roc-lang/roc
1
1
Fork 0
mirror of https://github.com/roc-lang/roc.git synced 2024-09-21 15:59:20 +03:00
Code Issues Packages Projects Releases Wiki Activity

Refactor SymbolStorage to emphasise stack/non-stack params

Browse Source 
We don't have much (any) code that cares about the difference between
heap pointers and other primitives, but we have a _lot_ of code that cares
if it's stack memory. So let's encode it that way.
This commit is contained in:
Brian Carroll 2021-09-29 20:35:52 +01:00
parent 1fe20b0422
commit f1b14c14e3
2 changed files with 45 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
compiler/gen_wasm/src/backend.rs
View File

@ -13,7 +13,8 @@ use roc_mono::layout::{Builtin, Layout};
use crate::layout::WasmLayout;
use crate::storage::SymbolStorage;
use crate::{
allocate_stack_frame, copy_memory, free_stack_frame, round_up_to_alignment, LocalId, PTR_TYPE,
allocate_stack_frame, copy_memory, free_stack_frame, round_up_to_alignment, LocalId, PTR_SIZE,
PTR_TYPE,
};
// Don't allocate any constant data at address zero or near it. Would be valid, but bug-prone.
@ -172,9 +173,20 @@ impl<'a> WasmBackend<'a> {
value_type,
size,
},
_ => SymbolStorage::ParamPointer {
WasmLayout::HeapMemory => SymbolStorage::ParamPrimitive {
local_id,
wasm_layout,
value_type: PTR_TYPE,
size: PTR_SIZE,
},
WasmLayout::StackMemory {
size,
alignment_bytes,
} => SymbolStorage::ParamStackMemory {
local_id,
size,
alignment_bytes,
},
}
}
@ -287,12 +299,17 @@ impl<'a> WasmBackend<'a> {
// Simple optimisation: if we are just returning the expression, we don't need a local
Stmt::Let(let_sym, expr, layout, Stmt::Ret(ret_sym)) if let_sym == ret_sym => {
let wasm_layout = WasmLayout::new(layout);
if let WasmLayout::StackMemory { .. } = wasm_layout {
if let WasmLayout::StackMemory {
size,
alignment_bytes,
} = wasm_layout
{
// Map this symbol to the first argument (pointer into caller's stack)
// Saves us from having to copy it later
let storage = SymbolStorage::ParamPointer {
let storage = SymbolStorage::ParamStackMemory {
local_id: LocalId(0),
wasm_layout,
size,
alignment_bytes,
};
self.symbol_storage_map.insert(*let_sym, storage);
}
@ -326,14 +343,10 @@ impl<'a> WasmBackend<'a> {
alignment_bytes,
..
}
| ParamPointer {
| ParamStackMemory {
local_id,
wasm_layout:
WasmLayout::StackMemory {
size,
alignment_bytes,
..
},
size,
alignment_bytes,
} => {
let from = *local_id;
let to = LocalId(0);
@ -342,7 +355,6 @@ impl<'a> WasmBackend<'a> {
ParamPrimitive { local_id, .. }
| VarPrimitive { local_id, .. }
| ParamPointer { local_id, .. }
| VarHeapMemory { local_id, .. } => {
self.instructions.push(GetLocal(local_id.0));
self.instructions.push(Return); // TODO: branch instead of return so we can clean up stack
@ -537,10 +549,7 @@ impl<'a> WasmBackend<'a> {
if let Layout::Struct(field_layouts) = layout {
match storage {
SymbolStorage::VarStackMemory { local_id, size, .. }
| SymbolStorage::ParamPointer {
local_id,
wasm_layout: WasmLayout::StackMemory { size, .. },
} => {
| SymbolStorage::ParamStackMemory { local_id, size, .. } => {
if size > 0 {
let mut relative_offset = 0;
for (field, _) in fields.iter().zip(field_layouts.iter()) {

46
compiler/gen_wasm/src/storage.rs
View File

@ -1,18 +1,14 @@
use crate::{copy_memory, layout::WasmLayout, LocalId, ALIGN_1, ALIGN_2, ALIGN_4, ALIGN_8};
use crate::{copy_memory, LocalId, ALIGN_1, ALIGN_2, ALIGN_4, ALIGN_8};
use parity_wasm::elements::{Instruction, Instruction::*, ValueType};
#[derive(Debug, Clone)]
pub enum SymbolStorage {
ParamPrimitive {
VarPrimitive {
local_id: LocalId,
value_type: ValueType,
size: u32,
},
ParamPointer {
local_id: LocalId,
wasm_layout: WasmLayout,
},
VarPrimitive {
ParamPrimitive {
local_id: LocalId,
value_type: ValueType,
size: u32,
@ -23,6 +19,11 @@ pub enum SymbolStorage {
offset: u32,
alignment_bytes: u32,
},
ParamStackMemory {
local_id: LocalId,
size: u32,
alignment_bytes: u32,
},
VarHeapMemory {
local_id: LocalId,
},
@ -32,7 +33,7 @@ impl SymbolStorage {
pub fn local_id(&self) -> LocalId {
match self {
Self::ParamPrimitive { local_id, .. } => *local_id,
Self::ParamPointer { local_id, .. } => *local_id,
Self::ParamStackMemory { local_id, .. } => *local_id,
Self::VarPrimitive { local_id, .. } => *local_id,
Self::VarStackMemory { local_id, .. } => *local_id,
Self::VarHeapMemory { local_id, .. } => *local_id,
@ -43,7 +44,7 @@ impl SymbolStorage {
match self {
Self::ParamPrimitive { value_type, .. } => *value_type,
Self::VarPrimitive { value_type, .. } => *value_type,
Self::ParamPointer { .. } => ValueType::I32,
Self::ParamStackMemory { .. } => ValueType::I32,
Self::VarStackMemory { .. } => ValueType::I32,
Self::VarHeapMemory { .. } => ValueType::I32,
}
@ -51,11 +52,7 @@ impl SymbolStorage {
pub fn has_stack_memory(&self) -> bool {
match self {
Self::ParamPointer {
wasm_layout: WasmLayout::StackMemory { .. },
..
} => true,
Self::ParamPointer { .. } => false,
Self::ParamStackMemory { .. } => true,
Self::VarStackMemory { .. } => true,
Self::ParamPrimitive { .. } => false,
Self::VarPrimitive { .. } => false,
@ -70,13 +67,9 @@ impl SymbolStorage {
alignment_bytes,
..
}
| Self::ParamPointer {
wasm_layout:
WasmLayout::StackMemory {
size,
alignment_bytes,
..
},
| Self::ParamStackMemory {
size,
alignment_bytes,
..
} => (*size, *alignment_bytes),
@ -123,13 +116,10 @@ impl SymbolStorage {
Ok(*size)
}
Self::ParamPointer {
Self::ParamStackMemory {
local_id,
wasm_layout:
WasmLayout::StackMemory {
size,
alignment_bytes,
},
size,
alignment_bytes,
}
| Self::VarStackMemory {
local_id,
@ -148,7 +138,7 @@ impl SymbolStorage {
Ok(*size)
}
Self::ParamPointer { local_id, .. } | Self::VarHeapMemory { local_id, .. } => {
Self::VarHeapMemory { local_id, .. } => {
instructions.push(GetLocal(to_pointer.0));
instructions.push(GetLocal(local_id.0));
instructions.push(I32Store(ALIGN_4, to_offset));