Improved code generation

src/build/core/CompileCall.go

@@ -1,7 +1,7 @@
 package core
 
 import (
-	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/expression"
 )
 
@@ -9,9 +9,43 @@ import (
 // All call registers must hold the correct parameter values before the function invocation.
 // Registers that are in use must be saved if they are modified by the function.
 // After the function call, they must be restored in reverse order.
-func (f *Function) CompileCall(expr *expression.Expression) error {
+func (f *Function) CompileCall(root *expression.Expression) error {
-	_, err := f.EvaluateCall(expr)
+	funcName := root.Children[0].Token.Text()
-	return err
+	parameters := root.Children[1:]
+	registers := f.cpu.Input[:len(parameters)]
+	isSyscall := funcName == "syscall"
+
+	if isSyscall {
+		registers = f.cpu.Syscall[:len(parameters)]
+	}
+
+	err := f.ExpressionsToRegisters(parameters, registers)
+
+	if err != nil {
+		return err
+	}
+
+	for _, register := range f.cpu.General {
+		if !f.cpu.IsFree(register) {
+			f.assembler.Register(asm.PUSH, register)
+		}
+	}
+
+	if isSyscall {
+		f.assembler.Syscall()
+	} else {
+		f.assembler.Call(funcName)
+	}
+
+	for i := len(f.cpu.General) - 1; i >= 0; i-- {
+		register := f.cpu.General[i]
+
+		if !f.cpu.IsFree(register) {
+			f.assembler.Register(asm.POP, register)
+		}
+	}
+
+	return nil
 }
 
 // CompileSyscall executes a syscall.
@@ -23,17 +57,3 @@ func (f *Function) CompileSyscall(expr *expression.Expression) error {
 	f.sideEffects++
 	return err
 }
-
-// ExpressionsToRegisters moves multiple expressions into the specified registers.
-func (f *Function) ExpressionsToRegisters(expressions []*expression.Expression, registers []cpu.Register) error {
-	for i := len(registers) - 1; i >= 0; i-- {
-		f.SaveRegister(registers[i])
-		err := f.EvaluateTo(expressions[i], registers[i])
-
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}

src/build/core/CompileDefinition.go

@@ -59,27 +59,6 @@ func (f *Function) AddVariable(variable *Variable) {
 	f.cpu.Use(variable.Register)
 }
 
-func (f *Function) addTemporary(root *expression.Expression) *Variable {
-	f.count.tmps++
-	name := fmt.Sprintf("t%d", f.count.tmps)
-	register := f.cpu.MustUseFree(f.cpu.General)
-
-	tmp := &Variable{
-		Name:     name,
-		Value:    root,
-		Alive:    1,
-		Register: register,
-	}
-
-	f.variables[name] = tmp
-
-	if config.Comments {
-		f.assembler.Comment(fmt.Sprintf("%s = %s (%s)", name, root, register))
-	}
-
-	return tmp
-}
-
 func (f *Function) useVariable(variable *Variable) {
 	variable.Alive--
 
@@ -121,7 +100,7 @@ func (f *Function) storeVariableInRegister(name string, value *expression.Expres
 		panic("no free registers")
 	}
 
-	err := f.EvaluateTo(value, reg)
+	err := f.ExpressionToRegister(value, reg)
 
 	f.AddVariable(&Variable{
 		Name:     name,

src/build/core/CompileReturn.go

@@ -12,5 +12,5 @@ func (f *Function) CompileReturn(node *ast.Return) error {
 		return nil
 	}
 
-	return f.EvaluateTo(node.Value, f.cpu.Return[0])
+	return f.ExpressionToRegister(node.Value, f.cpu.Output[0])
 }

src/build/core/Evaluate.go

@@ -1,123 +0,0 @@
-package core
-
-import (
-	"git.akyoto.dev/cli/q/src/build/asm"
-	"git.akyoto.dev/cli/q/src/build/ast"
-	"git.akyoto.dev/cli/q/src/build/cpu"
-	"git.akyoto.dev/cli/q/src/build/expression"
-	"git.akyoto.dev/cli/q/src/build/token"
-)
-
-// Evaluate evaluates the result of an expression and saves it into a temporary register.
-func (f *Function) Evaluate(root *expression.Expression) (*Variable, error) {
-	if root.IsLeaf() {
-		return f.EvaluateLeaf(root)
-	}
-
-	if ast.IsFunctionCall(root) {
-		return f.EvaluateCall(root)
-	}
-
-	left := root.Children[0]
-	right := root.Children[1]
-
-	tmpLeft, err := f.Evaluate(left)
-
-	if err != nil {
-		return nil, err
-	}
-
-	tmpLeftExpr := expression.NewLeaf(token.Token{
-		Kind:     token.Identifier,
-		Position: left.Token.Position,
-		Bytes:    []byte(tmpLeft.Name),
-	})
-
-	tmpLeftExpr.Parent = root
-	root.Children[0].Parent = nil
-	root.Children[0] = tmpLeftExpr
-
-	tmpRight, err := f.Evaluate(right)
-
-	if err != nil {
-		return nil, err
-	}
-
-	tmpRightExpr := expression.NewLeaf(token.Token{
-		Kind:     token.Identifier,
-		Position: left.Token.Position,
-		Bytes:    []byte(tmpRight.Name),
-	})
-
-	tmpRightExpr.Parent = root
-	root.Children[1].Parent = nil
-	root.Children[1] = tmpRightExpr
-
-	tmp := f.addTemporary(root)
-
-	f.assembler.RegisterRegister(asm.MOVE, tmp.Register, tmpLeft.Register)
-	f.useVariable(tmpLeft)
-
-	err = f.opRegisterRegister(root.Token, tmp.Register, tmpRight.Register)
-	f.useVariable(tmpRight)
-
-	return tmp, err
-}
-
-func (f *Function) EvaluateCall(root *expression.Expression) (*Variable, error) {
-	funcName := root.Children[0].Token.Text()
-	parameters := root.Children[1:]
-	registers := f.cpu.Call[:len(parameters)]
-	isSyscall := funcName == "syscall"
-
-	if isSyscall {
-		registers = f.cpu.Syscall[:len(parameters)]
-	}
-
-	err := f.ExpressionsToRegisters(parameters, registers)
-
-	for _, register := range f.cpu.General {
-		if !f.cpu.IsFree(register) {
-			f.assembler.Register(asm.PUSH, register)
-		}
-	}
-
-	if isSyscall {
-		f.assembler.Syscall()
-	} else {
-		f.assembler.Call(funcName)
-	}
-
-	for i := len(f.cpu.General) - 1; i >= 0; i-- {
-		register := f.cpu.General[i]
-
-		if !f.cpu.IsFree(register) {
-			f.assembler.Register(asm.POP, register)
-		}
-	}
-
-	tmp := f.addTemporary(root)
-	f.assembler.RegisterRegister(asm.MOVE, tmp.Register, f.cpu.Return[0])
-	return tmp, err
-}
-
-func (f *Function) EvaluateLeaf(root *expression.Expression) (*Variable, error) {
-	tmp := f.addTemporary(root)
-	err := f.TokenToRegister(root.Token, tmp.Register)
-	return tmp, err
-}
-
-func (f *Function) EvaluateTo(root *expression.Expression, register cpu.Register) error {
-	tmp, err := f.Evaluate(root)
-
-	if err != nil {
-		return err
-	}
-
-	if register != tmp.Register {
-		f.assembler.RegisterRegister(asm.MOVE, register, tmp.Register)
-	}
-
-	f.useVariable(tmp)
-	return nil
-}

src/build/core/Execute.go

@@ -1,11 +1,8 @@
 package core
 
 import (
-	"strconv"
-
 	"git.akyoto.dev/cli/q/src/build/ast"
 	"git.akyoto.dev/cli/q/src/build/cpu"
-	"git.akyoto.dev/cli/q/src/build/errors"
 	"git.akyoto.dev/cli/q/src/build/expression"
 	"git.akyoto.dev/cli/q/src/build/token"
 )
@@ -16,54 +13,24 @@ func (f *Function) Execute(operation token.Token, register cpu.Register, value *
 		return f.ExecuteLeaf(operation, register, value.Token)
 	}
 
-	var temporary cpu.Register
-
 	if ast.IsFunctionCall(value) {
-		temporary = f.cpu.Return[0]
+		err := f.CompileCall(value)
-	} else {
-		found := false
-		temporary, found = f.cpu.FindFree(f.cpu.General)
-
-		if !found {
-			panic("no free registers")
-		}
-	}
-
-	f.cpu.Use(temporary)
-	defer f.cpu.Free(temporary)
-	err := f.EvaluateTo(value, temporary)
-
-	if err != nil {
-		return err
-	}
-
-	return f.opRegisterRegister(operation, register, temporary)
-}
-
-// ExecuteLeaf performs an operation on a register with the given leaf operand.
-func (f *Function) ExecuteLeaf(operation token.Token, register cpu.Register, operand token.Token) error {
-	switch operand.Kind {
-	case token.Identifier:
-		name := operand.Text()
-		variable, exists := f.variables[name]
-
-		if !exists {
-			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, operand.Position)
-		}
-
-		defer f.useVariable(variable)
-		return f.opRegisterRegister(operation, register, variable.Register)
-
-	case token.Number:
-		value := operand.Text()
-		number, err := strconv.Atoi(value)
 
 		if err != nil {
 			return err
 		}
 
-		return f.opRegisterNumber(operation, register, number)
+		return f.ExecuteRegisterRegister(operation, register, f.cpu.Output[0])
 	}
 
-	return errors.New(errors.NotImplemented, f.File, operation.Position)
+	tmp := f.cpu.MustUseFree(f.cpu.General)
+	defer f.cpu.Free(tmp)
+
+	err := f.ExpressionToRegister(value, tmp)
+
+	if err != nil {
+		return err
+	}
+
+	return f.ExecuteRegisterRegister(operation, register, tmp)
 }

src/build/core/ExecuteLeaf.go

@@ -0,0 +1,37 @@
+package core
+
+import (
+	"strconv"
+
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/errors"
+	"git.akyoto.dev/cli/q/src/build/token"
+)
+
+// ExecuteLeaf performs an operation on a register with the given leaf operand.
+func (f *Function) ExecuteLeaf(operation token.Token, register cpu.Register, operand token.Token) error {
+	switch operand.Kind {
+	case token.Identifier:
+		name := operand.Text()
+		variable, exists := f.variables[name]
+
+		if !exists {
+			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, operand.Position)
+		}
+
+		defer f.useVariable(variable)
+		return f.ExecuteRegisterRegister(operation, register, variable.Register)
+
+	case token.Number:
+		value := operand.Text()
+		number, err := strconv.Atoi(value)
+
+		if err != nil {
+			return err
+		}
+
+		return f.ExecuteRegisterNumber(operation, register, number)
+	}
+
+	return errors.New(errors.NotImplemented, f.File, operation.Position)
+}

src/build/core/ExecuteRegisterNumber.go

@@ -0,0 +1,33 @@
+package core
+
+import (
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/errors"
+	"git.akyoto.dev/cli/q/src/build/token"
+)
+
+// ExecuteRegisterNumber performs an operation on a register and a number.
+func (f *Function) ExecuteRegisterNumber(operation token.Token, register cpu.Register, number int) error {
+	switch operation.Text() {
+	case "+", "+=":
+		f.assembler.RegisterNumber(asm.ADD, register, number)
+
+	case "-", "-=":
+		f.assembler.RegisterNumber(asm.SUB, register, number)
+
+	case "*", "*=":
+		f.assembler.RegisterNumber(asm.MUL, register, number)
+
+	case "/", "/=":
+		f.assembler.RegisterNumber(asm.DIV, register, number)
+
+	case "=":
+		f.assembler.RegisterNumber(asm.MOVE, register, number)
+
+	default:
+		return errors.New(&errors.InvalidOperator{Operator: operation.Text()}, f.File, operation.Position)
+	}
+
+	return nil
+}

src/build/core/ExecuteRegisterRegister.go

@@ -0,0 +1,35 @@
+package core
+
+import (
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/errors"
+	"git.akyoto.dev/cli/q/src/build/token"
+)
+
+// ExecuteRegisterRegister performs an operation on two registers.
+func (f *Function) ExecuteRegisterRegister(operation token.Token, destination cpu.Register, source cpu.Register) error {
+	switch operation.Text() {
+	case "+", "+=":
+		f.assembler.RegisterRegister(asm.ADD, destination, source)
+
+	case "-", "-=":
+		f.assembler.RegisterRegister(asm.SUB, destination, source)
+
+	case "*", "*=":
+		f.assembler.RegisterRegister(asm.MUL, destination, source)
+
+	case "/", "/=":
+		f.assembler.RegisterRegister(asm.DIV, destination, source)
+
+	case "=":
+		if destination != source {
+			f.assembler.RegisterRegister(asm.MOVE, destination, source)
+		}
+
+	default:
+		return errors.New(&errors.InvalidOperator{Operator: operation.Text()}, f.File, operation.Position)
+	}
+
+	return nil
+}

src/build/core/ExpressionToRegister.go

@@ -0,0 +1,33 @@
+package core
+
+import (
+	"git.akyoto.dev/cli/q/src/build/asm"
+	"git.akyoto.dev/cli/q/src/build/ast"
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/expression"
+)
+
+// ExpressionToRegister puts the result of an expression into the specified register.
+func (f *Function) ExpressionToRegister(root *expression.Expression, register cpu.Register) error {
+	if root.IsLeaf() {
+		return f.TokenToRegister(root.Token, register)
+	}
+
+	if ast.IsFunctionCall(root) {
+		err := f.CompileCall(root)
+		f.assembler.RegisterRegister(asm.MOVE, register, f.cpu.Output[0])
+		return err
+	}
+
+	left := root.Children[0]
+	right := root.Children[1]
+
+	err := f.ExpressionToRegister(left, register)
+
+	if err != nil {
+		return err
+	}
+
+	f.SaveRegister(register)
+	return f.Execute(root.Token, register, right)
+}

src/build/core/ExpressionsToRegisters.go

@@ -0,0 +1,20 @@
+package core
+
+import (
+	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/expression"
+)
+
+// ExpressionsToRegisters moves multiple expressions into the specified registers.
+func (f *Function) ExpressionsToRegisters(expressions []*expression.Expression, registers []cpu.Register) error {
+	for i := len(registers) - 1; i >= 0; i-- {
+		f.SaveRegister(registers[i])
+		err := f.ExpressionToRegister(expressions[i], registers[i])
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

src/build/core/Function.go

@@ -31,10 +31,10 @@ func NewFunction(name string, file *fs.File, body token.List) *Function {
 				Instructions: make([]asm.Instruction, 0, 32),
 			},
 			cpu: cpu.CPU{
-				Call:    x64.CallRegisters,
+				Input:   x64.CallRegisters,
 				General: x64.GeneralRegisters,
 				Syscall: x64.SyscallRegisters,
-				Return:  x64.ReturnValueRegisters,
+				Output:  x64.ReturnValueRegisters,
 			},
 			definitions: map[string]*Definition{},
 			variables:   map[string]*Variable{},

src/build/core/TokenToRegister.go

@@ -18,7 +18,7 @@ func (f *Function) TokenToRegister(t token.Token, register cpu.Register) error {
 		constant, exists := f.definitions[name]
 
 		if exists {
-			return f.EvaluateTo(constant.Value, register)
+			return f.ExpressionToRegister(constant.Value, register)
 		}
 
 		variable, exists := f.variables[name]

src/build/core/opRegister.go

@@ -1,60 +0,0 @@
-package core
-
-import (
-	"git.akyoto.dev/cli/q/src/build/asm"
-	"git.akyoto.dev/cli/q/src/build/cpu"
-	"git.akyoto.dev/cli/q/src/build/errors"
-	"git.akyoto.dev/cli/q/src/build/token"
-)
-
-// opRegisterNumber performs an operation on a register and a number.
-func (f *Function) opRegisterNumber(operation token.Token, register cpu.Register, number int) error {
-	switch operation.Text() {
-	case "+", "+=":
-		f.assembler.RegisterNumber(asm.ADD, register, number)
-
-	case "-", "-=":
-		f.assembler.RegisterNumber(asm.SUB, register, number)
-
-	case "*", "*=":
-		f.assembler.RegisterNumber(asm.MUL, register, number)
-
-	case "/", "/=":
-		f.assembler.RegisterNumber(asm.DIV, register, number)
-
-	case "=":
-		f.assembler.RegisterNumber(asm.MOVE, register, number)
-
-	default:
-		return errors.New(&errors.InvalidOperator{Operator: operation.Text()}, f.File, operation.Position)
-	}
-
-	return nil
-}
-
-// opRegisterRegister performs an operation on two registers.
-func (f *Function) opRegisterRegister(operation token.Token, destination cpu.Register, source cpu.Register) error {
-	switch operation.Text() {
-	case "+", "+=":
-		f.assembler.RegisterRegister(asm.ADD, destination, source)
-
-	case "-", "-=":
-		f.assembler.RegisterRegister(asm.SUB, destination, source)
-
-	case "*", "*=":
-		f.assembler.RegisterRegister(asm.MUL, destination, source)
-
-	case "/", "/=":
-		f.assembler.RegisterRegister(asm.DIV, destination, source)
-
-	case "=":
-		if destination != source {
-			f.assembler.RegisterRegister(asm.MOVE, destination, source)
-		}
-
-	default:
-		return errors.New(&errors.InvalidOperator{Operator: operation.Text()}, f.File, operation.Position)
-	}
-
-	return nil
-}

src/build/core/state.go

@@ -24,7 +24,6 @@ type state struct {
 // counter stores how often a certain statement appeared so we can generate a unique label from it.
 type counter struct {
 	loop int
-	tmps int
 }
 
 // PrintInstructions shows the assembly instructions.

src/build/cpu/CPU.go

@@ -2,10 +2,10 @@ package cpu
 
 // CPU represents the processor.
 type CPU struct {
-	Call    []Register
 	General []Register
 	Syscall []Register
-	Return  []Register
+	Input   []Register
+	Output  []Register
 	usage   uint64
 }