nativity/src/backend/intermediate_representation.zig
David Gonzalez Martin bca2f024cd ir for main function
2023-09-30 12:51:58 -06:00

509 lines
20 KiB
Zig

const std = @import("std");
const Allocator = std.mem.Allocator;
const assert = std.debug.assert;
const print = std.debug.print;
const Compilation = @import("../Compilation.zig");
const Module = Compilation.Module;
const Package = Compilation.Package;
const data_structures = @import("../data_structures.zig");
const ArrayList = data_structures.ArrayList;
const BlockList = data_structures.BlockList;
const AutoHashMap = data_structures.AutoHashMap;
pub const Result = struct {
blocks: BlockList(BasicBlock) = .{},
calls: BlockList(Call) = .{},
functions: BlockList(Function) = .{},
instructions: BlockList(Instruction) = .{},
jumps: BlockList(Jump) = .{},
loads: BlockList(Load) = .{},
phis: BlockList(Phi) = .{},
stores: BlockList(Store) = .{},
syscalls: BlockList(Syscall) = .{},
values: BlockList(Value) = .{},
stack_references: BlockList(StackReference) = .{},
};
pub fn initialize(compilation: *Compilation, module: *Module, package: *Package, main_file: Compilation.Type.Index) !Result {
_ = main_file;
_ = package;
print("\nFunction count: {}\n", .{module.functions.len});
var function_iterator = module.functions.iterator();
var builder = Builder{
.allocator = compilation.base_allocator,
.module = module,
};
while (function_iterator.next()) |sema_function| {
print("\nFunction: {}\n", .{sema_function});
try builder.function(sema_function);
}
return builder.ir;
}
pub const BasicBlock = struct {
instructions: ArrayList(Instruction.Index) = .{},
incomplete_phis: ArrayList(Instruction.Index) = .{},
filled: bool = false,
sealed: bool = false,
pub const List = BlockList(@This());
pub const Index = List.Index;
fn seal(basic_block: *BasicBlock) void {
for (basic_block.incomplete_phis.items) |incomplete_phi| {
_ = incomplete_phi;
unreachable;
}
basic_block.sealed = true;
}
};
pub const Instruction = union(enum) {
call: Call.Index,
jump: Jump.Index,
load: Load.Index,
phi: Phi.Index,
ret: Ret,
store: Store.Index,
syscall: Syscall.Index,
@"unreachable",
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Phi = struct {
value: Value.Index,
jump: Jump.Index,
block: BasicBlock.Index,
next: Phi.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Ret = struct {
value: Instruction.Index,
};
pub const Jump = struct {
source: BasicBlock.Index,
destination: BasicBlock.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Syscall = struct {
arguments: ArrayList(Value.Index),
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Load = struct {
value: Value.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Store = struct {
source: Value.Index,
destination: StackReference.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const StackReference = struct {
size: u64,
alignment: u64,
offset: u64,
pub const List = BlockList(@This());
pub const Index = List.Index;
};
const Call = struct {
function: Function.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
pub const Allocation = List.Allocation;
};
pub const Value = union(enum) {
integer: Integer,
load: Load.Index,
call: Call.Index,
stack_reference: StackReference.Index,
pub const List = BlockList(@This());
pub const Index = List.Index;
pub fn isInMemory(value: Value) bool {
return switch (value) {
.integer => false,
.load => true,
.call => true,
.stack_reference => true,
};
}
};
const Integer = struct {
value: u64,
sign: bool,
};
const Function = struct {
blocks: ArrayList(BasicBlock.Index) = .{},
pub const List = BlockList(@This());
pub const Index = List.Index;
};
pub const Builder = struct {
allocator: Allocator,
ir: Result = .{},
module: *Module,
current_basic_block: BasicBlock.Index = BasicBlock.Index.invalid,
current_function_index: Function.Index = Function.Index.invalid,
return_phi_node: Instruction.Index = Instruction.Index.invalid,
current_stack_offset: usize = 0,
stack_map: AutoHashMap(Compilation.Declaration.Index, StackReference.Index) = .{},
fn function(builder: *Builder, sema_function: Compilation.Function) !void {
builder.current_function_index = (try builder.ir.functions.append(builder.allocator, .{})).index;
// TODO: arguments
builder.current_basic_block = try builder.newBlock();
builder.current_stack_offset = 0;
builder.stack_map = .{};
const return_type = builder.module.types.get(builder.module.function_prototypes.get(sema_function.prototype).return_type);
const is_noreturn = return_type.* == .noreturn;
if (!is_noreturn) {
const exit_block = try builder.newBlock();
const phi = try builder.ir.phis.addOne(builder.allocator);
const phi_instruction = try builder.appendToBlock(exit_block, .{
.phi = phi.index,
});
phi.ptr.* = .{
.value = Value.Index.invalid,
.jump = Jump.Index.invalid,
.block = exit_block,
.next = Phi.Index.invalid,
};
const ret = try builder.appendToBlock(exit_block, .{
.ret = .{
.value = phi_instruction,
},
});
_ = ret;
builder.return_phi_node = phi_instruction;
}
const sema_block = sema_function.getBodyBlock(builder.module);
try builder.block(sema_block, .{ .emit_exit_block = !is_noreturn });
try builder.dumpFunction(std.io.getStdErr().writer(), builder.current_function_index);
}
fn dumpFunction(builder: *Builder, writer: anytype, index: Function.Index) !void {
const f = builder.ir.functions.get(index);
try writer.writeAll("Hello world!\n");
print("Function blocks: {}\n", .{f.blocks.items.len});
var function_instruction_index: usize = 0;
for (f.blocks.items, 0..) |block_index, function_block_index| {
print("#{}:\n", .{function_block_index});
const function_block = builder.ir.blocks.get(block_index);
for (function_block.instructions.items) |instruction_index| {
const instruction = builder.ir.instructions.get(instruction_index);
print("%{}: {}\n", .{ function_instruction_index, instruction });
function_instruction_index += 1;
}
print("\n", .{});
}
}
fn blockInsideBasicBlock(builder: *Builder, sema_block: *Compilation.Block, block_index: BasicBlock.Index) !BasicBlock.Index {
builder.current_basic_block = block_index;
try builder.block(sema_block, .{});
return builder.current_basic_block;
}
const BlockOptions = packed struct {
emit_exit_block: bool = true,
};
fn block(builder: *Builder, sema_block: *Compilation.Block, options: BlockOptions) error{OutOfMemory}!void {
for (sema_block.statements.items) |sema_statement_index| {
const sema_statement = builder.module.values.get(sema_statement_index);
switch (sema_statement.*) {
.loop => |loop_index| {
const sema_loop = builder.module.loops.get(loop_index);
const sema_loop_condition = builder.module.values.get(sema_loop.condition);
const sema_loop_body = builder.module.values.get(sema_loop.body);
const condition: Compilation.Value.Index = switch (sema_loop_condition.*) {
.bool => |bool_value| switch (bool_value) {
true => Compilation.Value.Index.invalid,
false => unreachable,
},
else => |t| @panic(@tagName(t)),
};
const original_block = builder.current_basic_block;
const jump_to_loop = try builder.append(.{
.jump = undefined,
});
const loop_body_block = try builder.newBlock();
const loop_prologue_block = if (options.emit_exit_block) try builder.newBlock() else BasicBlock.Index.invalid;
const loop_head_block = switch (condition.valid) {
false => loop_body_block,
true => unreachable,
};
builder.ir.instructions.get(jump_to_loop).jump = try builder.jump(.{
.source = original_block,
.destination = loop_head_block,
});
const sema_body_block = builder.module.blocks.get(sema_loop_body.block);
builder.current_basic_block = try builder.blockInsideBasicBlock(sema_body_block, loop_body_block);
if (loop_prologue_block.valid) {
builder.ir.blocks.get(loop_prologue_block).seal();
}
if (sema_body_block.reaches_end) {
_ = try builder.append(.{
.jump = try builder.jump(.{
.source = builder.current_basic_block,
.destination = loop_head_block,
}),
});
}
builder.ir.blocks.get(builder.current_basic_block).filled = true;
builder.ir.blocks.get(loop_body_block).seal();
if (!loop_head_block.eq(loop_body_block)) {
unreachable;
}
if (loop_prologue_block.valid) {
builder.current_basic_block = loop_prologue_block;
}
},
.syscall => |syscall_index| {
const sema_syscall = builder.module.syscalls.get(syscall_index);
var arguments = try ArrayList(Value.Index).initCapacity(builder.allocator, sema_syscall.argument_count + 1);
const sema_syscall_number = sema_syscall.number;
assert(sema_syscall_number.valid);
const number_value_index = try builder.emitValue(sema_syscall_number);
arguments.appendAssumeCapacity(number_value_index);
for (sema_syscall.getArguments()) |sema_syscall_argument| {
assert(sema_syscall_argument.valid);
const argument_value_index = try builder.emitValue(sema_syscall_argument);
arguments.appendAssumeCapacity(argument_value_index);
}
_ = try builder.append(.{
.syscall = (try builder.ir.syscalls.append(builder.allocator, .{
.arguments = arguments,
})).index,
});
},
.@"unreachable" => _ = try builder.append(.{
.@"unreachable" = {},
}),
.@"return" => |sema_ret_index| {
const sema_ret = builder.module.returns.get(sema_ret_index);
const return_value = try builder.emitValue(sema_ret.value);
const phi_instruction = builder.ir.instructions.get(builder.return_phi_node);
const phi = builder.ir.phis.get(phi_instruction.phi);
const exit_jump = try builder.jump(.{ .source = builder.current_basic_block, .destination = phi.block });
phi_instruction.phi = (try builder.ir.phis.append(builder.allocator, .{
.value = return_value,
.jump = exit_jump,
.next = phi_instruction.phi,
.block = phi.block,
})).index;
_ = try builder.append(.{
.jump = exit_jump,
});
},
.declaration => |sema_declaration_index| {
const sema_declaration = builder.module.declarations.get(sema_declaration_index);
assert(sema_declaration.scope_type == .local);
const sema_init_value = builder.module.values.get(sema_declaration.init_value);
const declaration_type = builder.module.types.get(sema_init_value.getType(builder.module));
const size = declaration_type.getSize();
const alignment = declaration_type.getAlignment();
const stack_offset = switch (size > 0) {
true => builder.allocateStack(size, alignment),
false => 0,
};
var value_index = try builder.emitValue(sema_declaration.init_value);
const value = builder.ir.values.get(value_index);
print("Value: {}\n", .{value.*});
value_index = switch (value.isInMemory()) {
false => try builder.load(value_index),
true => value_index,
};
if (stack_offset > 0) {
_ = try builder.store(.{
.source = value_index,
.destination = try builder.stackReference(stack_offset, declaration_type.*, sema_declaration_index),
});
}
},
else => |t| @panic(@tagName(t)),
}
}
}
fn stackReference(builder: *Builder, stack_offset: u64, t: Compilation.Type, value: Compilation.Declaration.Index) !StackReference.Index {
const stack_reference_allocation = try builder.ir.stack_references.append(builder.allocator, .{
.offset = stack_offset,
.size = t.getSize(),
.alignment = t.getAlignment(),
});
const index = stack_reference_allocation.index;
try builder.stack_map.put(builder.allocator, value, index);
return index;
}
fn store(builder: *Builder, descriptor: Store) !void {
const store_allocation = try builder.ir.stores.append(builder.allocator, descriptor);
_ = try builder.append(.{
.store = store_allocation.index,
});
}
fn allocateStack(builder: *Builder, size: u64, alignment: u64) u64 {
builder.current_stack_offset = std.mem.alignForward(u64, builder.current_stack_offset, alignment);
builder.current_stack_offset += size;
return builder.current_stack_offset;
}
fn load(builder: *Builder, value_index: Value.Index) !Value.Index {
print("Doing load!\n", .{});
const load_allocation = try builder.ir.loads.append(builder.allocator, .{
.value = value_index,
});
const instruction_index = try builder.append(.{
.load = load_allocation.index,
});
_ = instruction_index;
const result = try builder.ir.values.append(builder.allocator, .{
.load = load_allocation.index,
});
return result.index;
}
fn emitValue(builder: *Builder, sema_value_index: Compilation.Value.Index) !Value.Index {
const sema_value = builder.module.values.get(sema_value_index).*;
return switch (sema_value) {
// TODO
.integer => |integer| (try builder.ir.values.append(builder.allocator, .{
.integer = .{
.value = integer,
.sign = false,
},
})).index,
.call => |sema_call_index| {
const sema_call = builder.module.calls.get(sema_call_index);
const argument_list_index = sema_call.arguments;
if (argument_list_index.valid) {
unreachable;
}
const call_index = try builder.call(.{
.function = switch (builder.module.values.get(sema_call.value).*) {
.function => |function_index| .{
.index = function_index.index,
.block = function_index.block,
},
else => |t| @panic(@tagName(t)),
},
});
_ = try builder.append(.{
.call = call_index,
});
const value_allocation = try builder.ir.values.append(builder.allocator, .{
.call = call_index,
});
return value_allocation.index;
},
.declaration_reference => |sema_declaration_index| {
const sema_declaration = builder.module.declarations.get(sema_declaration_index);
const sema_init_value = builder.module.values.get(sema_declaration.init_value);
const init_type = sema_init_value.getType(builder.module);
_ = init_type;
switch (sema_declaration.scope_type) {
.local => {
const stack_reference = builder.stack_map.get(sema_declaration_index).?;
const value = try builder.ir.values.append(builder.allocator, .{
.stack_reference = stack_reference,
});
return value.index;
},
.global => unreachable,
}
// switch (sema_declaration.*) {
// else => |t| @panic(@tagName(t)),
// }
},
else => |t| @panic(@tagName(t)),
};
}
fn call(builder: *Builder, descriptor: Call) !Call.Index {
const call_allocation = try builder.ir.calls.append(builder.allocator, descriptor);
return call_allocation.index;
}
fn jump(builder: *Builder, descriptor: Jump) !Jump.Index {
const destination_block = builder.ir.blocks.get(descriptor.destination);
assert(!destination_block.sealed);
const jump_allocation = try builder.ir.jumps.append(builder.allocator, descriptor);
return jump_allocation.index;
}
fn append(builder: *Builder, instruction: Instruction) !Instruction.Index {
assert(builder.current_basic_block.valid);
return builder.appendToBlock(builder.current_basic_block, instruction);
}
fn appendToBlock(builder: *Builder, block_index: BasicBlock.Index, instruction: Instruction) !Instruction.Index {
const instruction_allocation = try builder.ir.instructions.append(builder.allocator, instruction);
try builder.ir.blocks.get(block_index).instructions.append(builder.allocator, instruction_allocation.index);
return instruction_allocation.index;
}
fn newBlock(builder: *Builder) !BasicBlock.Index {
const new_block_allocation = try builder.ir.blocks.append(builder.allocator, .{});
const current_function = builder.ir.functions.get(builder.current_function_index);
const function_block_index = current_function.blocks.items.len;
try current_function.blocks.append(builder.allocator, new_block_allocation.index);
print("Adding block: {}\n", .{function_block_index});
return new_block_allocation.index;
}
};