finished binary expression

asm/amd64/amd64.go

@@ -9,22 +9,6 @@ type Program struct {
 	Functions []Function
 }
 
-func (p *Program) Emit() string {
-	var builder strings.Builder
-
-	for _, function := range p.Functions {
-		builder.WriteString(function.Emit())
-		builder.WriteString("\n")
-	}
-
-	return builder.String()
-}
-
-type Function struct {
-	Name         string
-	Instructions []Instruction
-}
-
 // This calls the main function and uses it's return value to exit
 const executableAsmHeader = "format ELF64 executable\n" +
 	"segment readable executable\n" +
@@ -35,11 +19,28 @@ const executableAsmHeader = "format ELF64 executable\n" +
 	"  mov rax, 60\n" +
 	"  syscall\n"
 
+func (p *Program) Emit() string {
+	var builder strings.Builder
+	builder.WriteString(executableAsmHeader)
+
+	for _, function := range p.Functions {
+		builder.WriteString(function.Emit())
+		builder.WriteString("\n")
+	}
+
+	return builder.String()
+}
+
+type Function struct {
+	StackOffset  int64
+	Name         string
+	Instructions []Instruction
+}
+
 func (f *Function) Emit() string {
 	var builder strings.Builder
 
-	builder.WriteString(executableAsmHeader)
+	builder.WriteString(fmt.Sprintf("%s:\n  push rbp\n  mov rbp, rsp\n  add rsp, %d\n", f.Name, f.StackOffset))
-	builder.WriteString(fmt.Sprintf("%s:\n", f.Name))
 
 	for _, inst := range f.Instructions {
 		builder.WriteString(fmt.Sprintf("  %s\n", inst.InstructionString()))
@@ -51,25 +52,46 @@ func (f *Function) Emit() string {
 type Opcode string
 
 const (
-	Mov   Opcode = "mov"
+
-	Ret   Opcode = "ret"
+	// Two operands
-	Add   Opcode = "add"
+	Mov  Opcode = "mov" // Lhs: dst, Rhs: src, or better said intel syntax
-	Sub   Opcode = "sub"
+	Add  Opcode = "add"
-	Imull Opcode = "imul"
+	Sub  Opcode = "sub"
-	Idiv  Opcode = "idiv"
+	Imul Opcode = "imul"
+
+	// One operand
+	Idiv Opcode = "idiv"
+
+	// No operands
+	Ret Opcode = "ret"
+	Cdq Opcode = "cdq"
 )
 
 type Instruction struct {
 	Opcode Opcode
-	Lhs    Operand
+	// Dst
-	Rhs    Operand
+	Lhs Operand
+	// Src
+	Rhs Operand
 }
 
 func (i *Instruction) InstructionString() string {
+
+	if i.Opcode == Ret {
+		return fmt.Sprintf("mov rsp, rbp\n  pop rbp\n  ret\n")
+	}
+
+	// No operands
 	if i.Lhs == nil {
 		return fmt.Sprintf("%s", i.Opcode)
 	}
 
+	// One operand
+	if i.Rhs == nil {
+		return fmt.Sprintf("%s %s", i.Opcode, i.Lhs.OperandString(Eight))
+	}
+
+	// Two operands
 	return fmt.Sprintf("%s %s, %s", i.Opcode, i.Lhs.OperandString(Eight), i.Rhs.OperandString(Eight))
 }
 
@@ -84,6 +106,7 @@ type Register int
 const (
 	AX Register = iota
 	R10
+	R11
 
 	One OperandSize = iota
 	Four
@@ -108,6 +131,14 @@ func (r Register) OperandString(size OperandSize) string {
 			return "r10d"
 		}
 		return "r10"
+	case R11:
+		switch size {
+		case One:
+			return "r11b"
+		case Four:
+			return "r11d"
+		}
+		return "r11"
 	}
 	return "INVALID_REGISTER"
 }
@@ -121,5 +152,22 @@ func (i Imm) OperandString(size OperandSize) string {
 type Stack int64
 
 func (s Stack) OperandString(size OperandSize) string {
-	return fmt.Sprintf("rbp(%d)", s)
+
+	var sizeString string
+	switch size {
+	case One:
+		sizeString = "byte"
+	case Four:
+		sizeString = "dword"
+	case Eight:
+		sizeString = "qword"
+	}
+
+	return fmt.Sprintf("%s [rsp %+d]", sizeString, s)
+}
+
+type Pseudo string
+
+func (s Pseudo) OperandString(size OperandSize) string {
+	panic("Pseudo Operands cannot be represented in asm")
 }

asm/amd64/codegen.go

@@ -3,6 +3,7 @@ package amd64
 import (
 	"fmt"
 
+	"robaertschi.xyz/robaertschi/tt/ast"
 	"robaertschi.xyz/robaertschi/tt/ttir"
 )
 
@@ -10,6 +11,8 @@ func toAsmOperand(op ttir.Operand) Operand {
 	switch op := op.(type) {
 	case *ttir.Constant:
 		return Imm(op.Value)
+	case *ttir.Var:
+		return Pseudo(op.Value)
 	default:
 		panic(fmt.Sprintf("unkown operand %T", op))
 	}
@@ -22,9 +25,14 @@ func CgProgram(prog *ttir.Program) Program {
 		funcs = append(funcs, cgFunction(f))
 	}
 
-	return Program{
+	newProgram := Program{
 		Functions: funcs,
 	}
+
+	newProgram = replacePseudo(newProgram)
+	newProgram = instructionFixup(newProgram)
+
+	return newProgram
 }
 
 func cgFunction(f ttir.Function) Function {
@@ -53,7 +61,156 @@ func cgInstruction(i ttir.Instruction) []Instruction {
 				Opcode: Ret,
 			},
 		}
+	case *ttir.Binary:
+		return cgBinary(i)
 	}
 
 	return []Instruction{}
 }
+
+func cgBinary(b *ttir.Binary) []Instruction {
+	switch b.Operator {
+	case ast.Add, ast.Subtract, ast.Multiply:
+		var opcode Opcode
+		switch b.Operator {
+		case ast.Add:
+			opcode = Add
+		case ast.Subtract:
+			opcode = Sub
+		case ast.Multiply:
+			opcode = Imul
+		}
+
+		return []Instruction{
+			{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Lhs)},
+			{Opcode: opcode, Lhs: toAsmOperand(b.Dst), Rhs: toAsmOperand(b.Rhs)},
+		}
+	case ast.Divide:
+		return []Instruction{
+			{Opcode: Mov, Lhs: Register(AX), Rhs: toAsmOperand(b.Lhs)},
+			{Opcode: Cdq},
+			{Opcode: Idiv, Lhs: toAsmOperand(b.Rhs)},
+			{Opcode: Mov, Lhs: toAsmOperand(b.Dst), Rhs: Register(AX)},
+		}
+	}
+
+	panic(fmt.Sprintf("unknown binary operator, %v", b))
+}
+
+// Second pass, replace all the pseudos with stack addresses
+type replacePseudoPass struct {
+	identToOffset map[string]int64
+	currentOffset int64
+}
+
+func replacePseudo(prog Program) Program {
+	newFunctions := make([]Function, 0)
+
+	for _, f := range prog.Functions {
+		newFunctions = append(newFunctions, rpFunction(f))
+	}
+
+	return Program{Functions: newFunctions}
+}
+
+func rpFunction(f Function) Function {
+	newInstructions := make([]Instruction, 0)
+
+	r := &replacePseudoPass{
+		identToOffset: make(map[string]int64),
+	}
+	for _, i := range f.Instructions {
+		newInstructions = append(newInstructions, rpInstruction(i, r))
+	}
+
+	return Function{Instructions: newInstructions, Name: f.Name, StackOffset: r.currentOffset}
+}
+
+func rpInstruction(i Instruction, r *replacePseudoPass) Instruction {
+
+	newInstruction := Instruction{Opcode: i.Opcode}
+	if i.Lhs != nil {
+		newInstruction.Lhs = pseudoToStack(i.Lhs, r)
+	}
+	if i.Rhs != nil {
+		newInstruction.Rhs = pseudoToStack(i.Rhs, r)
+	}
+
+	return newInstruction
+}
+
+func pseudoToStack(op Operand, r *replacePseudoPass) Operand {
+	if pseudo, ok := op.(Pseudo); ok {
+		if offset, ok := r.identToOffset[string(pseudo)]; ok {
+			return Stack(offset)
+		} else {
+			r.currentOffset -= 4
+			r.identToOffset[string(pseudo)] = r.currentOffset
+			return Stack(r.currentOffset)
+		}
+	}
+	return op
+}
+
+// Third pass, fixup invalid instructions
+
+func instructionFixup(prog Program) Program {
+	newFuncs := make([]Function, 0)
+
+	for _, f := range prog.Functions {
+		newFuncs = append(newFuncs, fixupFunction(f))
+	}
+
+	return Program{Functions: newFuncs}
+}
+
+func fixupFunction(f Function) Function {
+	// The function will at minimum require the same amount of instructions, but never less
+	newInstructions := make([]Instruction, 0)
+
+	for _, i := range f.Instructions {
+		newInstructions = append(newInstructions, fixupInstruction(i)...)
+	}
+
+	return Function{Name: f.Name, Instructions: newInstructions, StackOffset: f.StackOffset}
+}
+
+func fixupInstruction(i Instruction) []Instruction {
+
+	switch i.Opcode {
+	case Mov:
+		if lhs, ok := i.Lhs.(Stack); ok {
+			if rhs, ok := i.Rhs.(Stack); ok {
+				return []Instruction{
+					{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
+					{Opcode: Mov, Lhs: lhs, Rhs: Register(R10)},
+				}
+			}
+		}
+	case Imul:
+		if lhs, ok := i.Lhs.(Stack); ok {
+			return []Instruction{
+				{Opcode: Mov, Lhs: Register(R11), Rhs: lhs},
+				{Opcode: Imul, Lhs: Register(R11), Rhs: i.Rhs},
+				{Opcode: Mov, Lhs: lhs, Rhs: Register(R11)},
+			}
+		}
+		fallthrough
+	case Add, Sub, Idiv /* Imul (fallthrough) */ :
+		if lhs, ok := i.Lhs.(Stack); ok {
+			if rhs, ok := i.Rhs.(Stack); ok {
+				return []Instruction{
+					{Opcode: Mov, Lhs: Register(R10), Rhs: rhs},
+					{Opcode: i.Opcode, Lhs: lhs, Rhs: Register(R10)},
+				}
+			}
+		} else if lhs, ok := i.Lhs.(Imm); ok && i.Opcode == Idiv {
+			return []Instruction{
+				{Opcode: Mov, Lhs: Register(R10), Rhs: lhs},
+				{Opcode: Idiv, Lhs: Register(R10)},
+			}
+		}
+	}
+
+	return []Instruction{i}
+}

cmd/cmd.go

@@ -17,10 +17,19 @@ import (
 	"robaertschi.xyz/robaertschi/tt/typechecker"
 )
 
+type ToPrintFlags int
+
+const (
+	PrintAst ToPrintFlags = 1 << iota
+	PrintTAst
+	PrintIr
+)
+
 type Arguments struct {
 	Output      string
 	Input       string
 	OnlyEmitAsm bool
+	ToPrint     ToPrintFlags
 }
 
 // Prefix writer writes a prefix before each new line from another io.Writer
@@ -109,19 +118,27 @@ func Compile(args Arguments) {
 	})
 
 	program := p.ParseProgram()
-
 	if p.Errors() > 0 {
 		fmt.Printf("Parser encountered 1 or more errors, quiting...\n")
 		os.Exit(1)
 	}
+	if (args.ToPrint & PrintAst) != 0 {
+		fmt.Printf("AST:\n%s\n", program.String())
+	}
 
 	tprogram, err := typechecker.New().CheckProgram(program)
 	if err != nil {
 		fmt.Printf("Typechecker failed with %e\n", err)
 		os.Exit(1)
 	}
+	if (args.ToPrint & PrintTAst) != 0 {
+		fmt.Printf("TAST:\n%s\n", tprogram.String())
+	}
 
 	ir := ttir.EmitProgram(tprogram)
+	if (args.ToPrint & PrintIr) != 0 {
+		fmt.Printf("TTIR:\n%s\n", ir.String())
+	}
 	asm := amd64.CgProgram(ir)
 
 	asmOutput := asm.Emit()

main.go

@@ -20,6 +20,10 @@ func main() {
 	flag.StringVar(&output, "o", "", "Output a executable named `file`")
 	flag.StringVar(&output, "output", "", "Output a executable named `file`")
 	onlyEmitAsm := flag.Bool("S", false, "Only emit the asembly file and exit")
+
+	printAst := flag.Bool("ast", false, "Print the AST out to stdout")
+	printTAst := flag.Bool("tast", false, "Print the typed AST out to stdout")
+	printIr := flag.Bool("ttir", false, "Print the TTIR out to stdout")
 	flag.Parse()
 
 	input := flag.Arg(0)
@@ -32,5 +36,16 @@ func main() {
 		output = strings.TrimSuffix(input, filepath.Ext(input))
 	}
 
-	cmd.Compile(cmd.Arguments{Output: output, Input: input, OnlyEmitAsm: *onlyEmitAsm})
+	var toPrint cmd.ToPrintFlags
+	if *printAst {
+		toPrint |= cmd.PrintAst
+	}
+	if *printTAst {
+		toPrint |= cmd.PrintTAst
+	}
+	if *printIr {
+		toPrint |= cmd.PrintIr
+	}
+
+	cmd.Compile(cmd.Arguments{Output: output, Input: input, OnlyEmitAsm: *onlyEmitAsm, ToPrint: toPrint})
 }

ttir/ttir.go

@@ -11,6 +11,14 @@ type Program struct {
 	Functions []Function
 }
 
+func (p *Program) String() string {
+	var builder strings.Builder
+	for _, f := range p.Functions {
+		builder.WriteString(f.String())
+	}
+	return builder.String()
+}
+
 type Function struct {
 	Name         string
 	Instructions []Instruction
@@ -48,7 +56,7 @@ type Binary struct {
 }
 
 func (b *Binary) String() string {
-	return fmt.Sprintf("%s = %s %s, %s", b.Dst, b.Operator, b.Lhs, b.Rhs)
+	return fmt.Sprintf("%s = %s %s, %s\n", b.Dst, b.Operator, b.Lhs, b.Rhs)
 }
 func (b *Binary) instruction() {}