (auto struct_node = lcontext.is_struct(named_type->name))
+						{
+							std::size_t field_id = -1;
+							for (std::size_t i = 0; i < struct_node->fields.size(); ++i)
+								if (struct_node->fields[i].name == field_access->field_name)
+								{
+									field_id = i;
+									break;
+								}
+
+							if (field_id == -1)
+								throw std::runtime_error("Invalid field \"" + field_access->field_name + "\"");
+
+							return base_offset - struct_node->fields[field_id].layout.offset;
+						}
+						else
+							throw std::runtime_error("Invalid struct \"" + named_type->name + "\"");
+					}
+					else
+						throw std::runtime_error("Invalid field access node");
+				}
+				else if (auto array_access = std::get_if<ast::array_access>(node.get()))
+				{
+					throw std::runtime_error("Not implemented");
+				}
+
+				throw std::runtime_error("Unknown lvalue node");
+			}
 		};
 
 		// Main compilation visitor

libs/jit/source/arch/aarch64/instruction_builder.cpp

@@ -25,6 +25,26 @@ namespace pslang::jit::aarch64
 		do_push(0xf8000c00u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
 	}
 
+	void instruction_builder::stur(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0xf8000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::sturw(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0xb8000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::sturh(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0x78000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::sturb(std::uint8_t reg_src, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0x38000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
 	void instruction_builder::ldr(std::uint8_t reg_dst, std::uint8_t reg_addr, std::uint16_t offset)
 	{
 		do_push(0xf9400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0xfffu) << 10));
@@ -40,6 +60,26 @@ namespace pslang::jit::aarch64
 		do_push(0xf8400400u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
 	}
 
+	void instruction_builder::ldur(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0xf8400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::ldurw(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0xb8400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::ldurh(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0x78400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
+	void instruction_builder::ldurb(std::uint8_t reg_dst, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0x38400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12));
+	}
+
 	void instruction_builder::ldr_pc(std::uint8_t reg_dst, std::int32_t offset)
 	{
 		do_push(0x58000000u | (reg_dst & REG_MASK) | ((((std::uint32_t)offset) & 0x7ffffu) << 5));
@@ -194,11 +234,21 @@ namespace pslang::jit::aarch64
 		do_push(0x3d400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((offset & 0xfffu) << 10) | ((mode & 0x3u) << 30));
 	}
 
+	void instruction_builder::ldur_fp(std::uint8_t reg_dst, std::uint8_t mode, std::uint8_t reg_addr, std::uint16_t offset)
+	{
+		do_push(0x3c400000u | (reg_dst & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12) | ((mode & 0x3u) << 30));
+	}
+
 	void instruction_builder::str_fp(std::uint8_t reg_src, std::uint8_t mode, std::uint8_t reg_addr, std::uint16_t offset)
 	{
 		do_push(0x3d000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((offset & 0xfffu) << 10) | ((mode & 0x3u) << 30));
 	}
 
+	void instruction_builder::stur_fp(std::uint8_t reg_src, std::uint8_t mode, std::uint8_t reg_addr, std::int16_t offset)
+	{
+		do_push(0x3c000000u | (reg_src & REG_MASK) | ((reg_addr & REG_MASK) << 5) | ((std::uint16_t(offset) & 0x1ffu) << 12) | ((mode & 0x3u) << 30));
+	}
+
 	void instruction_builder::fcvt(std::uint8_t reg_src, std::uint8_t mode_src, std::uint8_t reg_dst, std::uint8_t mode_dst)
 	{
 		do_push(0x1e224000u | (reg_dst & REG_MASK) | ((reg_src & REG_MASK) << 5) | (((mode_dst & 0x3u) ^ 0x2u) << 15) | (((mode_src & 0x3u) ^ 0x2u) << 22));
@@ -236,7 +286,7 @@ namespace pslang::jit::aarch64
 
 	void instruction_builder::fmov(std::uint8_t reg_src, std::uint8_t reg_dst, std::uint8_t mode, std::uint8_t op)
 	{
-		do_push(0x9e260000u | (reg_dst & REG_MASK) | ((reg_src & REG_MASK) << 5) | (((mode & 0x3u) ^ 0x2u) << 22) | ((op & 0x1u) << 16));
+		do_push(0x1e260000u | (reg_dst & REG_MASK) | ((reg_src & REG_MASK) << 5) | (mode == 2 ? 0u : 0x8000000u) | (((mode & 0x3u) ^ 0x2u) << 22) | ((op & 0x1u) << 16));
 	}
 
 	void instruction_builder::scvtf(std::uint8_t reg_src, std::uint8_t reg_dst, std::uint8_t mode)

libs/types/include/pslang/types/type_fwd.hpp

@@ -24,6 +24,6 @@ namespace pslang::types
 	bool is_builtin_type(type const & type);
 	bool is_function_type(type const & type);
 
-	std::size_t builtin_type_size(type const & type);
+	std::size_t type_size(type const & type);
 
 }

libs/types/source/type.cpp

@@ -130,10 +130,13 @@ namespace pslang::types
 		return false;
 	}
 
-	std::size_t builtin_type_size(type const & type)
+	std::size_t type_size(type const & type)
 	{
 		if (std::get_if<unit_type>(&type))
-			return 1;
+			return 0;
+
+		if (std::get_if<function_type>(&type))
+			return 8;
 
 		if (auto ptype = std::get_if<primitive_type>(&type))
 		{
@@ -148,7 +151,7 @@ namespace pslang::types
 			}, *ptype);
 		}
 
-		return 0;
+		throw std::runtime_error("Unknown type");
 	}
 
 }

plans.txt

@@ -1,4 +1,5 @@
 Future plans:
+* Split compiler into IR generation, IR optimization, and target-specific bytecode emitter
 * Globals (requires a separate mmaped segment in JIT compiler)
 * Pointers: pointer types, address-of operator (&), dereferencing, scope-based lifetime tracking in interpreter
 * Function overloading: separate functions from values (again) in interpreter, allow casting to specific function type to take function value
@@ -15,9 +16,26 @@ Interpreter backlog:
 * C FFI (foreign functions)
 
 Aarch64 compiler backlog:
-* Structs
+* Struct fields in structs (initialization & field access)
+* Struct function arguments & return values
 * Arrays
 
+IR outline:
+* Doubly-linked list (std::list will do) of instruction nodes
+* Nodes reference other nodes for input data or branching target
+* No temporary variables, nodes themselves represent data flow
+* Assignment expressions turn into nodes that assign to previously-defined nodes
+* Jump targets (first `while` node, node after an `if`, etc) are generated as nop nodes, to prevent them from being removed by the optimizer
+* Structs & arrays can be split into several independent nodes per-field (before pointers are introduced)
+
+IR optimizations:
+* Inlining: track function IR size (number of nodes will do), substitute its code instead of calling if it is small enough (pay attention to recursion)
+* Constant folding & propagation: if all node arguments are `const` nodes, replace the current node with the computed value
+* Arithmetic simplification: replace a+0 with a, etc
+* Branch removal: `if` nodes with condition nodes being `const` are replaced with unconditional jumps
+* Jump removal: `jump` that jumps to the immediate successor node is removed
+* Dead code elimination: DFS from function `return` nodes & impure function calls, remove all nodes not visited (make sure to not remove function arguments)
+
 General backlog:
 * Mutually recursive structs (relevant only with pointers)
 * Empty array expression