Simplified ssa package

src/compiler/showSSA.go

@@ -15,7 +15,7 @@ func showSSA(root *core.Function) {
 		for _, block := range f.Blocks {
 			for i, instr := range block.Instructions {
 				ansi.Dim.Printf("%%%-1d = ", i)
-				fmt.Printf("%-30s ", instr.Debug(false))
+				fmt.Printf("%-30s ", instr.String())
 				ansi.Dim.Printf(" %-30s", instr.Type().Name())
 				fmt.Println()
 			}

src/core/Evaluate.go

@@ -149,10 +149,10 @@ func (f *Function) Evaluate(expr *expression.Expression) (ssa.Value, error) {
 		}
 
 		if fn.IsExtern() {
-			v := f.Append(&ssa.CallExtern{
+			v := f.Append(&ssa.CallExtern{Call: ssa.Call{
 				Arguments: args,
 				Source:    ssa.Source(expr.Source),
-			})
+			}})
 
 			return v, nil
 		}
@@ -179,7 +179,7 @@ func (f *Function) Evaluate(expr *expression.Expression) (ssa.Value, error) {
 				return nil, errors.New(&UnknownStructField{StructName: structure.Name(), FieldName: rightText}, f.File, right.Token.Position)
 			}
 
-			v := f.Append(&ssa.StructField{
+			v := f.Append(&ssa.Field{
 				Struct: identifier,
 				Field:  field,
 				Source: ssa.Source(expr.Source),

src/ssa/Arguments.go

@@ -1,21 +0,0 @@
-package ssa
-
-type Arguments []Value
-
-func (v Arguments) Dependencies() []Value {
-	return v
-}
-
-func (a Arguments) Equals(b Arguments) bool {
-	if len(a) != len(b) {
-		return false
-	}
-
-	for i := range a {
-		if !a[i].Equals(b[i]) {
-			return false
-		}
-	}
-
-	return true
-}

src/ssa/BinaryOp.go

@@ -12,14 +12,13 @@ type BinaryOp struct {
 	Left  Value
 	Right Value
 	Op    token.Kind
-	Id
 	Liveness
 	Source
 }
 
-func (v *BinaryOp) Dependencies() []Value {
+func (v *BinaryOp) Inputs() []Value  { return []Value{v.Left, v.Right} }
-	return []Value{v.Left, v.Right}
+func (v *BinaryOp) IsConst() bool    { return v.Left.IsConst() && v.Right.IsConst() }
-}
+func (v *BinaryOp) Type() types.Type { return v.Left.Type() }
 
 func (a *BinaryOp) Equals(v Value) bool {
 	b, sameType := v.(*BinaryOp)
@@ -39,22 +38,6 @@ func (a *BinaryOp) Equals(v Value) bool {
 	return true
 }
 
-func (v *BinaryOp) IsConst() bool {
-	return true
-}
-
-func (v *BinaryOp) Debug(expand bool) string {
-	if expand {
-		return fmt.Sprintf("%s %s %s", v.Left, expression.Operators[v.Op].Symbol, v.Right)
-	}
-
-	return fmt.Sprintf("%%%d %s %%%d", v.Left.ID(), expression.Operators[v.Op].Symbol, v.Right.ID())
-}
-
 func (v *BinaryOp) String() string {
-	return v.Debug(true)
+	return fmt.Sprintf("%s %s %s", v.Left, expression.Operators[v.Op].Symbol, v.Right)
-}
-
-func (v *BinaryOp) Type() types.Type {
-	return v.Left.Type()
 }

src/ssa/Block.go

@@ -7,7 +7,7 @@ type Block struct {
 
 // Append adds a new instruction to the block.
 func (block *Block) Append(instr Value) Value {
-	for _, dep := range instr.Dependencies() {
+	for _, dep := range instr.Inputs() {
 		dep.(HasLiveness).AddUser(instr)
 	}
 

src/ssa/Bytes.go

@@ -8,15 +8,15 @@ import (
 )
 
 type Bytes struct {
-	Id
 	Bytes []byte
 	Liveness
 	Source
 }
 
-func (v *Bytes) Dependencies() []Value {
+func (v *Bytes) Inputs() []Value  { return nil }
-	return nil
+func (v *Bytes) IsConst() bool    { return true }
-}
+func (v *Bytes) String() string   { return strconv.Quote(string(v.Bytes)) }
+func (v *Bytes) Type() types.Type { return types.CString }
 
 func (a *Bytes) Equals(v Value) bool {
 	b, sameType := v.(*Bytes)
@@ -26,20 +26,4 @@ func (a *Bytes) Equals(v Value) bool {
 	}
 
 	return bytes.Equal(a.Bytes, b.Bytes)
-}
-
-func (v *Bytes) IsConst() bool {
-	return true
-}
-
-func (v *Bytes) Debug(expand bool) string {
-	return v.String()
-}
-
-func (v *Bytes) String() string {
-	return strconv.Quote(string(v.Bytes))
-}
-
-func (v *Bytes) Type() types.Type {
-	return types.CString
 }

src/ssa/Call.go

@@ -1,19 +1,19 @@
 package ssa
 
 import (
-	"strconv"
+	"fmt"
-	"strings"
 
 	"git.urbach.dev/cli/q/src/types"
 )
 
 type Call struct {
-	Id
 	Arguments
 	Liveness
 	Source
 }
 
+func (v *Call) IsConst() bool { return false }
+
 func (a *Call) Equals(v Value) bool {
 	b, sameType := v.(*Call)
 
@@ -24,42 +24,8 @@ func (a *Call) Equals(v Value) bool {
 	return a.Arguments.Equals(b.Arguments)
 }
 
-func (v *Call) IsConst() bool {
-	return false
-}
-
-func (v *Call) Debug(expand bool) string {
-	tmp := strings.Builder{}
-
-	if expand {
-		tmp.WriteString(v.Arguments[0].String())
-	} else {
-		tmp.WriteString("%")
-		tmp.WriteString(strconv.Itoa(v.Arguments[0].ID()))
-	}
-
-	tmp.WriteString("(")
-	args := v.Arguments[1:]
-
-	for i, arg := range args {
-		if expand {
-			tmp.WriteString(arg.String())
-		} else {
-			tmp.WriteString("%")
-			tmp.WriteString(strconv.Itoa(arg.ID()))
-		}
-
-		if i != len(args)-1 {
-			tmp.WriteString(", ")
-		}
-	}
-
-	tmp.WriteString(")")
-	return tmp.String()
-}
-
 func (v *Call) String() string {
-	return v.Debug(true)
+	return fmt.Sprintf("%s(%s)", v.Arguments[0].String(), v.Arguments[1:].String())
 }
 
 func (v *Call) Type() types.Type {

src/ssa/CallExtern.go

@@ -1,73 +1,3 @@
 package ssa
 
-import (
+type CallExtern struct{ Call }
-	"strconv"
-	"strings"
-
-	"git.urbach.dev/cli/q/src/types"
-)
-
-type CallExtern struct {
-	Id
-	Arguments
-	Liveness
-	Source
-}
-
-func (a *CallExtern) Equals(v Value) bool {
-	b, sameType := v.(*CallExtern)
-
-	if !sameType {
-		return false
-	}
-
-	return a.Arguments.Equals(b.Arguments)
-}
-
-func (v *CallExtern) IsConst() bool {
-	return false
-}
-
-func (v *CallExtern) Debug(expand bool) string {
-	tmp := strings.Builder{}
-
-	if expand {
-		tmp.WriteString(v.Arguments[0].String())
-	} else {
-		tmp.WriteString("%")
-		tmp.WriteString(strconv.Itoa(v.Arguments[0].ID()))
-	}
-
-	tmp.WriteString("(")
-	args := v.Arguments[1:]
-
-	for i, arg := range args {
-		if expand {
-			tmp.WriteString(arg.String())
-		} else {
-			tmp.WriteString("%")
-			tmp.WriteString(strconv.Itoa(arg.ID()))
-		}
-
-		if i != len(args)-1 {
-			tmp.WriteString(", ")
-		}
-	}
-
-	tmp.WriteString(")")
-	return tmp.String()
-}
-
-func (v *CallExtern) String() string {
-	return v.Debug(true)
-}
-
-func (v *CallExtern) Type() types.Type {
-	typ := v.Arguments[0].(*Function).Typ
-
-	if len(typ.Output) == 0 {
-		return types.Void
-	}
-
-	return typ.Output[0]
-}

src/ssa/Field.go

@@ -0,0 +1,29 @@
+package ssa
+
+import (
+	"fmt"
+
+	"git.urbach.dev/cli/q/src/types"
+)
+
+type Field struct {
+	Struct Value
+	Field  *types.Field
+	Liveness
+	Source
+}
+
+func (v *Field) IsConst() bool    { return true }
+func (v *Field) Type() types.Type { return v.Field.Type }
+func (v *Field) String() string   { return fmt.Sprintf("%s.%s", v.Struct, v.Field) }
+func (v *Field) Inputs() []Value  { return []Value{v.Struct} }
+
+func (a *Field) Equals(v Value) bool {
+	b, sameType := v.(*Field)
+
+	if !sameType {
+		return false
+	}
+
+	return a.Field == b.Field
+}

src/ssa/Function.go

@@ -6,14 +6,14 @@ type Function struct {
 	UniqueName string
 	Typ        *types.Function
 	IsExtern   bool
-	Id
 	Liveness
 	Source
 }
 
-func (v *Function) Dependencies() []Value {
+func (v *Function) Inputs() []Value  { return nil }
-	return nil
+func (v *Function) IsConst() bool    { return true }
-}
+func (v *Function) String() string   { return v.UniqueName }
+func (v *Function) Type() types.Type { return v.Typ }
 
 func (a *Function) Equals(v Value) bool {
 	b, sameType := v.(*Function)
@@ -23,20 +23,4 @@ func (a *Function) Equals(v Value) bool {
 	}
 
 	return a.UniqueName == b.UniqueName
-}
-
-func (v *Function) IsConst() bool {
-	return true
-}
-
-func (v *Function) Debug(expand bool) string {
-	return v.String()
-}
-
-func (v *Function) String() string {
-	return v.UniqueName
-}
-
-func (v *Function) Type() types.Type {
-	return v.Typ
 }

src/ssa/HasLiveness.go

@@ -1,6 +0,0 @@
-package ssa
-
-type HasLiveness interface {
-	AddUser(Value)
-	Users() []Value
-}

src/ssa/HasSource.go

@@ -1,8 +0,0 @@
-package ssa
-
-import "git.urbach.dev/cli/q/src/token"
-
-type HasSource interface {
-	Start() token.Position
-	End() token.Position
-}

src/ssa/ID.go

@@ -1,11 +0,0 @@
-package ssa
-
-type Id int
-
-func (id Id) ID() int {
-	return int(id)
-}
-
-func (id *Id) SetID(newId int) {
-	*id = Id(newId)
-}

src/ssa/IR.go

@@ -3,7 +3,6 @@ package ssa
 // IR is a list of basic blocks.
 type IR struct {
 	Blocks []*Block
-	nextId int
 }
 
 // AddBlock adds a new block to the function.
@@ -28,8 +27,6 @@ func (f *IR) Append(instr Value) Value {
 		return existing
 	}
 
-	instr.SetID(f.nextId)
-	f.nextId++
 	return f.Blocks[len(f.Blocks)-1].Append(instr)
 }
 

src/ssa/Int.go

@@ -8,14 +8,14 @@ import (
 
 type Int struct {
 	Int int
-	Id
 	Liveness
 	Source
 }
 
-func (v *Int) Dependencies() []Value {
+func (v *Int) Inputs() []Value  { return nil }
-	return nil
+func (v *Int) IsConst() bool    { return true }
-}
+func (v *Int) String() string   { return strconv.Itoa(v.Int) }
+func (v *Int) Type() types.Type { return types.AnyInt }
 
 func (a *Int) Equals(v Value) bool {
 	b, sameType := v.(*Int)
@@ -25,20 +25,4 @@ func (a *Int) Equals(v Value) bool {
 	}
 
 	return a.Int == b.Int
-}
-
-func (v *Int) IsConst() bool {
-	return true
-}
-
-func (v *Int) Debug(expand bool) string {
-	return v.String()
-}
-
-func (v *Int) String() string {
-	return strconv.Itoa(v.Int)
-}
-
-func (v *Int) Type() types.Type {
-	return types.AnyInt
 }

src/ssa/Liveness.go

@@ -1,13 +0,0 @@
-package ssa
-
-type Liveness struct {
-	users []Value
-}
-
-func (v *Liveness) AddUser(user Value) {
-	v.users = append(v.users, user)
-}
-
-func (v *Liveness) Users() []Value {
-	return v.users
-}

src/ssa/Parameter.go

@@ -10,14 +10,14 @@ type Parameter struct {
 	Index uint8
 	Name  string
 	Typ   types.Type
-	Id
 	Liveness
 	Source
 }
 
-func (v *Parameter) Dependencies() []Value {
+func (v *Parameter) Inputs() []Value  { return nil }
-	return nil
+func (v *Parameter) IsConst() bool    { return true }
-}
+func (v *Parameter) String() string   { return fmt.Sprintf("args[%d]", v.Index) }
+func (v *Parameter) Type() types.Type { return v.Typ }
 
 func (a *Parameter) Equals(v Value) bool {
 	b, sameType := v.(*Parameter)
@@ -27,20 +27,4 @@ func (a *Parameter) Equals(v Value) bool {
 	}
 
 	return a.Index == b.Index
-}
-
-func (v *Parameter) IsConst() bool {
-	return true
-}
-
-func (v *Parameter) Debug(expand bool) string {
-	return v.String()
-}
-
-func (v *Parameter) String() string {
-	return fmt.Sprintf("args[%d]", v.Index)
-}
-
-func (v *Parameter) Type() types.Type {
-	return v.Typ
 }

src/ssa/Return.go

@@ -1,18 +1,21 @@
 package ssa
 
 import (
-	"strconv"
+	"fmt"
-	"strings"
 
 	"git.urbach.dev/cli/q/src/types"
 )
 
 type Return struct {
-	Id
 	Arguments
 	Source
 }
 
+func (v *Return) AddUser(Value)    { panic("return can not be used as a dependency") }
+func (v *Return) IsConst() bool    { return false }
+func (v *Return) Type() types.Type { return types.Void }
+func (v *Return) Users() []Value   { return nil }
+
 func (a *Return) Equals(v Value) bool {
 	b, sameType := v.(*Return)
 
@@ -33,38 +36,10 @@ func (a *Return) Equals(v Value) bool {
 	return true
 }
 
-func (v *Return) IsConst() bool {
+func (v *Return) String() string {
-	return false
-}
-
-func (v *Return) Debug(expand bool) string {
 	if len(v.Arguments) == 0 {
 		return "return"
 	}
 
-	tmp := strings.Builder{}
+	return fmt.Sprintf("return %s", v.Arguments.String())
-	tmp.WriteString("return ")
-
-	for i, arg := range v.Arguments {
-		if expand {
-			tmp.WriteString(arg.String())
-		} else {
-			tmp.WriteString("%")
-			tmp.WriteString(strconv.Itoa(arg.ID()))
-		}
-
-		if i != len(v.Arguments)-1 {
-			tmp.WriteString(", ")
-		}
-	}
-
-	return tmp.String()
-}
-
-func (v *Return) String() string {
-	return v.Debug(true)
-}
-
-func (v *Return) Type() types.Type {
-	return types.Void
 }

src/ssa/Source.go

@@ -1,13 +0,0 @@
-package ssa
-
-import "git.urbach.dev/cli/q/src/token"
-
-type Source token.List
-
-func (v Source) Start() token.Position {
-	return v[0].Position
-}
-
-func (v Source) End() token.Position {
-	return v[len(v)-1].End()
-}

src/ssa/Struct.go

@@ -1,20 +1,22 @@
 package ssa
 
 import (
-	"strconv"
+	"fmt"
-	"strings"
 
 	"git.urbach.dev/cli/q/src/types"
 )
 
 type Struct struct {
 	Typ *types.Struct
-	Id
 	Arguments
 	Liveness
 	Source
 }
 
+func (v *Struct) IsConst() bool    { return true }
+func (v *Struct) String() string   { return fmt.Sprintf("%s{%s}", v.Typ.Name(), v.Arguments.String()) }
+func (v *Struct) Type() types.Type { return v.Typ }
+
 func (a *Struct) Equals(v Value) bool {
 	b, sameType := v.(*Struct)
 
@@ -23,38 +25,4 @@ func (a *Struct) Equals(v Value) bool {
 	}
 
 	return a.Arguments.Equals(b.Arguments)
-}
-
-func (v *Struct) IsConst() bool {
-	return true
-}
-
-func (v *Struct) Debug(expand bool) string {
-	tmp := strings.Builder{}
-	tmp.WriteString(v.Typ.Name())
-	tmp.WriteString("{")
-
-	for i, arg := range v.Arguments {
-		if expand {
-			tmp.WriteString(arg.String())
-		} else {
-			tmp.WriteString("%")
-			tmp.WriteString(strconv.Itoa(arg.ID()))
-		}
-
-		if i != len(v.Arguments)-1 {
-			tmp.WriteString(", ")
-		}
-	}
-
-	tmp.WriteString("}")
-	return tmp.String()
-}
-
-func (v *Struct) String() string {
-	return v.Debug(false)
-}
-
-func (v *Struct) Type() types.Type {
-	return v.Typ
 }

src/ssa/StructField.go

@@ -1,49 +0,0 @@
-package ssa
-
-import (
-	"fmt"
-
-	"git.urbach.dev/cli/q/src/types"
-)
-
-type StructField struct {
-	Struct Value
-	Field  *types.Field
-	Id
-	Liveness
-	Source
-}
-
-func (v *StructField) Dependencies() []Value {
-	return []Value{v.Struct}
-}
-
-func (a *StructField) Equals(v Value) bool {
-	b, sameType := v.(*StructField)
-
-	if !sameType {
-		return false
-	}
-
-	return a.Field == b.Field
-}
-
-func (v *StructField) IsConst() bool {
-	return true
-}
-
-func (v *StructField) Debug(expand bool) string {
-	if expand {
-		return fmt.Sprintf("%s.%s", v.Struct, v.Field)
-	}
-
-	return fmt.Sprintf("%%%d.%s", v.Struct.ID(), v.Field)
-}
-
-func (v *StructField) String() string {
-	return v.Debug(true)
-}
-
-func (v *StructField) Type() types.Type {
-	return v.Field.Type
-}

src/ssa/Struct_test.go

@@ -0,0 +1,18 @@
+package ssa_test
+
+import (
+	"testing"
+
+	"git.urbach.dev/cli/q/src/ssa"
+	"git.urbach.dev/cli/q/src/types"
+	"git.urbach.dev/go/assert"
+)
+
+func TestStruct(t *testing.T) {
+	fn := ssa.IR{}
+	hello := []byte("Hello")
+	pointer := fn.Append(&ssa.Bytes{Bytes: hello})
+	length := fn.Append(&ssa.Int{Int: len(hello)})
+	str := fn.Append(&ssa.Struct{Typ: types.String, Arguments: ssa.Arguments{pointer, length}})
+	assert.Equal(t, str.String(), "string{\"Hello\", 5}")
+}

src/ssa/Syscall.go

@@ -1,19 +1,21 @@
 package ssa
 
 import (
-	"strconv"
+	"fmt"
-	"strings"
 
 	"git.urbach.dev/cli/q/src/types"
 )
 
 type Syscall struct {
-	Id
 	Arguments
 	Liveness
 	Source
 }
 
+func (v *Syscall) IsConst() bool    { return false }
+func (v *Syscall) String() string   { return fmt.Sprintf("syscall(%s)", v.Arguments.String()) }
+func (v *Syscall) Type() types.Type { return types.Any }
+
 func (a *Syscall) Equals(v Value) bool {
 	b, sameType := v.(*Syscall)
 
@@ -22,37 +24,4 @@ func (a *Syscall) Equals(v Value) bool {
 	}
 
 	return a.Arguments.Equals(b.Arguments)
-}
-
-func (v *Syscall) IsConst() bool {
-	return false
-}
-
-func (v *Syscall) Debug(expand bool) string {
-	tmp := strings.Builder{}
-	tmp.WriteString("syscall(")
-
-	for i, arg := range v.Arguments {
-		if expand {
-			tmp.WriteString(arg.String())
-		} else {
-			tmp.WriteString("%")
-			tmp.WriteString(strconv.Itoa(arg.ID()))
-		}
-
-		if i != len(v.Arguments)-1 {
-			tmp.WriteString(", ")
-		}
-	}
-
-	tmp.WriteString(")")
-	return tmp.String()
-}
-
-func (v *Syscall) String() string {
-	return v.Debug(true)
-}
-
-func (v *Syscall) Type() types.Type {
-	return types.Any
 }

src/ssa/Value.go

@@ -1,16 +1,23 @@
 package ssa
 
-import (
+import "git.urbach.dev/cli/q/src/types"
-	"git.urbach.dev/cli/q/src/types"
-)
 
 type Value interface {
-	Debug(bool) string
+	// Type returns the data type.
-	Dependencies() []Value
-	Equals(Value) bool
-	ID() int
-	IsConst() bool
-	SetID(int)
-	String() string
 	Type() types.Type
+
+	// Users returns all values that reference this value as an input.
+	Users() []Value
+
+	// Inputs returns all values that are needed for this value to be calculated.
+	Inputs() []Value
+
+	// Equals returns true if it's equal to the given value.
+	Equals(Value) bool
+
+	// IsConst returns true if the calculation of the value has no side effects.
+	IsConst() bool
+
+	// Strings returns a human-readable form of the value.
+	String() string
 }

src/ssa/bench_test.go

@@ -1,190 +0,0 @@
-package ssa_test
-
-import (
-	"os"
-	"runtime/debug"
-	"testing"
-
-	"git.urbach.dev/cli/q/src/ssa"
-	"git.urbach.dev/go/assert"
-)
-
-// This benchmark compares the performance of fat structs and interfaces.
-// It allocates `actual` objects where `actual` must be divisible by 2.
-const (
-	actual   = 64
-	estimate = 8
-)
-
-type FatStruct struct {
-	Type byte
-	A    int
-	B    int
-	C    int
-	D    int
-	E    int
-	F    int
-	G    int
-}
-
-type Instruction interface{}
-
-type BinaryInstruction struct {
-	A int
-	B int
-}
-
-type OtherInstruction struct {
-	C int
-	D int
-	E int
-	F int
-	G int
-}
-
-func TestMain(m *testing.M) {
-	debug.SetGCPercent(-1)
-	os.Exit(m.Run())
-}
-
-func BenchmarkFatStructRaw(b *testing.B) {
-	for b.Loop() {
-		entries := make([]FatStruct, 0, estimate)
-
-		for i := range actual {
-			entries = append(entries, FatStruct{
-				Type: byte(i % 2),
-				A:    i,
-				B:    i,
-			})
-		}
-
-		count := 0
-
-		for _, entry := range entries {
-			switch entry.Type {
-			case 0:
-				count++
-			case 1:
-			}
-		}
-
-		assert.Equal(b, count, actual/2)
-	}
-}
-
-func BenchmarkFatStructPtr(b *testing.B) {
-	for b.Loop() {
-		entries := make([]*FatStruct, 0, estimate)
-
-		for i := range actual {
-			entries = append(entries, &FatStruct{
-				Type: byte(i % 2),
-				A:    i,
-				B:    i,
-			})
-		}
-
-		count := 0
-
-		for _, entry := range entries {
-			switch entry.Type {
-			case 0:
-				count++
-			case 1:
-			}
-		}
-
-		assert.Equal(b, count, actual/2)
-	}
-}
-
-func BenchmarkInterfaceRaw(b *testing.B) {
-	for b.Loop() {
-		entries := make([]Instruction, 0, estimate)
-
-		for i := range actual {
-			if i%2 == 0 {
-				entries = append(entries, BinaryInstruction{
-					A: i,
-					B: i,
-				})
-			} else {
-				entries = append(entries, OtherInstruction{
-					C: i,
-					D: i,
-				})
-			}
-		}
-
-		count := 0
-
-		for _, entry := range entries {
-			switch entry.(type) {
-			case BinaryInstruction:
-				count++
-			case OtherInstruction:
-			}
-		}
-
-		assert.Equal(b, count, actual/2)
-	}
-}
-
-func BenchmarkInterfacePtr(b *testing.B) {
-	for b.Loop() {
-		entries := make([]Instruction, 0, estimate)
-
-		for i := range actual {
-			if i%2 == 0 {
-				entries = append(entries, &BinaryInstruction{
-					A: i,
-					B: i,
-				})
-			} else {
-				entries = append(entries, &OtherInstruction{
-					C: i,
-					D: i,
-				})
-			}
-		}
-
-		count := 0
-
-		for _, entry := range entries {
-			switch entry.(type) {
-			case *BinaryInstruction:
-				count++
-			case *OtherInstruction:
-			}
-		}
-
-		assert.Equal(b, count, actual/2)
-	}
-}
-
-func BenchmarkSSA(b *testing.B) {
-	for b.Loop() {
-		f := ssa.IR{}
-
-		for i := range actual {
-			if i%2 == 0 {
-				f.Append(&ssa.Return{})
-			} else {
-				f.Append(&ssa.Call{})
-			}
-		}
-
-		count := 0
-
-		for instr := range f.Values {
-			switch instr.(type) {
-			case *ssa.Return:
-				count++
-			case *ssa.Call:
-			}
-		}
-
-		assert.Equal(b, count, actual/2)
-	}
-}

src/ssa/common.go

@@ -0,0 +1,65 @@
+package ssa
+
+import (
+	"strings"
+
+	"git.urbach.dev/cli/q/src/token"
+)
+
+// Arguments defines a list of values that this value depends on.
+type Arguments []Value
+
+func (v Arguments) Inputs() []Value { return v }
+
+// String returns a comma-separated list of all arguments.
+func (v Arguments) String() string {
+	tmp := strings.Builder{}
+
+	for i, arg := range v {
+		tmp.WriteString(arg.String())
+
+		if i != len(v)-1 {
+			tmp.WriteString(", ")
+		}
+	}
+
+	return tmp.String()
+}
+
+func (a Arguments) Equals(b Arguments) bool {
+	if len(a) != len(b) {
+		return false
+	}
+
+	for i := range a {
+		if !a[i].Equals(b[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Liveness tracks where the value is used.
+type Liveness struct {
+	users []Value
+}
+
+func (v *Liveness) AddUser(user Value) { v.users = append(v.users, user) }
+func (v *Liveness) Users() []Value     { return v.users }
+
+type HasLiveness interface {
+	AddUser(Value)
+	Users() []Value
+}
+
+// Source tracks the source tokens.
+type Source token.List
+
+func (v Source) Start() token.Position { return v[0].Position }
+func (v Source) End() token.Position   { return v[len(v)-1].End() }
+
+type HasSource interface {
+	Start() token.Position
+	End() token.Position
+}

src/ssa2asm/GenerateAssembly.go

@@ -16,9 +16,7 @@ func (f *Compiler) GenerateAssembly(ir ssa.IR, isLeaf bool) {
 	}
 
 	for instr := range ir.Values {
-		live, isLive := instr.(ssa.HasLiveness)
+		if len(instr.Users()) > 0 {
-
-		if isLive && len(live.Users()) > 0 {
 			continue
 		}
 

src/ssa2asm/ValueToRegister.go

@@ -91,7 +91,7 @@ func (f *Compiler) ValueToRegister(instr ssa.Value, destination cpu.Register) {
 			Source:      source,
 		})
 
-	case *ssa.StructField:
+	case *ssa.Field:
 		parameter := instr.Struct.(*ssa.Parameter)
 		field := instr.Field
 		source := f.CPU.Call[parameter.Index+field.Index]