WIP.

src/backend/binaryen.rs

@@ -1,5 +1,7 @@
 //! Binaryen bindings.
 
+use crate::entity::EntityRef;
+use crate::ir;
 use anyhow::{bail, Result};
 use lazy_static::lazy_static;
 use libc::{c_char, c_void};
@@ -118,14 +120,14 @@ impl Function {
 
     pub fn create(
         module: &mut Module,
-        params: impl Iterator<Item = wasmparser::Type>,
-        results: impl Iterator<Item = wasmparser::Type>,
-        locals: impl Iterator<Item = wasmparser::Type>,
+        params: impl Iterator<Item = ir::Type>,
+        results: impl Iterator<Item = ir::Type>,
+        locals: impl Iterator<Item = ir::Type>,
         body: Expression,
     ) -> Function {
         let params = tys_to_binaryen(params);
         let results = tys_to_binaryen(results);
-        let locals: Vec<BinaryenType> = locals.map(|ty| Type::from(ty).to_kind()).collect();
+        let locals: Vec<BinaryenType> = locals.map(|ty| Type::from(ty).to_binaryen()).collect();
         let ptr = unsafe {
             BinaryenAddFunc(
                 module.0,
@@ -140,8 +142,8 @@ impl Function {
         Function(module.0, ptr)
     }
 
-    pub fn add_local(&mut self, ty: wasmparser::Type) -> usize {
-        (unsafe { BinaryenFunctionAddVar(self.1, Type::from(ty).to_kind()) }) as usize
+    pub fn add_local(&mut self, ty: ir::Type) -> usize {
+        (unsafe { BinaryenFunctionAddVar(self.1, Type::from(ty).to_binaryen()) }) as usize
     }
 }
 
@@ -264,7 +266,7 @@ pub enum Type {
 }
 
 impl Type {
-    fn from_kind(kind: BinaryenType) -> Option<Type> {
+    fn from_binaryen(kind: BinaryenType) -> Option<Type> {
         let tys = &*TYPE_IDS;
         if kind == tys.none_t {
             Some(Type::None)
@@ -281,7 +283,7 @@ impl Type {
         }
     }
 
-    pub(crate) fn to_kind(&self) -> BinaryenType {
+    pub(crate) fn to_binaryen(&self) -> BinaryenType {
         let tys = &*TYPE_IDS;
         match self {
             &Type::None => tys.none_t,
@@ -294,21 +296,21 @@ impl Type {
     }
 }
 
-impl From<wasmparser::Type> for Type {
-    fn from(ty: wasmparser::Type) -> Self {
+impl From<ir::Type> for Type {
+    fn from(ty: ir::Type) -> Self {
         match ty {
-            wasmparser::Type::I32 => Type::I32,
-            wasmparser::Type::I64 => Type::I64,
-            wasmparser::Type::F32 => Type::F32,
-            wasmparser::Type::F64 => Type::F64,
-            wasmparser::Type::V128 => Type::V128,
+            ir::Type::I32 => Type::I32,
+            ir::Type::I64 => Type::I64,
+            ir::Type::F32 => Type::F32,
+            ir::Type::F64 => Type::F64,
+            ir::Type::V128 => Type::V128,
             _ => unimplemented!(),
         }
     }
 }
 
-pub fn tys_to_binaryen(tys: impl Iterator<Item = wasmparser::Type>) -> BinaryenType {
-    let tys: Vec<BinaryenType> = tys.map(|ty| Type::from(ty).to_kind()).collect();
+pub fn tys_to_binaryen(tys: impl Iterator<Item = ir::Type>) -> BinaryenType {
+    let tys: Vec<BinaryenType> = tys.map(|ty| Type::from(ty).to_binaryen()).collect();
     unsafe { BinaryenTypeCreate(tys.as_ptr(), tys.len() as BinaryenIndex) }
 }
 
@@ -322,7 +324,7 @@ fn name_to_string(name: *const c_char) -> Option<String> {
 
 impl Expression {
     pub fn ty(&self) -> Type {
-        Type::from_kind(unsafe { BinaryenExpressionGetType(self.1) }).unwrap()
+        Type::from_binaryen(unsafe { BinaryenExpressionGetType(self.1) }).unwrap()
     }
 
     pub fn deep_clone(&self) -> Self {
@@ -345,6 +347,44 @@ impl Expression {
             )
         })
     }
+
+    pub fn block_append_child(&mut self, child: Expression) {
+        unsafe {
+            BinaryenBlockAppendChild(self.1, child.1);
+        }
+    }
+
+    pub fn unreachable(module: &Module) -> Expression {
+        Expression(module.0, unsafe { BinaryenUnreachable(module.0) })
+    }
+
+    pub fn local_get(module: &Module, local: ir::Local, ty: ir::Type) -> Expression {
+        let local = local.index() as BinaryenIndex;
+        let ty = Type::from(ty).to_binaryen();
+        let expr = unsafe { BinaryenLocalGet(module.0, local, ty) };
+        Expression(module.0, expr)
+    }
+
+    pub fn local_set(module: &Module, local: ir::Local, value: Expression) -> Expression {
+        let local = local.index() as BinaryenIndex;
+        let expr = unsafe { BinaryenLocalSet(module.0, local, value.1) };
+        Expression(module.0, expr)
+    }
+
+    pub fn ret(module: &Module, values: &[Expression]) -> Expression {
+        let expr = if values.len() == 0 {
+            unsafe { BinaryenReturn(module.0, std::ptr::null()) }
+        } else if values.len() == 1 {
+            unsafe { BinaryenReturn(module.0, values[0].1) }
+        } else {
+            let exprs = values.iter().map(|e| e.1).collect::<Vec<_>>();
+            let tuple = unsafe {
+                BinaryenTupleMake(module.0, exprs.as_ptr(), exprs.len() as BinaryenIndex)
+            };
+            unsafe { BinaryenReturn(module.0, tuple) }
+        };
+        Expression(module.0, expr)
+    }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -387,13 +427,13 @@ lazy_static! {
 }
 
 impl UnaryOp {
-    fn from_kind(kind: u32) -> UnaryOp {
+    fn from_binaryen(kind: u32) -> UnaryOp {
         UnaryOp::Other(kind)
     }
 }
 
 impl BinaryOp {
-    fn from_kind(kind: u32) -> BinaryOp {
+    fn from_binaryen(kind: u32) -> BinaryOp {
         let ids = &*OP_IDS;
         if kind == ids.i32_add {
             BinaryOp::I32Add
@@ -447,9 +487,6 @@ pub struct Relooper(BinaryenModule, BinaryenRelooper);
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub struct RelooperBlock(BinaryenRelooperBlock);
 
-#[derive(Clone, Copy, PartialEq, Eq)]
-pub struct RelooperBlockWithSwitch(BinaryenRelooperBlock);
-
 impl Relooper {
     pub fn new(module: &Module) -> Relooper {
         let ptr = unsafe { RelooperCreate(module.0) };
@@ -467,12 +504,8 @@ impl Relooper {
         RelooperBlock(unsafe { RelooperAddBlock(self.1, expr.1) })
     }
 
-    pub fn add_block_with_switch(
-        &mut self,
-        expr: Expression,
-        sel: Expression,
-    ) -> RelooperBlockWithSwitch {
-        RelooperBlockWithSwitch(unsafe { RelooperAddBlockWithSwitch(self.1, expr.1, sel.1) })
+    pub fn add_block_with_switch(&mut self, expr: Expression, sel: Expression) -> RelooperBlock {
+        RelooperBlock(unsafe { RelooperAddBlockWithSwitch(self.1, expr.1, sel.1) })
     }
 }
 
@@ -488,9 +521,7 @@ impl RelooperBlock {
             RelooperAddBranch(self.0, to.0, std::ptr::null(), edge.1);
         }
     }
-}
 
-impl RelooperBlockWithSwitch {
     pub fn switch(&self, to: RelooperBlock, edge: Expression, indices: &[BinaryenIndex]) {
         unsafe {
             RelooperAddBranchForSwitch(
@@ -548,6 +579,10 @@ extern "C" {
     fn BinaryenBlockGetNumChildren(ptr: BinaryenExpression) -> u32;
     fn BinaryenBlockGetChildAt(ptr: BinaryenExpression, index: u32) -> BinaryenExpression;
     fn BinaryenBlockGetName(ptr: BinaryenExpression) -> *const c_char;
+    fn BinaryenBlockAppendChild(
+        ptr: BinaryenExpression,
+        child: BinaryenExpression,
+    ) -> BinaryenIndex;
 
     fn BinaryenLoopGetBody(ptr: BinaryenExpression) -> BinaryenExpression;
     fn BinaryenLoopGetName(ptr: BinaryenExpression) -> *const c_char;
@@ -654,6 +689,12 @@ extern "C" {
     fn BinaryenShrSInt32() -> u32;
 
     fn BinaryenConst(module: BinaryenModule, lit: BinaryenLiteral) -> BinaryenExpression;
+    fn BinaryenUnreachable(module: BinaryenModule) -> BinaryenExpression;
+    fn BinaryenLocalGet(
+        module: BinaryenModule,
+        local: BinaryenIndex,
+        ty: BinaryenType,
+    ) -> BinaryenExpression;
     fn BinaryenLocalSet(
         module: BinaryenModule,
         index: u32,
@@ -666,6 +707,12 @@ extern "C" {
         n_children: BinaryenIndex,
         ty: BinaryenType,
     ) -> BinaryenExpression;
+    fn BinaryenTupleMake(
+        module: BinaryenModule,
+        operands: *const BinaryenExpression,
+        n_operands: BinaryenIndex,
+    ) -> BinaryenExpression;
+    fn BinaryenReturn(module: BinaryenModule, expr: BinaryenExpression) -> BinaryenExpression;
 
     fn BinaryenAddFunc(
         module: BinaryenModule,

src/backend/lower.rs

@@ -1,10 +1,9 @@
-/*
 use crate::backend::binaryen;
 use crate::entity::EntityRef;
 use crate::ir::*;
 use crate::Operator;
 use fxhash::FxHashMap;
-use wasmparser::Type;
+use std::collections::BTreeMap;
 
 /// Creates a body expression for a function. Returns that expression,
 /// and new locals (as their types) that were created as temporaries
@@ -16,36 +15,133 @@ pub(crate) fn generate_body(
     let mut ctx = ElabCtx::new(body, into_mod);
 
     // For each block, generate an expr.
-    let mut block_exprs: FxHashMap<Block, binaryen::Expression> = FxHashMap::default();
+    let mut block_exprs: BTreeMap<Block, binaryen::Expression> = BTreeMap::default();
     for (block_id, block) in body.blocks.entries() {
-        let exprs = block
-            .insts
-            .iter()
-            .flat_map(|&inst| {
-                let inst = body.resolve_alias(inst);
-                ctx.elaborate_value(into_mod, inst)
-            })
-            .collect::<Vec<binaryen::Expression>>();
+        let mut exprs = vec![];
+        for (i, (ty, _param)) in block.params.iter().enumerate() {
+            let val = binaryen::Expression::local_get(
+                into_mod,
+                *ctx.block_param_next_locals.get(&(block_id, i)).unwrap(),
+                *ty,
+            );
+            let set = binaryen::Expression::local_set(
+                into_mod,
+                *ctx.block_param_locals.get(&(block_id, i)).unwrap(),
+                val,
+            );
+            exprs.push(set);
+        }
+        for &inst in &block.insts {
+            let inst = body.resolve_alias(inst);
+            if let Some(expr) = ctx.elaborate_value(into_mod, inst) {
+                exprs.push(expr);
+            }
+        }
         block_exprs.insert(block_id, binaryen::Expression::block(into_mod, &exprs[..]));
     }
 
     // Combine blocks into a single body expression, using the
     // relooper/stackifier support built into Binaryen.
     let mut relooper = binaryen::Relooper::new(into_mod);
-    let mut entry = None;
-    let mut relooper_blocks: FxHashMap<Block, binaryen::RelooperBlock> = FxHashMap::default();
-    for (block_id, block_expr) in block_exprs {}
+
+    // Create the blocks.
+    let mut relooper_blocks: FxHashMap<Block, (binaryen::Expression, binaryen::RelooperBlock)> =
+        FxHashMap::default();
+    for (block_id, block_expr) in &mut block_exprs {
+        let block = match &body.blocks[*block_id].terminator {
+            &Terminator::Select { value, .. } => {
+                let sel = ctx.get_val(value, into_mod);
+                relooper.add_block_with_switch(block_expr.clone(), sel)
+            }
+            _ => relooper.add_block(block_expr.clone()),
+        };
+        relooper_blocks.insert(*block_id, (block_expr.clone(), block));
+    }
+
+    // Add edges.
+    for &block_id in block_exprs.keys() {
+        let (mut block_expr, block) = relooper_blocks.get(&block_id).unwrap().clone();
+        match &body.blocks[block_id].terminator {
+            &Terminator::Br { ref target } => {
+                let (target_block, edge) = build_ssa_edge(&ctx, target, &relooper_blocks, into_mod);
+                block.branch(target_block, edge);
+            }
+            &Terminator::CondBr {
+                cond,
+                ref if_true,
+                ref if_false,
+            } => {
+                let (true_block, true_edge) =
+                    build_ssa_edge(&ctx, if_true, &relooper_blocks, into_mod);
+                let (false_block, false_edge) =
+                    build_ssa_edge(&ctx, if_false, &relooper_blocks, into_mod);
+                let cond = ctx.get_val(cond, into_mod);
+                block.cond_branch(true_block, cond, true_edge);
+                block.branch(false_block, false_edge);
+            }
+            &Terminator::Select {
+                value: _,
+                ref targets,
+                ref default,
+            } => {
+                for (i, target) in targets.iter().enumerate() {
+                    let (target_block, edge) =
+                        build_ssa_edge(&ctx, target, &relooper_blocks, into_mod);
+                    block.switch(target_block, edge, &[i as u32]);
+                }
+                let (target_block, edge) =
+                    build_ssa_edge(&ctx, default, &relooper_blocks, into_mod);
+                block.switch(target_block, edge, &[]);
+            }
+            &Terminator::Return { ref values } => {
+                let values = values
+                    .iter()
+                    .map(|value| ctx.get_val(*value, into_mod))
+                    .collect::<Vec<_>>();
+                block_expr.block_append_child(binaryen::Expression::ret(into_mod, &values[..]));
+            }
+            &Terminator::Unreachable | &Terminator::None => {
+                block_expr.block_append_child(binaryen::Expression::unreachable(into_mod));
+            }
+        }
+    }
 
     let index_var = ctx.new_local(Type::I32);
-    let expr = relooper.construct(entry.unwrap(), index_var.index());
+    let entry = relooper_blocks.get(&ctx.body.entry).unwrap().1.clone();
+    let expr = relooper.construct(entry, index_var.index());
     (ctx.new_locals, expr)
 }
 
+fn build_ssa_edge(
+    ctx: &ElabCtx<'_>,
+    target: &BlockTarget,
+    blocks: &FxHashMap<Block, (binaryen::Expression, binaryen::RelooperBlock)>,
+    into_mod: &mut binaryen::Module,
+) -> (binaryen::RelooperBlock, binaryen::Expression) {
+    // Copy all block args to the "next" locals. Build an edge block
+    // with these get-set pairs.
+    let mut sets = vec![];
+    for (i, arg) in target.args.iter().enumerate() {
+        let value = ctx.get_val(*arg, into_mod);
+        let set = binaryen::Expression::local_set(
+            into_mod,
+            *ctx.block_param_next_locals.get(&(target.block, i)).unwrap(),
+            value,
+        );
+        sets.push(set);
+    }
+
+    let edge_block = binaryen::Expression::block(into_mod, &sets[..]);
+    let block = blocks.get(&target.block).unwrap().1.clone();
+    (block, edge_block)
+}
+
 #[derive(Clone, Debug)]
 struct ElabCtx<'a> {
     body: &'a FunctionBody,
     op_result_locals: FxHashMap<(Value, usize), Local>,
     block_param_locals: FxHashMap<(Block, usize), Local>,
+    block_param_next_locals: FxHashMap<(Block, usize), Local>,
     new_locals: Vec<Type>,
 }
 
@@ -93,7 +189,6 @@ impl<'a> ElabCtx<'a> {
 
     fn get_val_local(&self, value: Value) -> Local {
         match &self.body.values[value] {
-            &ValueDef::Arg(idx, _) => Local::new(idx),
             &ValueDef::BlockParam(block, idx, _) => {
                 self.block_param_locals.get(&(block, idx)).copied().unwrap()
             }
@@ -102,10 +197,15 @@ impl<'a> ElabCtx<'a> {
                 self.op_result_locals.get(&(value, idx)).copied().unwrap()
             }
             &ValueDef::Alias(val) => self.get_val_local(val),
-            &ValueDef::Placeholder(_) => unreachable!(),
+            &ValueDef::Placeholder(_) | &ValueDef::None => unreachable!(),
         }
     }
 
+    fn get_val(&self, value: Value, into_mod: &mut binaryen::Module) -> binaryen::Expression {
+        let local = self.get_val_local(value);
+        binaryen::Expression::local_get(into_mod, local, self.body.values[value].ty().unwrap())
+    }
+
     fn new_local(&mut self, ty: Type) -> Local {
         let index = Local::new(self.body.locals.len() + self.new_locals.len());
         self.new_locals.push(ty);
@@ -152,4 +252,3 @@ pub(crate) fn create_new_func(
         body_expr,
     );
 }
-*/

src/ir/value.rs

@@ -13,6 +13,17 @@ pub enum ValueDef {
 }
 
 impl ValueDef {
+    pub fn ty(&self) -> Option<Type> {
+        match self {
+            &ValueDef::BlockParam(_, _, ty) => Some(ty),
+            &ValueDef::Operator(_, _, ref tys) if tys.len() == 0 => None,
+            &ValueDef::Operator(_, _, ref tys) if tys.len() == 1 => Some(tys[0]),
+            &ValueDef::PickOutput(_, _, ty) => Some(ty),
+            &ValueDef::Placeholder(ty) => Some(ty),
+            _ => None,
+        }
+    }
+
     pub fn visit_uses<F: FnMut(Value)>(&self, mut f: F) {
         match self {
             &ValueDef::BlockParam { .. } => {}