roc/compiler/gen/src/llvm/refcounting.rs
2020-10-17 01:48:55 +02:00

1252 lines
38 KiB
Rust

use crate::layout_id::LayoutIds;
use crate::llvm::build::{
cast_basic_basic, cast_struct_struct, create_entry_block_alloca, set_name, Env, Scope,
FAST_CALL_CONV, LLVM_SADD_WITH_OVERFLOW_I64,
};
use crate::llvm::build_list::list_len;
use crate::llvm::convert::{basic_type_from_layout, block_of_memory, ptr_int};
use bumpalo::collections::Vec;
use inkwell::basic_block::BasicBlock;
use inkwell::context::Context;
use inkwell::module::Linkage;
use inkwell::values::{BasicValueEnum, FunctionValue, IntValue, PointerValue, StructValue};
use inkwell::{AddressSpace, IntPredicate};
use roc_module::symbol::Symbol;
use roc_mono::layout::{Builtin, Layout, MemoryMode};
pub const REFCOUNT_MAX: usize = 0 as usize;
pub fn refcount_1(ctx: &Context, ptr_bytes: u32) -> IntValue<'_> {
match ptr_bytes {
1 => ctx.i8_type().const_int(i8::MIN as u64, false),
2 => ctx.i16_type().const_int(i16::MIN as u64, false),
4 => ctx.i32_type().const_int(i32::MIN as u64, false),
8 => ctx.i64_type().const_int(i64::MIN as u64, false),
_ => panic!(
"Invalid target: Roc does't support compiling to {}-bit systems.",
ptr_bytes * 8
),
}
}
pub fn decrement_refcount_struct<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout_ids: &mut LayoutIds<'a>,
value: BasicValueEnum<'ctx>,
layouts: &[Layout<'a>],
) {
let wrapper_struct = value.into_struct_value();
for (i, field_layout) in layouts.iter().enumerate() {
if field_layout.contains_refcounted() {
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "decrement_struct_field")
.unwrap();
decrement_refcount_layout(env, parent, layout_ids, field_ptr, field_layout)
}
}
}
pub fn decrement_refcount_layout<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout_ids: &mut LayoutIds<'a>,
value: BasicValueEnum<'ctx>,
layout: &Layout<'a>,
) {
use Layout::*;
match layout {
Builtin(builtin) => {
decrement_refcount_builtin(env, parent, layout_ids, value, layout, builtin)
}
Closure(_, closure_layout, _) => {
if closure_layout.contains_refcounted() {
let wrapper_struct = value.into_struct_value();
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, 1, "decrement_closure_data")
.unwrap();
decrement_refcount_layout(
env,
parent,
layout_ids,
field_ptr,
&closure_layout.into_layout(),
)
}
}
Struct(layouts) => {
decrement_refcount_struct(env, parent, layout_ids, value, layouts);
}
RecursivePointer => todo!("TODO implement decrement layout of recursive tag union"),
Union(tags) => {
debug_assert!(!tags.is_empty());
let wrapper_struct = value.into_struct_value();
// read the tag_id
let tag_id = env
.builder
.build_extract_value(wrapper_struct, 0, "read_tag_id")
.unwrap()
.into_int_value();
// next, make a jump table for all possible values of the tag_id
let mut cases = Vec::with_capacity_in(tags.len(), env.arena);
let merge_block = env.context.append_basic_block(parent, "decrement_merge");
for (tag_id, field_layouts) in tags.iter().enumerate() {
let block = env.context.append_basic_block(parent, "tag_id_decrement");
env.builder.position_at_end(block);
for (i, field_layout) in field_layouts.iter().enumerate() {
if field_layout.contains_refcounted() {
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "decrement_struct_field")
.unwrap();
decrement_refcount_layout(env, parent, layout_ids, field_ptr, field_layout)
}
}
env.builder.build_unconditional_branch(merge_block);
cases.push((env.context.i8_type().const_int(tag_id as u64, false), block));
}
let (_, default_block) = cases.pop().unwrap();
env.builder.build_switch(tag_id, default_block, &cases);
env.builder.position_at_end(merge_block);
}
RecursiveUnion(tags) => {
build_dec_union(env, layout_ids, tags, value);
}
FunctionPointer(_, _) | Pointer(_) => {}
}
}
#[inline(always)]
fn decrement_refcount_builtin<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout_ids: &mut LayoutIds<'a>,
value: BasicValueEnum<'ctx>,
layout: &Layout<'a>,
builtin: &Builtin<'a>,
) {
use Builtin::*;
match builtin {
List(memory_mode, element_layout) => {
let wrapper_struct = value.into_struct_value();
if element_layout.contains_refcounted() {
use crate::llvm::build_list::{incrementing_elem_loop, load_list};
use inkwell::types::BasicType;
let ptr_type =
basic_type_from_layout(env.arena, env.context, element_layout, env.ptr_bytes)
.ptr_type(AddressSpace::Generic);
let (len, ptr) = load_list(env.builder, wrapper_struct, ptr_type);
let loop_fn = |_index, element| {
decrement_refcount_layout(env, parent, layout_ids, element, element_layout);
};
incrementing_elem_loop(
env.builder,
env.context,
parent,
ptr,
len,
"dec_index",
loop_fn,
);
}
if let MemoryMode::Refcounted = memory_mode {
build_dec_list(env, layout_ids, layout, wrapper_struct);
}
}
Set(element_layout) => {
if element_layout.contains_refcounted() {
// TODO decrement all values
}
todo!();
}
Map(key_layout, value_layout) => {
if key_layout.contains_refcounted() || value_layout.contains_refcounted() {
// TODO decrement all values
}
todo!();
}
Str => {
let wrapper_struct = value.into_struct_value();
build_dec_str(env, layout_ids, layout, wrapper_struct);
}
_ => {}
}
}
pub fn increment_refcount_layout<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout_ids: &mut LayoutIds<'a>,
value: BasicValueEnum<'ctx>,
layout: &Layout<'a>,
) {
use Layout::*;
match layout {
Builtin(builtin) => {
increment_refcount_builtin(env, parent, layout_ids, value, layout, builtin)
}
RecursiveUnion(tags) => {
build_inc_union(env, layout_ids, tags, value);
}
_ => {}
}
}
#[inline(always)]
fn increment_refcount_builtin<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout_ids: &mut LayoutIds<'a>,
value: BasicValueEnum<'ctx>,
layout: &Layout<'a>,
builtin: &Builtin<'a>,
) {
use Builtin::*;
match builtin {
List(memory_mode, element_layout) => {
let wrapper_struct = value.into_struct_value();
if element_layout.contains_refcounted() {
use crate::llvm::build_list::{incrementing_elem_loop, load_list};
use inkwell::types::BasicType;
let ptr_type =
basic_type_from_layout(env.arena, env.context, element_layout, env.ptr_bytes)
.ptr_type(AddressSpace::Generic);
let (len, ptr) = load_list(env.builder, wrapper_struct, ptr_type);
let loop_fn = |_index, element| {
increment_refcount_layout(env, parent, layout_ids, element, element_layout);
};
incrementing_elem_loop(
env.builder,
env.context,
parent,
ptr,
len,
"inc_index",
loop_fn,
);
}
if let MemoryMode::Refcounted = memory_mode {
build_inc_list(env, layout_ids, layout, wrapper_struct);
}
}
Set(element_layout) => {
if element_layout.contains_refcounted() {
// TODO decrement all values
}
todo!();
}
Map(key_layout, value_layout) => {
if key_layout.contains_refcounted() || value_layout.contains_refcounted() {
// TODO decrement all values
}
todo!();
}
Str => {
let wrapper_struct = value.into_struct_value();
build_inc_str(env, layout_ids, layout, wrapper_struct);
}
_ => {}
}
}
pub fn build_inc_list<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
original_wrapper: StructValue<'ctx>,
) {
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::INC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_inc_list_help(env, layout_ids, layout, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[original_wrapper.into()], "increment_list");
call.set_call_convention(FAST_CALL_CONV);
}
fn build_inc_list_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
_layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
fn_val: FunctionValue<'ctx>,
) {
let builder = env.builder;
let ctx = env.context;
// Add a basic block for the entry point
let entry = ctx.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
let original_wrapper = arg_val.into_struct_value();
let len = list_len(builder, original_wrapper);
let is_non_empty = builder.build_int_compare(
IntPredicate::UGT,
len,
ctx.i64_type().const_zero(),
"len > 0",
);
// build blocks
let increment_block = ctx.append_basic_block(parent, "increment_block");
let cont_block = ctx.append_basic_block(parent, "after_increment_block");
builder.build_conditional_branch(is_non_empty, increment_block, cont_block);
builder.position_at_end(increment_block);
let refcount_ptr = list_get_refcount_ptr(env, layout, original_wrapper);
increment_refcount_help(env, refcount_ptr);
builder.build_unconditional_branch(cont_block);
builder.position_at_end(cont_block);
// this function returns void
builder.build_return(None);
}
pub fn build_dec_list<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
original_wrapper: StructValue<'ctx>,
) {
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::DEC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_dec_list_help(env, layout_ids, layout, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[original_wrapper.into()], "decrement_list");
call.set_call_convention(FAST_CALL_CONV);
}
fn build_dec_list_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
_layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
fn_val: FunctionValue<'ctx>,
) {
let builder = env.builder;
let ctx = env.context;
// Add a basic block for the entry point
let entry = ctx.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
// the block we'll always jump to when we're done
let cont_block = ctx.append_basic_block(parent, "after_decrement_block");
let decrement_block = ctx.append_basic_block(parent, "decrement_block");
// currently, an empty list has a null-pointer in its length is 0
// so we must first check the length
let original_wrapper = arg_val.into_struct_value();
let len = list_len(builder, original_wrapper);
let is_non_empty = builder.build_int_compare(
IntPredicate::UGT,
len,
ctx.i64_type().const_zero(),
"len > 0",
);
// if the length is 0, we're done and jump to the continuation block
// otherwise, actually read and check the refcount
builder.build_conditional_branch(is_non_empty, decrement_block, cont_block);
builder.position_at_end(decrement_block);
let refcount_ptr = list_get_refcount_ptr(env, layout, original_wrapper);
decrement_refcount_help(env, parent, refcount_ptr, cont_block);
// this function returns void
builder.build_return(None);
}
pub fn build_inc_str<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
original_wrapper: StructValue<'ctx>,
) {
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::INC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_inc_str_help(env, layout_ids, layout, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[original_wrapper.into()], "increment_str");
call.set_call_convention(FAST_CALL_CONV);
}
fn build_inc_str_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
_layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
fn_val: FunctionValue<'ctx>,
) {
let builder = env.builder;
let ctx = env.context;
// Add a basic block for the entry point
let entry = ctx.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
let str_wrapper = arg_val.into_struct_value();
let len = builder
.build_extract_value(str_wrapper, Builtin::WRAPPER_LEN, "read_str_ptr")
.unwrap()
.into_int_value();
// Small strings have 1 as the first bit of length, making them negative.
// Thus, to check for big and non empty, just needs a signed len > 0.
let is_big_and_non_empty = builder.build_int_compare(
IntPredicate::SGT,
len,
ptr_int(ctx, env.ptr_bytes).const_zero(),
"len > 0",
);
// the block we'll always jump to when we're done
let cont_block = ctx.append_basic_block(parent, "after_increment_block");
let decrement_block = ctx.append_basic_block(parent, "increment_block");
builder.build_conditional_branch(is_big_and_non_empty, decrement_block, cont_block);
builder.position_at_end(decrement_block);
let refcount_ptr = list_get_refcount_ptr(env, layout, str_wrapper);
increment_refcount_help(env, refcount_ptr);
builder.build_unconditional_branch(cont_block);
builder.position_at_end(cont_block);
// this function returns void
builder.build_return(None);
}
pub fn build_dec_str<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
original_wrapper: StructValue<'ctx>,
) {
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::DEC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_dec_str_help(env, layout_ids, layout, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[original_wrapper.into()], "decrement_str");
call.set_call_convention(FAST_CALL_CONV);
}
fn build_dec_str_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
_layout_ids: &mut LayoutIds<'a>,
layout: &Layout<'a>,
fn_val: FunctionValue<'ctx>,
) {
let builder = env.builder;
let ctx = env.context;
// Add a basic block for the entry point
let entry = ctx.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
let str_wrapper = arg_val.into_struct_value();
let len = builder
.build_extract_value(str_wrapper, Builtin::WRAPPER_LEN, "read_str_ptr")
.unwrap()
.into_int_value();
// Small strings have 1 as the first bit of length, making them negative.
// Thus, to check for big and non empty, just needs a signed len > 0.
let is_big_and_non_empty = builder.build_int_compare(
IntPredicate::SGT,
len,
ptr_int(ctx, env.ptr_bytes).const_zero(),
"len > 0",
);
// the block we'll always jump to when we're done
let cont_block = ctx.append_basic_block(parent, "after_decrement_block");
let decrement_block = ctx.append_basic_block(parent, "decrement_block");
builder.build_conditional_branch(is_big_and_non_empty, decrement_block, cont_block);
builder.position_at_end(decrement_block);
let refcount_ptr = list_get_refcount_ptr(env, layout, str_wrapper);
decrement_refcount_help(env, parent, refcount_ptr, cont_block);
// this function returns void
builder.build_return(None);
}
fn increment_refcount_ptr<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout: &Layout<'a>,
field_ptr: PointerValue<'ctx>,
) {
let refcount_ptr = get_refcount_ptr(env, layout, field_ptr);
increment_refcount_help(env, refcount_ptr);
}
fn increment_refcount_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
refcount_ptr: PointerValue<'ctx>,
) {
let builder = env.builder;
let ctx = env.context;
let refcount_type = ptr_int(ctx, env.ptr_bytes);
let refcount = env
.builder
.build_load(refcount_ptr, "get_refcount")
.into_int_value();
let max = builder.build_int_compare(
IntPredicate::EQ,
refcount,
refcount_type.const_int(REFCOUNT_MAX as u64, false),
"refcount_max_check",
);
let incremented = builder.build_int_add(
refcount,
refcount_type.const_int(1 as u64, false),
"increment_refcount",
);
let selected = builder.build_select(max, refcount, incremented, "select_refcount");
builder.build_store(refcount_ptr, selected);
}
fn decrement_refcount_ptr<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
layout: &Layout<'a>,
field_ptr: PointerValue<'ctx>,
) {
let ctx = env.context;
// the block we'll always jump to when we're done
let cont_block = ctx.append_basic_block(parent, "after_decrement_block");
let refcount_ptr = get_refcount_ptr(env, layout, field_ptr);
decrement_refcount_help(env, parent, refcount_ptr, cont_block);
}
fn decrement_refcount_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
parent: FunctionValue<'ctx>,
refcount_ptr: PointerValue<'ctx>,
cont_block: BasicBlock,
) {
let builder = env.builder;
let ctx = env.context;
let refcount_type = ptr_int(ctx, env.ptr_bytes);
let refcount = env
.builder
.build_load(refcount_ptr, "get_refcount")
.into_int_value();
let add_with_overflow = env
.call_intrinsic(
LLVM_SADD_WITH_OVERFLOW_I64,
&[
refcount.into(),
refcount_type.const_int((-1 as i64) as u64, true).into(),
],
)
.into_struct_value();
let has_overflowed = builder
.build_extract_value(add_with_overflow, 1, "has_overflowed")
.unwrap();
let has_overflowed_comparison = builder.build_int_compare(
IntPredicate::EQ,
has_overflowed.into_int_value(),
ctx.bool_type().const_int(1 as u64, false),
"has_overflowed",
);
// build blocks
let then_block = ctx.append_basic_block(parent, "then");
let else_block = ctx.append_basic_block(parent, "else");
// TODO what would be most optimial for the branch predictor
//
// are most refcounts 1 most of the time? or not?
builder.build_conditional_branch(has_overflowed_comparison, then_block, else_block);
// build then block
{
builder.position_at_end(then_block);
if !env.leak {
builder.build_free(refcount_ptr);
}
builder.build_unconditional_branch(cont_block);
}
// build else block
{
builder.position_at_end(else_block);
let max = builder.build_int_compare(
IntPredicate::EQ,
refcount,
refcount_type.const_int(REFCOUNT_MAX as u64, false),
"refcount_max_check",
);
let decremented = builder
.build_extract_value(add_with_overflow, 0, "decrement_refcount")
.unwrap()
.into_int_value();
let selected = builder.build_select(max, refcount, decremented, "select_refcount");
builder.build_store(refcount_ptr, selected);
builder.build_unconditional_branch(cont_block);
}
// emit merge block
builder.position_at_end(cont_block);
}
/// Build an increment or decrement function for a specific layout
pub fn build_header<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout: &Layout<'a>,
fn_name: String,
) -> FunctionValue<'ctx> {
let arena = env.arena;
let context = &env.context;
let arg_type = basic_type_from_layout(arena, env.context, &layout, env.ptr_bytes);
// inc and dec return void
let fn_type = context.void_type().fn_type(&[arg_type], false);
let fn_val = env
.module
.add_function(fn_name.as_str(), fn_type, Some(Linkage::Private));
// Because it's an internal-only function, it should use the fast calling convention.
fn_val.set_call_conventions(FAST_CALL_CONV);
fn_val
}
pub fn build_dec_union<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
fields: &'a [&'a [Layout<'a>]],
value: BasicValueEnum<'ctx>,
) {
let layout = Layout::Union(fields);
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::DEC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_dec_union_help(env, layout_ids, fields, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[value], "decrement_union");
call.set_call_convention(FAST_CALL_CONV);
}
pub fn build_dec_union_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
tags: &[&[Layout<'a>]],
fn_val: FunctionValue<'ctx>,
) {
debug_assert!(!tags.is_empty());
use inkwell::types::BasicType;
let context = &env.context;
let builder = env.builder;
// Add a basic block for the entry point
let entry = context.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let layout = Layout::Union(tags);
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
let layout = Layout::RecursiveUnion(tags);
let before_block = env.builder.get_insert_block().expect("to be in a function");
let wrapper_struct = arg_val.into_struct_value();
// let tag_id_u8 = cast_basic_basic(env.builder, tag_id.into(), env.context.i8_type().into());
// next, make a jump table for all possible values of the tag_id
let mut cases = Vec::with_capacity_in(tags.len(), env.arena);
let merge_block = env.context.append_basic_block(parent, "decrement_merge");
for (tag_id, field_layouts) in tags.iter().enumerate() {
let block = env.context.append_basic_block(parent, "tag_id_decrement");
env.builder.position_at_end(block);
let wrapper_type = basic_type_from_layout(
env.arena,
env.context,
&Layout::Struct(field_layouts),
env.ptr_bytes,
);
let wrapper_struct =
cast_struct_struct(env.builder, wrapper_struct, wrapper_type.into_struct_type());
for (i, field_layout) in field_layouts.iter().enumerate() {
if let Layout::RecursivePointer = field_layout {
// a *i64 pointer to the recursive data
// we need to cast this pointer to the appropriate type
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "decrement_struct_field")
.unwrap();
// recursively decrement
let union_type = block_of_memory(env.context, &layout, env.ptr_bytes);
let recursive_field_ptr = cast_basic_basic(
env.builder,
field_ptr,
union_type.ptr_type(AddressSpace::Generic).into(),
)
.into_pointer_value();
let recursive_field = env
.builder
.build_load(recursive_field_ptr, "load_recursive_field");
// recursively decrement the field
let call =
env.builder
.build_call(fn_val, &[recursive_field], "recursive_tag_decrement");
// Because it's an internal-only function, use the fast calling convention.
call.set_call_convention(FAST_CALL_CONV);
// TODO do this decrement before the recursive call?
// Then the recursive call is potentially TCE'd
decrement_refcount_ptr(env, parent, &layout, field_ptr.into_pointer_value());
} else if field_layout.contains_refcounted() {
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "decrement_struct_field")
.unwrap();
decrement_refcount_layout(env, parent, layout_ids, field_ptr, field_layout);
}
}
env.builder.build_unconditional_branch(merge_block);
cases.push((
env.context.i64_type().const_int(tag_id as u64, false),
block,
));
}
cases.reverse();
let (_, default_block) = cases.pop().unwrap();
env.builder.position_at_end(before_block);
// read the tag_id
let current_tag_id = {
// the first element of the wrapping struct is an array of i64
let first_array = env
.builder
.build_extract_value(wrapper_struct, 0, "read_tag_id")
.unwrap()
.into_array_value();
env.builder
.build_extract_value(first_array, 0, "read_tag_id_2")
.unwrap()
.into_int_value()
};
// switch on it
env.builder
.build_switch(current_tag_id, default_block, &cases);
env.builder.position_at_end(merge_block);
// this function returns void
builder.build_return(None);
}
pub fn build_inc_union<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
fields: &'a [&'a [Layout<'a>]],
value: BasicValueEnum<'ctx>,
) {
let layout = Layout::Union(fields);
let block = env.builder.get_insert_block().expect("to be in a function");
let symbol = Symbol::INC;
let fn_name = layout_ids
.get(symbol, &layout)
.to_symbol_string(symbol, &env.interns);
let function = match env.module.get_function(fn_name.as_str()) {
Some(function_value) => function_value,
None => {
let function_value = build_header(env, &layout, fn_name);
build_inc_union_help(env, layout_ids, fields, function_value);
function_value
}
};
env.builder.position_at_end(block);
let call = env
.builder
.build_call(function, &[value], "increment_union");
call.set_call_convention(FAST_CALL_CONV);
}
pub fn build_inc_union_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout_ids: &mut LayoutIds<'a>,
tags: &[&[Layout<'a>]],
fn_val: FunctionValue<'ctx>,
) {
debug_assert!(!tags.is_empty());
use inkwell::types::BasicType;
let context = &env.context;
let builder = env.builder;
// Add a basic block for the entry point
let entry = context.append_basic_block(fn_val, "entry");
builder.position_at_end(entry);
let mut scope = Scope::default();
// Add args to scope
let arg_symbol = Symbol::ARG_1;
let layout = Layout::Union(tags);
let arg_val = fn_val.get_param_iter().next().unwrap();
set_name(arg_val, arg_symbol.ident_string(&env.interns));
let alloca = create_entry_block_alloca(
env,
fn_val,
arg_val.get_type(),
arg_symbol.ident_string(&env.interns),
);
builder.build_store(alloca, arg_val);
scope.insert(arg_symbol, (layout.clone(), alloca));
let parent = fn_val;
let layout = Layout::RecursiveUnion(tags);
let before_block = env.builder.get_insert_block().expect("to be in a function");
let wrapper_struct = arg_val.into_struct_value();
// read the tag_id
let tag_id = {
// the first element of the wrapping struct is an array of i64
let first_array = env
.builder
.build_extract_value(wrapper_struct, 0, "read_tag_id")
.unwrap()
.into_array_value();
env.builder
.build_extract_value(first_array, 0, "read_tag_id_2")
.unwrap()
.into_int_value()
};
let tag_id_u8 = cast_basic_basic(env.builder, tag_id.into(), env.context.i8_type().into());
// next, make a jump table for all possible values of the tag_id
let mut cases = Vec::with_capacity_in(tags.len(), env.arena);
let merge_block = env.context.append_basic_block(parent, "decrement_merge");
for (tag_id, field_layouts) in tags.iter().enumerate() {
let block = env.context.append_basic_block(parent, "tag_id_decrement");
env.builder.position_at_end(block);
let wrapper_type = basic_type_from_layout(
env.arena,
env.context,
&Layout::Struct(field_layouts),
env.ptr_bytes,
);
let wrapper_struct =
cast_struct_struct(env.builder, wrapper_struct, wrapper_type.into_struct_type());
for (i, field_layout) in field_layouts.iter().enumerate() {
if let Layout::RecursivePointer = field_layout {
// a *i64 pointer to the recursive data
// we need to cast this pointer to the appropriate type
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "decrement_struct_field")
.unwrap();
// recursively increment
let union_type = block_of_memory(env.context, &layout, env.ptr_bytes);
let recursive_field_ptr = cast_basic_basic(
env.builder,
field_ptr,
union_type.ptr_type(AddressSpace::Generic).into(),
)
.into_pointer_value();
let recursive_field = env
.builder
.build_load(recursive_field_ptr, "load_recursive_field");
// recursively increment the field
let call =
env.builder
.build_call(fn_val, &[recursive_field], "recursive_tag_increment");
// Because it's an internal-only function, use the fast calling convention.
call.set_call_convention(FAST_CALL_CONV);
// TODO do this increment before the recursive call?
// Then the recursive call is potentially TCE'd
increment_refcount_ptr(env, &layout, field_ptr.into_pointer_value());
} else if field_layout.contains_refcounted() {
let field_ptr = env
.builder
.build_extract_value(wrapper_struct, i as u32, "increment_struct_field")
.unwrap();
increment_refcount_layout(env, parent, layout_ids, field_ptr, field_layout);
}
}
env.builder.build_unconditional_branch(merge_block);
cases.push((env.context.i8_type().const_int(tag_id as u64, false), block));
}
let (_, default_block) = cases.pop().unwrap();
env.builder.position_at_end(before_block);
env.builder
.build_switch(tag_id_u8.into_int_value(), default_block, &cases);
env.builder.position_at_end(merge_block);
// this function returns void
builder.build_return(None);
}
pub fn refcount_is_one_comparison<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
refcount: IntValue<'ctx>,
) -> IntValue<'ctx> {
env.builder.build_int_compare(
IntPredicate::EQ,
refcount,
refcount_1(env.context, env.ptr_bytes),
"refcount_one_check",
)
}
pub fn list_get_refcount_ptr<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout: &Layout<'a>,
list_wrapper: StructValue<'ctx>,
) -> PointerValue<'ctx> {
// fetch the pointer to the array data, as an integer
let ptr_as_int = env
.builder
.build_extract_value(list_wrapper, Builtin::WRAPPER_PTR, "read_list_ptr")
.unwrap()
.into_int_value();
get_refcount_ptr_help(env, layout, ptr_as_int)
}
fn get_refcount_ptr<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout: &Layout<'a>,
ptr: PointerValue<'ctx>,
) -> PointerValue<'ctx> {
let refcount_type = ptr_int(env.context, env.ptr_bytes);
let ptr_as_int =
cast_basic_basic(env.builder, ptr.into(), refcount_type.into()).into_int_value();
get_refcount_ptr_help(env, layout, ptr_as_int)
}
fn get_refcount_ptr_help<'a, 'ctx, 'env>(
env: &Env<'a, 'ctx, 'env>,
layout: &Layout<'a>,
ptr_as_int: IntValue<'ctx>,
) -> PointerValue<'ctx> {
let builder = env.builder;
let ctx = env.context;
let value_bytes = layout.stack_size(env.ptr_bytes) as u64;
let offset = match layout {
Layout::Builtin(Builtin::List(_, _)) => env.ptr_bytes as u64,
Layout::Builtin(Builtin::Str) => env.ptr_bytes as u64,
_ => (env.ptr_bytes as u64).max(value_bytes),
};
// pointer to usize
let refcount_type = ptr_int(ctx, env.ptr_bytes);
// subtract offset, to access the refcount
let refcount_ptr = builder.build_int_sub(
ptr_as_int,
refcount_type.const_int(offset, false),
"make_refcount_ptr",
);
builder.build_int_to_ptr(
refcount_ptr,
refcount_type.ptr_type(AddressSpace::Generic),
"get_refcount_ptr",
)
}