add reg.Type

operand/checks.go

@@ -115,7 +115,7 @@ func IsYmm(op Op) bool {
 
 // IsRegisterKindSize returns true if op is a register of the given kind and size in bytes.
 func IsRegisterKindSize(op Op, k reg.Kind, n uint) bool {
-	r, ok := op.(reg.Register)
+	r, ok := op.(reg.Type)
 	return ok && r.Kind() == k && r.Bytes() == n
 }
 

pass/cfg.go

@@ -37,7 +37,7 @@ func LabelTarget(fn *avo.Function) error {
 	return nil
 }
 
-// CFG constructs the call-flow-graph of each function.
+// CFG constructs the call-flow-graph for the function.
 func CFG(fn *avo.Function) error {
 	is := fn.Instructions()
 	n := len(is)

reg/types.go

@@ -1,5 +1,7 @@
 package reg
 
+import "fmt"
+
 type Size uint
 
 const (
@@ -44,10 +46,16 @@ type private interface {
 	private()
 }
 
-type Virtual interface {
-	VirtualID() uint16
+type Type interface {
 	Kind() Kind
 	Bytes() uint
+	Asm() string
+	private
+}
+
+type Virtual interface {
+	VirtualID() uint16
+	Type
 }
 
 type virtual struct {
@@ -59,13 +67,17 @@ type virtual struct {
 func (v virtual) VirtualID() uint16 { return v.id }
 func (v virtual) Kind() Kind        { return v.kind }
 
+func (v virtual) Asm() string {
+	// TODO(mbm): decide on virtual register syntax
+	return fmt.Sprintf("<virtual:%v:%v:%v>", v.id, v.Kind(), v.Bytes())
+}
+
+func (v virtual) private() {}
+
 type Register interface {
 	PhysicalID() uint16
-	Kind() Kind
 	Mask() uint16
-	Bytes() uint
-	Asm() string
-	private
+	Type
 }
 
 type register struct {