Implement codegen for binops

examples/custom_binop.reid

@@ -5,8 +5,8 @@ impl binop (lhs: u16) + (rhs: u32) -> u32 {
 }
 
 fn main() -> u32 {
-  let value = 6;
-  let other = 15;
+  let value = 6 as u16;
+  let other = 15 as u32;
 
-  return value * other + 7 * -value;
+  return value + other;
 }

reid/src/allocator.rs

@@ -6,8 +6,8 @@ use reid_lib::{
 };
 
 use crate::mir::{
-    self, CustomTypeKey, FunctionCall, FunctionDefinition, IfExpression, SourceModuleId,
-    TypeDefinition, TypeKind, WhileStatement,
+    self, CustomTypeKey, FunctionCall, FunctionDefinition, FunctionDefinitionKind, IfExpression,
+    SourceModuleId, TypeDefinition, TypeKind, WhileStatement,
 };
 
 #[derive(Debug)]
@@ -28,8 +28,12 @@ impl Allocator {
         }
     }
 
-    pub fn from(func: &FunctionDefinition, scope: &mut AllocatorScope) -> Allocator {
-        func.allocate(scope)
+    pub fn from(
+        func: &FunctionDefinitionKind,
+        params: &Vec<(String, TypeKind)>,
+        scope: &mut AllocatorScope,
+    ) -> Allocator {
+        func.allocate(scope, params)
     }
 
     pub fn allocate(&mut self, name: &String, ty: &TypeKind) -> Option<InstructionValue> {
@@ -45,12 +49,16 @@ impl Allocator {
 #[derive(Clone, Debug)]
 pub struct Allocation(String, TypeKind, InstructionValue);
 
-impl mir::FunctionDefinition {
-    fn allocate<'ctx, 'a>(&self, scope: &mut AllocatorScope<'ctx, 'a>) -> Allocator {
+impl mir::FunctionDefinitionKind {
+    fn allocate<'ctx, 'a>(
+        &self,
+        scope: &mut AllocatorScope<'ctx, 'a>,
+        parameters: &Vec<(String, TypeKind)>,
+    ) -> Allocator {
         let mut allocated = Vec::new();
-        match &self.kind {
+        match &self {
             mir::FunctionDefinitionKind::Local(block, _) => {
-                for param in &self.parameters {
+                for param in parameters {
                     let allocation = scope
                         .block
                         .build_named(

reid/src/ast/process.rs

@@ -110,8 +110,11 @@ impl ast::Module {
                         lhs: (lhs.0.clone(), lhs.1 .0.into_mir(module_id)),
                         op: op.mir(),
                         rhs: (rhs.0.clone(), rhs.1 .0.into_mir(module_id)),
-                        return_ty: return_ty.0.into_mir(module_id),
-                        block: block.into_mir(module_id),
+                        return_type: return_ty.0.into_mir(module_id),
+                        fn_kind: mir::FunctionDefinitionKind::Local(
+                            block.into_mir(module_id),
+                            block.2.as_meta(module_id),
+                        ),
                         meta: signature_range.as_meta(module_id),
                     });
                 }

reid/src/codegen.rs

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, collections::HashMap, mem, rc::Rc};
+use std::{cell::RefCell, collections::HashMap, hash::Hash, mem, rc::Rc};
 
 use reid_lib::{
     builder::{InstructionValue, TypeValue},
@@ -18,7 +18,10 @@ use crate::{
     allocator::{Allocator, AllocatorScope},
     lexer::{FullToken, Position},
     mir::{
-        self, implement::TypeCategory, CustomTypeKey, Metadata, NamedVariableRef, SourceModuleId,
+        self,
+        implement::TypeCategory,
+        pass::{ScopeBinopDef, ScopeBinopKey},
+        CustomTypeKey, FunctionDefinitionKind, Metadata, NamedVariableRef, SourceModuleId,
         StructField, StructType, TypeDefinition, TypeDefinitionKind, TypeKind, VagueLiteral,
         WhileStatement,
     },
@@ -77,17 +80,55 @@ pub struct Scope<'ctx, 'scope> {
     modules: &'scope HashMap<SourceModuleId, ModuleCodegen<'ctx>>,
     tokens: &'ctx Vec<FullToken>,
     module: &'ctx Module<'ctx>,
-    pub(super) module_id: SourceModuleId,
-    function: &'ctx StackFunction<'ctx>,
+    module_id: SourceModuleId,
+    function: &'ctx Function<'ctx>,
     pub(super) block: Block<'ctx>,
-    pub(super) types: &'scope HashMap<TypeValue, TypeDefinition>,
-    pub(super) type_values: &'scope HashMap<CustomTypeKey, TypeValue>,
-    functions: &'scope HashMap<String, StackFunction<'ctx>>,
+    types: &'scope HashMap<TypeValue, TypeDefinition>,
+    type_values: &'scope HashMap<CustomTypeKey, TypeValue>,
+    functions: &'scope HashMap<String, Function<'ctx>>,
+    binops: &'scope HashMap<ScopeBinopKey, StackBinopDefinition<'ctx>>,
     stack_values: HashMap<String, StackValue>,
     debug: Option<Debug<'ctx>>,
     allocator: Rc<RefCell<Allocator>>,
 }
 
+impl<'ctx, 'a> Scope<'ctx, 'a> {
+    fn with_block(&self, block: Block<'ctx>) -> Scope<'ctx, 'a> {
+        Scope {
+            block,
+            modules: self.modules,
+            tokens: self.tokens,
+            function: self.function,
+            context: self.context,
+            module: self.module,
+            module_id: self.module_id,
+            functions: self.functions,
+            types: self.types,
+            type_values: self.type_values,
+            stack_values: self.stack_values.clone(),
+            debug: self.debug.clone(),
+            allocator: self.allocator.clone(),
+            binops: self.binops,
+        }
+    }
+
+    /// Takes the block out from this scope, swaps the given block in it's place
+    /// and returns the old block.
+    fn swap_block(&mut self, block: Block<'ctx>) -> Block<'ctx> {
+        let mut old_block = block;
+        mem::swap(&mut self.block, &mut old_block);
+        old_block
+    }
+
+    fn get_typedef(&self, key: &CustomTypeKey) -> Option<&TypeDefinition> {
+        self.type_values.get(key).and_then(|v| self.types.get(v))
+    }
+
+    fn allocate(&self, name: &String, ty: &TypeKind) -> Option<InstructionValue> {
+        self.allocator.borrow_mut().allocate(name, ty)
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct Debug<'ctx> {
     info: &'ctx DebugInformation,
@@ -95,10 +136,6 @@ pub struct Debug<'ctx> {
     types: &'ctx HashMap<TypeKind, DebugTypeValue>,
 }
 
-pub struct StackFunction<'ctx> {
-    ir: Function<'ctx>,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct StackValue(StackValueKind, TypeKind);
 
@@ -148,39 +185,32 @@ impl StackValueKind {
     }
 }
 
-impl<'ctx, 'a> Scope<'ctx, 'a> {
-    fn with_block(&self, block: Block<'ctx>) -> Scope<'ctx, 'a> {
-        Scope {
-            block,
-            modules: self.modules,
-            tokens: self.tokens,
-            function: self.function,
-            context: self.context,
-            module: self.module,
-            module_id: self.module_id,
-            functions: self.functions,
-            types: self.types,
-            type_values: self.type_values,
-            stack_values: self.stack_values.clone(),
-            debug: self.debug.clone(),
-            allocator: self.allocator.clone(),
-        }
-    }
+pub struct StackBinopDefinition<'ctx> {
+    parameters: ((String, TypeKind), (String, TypeKind)),
+    return_ty: TypeKind,
+    ir: Function<'ctx>,
+}
 
-    /// Takes the block out from this scope, swaps the given block in it's place
-    /// and returns the old block.
-    fn swap_block(&mut self, block: Block<'ctx>) -> Block<'ctx> {
-        let mut old_block = block;
-        mem::swap(&mut self.block, &mut old_block);
-        old_block
-    }
-
-    fn get_typedef(&self, key: &CustomTypeKey) -> Option<&TypeDefinition> {
-        self.type_values.get(key).and_then(|v| self.types.get(v))
-    }
-
-    fn allocate(&self, name: &String, ty: &TypeKind) -> Option<InstructionValue> {
-        self.allocator.borrow_mut().allocate(name, ty)
+impl<'ctx> StackBinopDefinition<'ctx> {
+    fn codegen<'a>(
+        &self,
+        lhs: &StackValue,
+        rhs: &StackValue,
+        scope: &mut Scope<'ctx, 'a>,
+    ) -> StackValue {
+        let (lhs, rhs) = if lhs.1 == self.parameters.0 .1 && rhs.1 == self.parameters.1 .1 {
+            (lhs, rhs)
+        } else {
+            (rhs, lhs)
+        };
+        let instr = scope
+            .block
+            .build(Instr::FunctionCall(
+                self.ir.value(),
+                vec![lhs.instr(), rhs.instr()],
+            ))
+            .unwrap();
+        StackValue(StackValueKind::Immutable(instr), self.return_ty.clone())
     }
 }
 
@@ -327,180 +357,271 @@ impl mir::Module {
                 ),
             };
 
-            functions.insert(function.name.clone(), StackFunction { ir: func });
+            functions.insert(function.name.clone(), func);
+        }
+
+        let mut binops = HashMap::new();
+        for binop in &self.binop_defs {
+            let binop_fn_name = format!(
+                "binop.{}.{:?}.{}.{}",
+                binop.lhs.1, binop.op, binop.rhs.1, binop.return_type
+            );
+            let ir_function = module.function(
+                &binop_fn_name,
+                binop.return_type.get_type(&type_values),
+                vec![
+                    binop.lhs.1.get_type(&type_values),
+                    binop.rhs.1.get_type(&type_values),
+                ],
+                FunctionFlags::default(),
+            );
+            let mut entry = ir_function.block("entry");
+
+            let allocator = Allocator::from(
+                &binop.fn_kind,
+                &vec![binop.lhs.clone(), binop.rhs.clone()],
+                &mut AllocatorScope {
+                    block: &mut entry,
+                    module_id: self.module_id,
+                    type_values: &type_values,
+                },
+            );
+
+            let mut scope = Scope {
+                context,
+                modules: &modules,
+                tokens,
+                module: &module,
+                module_id: self.module_id,
+                function: &ir_function,
+                block: entry,
+                functions: &functions,
+                types: &types,
+                type_values: &type_values,
+                stack_values: HashMap::new(),
+                debug: Some(Debug {
+                    info: &debug,
+                    scope: compile_unit,
+                    types: &debug_types,
+                }),
+                binops: &binops,
+                allocator: Rc::new(RefCell::new(allocator)),
+            };
+
+            binop
+                .fn_kind
+                .codegen(
+                    binop_fn_name.clone(),
+                    false,
+                    &mut scope,
+                    &vec![binop.lhs.clone(), binop.rhs.clone()],
+                    &binop.return_type,
+                    &ir_function,
+                    match &binop.fn_kind {
+                        FunctionDefinitionKind::Local(_, meta) => {
+                            meta.into_debug(tokens, compile_unit)
+                        }
+                        FunctionDefinitionKind::Extern(_) => None,
+                        FunctionDefinitionKind::Intrinsic(_) => None,
+                    },
+                )
+                .unwrap();
+
+            binops.insert(
+                ScopeBinopKey {
+                    params: (binop.lhs.1.clone(), binop.rhs.1.clone()),
+                    operator: binop.op,
+                },
+                StackBinopDefinition {
+                    parameters: (binop.lhs.clone(), binop.rhs.clone()),
+                    return_ty: binop.return_type.clone(),
+                    ir: ir_function,
+                },
+            );
         }
 
         for mir_function in &self.functions {
             let function = functions.get(&mir_function.name).unwrap();
+            let mut entry = function.block("entry");
 
-            match &mir_function.kind {
-                mir::FunctionDefinitionKind::Local(block, _) => {
-                    let mut entry = function.ir.block("entry");
-                    let mut allocator = Allocator::from(
-                        mir_function,
-                        &mut AllocatorScope {
-                            block: &mut entry,
-                            module_id: self.module_id,
-                            type_values: &type_values,
-                        },
-                    );
+            let allocator = Allocator::from(
+                &mir_function.kind,
+                &mir_function.parameters,
+                &mut AllocatorScope {
+                    block: &mut entry,
+                    module_id: self.module_id,
+                    type_values: &type_values,
+                },
+            );
 
-                    // Insert debug information
-                    let debug_scope = if let Some(location) =
-                        mir_function.signature().into_debug(tokens, compile_unit)
-                    {
+            let mut scope = Scope {
+                context,
+                modules: &modules,
+                tokens,
+                module: &module,
+                module_id: self.module_id,
+                function,
+                block: entry,
+                functions: &functions,
+                types: &types,
+                type_values: &type_values,
+                stack_values: HashMap::new(),
+                debug: Some(Debug {
+                    info: &debug,
+                    scope: compile_unit,
+                    types: &debug_types,
+                }),
+                binops: &binops,
+                allocator: Rc::new(RefCell::new(allocator)),
+            };
+
+            mir_function
+                .kind
+                .codegen(
+                    mir_function.name.clone(),
+                    mir_function.is_pub,
+                    &mut scope,
+                    &mir_function.parameters,
+                    &mir_function.return_type,
+                    &function,
+                    match &mir_function.kind {
+                        FunctionDefinitionKind::Local(..) => {
+                            mir_function.signature().into_debug(tokens, compile_unit)
+                        }
+                        FunctionDefinitionKind::Extern(_) => None,
+                        FunctionDefinitionKind::Intrinsic(_) => None,
+                    },
+                )
+                .unwrap();
+        }
+
+        Ok(ModuleCodegen { module })
+    }
+}
+
+impl FunctionDefinitionKind {
+    fn codegen<'ctx, 'scope>(
+        &self,
+        name: String,
+        is_pub: bool,
+        scope: &mut Scope,
+        parameters: &Vec<(String, TypeKind)>,
+        return_type: &TypeKind,
+        ir_function: &Function,
+        debug_location: Option<DebugLocation>,
+    ) -> Result<(), ErrorKind> {
+        match &self {
+            mir::FunctionDefinitionKind::Local(block, _) => {
+                // Insert debug information
+                if let Some(debug) = &scope.debug {
+                    if let Some(location) = debug_location {
                         // let debug_scope = debug.inner_scope(&outer_scope, location);
 
-                        let fn_param_ty = &mir_function.return_type.get_debug_type_hard(
-                            compile_unit,
-                            &debug,
-                            &debug_types,
-                            &type_values,
-                            &types,
-                            self.module_id,
-                            &self.tokens,
-                            &modules,
-                        );
+                        let fn_param_ty = &return_type.get_debug_type(&debug, scope);
 
                         let debug_ty =
-                            debug.debug_type(DebugTypeData::Subprogram(DebugSubprogramType {
-                                parameters: vec![*fn_param_ty],
-                                flags: DwarfFlags,
-                            }));
+                            debug
+                                .info
+                                .debug_type(DebugTypeData::Subprogram(DebugSubprogramType {
+                                    parameters: vec![*fn_param_ty],
+                                    flags: DwarfFlags,
+                                }));
 
-                        let subprogram = debug.subprogram(DebugSubprogramData {
-                            name: mir_function.name.clone(),
-                            outer_scope: compile_unit.clone(),
+                        let subprogram = debug.info.subprogram(DebugSubprogramData {
+                            name: name.clone(),
+                            outer_scope: debug.scope.clone(),
                             location,
                             ty: debug_ty,
                             opts: DebugSubprogramOptionals {
-                                is_local: !mir_function.is_pub,
+                                is_local: !is_pub,
                                 is_definition: true,
                                 ..DebugSubprogramOptionals::default()
                             },
                         });
 
-                        function.ir.set_debug(subprogram);
-
-                        Some(subprogram)
-                    } else {
-                        None
-                    };
-
-                    // Compile actual IR part
-                    let mut stack_values = HashMap::new();
-                    for (i, (p_name, p_ty)) in mir_function.parameters.iter().enumerate() {
-                        // Codegen actual parameters
-                        let arg_name = format!("arg.{}", p_name);
-                        let param = entry
-                            .build_named(format!("{}.get", arg_name), Instr::Param(i))
-                            .unwrap();
-
-                        let alloca = allocator.allocate(&p_name, &p_ty).unwrap();
-
-                        entry
-                            .build_named(format!("{}.store", arg_name), Instr::Store(alloca, param))
-                            .unwrap();
-                        stack_values.insert(
-                            p_name.clone(),
-                            StackValue(
-                                StackValueKind::mutable(p_ty.is_mutable(), alloca),
-                                TypeKind::CodegenPtr(Box::new(p_ty.clone())),
-                            ),
-                        );
-
-                        // Generate debug info
-                        if let (Some(debug_scope), Some(location)) = (
-                            &debug_scope,
-                            mir_function.signature().into_debug(tokens, compile_unit),
-                        ) {
-                            // debug.metadata(
-                            //     &location,
-                            //     DebugMetadata::ParamVar(DebugParamVariable {
-                            //         name: p_name.clone(),
-                            //         arg_idx: i as u32,
-                            //         ty: p_ty.get_debug_type_hard(
-                            //             *debug_scope,
-                            //             &debug,
-                            //             &debug_types,
-                            //             &type_values,
-                            //             &types,
-                            //             self.module_id,
-                            //             &self.tokens,
-                            //             &modules,
-                            //         ),
-                            //         always_preserve: true,
-                            //         flags: DwarfFlags,
-                            //     }),
-                            // );
-                        }
-                    }
-
-                    let mut scope = Scope {
-                        context,
-                        modules: &modules,
-                        tokens,
-                        module: &module,
-                        module_id: self.module_id,
-                        function,
-                        block: entry,
-                        functions: &functions,
-                        types: &types,
-                        type_values: &type_values,
-                        stack_values,
-                        debug: debug_scope.and_then(|scope| {
-                            Some(Debug {
-                                info: &debug,
-                                scope,
-                                types: &debug_types,
-                            })
-                        }),
-                        allocator: Rc::new(RefCell::new(allocator)),
-                    };
-
-                    let state = State::default();
-                    if let Some(ret) = block.codegen(&mut scope, &state)? {
-                        scope.block.terminate(Term::Ret(ret.instr())).unwrap();
-                    } else {
-                        if !scope.block.delete_if_unused().unwrap() {
-                            // Add a void return just in case if the block
-                            // wasn't unused but didn't have a terminator yet
-                            scope.block.terminate(Term::RetVoid).ok();
-                        }
-                    }
-
-                    if let Some(debug) = scope.debug {
-                        let location =
-                            &block.return_meta().into_debug(tokens, debug.scope).unwrap();
-                        let location = debug.info.location(&debug.scope, *location);
-                        scope.block.set_terminator_location(location).unwrap();
+                        ir_function.set_debug(subprogram);
+                        scope.debug = Some(Debug {
+                            info: debug.info,
+                            scope: subprogram,
+                            types: debug.types,
+                        });
                     }
                 }
-                mir::FunctionDefinitionKind::Extern(_) => {}
-                mir::FunctionDefinitionKind::Intrinsic(kind) => {
-                    let entry = function.ir.block("entry");
-                    let mut scope = Scope {
-                        context,
-                        modules: &modules,
-                        tokens,
-                        module: &module,
-                        module_id: self.module_id,
-                        function,
-                        block: entry,
-                        functions: &functions,
-                        types: &types,
-                        type_values: &type_values,
-                        stack_values: Default::default(),
-                        debug: None,
-                        allocator: Rc::new(RefCell::new(Allocator::empty())),
-                    };
 
-                    kind.codegen(&mut scope)?
+                // Compile actual IR part
+                for (i, (p_name, p_ty)) in parameters.iter().enumerate() {
+                    // Codegen actual parameters
+                    let arg_name = format!("arg.{}", p_name);
+                    let param = scope
+                        .block
+                        .build_named(format!("{}.get", arg_name), Instr::Param(i))
+                        .unwrap();
+
+                    let alloca = scope.allocate(&p_name, &p_ty).unwrap();
+
+                    scope
+                        .block
+                        .build_named(format!("{}.store", arg_name), Instr::Store(alloca, param))
+                        .unwrap();
+                    scope.stack_values.insert(
+                        p_name.clone(),
+                        StackValue(
+                            StackValueKind::mutable(p_ty.is_mutable(), alloca),
+                            TypeKind::CodegenPtr(Box::new(p_ty.clone())),
+                        ),
+                    );
+
+                    // Generate debug info
+                    // if let (Some(debug_scope), Some(location)) = (
+                    //     &debug_scope,
+                    //     mir_function.signature().into_debug(tokens, compile_unit),
+                    // ) {
+                    //     debug.metadata(
+                    //         &location,
+                    //         DebugMetadata::ParamVar(DebugParamVariable {
+                    //             name: p_name.clone(),
+                    //             arg_idx: i as u32,
+                    //             ty: p_ty.get_debug_type_hard(
+                    //                 *debug_scope,
+                    //                 &debug,
+                    //                 &debug_types,
+                    //                 &type_values,
+                    //                 &types,
+                    //                 self.module_id,
+                    //                 &self.tokens,
+                    //                 &modules,
+                    //             ),
+                    //             always_preserve: true,
+                    //             flags: DwarfFlags,
+                    //         }),
+                    //     );
+                    // }
+                }
+
+                let state = State::default();
+                if let Some(ret) = block.codegen(scope, &state)? {
+                    scope.block.terminate(Term::Ret(ret.instr())).unwrap();
+                } else {
+                    if !scope.block.delete_if_unused().unwrap() {
+                        // Add a void return just in case if the block
+                        // wasn't unused but didn't have a terminator yet
+                        scope.block.terminate(Term::RetVoid).ok();
+                    }
+                }
+
+                if let Some(debug) = &scope.debug {
+                    let location = &block
+                        .return_meta()
+                        .into_debug(scope.tokens, debug.scope)
+                        .unwrap();
+                    let location = debug.info.location(&debug.scope, *location);
+                    scope.block.set_terminator_location(location).unwrap();
                 }
             }
-        }
-
-        Ok(ModuleCodegen { module })
+            mir::FunctionDefinitionKind::Extern(_) => {}
+            mir::FunctionDefinitionKind::Intrinsic(kind) => kind.codegen(scope)?,
+        };
+        Ok(())
     }
 }
 
@@ -639,9 +760,9 @@ impl mir::Statement {
             mir::StmtKind::While(WhileStatement {
                 condition, block, ..
             }) => {
-                let condition_block = scope.function.ir.block("while.cond");
-                let condition_true_block = scope.function.ir.block("while.body");
-                let condition_failed_block = scope.function.ir.block("while.end");
+                let condition_block = scope.function.block("while.cond");
+                let condition_true_block = scope.function.block("while.body");
+                let condition_failed_block = scope.function.block("while.end");
 
                 scope
                     .block
@@ -741,85 +862,102 @@ impl mir::Expression {
                 lit.as_type(),
             )),
             mir::ExprKind::BinOp(binop, lhs_exp, rhs_exp) => {
-                let lhs = lhs_exp
+                let lhs_val = lhs_exp
                     .codegen(scope, state)?
-                    .expect("lhs has no return value")
-                    .instr();
-                let rhs = rhs_exp
+                    .expect("lhs has no return value");
+                let rhs_val = rhs_exp
                     .codegen(scope, state)?
-                    .expect("rhs has no return value")
-                    .instr();
-                let lhs_type = lhs_exp
-                    .return_type(&Default::default(), scope.module_id)
-                    .unwrap()
-                    .1;
-                let instr = match (
-                    binop,
-                    lhs_type.signed(),
-                    lhs_type.category() == TypeCategory::Real,
-                ) {
-                    (mir::BinaryOperator::Add, _, false) => Instr::Add(lhs, rhs),
-                    (mir::BinaryOperator::Add, _, true) => Instr::FAdd(lhs, rhs),
-                    (mir::BinaryOperator::Minus, _, false) => Instr::Sub(lhs, rhs),
-                    (mir::BinaryOperator::Minus, _, true) => Instr::FSub(lhs, rhs),
-                    (mir::BinaryOperator::Mult, _, false) => Instr::Mul(lhs, rhs),
-                    (mir::BinaryOperator::Mult, _, true) => Instr::FMul(lhs, rhs),
-                    (mir::BinaryOperator::And, _, _) => Instr::And(lhs, rhs),
-                    (mir::BinaryOperator::Cmp(i), _, false) => Instr::ICmp(i.predicate(), lhs, rhs),
-                    (mir::BinaryOperator::Cmp(i), _, true) => Instr::FCmp(i.predicate(), lhs, rhs),
-                    (mir::BinaryOperator::Div, false, false) => Instr::UDiv(lhs, rhs),
-                    (mir::BinaryOperator::Div, true, false) => Instr::SDiv(lhs, rhs),
-                    (mir::BinaryOperator::Div, _, true) => Instr::FDiv(lhs, rhs),
-                    (mir::BinaryOperator::Mod, false, false) => {
-                        let div = scope
-                            .block
-                            .build(Instr::UDiv(lhs, rhs))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        let mul = scope
-                            .block
-                            .build(Instr::Mul(rhs, div))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        Instr::Sub(lhs, mul)
-                    }
-                    (mir::BinaryOperator::Mod, true, false) => {
-                        let div = scope
-                            .block
-                            .build(Instr::SDiv(lhs, rhs))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        let mul = scope
-                            .block
-                            .build(Instr::Mul(rhs, div))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        Instr::Sub(lhs, mul)
-                    }
-                    (mir::BinaryOperator::Mod, _, true) => {
-                        let div = scope
-                            .block
-                            .build(Instr::FDiv(lhs, rhs))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        let mul = scope
-                            .block
-                            .build(Instr::Mul(rhs, div))
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location);
-                        Instr::Sub(lhs, mul)
-                    }
-                };
-                Some(StackValue(
-                    StackValueKind::Immutable(
-                        scope
-                            .block
-                            .build(instr)
-                            .unwrap()
-                            .maybe_location(&mut scope.block, location),
-                    ),
-                    lhs_type,
-                ))
+                    .expect("rhs has no return value");
+                let lhs = lhs_val.instr();
+                let rhs = rhs_val.instr();
+
+                let operation = scope.binops.get(&ScopeBinopKey {
+                    params: (lhs_val.1.clone(), rhs_val.1.clone()),
+                    operator: *binop,
+                });
+
+                if let Some(operation) = operation {
+                    Some(operation.codegen(&lhs_val, &rhs_val, scope))
+                } else {
+                    dbg!((lhs_val.1.clone(), rhs_val.1.clone()));
+                    dbg!(&operation.map(|b| &b.return_ty));
+
+                    let lhs_type = lhs_exp
+                        .return_type(&Default::default(), scope.module_id)
+                        .unwrap()
+                        .1;
+                    let instr = match (
+                        binop,
+                        lhs_type.signed(),
+                        lhs_type.category() == TypeCategory::Real,
+                    ) {
+                        (mir::BinaryOperator::Add, _, false) => Instr::Add(lhs, rhs),
+                        (mir::BinaryOperator::Add, _, true) => Instr::FAdd(lhs, rhs),
+                        (mir::BinaryOperator::Minus, _, false) => Instr::Sub(lhs, rhs),
+                        (mir::BinaryOperator::Minus, _, true) => Instr::FSub(lhs, rhs),
+                        (mir::BinaryOperator::Mult, _, false) => Instr::Mul(lhs, rhs),
+                        (mir::BinaryOperator::Mult, _, true) => Instr::FMul(lhs, rhs),
+                        (mir::BinaryOperator::And, _, _) => Instr::And(lhs, rhs),
+                        (mir::BinaryOperator::Cmp(i), _, false) => {
+                            Instr::ICmp(i.predicate(), lhs, rhs)
+                        }
+                        (mir::BinaryOperator::Cmp(i), _, true) => {
+                            Instr::FCmp(i.predicate(), lhs, rhs)
+                        }
+                        (mir::BinaryOperator::Div, false, false) => Instr::UDiv(lhs, rhs),
+                        (mir::BinaryOperator::Div, true, false) => Instr::SDiv(lhs, rhs),
+                        (mir::BinaryOperator::Div, _, true) => Instr::FDiv(lhs, rhs),
+                        (mir::BinaryOperator::Mod, false, false) => {
+                            let div = scope
+                                .block
+                                .build(Instr::UDiv(lhs, rhs))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            let mul = scope
+                                .block
+                                .build(Instr::Mul(rhs, div))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            Instr::Sub(lhs, mul)
+                        }
+                        (mir::BinaryOperator::Mod, true, false) => {
+                            let div = scope
+                                .block
+                                .build(Instr::SDiv(lhs, rhs))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            let mul = scope
+                                .block
+                                .build(Instr::Mul(rhs, div))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            Instr::Sub(lhs, mul)
+                        }
+                        (mir::BinaryOperator::Mod, _, true) => {
+                            let div = scope
+                                .block
+                                .build(Instr::FDiv(lhs, rhs))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            let mul = scope
+                                .block
+                                .build(Instr::Mul(rhs, div))
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location);
+                            Instr::Sub(lhs, mul)
+                        }
+                    };
+                    Some(StackValue(
+                        StackValueKind::Immutable(
+                            scope
+                                .block
+                                .build(instr)
+                                .unwrap()
+                                .maybe_location(&mut scope.block, location),
+                        ),
+                        lhs_type,
+                    ))
+                }
             }
             mir::ExprKind::FunctionCall(call) => {
                 let ret_type_kind = call
@@ -850,7 +988,7 @@ impl mir::Expression {
                     .block
                     .build_named(
                         call.name.clone(),
-                        Instr::FunctionCall(callee.ir.value(), param_instrs),
+                        Instr::FunctionCall(callee.value(), param_instrs),
                     )
                     .unwrap();
 
@@ -898,7 +1036,7 @@ impl mir::Expression {
             }
             mir::ExprKind::If(if_expression) => if_expression.codegen(scope, state)?,
             mir::ExprKind::Block(block) => {
-                let inner = scope.function.ir.block("inner");
+                let inner = scope.function.block("inner");
                 scope.block.terminate(Term::Br(inner.value())).unwrap();
 
                 let mut inner_scope = scope.with_block(inner);
@@ -907,7 +1045,7 @@ impl mir::Expression {
                 } else {
                     None
                 };
-                let outer = scope.function.ir.block("outer");
+                let outer = scope.function.block("outer");
                 inner_scope.block.terminate(Term::Br(outer.value())).ok();
                 scope.swap_block(outer);
                 ret
@@ -1310,9 +1448,9 @@ impl mir::IfExpression {
         let condition = self.0.codegen(scope, state)?.unwrap();
 
         // Create blocks
-        let mut then_b = scope.function.ir.block("then");
-        let mut else_b = scope.function.ir.block("else");
-        let after_b = scope.function.ir.block("after");
+        let mut then_b = scope.function.block("then");
+        let mut else_b = scope.function.block("else");
+        let after_b = scope.function.block("after");
 
         if let Some(debug) = &scope.debug {
             let before_location = self.0 .1.into_debug(scope.tokens, debug.scope).unwrap();

reid/src/mir/fmt.rs

@@ -64,9 +64,9 @@ impl Display for BinopDefinition {
         write!(
             f,
             "impl binop ({}: {:#}) {} ({}: {:#}) -> {:#} ",
-            self.lhs.0, self.lhs.1, self.op, self.rhs.0, self.rhs.1, self.return_ty
+            self.lhs.0, self.lhs.1, self.op, self.rhs.0, self.rhs.1, self.return_type
         )?;
-        Display::fmt(&self.block, f)
+        Display::fmt(&self.fn_kind, f)
     }
 }
 

reid/src/mir/implement.rs

@@ -1,4 +1,4 @@
-use super::{typecheck::ErrorKind, typerefs::TypeRefs, VagueType as Vague, *};
+use super::{pass::ScopeBinopDef, typecheck::ErrorKind, typerefs::TypeRefs, VagueType as Vague, *};
 
 #[derive(Debug, Clone)]
 pub enum ReturnTypeOther {
@@ -95,7 +95,7 @@ impl TypeKind {
 
     /// Return the type that is the result of a binary operator between two
     /// values of this type
-    pub fn binop_type(&self, op: &BinaryOperator) -> TypeKind {
+    pub fn simple_binop_type(&self, op: &BinaryOperator) -> TypeKind {
         // TODO make some type of mechanism that allows to binop two values of
         // differing types..
         // TODO Return None for arrays later
@@ -110,9 +110,23 @@ impl TypeKind {
         }
     }
 
+    pub fn binop_type(
+        lhs: &TypeKind,
+        rhs: &TypeKind,
+        binop: &ScopeBinopDef,
+    ) -> Option<(TypeKind, TypeKind, TypeKind)> {
+        let lhs_ty = lhs.collapse_into(&binop.hands.0);
+        let rhs_ty = rhs.collapse_into(&binop.hands.1);
+        if let (Ok(lhs_ty), Ok(rhs_ty)) = (lhs_ty, rhs_ty) {
+            Some((lhs_ty, rhs_ty, binop.return_ty.clone()))
+        } else {
+            None
+        }
+    }
+
     /// Reverse of binop_type, where the given hint is the known required output
     /// type of the binop, and the output is the hint for the lhs/rhs type.
-    pub fn binop_hint(&self, op: &BinaryOperator) -> Option<TypeKind> {
+    pub fn simple_binop_hint(&self, op: &BinaryOperator) -> Option<TypeKind> {
         match op {
             BinaryOperator::Add
             | BinaryOperator::Minus
@@ -124,6 +138,22 @@ impl TypeKind {
         }
     }
 
+    pub fn binop_hint(
+        &self,
+        lhs: &TypeKind,
+        rhs: &TypeKind,
+        binop: &ScopeBinopDef,
+    ) -> Option<(TypeKind, TypeKind)> {
+        self.collapse_into(&binop.return_ty).ok()?;
+        let lhs_ty = lhs.collapse_into(&binop.hands.0);
+        let rhs_ty = rhs.collapse_into(&binop.hands.1);
+        if let (Ok(lhs_ty), Ok(rhs_ty)) = (lhs_ty, rhs_ty) {
+            Some((lhs_ty, rhs_ty))
+        } else {
+            None
+        }
+    }
+
     pub fn signed(&self) -> bool {
         match self {
             TypeKind::Bool => false,
@@ -259,6 +289,40 @@ impl TypeKind {
             },
         }
     }
+
+    pub fn try_collapse_two(
+        (lhs1, rhs1): (&TypeKind, &TypeKind),
+        (lhs2, rhs2): (&TypeKind, &TypeKind),
+    ) -> Option<(TypeKind, TypeKind)> {
+        if lhs1.collapse_into(&lhs2).is_ok() && rhs1.collapse_into(&rhs2).is_ok() {
+            Some((lhs1.clone(), rhs2.clone()))
+        } else if lhs1.collapse_into(&rhs2).is_ok() && rhs1.collapse_into(&lhs2).is_ok() {
+            Some((rhs1.clone(), lhs1.clone()))
+        } else {
+            None
+        }
+    }
+}
+
+impl BinaryOperator {
+    pub fn is_commutative(&self) -> bool {
+        match self {
+            BinaryOperator::Add => true,
+            BinaryOperator::Minus => false,
+            BinaryOperator::Mult => true,
+            BinaryOperator::Div => false,
+            BinaryOperator::Mod => false,
+            BinaryOperator::And => true,
+            BinaryOperator::Cmp(cmp_operator) => match cmp_operator {
+                CmpOperator::LT => false,
+                CmpOperator::LE => false,
+                CmpOperator::GT => false,
+                CmpOperator::GE => false,
+                CmpOperator::EQ => true,
+                CmpOperator::NE => true,
+            },
+        }
+    }
 }
 
 #[derive(PartialEq, Eq, PartialOrd, Ord)]

reid/src/mir/mod.rs

@@ -214,7 +214,7 @@ impl VagueLiteral {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum BinaryOperator {
     Add,
     Minus,
@@ -226,7 +226,7 @@ pub enum BinaryOperator {
 }
 
 /// Specifically the operators that LLVM likes to take in as "icmp" parameters
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum CmpOperator {
     LT,
     LE,
@@ -370,14 +370,18 @@ pub struct BinopDefinition {
     pub lhs: (String, TypeKind),
     pub op: BinaryOperator,
     pub rhs: (String, TypeKind),
-    pub return_ty: TypeKind,
-    pub block: Block,
+    pub return_type: TypeKind,
+    pub fn_kind: FunctionDefinitionKind,
     pub meta: Metadata,
 }
 
 impl BinopDefinition {
-    pub fn block_meta(&self) -> Metadata {
-        self.block.meta
+    pub fn block_meta(&self) -> Option<Metadata> {
+        match &self.fn_kind {
+            FunctionDefinitionKind::Local(block, _) => Some(block.meta),
+            FunctionDefinitionKind::Extern(_) => None,
+            FunctionDefinitionKind::Intrinsic(_) => None,
+        }
     }
 
     pub fn signature(&self) -> Metadata {

reid/src/mir/pass.rs

@@ -1,7 +1,7 @@
 //! This module contains relevant code for [`Pass`] and shared code between
 //! passes. Passes can be performed on Reid MIR to e.g. typecheck the code.
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::convert::Infallible;
 use std::error::Error as STDError;
 
@@ -111,10 +111,15 @@ impl<Key: std::hash::Hash + Eq, T: Clone + std::fmt::Debug> Storage<Key, T> {
     pub fn get(&self, key: &Key) -> Option<&T> {
         self.0.get(key)
     }
+
+    pub fn iter(&self) -> impl Iterator<Item = (&Key, &T)> {
+        self.0.iter()
+    }
 }
 
 #[derive(Clone, Default, Debug)]
 pub struct Scope<Data: Clone + Default> {
+    pub binops: Storage<ScopeBinopKey, ScopeBinopDef>,
     pub function_returns: Storage<String, ScopeFunction>,
     pub variables: Storage<String, ScopeVariable>,
     pub types: Storage<CustomTypeKey, TypeDefinition>,
@@ -128,6 +133,7 @@ impl<Data: Clone + Default> Scope<Data> {
         Scope {
             function_returns: self.function_returns.clone(),
             variables: self.variables.clone(),
+            binops: self.binops.clone(),
             types: self.types.clone(),
             return_type_hint: self.return_type_hint.clone(),
             data: self.data.clone(),
@@ -162,6 +168,58 @@ pub struct ScopeVariable {
     pub mutable: bool,
 }
 
+#[derive(Clone, Debug, Eq)]
+pub struct ScopeBinopKey {
+    pub params: (TypeKind, TypeKind),
+    pub operator: BinaryOperator,
+}
+
+#[derive(Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub enum CommutativeKind {
+    True,
+    False,
+    Any,
+}
+
+impl PartialEq for ScopeBinopKey {
+    fn eq(&self, other: &Self) -> bool {
+        if self.operator != other.operator {
+            return false;
+        }
+        if self.operator.is_commutative() != other.operator.is_commutative() {
+            return false;
+        }
+        let operators_eq = self.params == other.params;
+        let swapped_ops_eq = (self.params.1.clone(), self.params.0.clone()) == other.params;
+        if self.operator.is_commutative() {
+            operators_eq || swapped_ops_eq
+        } else {
+            operators_eq
+        }
+    }
+}
+
+impl std::hash::Hash for ScopeBinopKey {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        if self.operator.is_commutative() {
+            let mut sorted = vec![&self.params.0, &self.params.1];
+            sorted.sort();
+            sorted.hash(state);
+            self.operator.hash(state);
+        } else {
+            self.params.hash(state);
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct ScopeBinopDef {
+    pub hands: (TypeKind, TypeKind),
+    pub operator: BinaryOperator,
+    pub commutative: bool,
+    pub return_ty: TypeKind,
+}
+
 pub struct PassState<'st, 'sc, Data: Clone + Default, TError: STDError + Clone> {
     state: &'st mut State<TError>,
     pub scope: &'sc mut Scope<Data>,
@@ -301,6 +359,24 @@ impl Module {
                 .ok();
         }
 
+        for binop in &self.binop_defs {
+            scope
+                .binops
+                .set(
+                    ScopeBinopKey {
+                        params: (binop.lhs.1.clone(), binop.rhs.1.clone()),
+                        operator: binop.op,
+                    },
+                    ScopeBinopDef {
+                        hands: (binop.lhs.1.clone(), binop.rhs.1.clone()),
+                        operator: binop.op,
+                        commutative: true,
+                        return_ty: binop.return_type.clone(),
+                    },
+                )
+                .ok();
+        }
+
         for function in &self.functions {
             scope
                 .function_returns

reid/src/mir/typecheck.rs

@@ -70,6 +70,8 @@ pub enum ErrorKind {
     NotCastableTo(TypeKind, TypeKind),
     #[error("Cannot divide by zero")]
     DivideZero,
+    #[error("Binary operation between {0} and {1} is already defined!")]
+    BinaryOpAlreadyDefined(TypeKind, TypeKind),
 }
 
 /// Struct used to implement a type-checking pass that can be performed on the
@@ -134,7 +136,7 @@ impl<'t> Pass for TypeCheck<'t> {
 
         for binop in &mut module.binop_defs {
             let res = binop.typecheck(&self.refs, &mut state.inner());
-            state.ok(res, binop.block_meta());
+            state.ok(res, binop.block_meta().unwrap_or(binop.signature()));
         }
 
         for function in &mut module.functions {
@@ -201,18 +203,22 @@ impl BinopDefinition {
             state.ok(res, self.signature());
         }
 
-        let return_type = self.return_ty.clone().assert_known(typerefs, state)?;
+        let return_type = self.return_type.clone().assert_known(typerefs, state)?;
 
-        state.scope.return_type_hint = Some(self.return_ty.clone());
-        let inferred = self
-            .block
-            .typecheck(&mut state.inner(), &typerefs, Some(&return_type));
+        state.scope.return_type_hint = Some(self.return_type.clone());
+        let inferred =
+            self.fn_kind
+                .typecheck(&typerefs, &mut state.inner(), Some(return_type.clone()));
 
         match inferred {
             Ok(t) => return_type
                 .collapse_into(&t.1)
                 .or(Err(ErrorKind::ReturnTypeMismatch(return_type, t.1))),
-            Err(e) => Ok(state.or_else(Err(e), return_type, self.block_meta())),
+            Err(e) => Ok(state.or_else(
+                Err(e),
+                return_type,
+                self.block_meta().unwrap_or(self.signature()),
+            )),
         }
     }
 }
@@ -244,10 +250,30 @@ impl FunctionDefinition {
         }
 
         let return_type = self.return_type.clone().assert_known(typerefs, state)?;
-        let inferred = match &mut self.kind {
+        let inferred = self
+            .kind
+            .typecheck(typerefs, state, Some(self.return_type.clone()));
+
+        match inferred {
+            Ok(t) => return_type
+                .collapse_into(&t.1)
+                .or(Err(ErrorKind::ReturnTypeMismatch(return_type, t.1))),
+            Err(e) => Ok(state.or_else(Err(e), return_type, self.block_meta())),
+        }
+    }
+}
+
+impl FunctionDefinitionKind {
+    fn typecheck(
+        &mut self,
+        typerefs: &TypeRefs,
+        state: &mut TypecheckPassState,
+        hint: Option<TypeKind>,
+    ) -> Result<(ReturnKind, TypeKind), ErrorKind> {
+        match self {
             FunctionDefinitionKind::Local(block, _) => {
-                state.scope.return_type_hint = Some(self.return_type.clone());
-                block.typecheck(&mut state.inner(), &typerefs, Some(&return_type))
+                state.scope.return_type_hint = hint.clone();
+                block.typecheck(&mut state.inner(), &typerefs, hint.as_ref())
             }
             FunctionDefinitionKind::Extern(_) => {
                 Ok((ReturnKind::Soft, TypeKind::Vague(Vague::Unknown)))
@@ -255,13 +281,6 @@ impl FunctionDefinition {
             FunctionDefinitionKind::Intrinsic(..) => {
                 Ok((ReturnKind::Soft, TypeKind::Vague(Vague::Unknown)))
             }
-        };
-
-        match inferred {
-            Ok(t) => return_type
-                .collapse_into(&t.1)
-                .or(Err(ErrorKind::ReturnTypeMismatch(return_type, t.1))),
-            Err(e) => Ok(state.or_else(Err(e), return_type, self.block_meta())),
         }
     }
 }
@@ -489,34 +508,63 @@ impl Expression {
                 Ok(literal.as_type())
             }
             ExprKind::BinOp(op, lhs, rhs) => {
-                // TODO make sure lhs and rhs can actually do this binary
-                // operation once relevant
-                let lhs_res = lhs.typecheck(
-                    state,
-                    &typerefs,
-                    hint_t.and_then(|t| t.binop_hint(op)).as_ref(),
-                );
+                // First find unfiltered parameters to binop
+                let lhs_res = lhs.typecheck(state, &typerefs, None);
                 let lhs_type = state.or_else(lhs_res, TypeKind::Vague(Vague::Unknown), lhs.1);
-                let rhs_res = rhs.typecheck(state, &typerefs, Some(&lhs_type));
+                let rhs_res = rhs.typecheck(state, &typerefs, None);
                 let rhs_type = state.or_else(rhs_res, TypeKind::Vague(Vague::Unknown), rhs.1);
 
-                if let Some(collapsed) = state.ok(rhs_type.collapse_into(&rhs_type), self.1) {
-                    // Try to coerce both sides again with collapsed type
-                    lhs.typecheck(state, &typerefs, Some(&collapsed)).ok();
-                    rhs.typecheck(state, &typerefs, Some(&collapsed)).ok();
-                }
+                let operator = state
+                    .scope
+                    .binops
+                    .get(&pass::ScopeBinopKey {
+                        params: (lhs_type.clone(), rhs_type.clone()),
+                        operator: *op,
+                    })
+                    .cloned();
 
-                let both_t = lhs_type.collapse_into(&rhs_type)?;
+                if let Some(operator) = operator {
+                    // Re-typecheck with found operator hints
+                    let (lhs_ty, rhs_ty) = TypeKind::try_collapse_two(
+                        (&lhs_type, &rhs_type),
+                        (&operator.hands.0, &operator.hands.1),
+                    )
+                    .unwrap();
+                    let lhs_res = lhs.typecheck(state, &typerefs, Some(&lhs_ty));
+                    let rhs_res = rhs.typecheck(state, &typerefs, Some(&rhs_ty));
+                    state.or_else(lhs_res, TypeKind::Vague(Vague::Unknown), lhs.1);
+                    state.or_else(rhs_res, TypeKind::Vague(Vague::Unknown), rhs.1);
+                    Ok(operator.return_ty)
+                } else {
+                    // Re-typecheck with typical everyday binop
+                    let lhs_res = lhs.typecheck(
+                        state,
+                        &typerefs,
+                        hint_t.and_then(|t| t.simple_binop_hint(op)).as_ref(),
+                    );
+                    let lhs_type = state.or_else(lhs_res, TypeKind::Vague(Vague::Unknown), lhs.1);
+                    let rhs_res = rhs.typecheck(state, &typerefs, Some(&lhs_type));
+                    let rhs_type = state.or_else(rhs_res, TypeKind::Vague(Vague::Unknown), rhs.1);
 
-                if *op == BinaryOperator::Minus && !lhs_type.signed() {
-                    if let (Some(lhs_val), Some(rhs_val)) = (lhs.num_value()?, rhs.num_value()?) {
-                        if lhs_val < rhs_val {
-                            return Err(ErrorKind::NegativeUnsignedValue(lhs_type));
+                    let both_t = lhs_type.collapse_into(&rhs_type)?;
+
+                    if *op == BinaryOperator::Minus && !lhs_type.signed() {
+                        if let (Some(lhs_val), Some(rhs_val)) = (lhs.num_value()?, rhs.num_value()?)
+                        {
+                            if lhs_val < rhs_val {
+                                return Err(ErrorKind::NegativeUnsignedValue(lhs_type));
+                            }
                         }
                     }
-                }
 
-                Ok(both_t.binop_type(op))
+                    if let Some(collapsed) = state.ok(rhs_type.collapse_into(&rhs_type), self.1) {
+                        // Try to coerce both sides again with collapsed type
+                        lhs.typecheck(state, &typerefs, Some(&collapsed)).ok();
+                        rhs.typecheck(state, &typerefs, Some(&collapsed)).ok();
+                    }
+
+                    Ok(both_t.simple_binop_type(op))
+                }
             }
             ExprKind::FunctionCall(function_call) => {
                 let true_function = state
@@ -795,7 +843,7 @@ impl Expression {
                 Ok(*inner)
             }
             ExprKind::CastTo(expression, type_kind) => {
-                let expr = expression.typecheck(state, typerefs, None)?;
+                let expr = expression.typecheck(state, typerefs, Some(&type_kind))?;
                 expr.resolve_ref(typerefs).cast_into(type_kind)
             }
         }

reid/src/mir/typeinference.rs

@@ -4,12 +4,16 @@
 //! must then be passed through TypeCheck with the same [`TypeRefs`] in order to
 //! place the correct types from the IDs and check that there are no issues.
 
-use std::{collections::HashMap, convert::Infallible, iter};
+use std::{
+    collections::{HashMap, HashSet},
+    convert::Infallible,
+    iter,
+};
 
 use crate::{mir::TypeKind, util::try_all};
 
 use super::{
-    pass::{Pass, PassResult, PassState},
+    pass::{self, Pass, PassResult, PassState, ScopeBinopDef, ScopeBinopKey},
     typecheck::{ErrorKind, ErrorTypedefKind},
     typerefs::{ScopeTypeRefs, TypeRef, TypeRefs},
     BinopDefinition, Block, CustomTypeKey, ExprKind, Expression, FunctionDefinition,
@@ -55,9 +59,28 @@ impl<'t> Pass for TypeInference<'t> {
             }
         }
 
+        let mut seen_binops = HashSet::new();
+        for binop in &module.binop_defs {
+            let binop_key = ScopeBinopKey {
+                params: (binop.lhs.1.clone(), binop.rhs.1.clone()),
+                operator: binop.op,
+            };
+            if seen_binops.contains(&binop_key) {
+                state.note_errors(
+                    &vec![ErrorKind::BinaryOpAlreadyDefined(
+                        binop.lhs.1.clone(),
+                        binop.rhs.1.clone(),
+                    )],
+                    binop.signature(),
+                );
+            } else {
+                seen_binops.insert(binop_key);
+            }
+        }
+
         for binop in &mut module.binop_defs {
             let res = binop.infer_types(&self.refs, &mut state.inner());
-            state.ok(res, binop.block_meta());
+            state.ok(res, binop.block_meta().unwrap_or(binop.signature()));
         }
 
         for function in &mut module.functions {
@@ -101,18 +124,12 @@ impl BinopDefinition {
             self.signature(),
         );
 
-        state.scope.return_type_hint = Some(self.return_ty.clone());
-        let ret_res = self.block.infer_types(state, &scope_hints);
-        let (_, mut ret_ty) = state.or_else(
-            ret_res,
-            (
-                ReturnKind::Soft,
-                scope_hints.from_type(&Vague(Unknown)).unwrap(),
-            ),
-            self.block_meta(),
-        );
-
-        ret_ty.narrow(&scope_hints.from_type(&self.return_ty).unwrap());
+        let ret_ty =
+            self.fn_kind
+                .infer_types(state, &scope_hints, Some(self.return_type.clone()))?;
+        if let Some(mut ret_ty) = ret_ty {
+            ret_ty.narrow(&scope_hints.from_type(&self.return_type).unwrap());
+        }
 
         Ok(())
     }
@@ -124,10 +141,10 @@ impl FunctionDefinition {
         type_refs: &TypeRefs,
         state: &mut TypeInferencePassState,
     ) -> Result<(), ErrorKind> {
-        let scope_hints = ScopeTypeRefs::from(type_refs);
+        let scope_refs = ScopeTypeRefs::from(type_refs);
         for param in &self.parameters {
             let param_t = state.or_else(param.1.assert_unvague(), Vague(Unknown), self.signature());
-            let res = scope_hints
+            let res = scope_refs
                 .new_var(param.0.clone(), false, &param_t)
                 .or(Err(ErrorKind::VariableAlreadyDefined(param.0.clone())));
             state.ok(res, self.signature());
@@ -138,21 +155,51 @@ impl FunctionDefinition {
                 state.scope.return_type_hint = Some(self.return_type.clone());
 
                 // Infer block return type
-                let ret_res = block.infer_types(state, &scope_hints);
+                let ret_res = block.infer_types(state, &scope_refs);
 
                 // Narrow block type to declared function type
                 if let Some(mut ret_ty) = state.ok(ret_res.map(|(_, ty)| ty), self.block_meta()) {
-                    ret_ty.narrow(&scope_hints.from_type(&self.return_type).unwrap());
+                    ret_ty.narrow(&scope_refs.from_type(&self.return_type).unwrap());
                 }
             }
             FunctionDefinitionKind::Extern(_) => {}
             FunctionDefinitionKind::Intrinsic(_) => {}
         };
+        let return_ty = self
+            .kind
+            .infer_types(state, &scope_refs, Some(self.return_type.clone()));
+
+        if let Some(Some(mut ret_ty)) = state.ok(return_ty, self.block_meta()) {
+            ret_ty.narrow(&scope_refs.from_type(&self.return_type).unwrap());
+        }
 
         Ok(())
     }
 }
 
+impl FunctionDefinitionKind {
+    fn infer_types<'s>(
+        &mut self,
+        state: &mut TypeInferencePassState,
+        scope_refs: &'s ScopeTypeRefs,
+        hint: Option<TypeKind>,
+    ) -> Result<Option<TypeRef<'s>>, ErrorKind> {
+        Ok(match self {
+            FunctionDefinitionKind::Local(block, _) => {
+                state.scope.return_type_hint = hint;
+
+                // Infer block return type
+                let ret_res = block.infer_types(state, &scope_refs);
+
+                // Narrow block type to declared function type
+                Some(ret_res.map(|(_, ty)| ty)?)
+            }
+            FunctionDefinitionKind::Extern(_) => None,
+            FunctionDefinitionKind::Intrinsic(_) => None,
+        })
+    }
+}
+
 impl Block {
     fn infer_types<'s>(
         &mut self,
@@ -265,7 +312,7 @@ impl Expression {
                 let mut lhs_ref = lhs.infer_types(state, type_refs)?;
                 let mut rhs_ref = rhs.infer_types(state, type_refs)?;
                 type_refs
-                    .binop(op, &mut lhs_ref, &mut rhs_ref)
+                    .binop(op, &mut lhs_ref, &mut rhs_ref, &state.scope.binops)
                     .ok_or(ErrorKind::TypesIncompatible(
                         lhs_ref.resolve_deep().unwrap(),
                         rhs_ref.resolve_deep().unwrap(),

reid/src/mir/typerefs.rs

@@ -6,7 +6,11 @@ use std::{
 
 use crate::mir::VagueType;
 
-use super::{typecheck::ErrorKind, BinaryOperator, TypeKind};
+use super::{
+    pass::{ScopeBinopDef, ScopeBinopKey, Storage},
+    typecheck::ErrorKind,
+    BinaryOperator, TypeKind,
+};
 
 #[derive(Clone)]
 pub struct TypeRef<'scope>(
@@ -227,8 +231,31 @@ impl<'outer> ScopeTypeRefs<'outer> {
         op: &BinaryOperator,
         lhs: &mut TypeRef<'outer>,
         rhs: &mut TypeRef<'outer>,
+        binops: &Storage<ScopeBinopKey, ScopeBinopDef>,
     ) -> Option<TypeRef<'outer>> {
+        for (_, binop) in binops.iter() {
+            if let Some(ret) = try_binop(lhs, rhs, binop) {
+                return Some(ret);
+            }
+            if binop.commutative {
+                if let Some(ret) = try_binop(rhs, lhs, binop) {
+                    return Some(ret);
+                }
+            }
+        }
         let ty = lhs.narrow(rhs)?;
-        self.from_type(&ty.as_type().binop_type(op))
+        self.from_type(&ty.as_type().simple_binop_type(op))
     }
 }
+
+fn try_binop<'o>(
+    lhs: &mut TypeRef<'o>,
+    rhs: &mut TypeRef<'o>,
+    binop: &ScopeBinopDef,
+) -> Option<TypeRef<'o>> {
+    let (lhs_ty, rhs_ty, ret_ty) =
+        TypeKind::binop_type(&lhs.resolve_deep()?, &rhs.resolve_deep()?, binop)?;
+    lhs.narrow(&lhs.1.from_type(&lhs_ty).unwrap()).unwrap();
+    rhs.narrow(&rhs.1.from_type(&rhs_ty).unwrap()).unwrap();
+    lhs.1.from_type(&ret_ty)
+}