cmd/compile: get rid of Type's {This,In,Out}tuple fields

Boolean expressions involving t.Thistuple were converted to use
t.Recv(), because it's a bit clearer and will hopefully reveal cases
where we could remove redundant calls to t.Recv() (in followup CLs).

The other cases were all converted to use t.Recvs().NumFields(),
t.Params().NumFields(), or t.Results().NumFields().

Change-Id: I4df91762e7dc4b2ddae35995f8dd604a52c09b09
Reviewed-on: https://go-review.googlesource.com/20796Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/gc/closure.go

@@ -595,7 +595,7 @@ func makepartialcall(fn *Node, t0 *Type, meth *Node) *Node {
 	call := Nod(OCALL, Nod(OXDOT, ptr, meth), nil)
 	call.List.Set(callargs)
 	call.Isddd = ddd
-	if t0.Outtuple == 0 {
+	if t0.Results().NumFields() == 0 {
 		body = append(body, call)
 	} else {
 		n := Nod(OAS2, nil, nil)

src/cmd/compile/internal/gc/dcl.go

@@ -655,37 +655,31 @@ func funcargs2(t *Type) {
 		Fatalf("funcargs2 %v", t)
 	}
 
-	if t.Thistuple != 0 {
-		for _, ft := range t.Recvs().Fields().Slice() {
-			if ft.Nname == nil || ft.Nname.Sym == nil {
-				continue
-			}
-			n := ft.Nname // no need for newname(ft->nname->sym)
-			n.Type = ft.Type
-			declare(n, PPARAM)
+	for _, ft := range t.Recvs().Fields().Slice() {
+		if ft.Nname == nil || ft.Nname.Sym == nil {
+			continue
 		}
+		n := ft.Nname // no need for newname(ft->nname->sym)
+		n.Type = ft.Type
+		declare(n, PPARAM)
 	}
 
-	if t.Intuple != 0 {
-		for _, ft := range t.Params().Fields().Slice() {
-			if ft.Nname == nil || ft.Nname.Sym == nil {
-				continue
-			}
-			n := ft.Nname
-			n.Type = ft.Type
-			declare(n, PPARAM)
+	for _, ft := range t.Params().Fields().Slice() {
+		if ft.Nname == nil || ft.Nname.Sym == nil {
+			continue
 		}
+		n := ft.Nname
+		n.Type = ft.Type
+		declare(n, PPARAM)
 	}
 
-	if t.Outtuple != 0 {
-		for _, ft := range t.Results().Fields().Slice() {
-			if ft.Nname == nil || ft.Nname.Sym == nil {
-				continue
-			}
-			n := ft.Nname
-			n.Type = ft.Type
-			declare(n, PPARAMOUT)
+	for _, ft := range t.Results().Fields().Slice() {
+		if ft.Nname == nil || ft.Nname.Sym == nil {
+			continue
 		}
+		n := ft.Nname
+		n.Type = ft.Type
+		declare(n, PPARAMOUT)
 	}
 }
 
@@ -1068,13 +1062,8 @@ func functype0(t *Type, this *Node, in, out []*Node) {
 		t.Broke = true
 	}
 
-	if this != nil {
-		t.Thistuple = 1
-	}
-	t.Outtuple = len(out)
-	t.Intuple = len(in)
 	t.Outnamed = false
-	if t.Outtuple > 0 && out[0].Left != nil && out[0].Left.Orig != nil {
+	if len(out) > 0 && out[0].Left != nil && out[0].Left.Orig != nil {
 		s := out[0].Left.Orig.Sym
 		if s != nil && (s.Name[0] != '~' || s.Name[1] != 'r') { // ~r%d is the name invented for an unnamed result
 			t.Outnamed = true

src/cmd/compile/internal/gc/esc.go

@@ -810,7 +810,7 @@ func esc(e *EscState, n *Node, up *Node) {
 
 	case ORETURN:
 		ll := n.List
-		if n.List.Len() == 1 && Curfn.Type.Outtuple > 1 {
+		if n.List.Len() == 1 && Curfn.Type.Results().NumFields() > 1 {
 			// OAS2FUNC in disguise
 			// esccall already done on n->list->n
 			// tie n->list->n->escretval to curfn->dcl PPARAMOUT's

src/cmd/compile/internal/gc/export.go

@@ -130,7 +130,7 @@ func reexportdep(n *Node) {
 			}
 
 			// nodes for method calls.
-			if n.Type == nil || n.Type.Thistuple > 0 {
+			if n.Type == nil || n.Type.Recv() != nil {
 				break
 			}
 			fallthrough

src/cmd/compile/internal/gc/fmt.go

@@ -630,7 +630,7 @@ func typefmt(t *Type, flag FmtFlag) string {
 		if flag&FmtShort != 0 {
 			// no leading func
 		} else {
-			if t.Thistuple != 0 {
+			if t.Recv() != nil {
 				buf.WriteString("method")
 				buf.WriteString(Tconv(t.Recvs(), 0))
 				buf.WriteString(" ")
@@ -639,7 +639,7 @@ func typefmt(t *Type, flag FmtFlag) string {
 		}
 		buf.WriteString(Tconv(t.Params(), 0))
 
-		switch t.Outtuple {
+		switch t.Results().NumFields() {
 		case 0:
 			break
 

src/cmd/compile/internal/gc/inl.go

@@ -34,7 +34,7 @@ import (
 // Get the function's package. For ordinary functions it's on the ->sym, but for imported methods
 // the ->sym can be re-used in the local package, so peel it off the receiver's type.
 func fnpkg(fn *Node) *Pkg {
-	if fn.Type.Thistuple != 0 {
+	if fn.Type.Recv() != nil {
 		// method
 		rcvr := fn.Type.Recv().Type
 
@@ -592,7 +592,7 @@ func mkinlcall1(np **Node, fn *Node, isddd bool) {
 	}
 
 	// assign receiver.
-	if fn.Type.Thistuple != 0 && n.Left.Op == ODOTMETH {
+	if fn.Type.Recv() != nil && n.Left.Op == ODOTMETH {
 		// method call with a receiver.
 		t := fn.Type.Recv()
 
@@ -635,8 +635,8 @@ func mkinlcall1(np **Node, fn *Node, isddd bool) {
 	if n.List.Len() == 1 {
 		switch n.List.First().Op {
 		case OCALL, OCALLFUNC, OCALLINTER, OCALLMETH:
-			if n.List.First().Left.Type.Outtuple > 1 {
-				multiret = n.List.First().Left.Type.Outtuple - 1
+			if n.List.First().Left.Type.Results().NumFields() > 1 {
+				multiret = n.List.First().Left.Type.Results().NumFields() - 1
 			}
 		}
 	}
@@ -644,9 +644,9 @@ func mkinlcall1(np **Node, fn *Node, isddd bool) {
 	if variadic {
 		varargcount = n.List.Len() + multiret
 		if n.Left.Op != ODOTMETH {
-			varargcount -= fn.Type.Thistuple
+			varargcount -= fn.Type.Recvs().NumFields()
 		}
-		varargcount -= fn.Type.Intuple - 1
+		varargcount -= fn.Type.Params().NumFields() - 1
 	}
 
 	// assign arguments to the parameters' temp names
@@ -656,7 +656,7 @@ func mkinlcall1(np **Node, fn *Node, isddd bool) {
 	li := 0
 
 	// TODO: if len(nlist) == 1 but multiple args, check that n->list->n is a call?
-	if fn.Type.Thistuple != 0 && n.Left.Op != ODOTMETH {
+	if fn.Type.Recv() != nil && n.Left.Op != ODOTMETH {
 		// non-method call to method
 		if n.List.Len() == 0 {
 			Fatalf("non-method call to method without first arg: %v", Nconv(n, FmtSign))

src/cmd/compile/internal/gc/order.go

@@ -326,14 +326,14 @@ func ismulticall(l Nodes) bool {
 	}
 
 	// call must return multiple values
-	return n.Left.Type.Outtuple > 1
+	return n.Left.Type.Results().NumFields() > 1
 }
 
 // Copyret emits t1, t2, ... = n, where n is a function call,
 // and then returns the list t1, t2, ....
 func copyret(n *Node, order *Order) []*Node {
 	if n.Type.Etype != TSTRUCT || !n.Type.Funarg {
-		Fatalf("copyret %v %d", n.Type, n.Left.Type.Outtuple)
+		Fatalf("copyret %v %d", n.Type, n.Left.Type.Results().NumFields())
 	}
 
 	var l1 []*Node

src/cmd/compile/internal/gc/pgen.go

@@ -147,18 +147,18 @@ func emitptrargsmap() {
 	nptr := int(Curfn.Type.Argwid / int64(Widthptr))
 	bv := bvalloc(int32(nptr) * 2)
 	nbitmap := 1
-	if Curfn.Type.Outtuple > 0 {
+	if Curfn.Type.Results().NumFields() > 0 {
 		nbitmap = 2
 	}
 	off := duint32(sym, 0, uint32(nbitmap))
 	off = duint32(sym, off, uint32(bv.n))
 	var xoffset int64
-	if Curfn.Type.Thistuple > 0 {
+	if Curfn.Type.Recv() != nil {
 		xoffset = 0
 		onebitwalktype1(Curfn.Type.Recvs(), &xoffset, bv)
 	}
 
-	if Curfn.Type.Intuple > 0 {
+	if Curfn.Type.Params().NumFields() > 0 {
 		xoffset = 0
 		onebitwalktype1(Curfn.Type.Params(), &xoffset, bv)
 	}
@@ -166,7 +166,7 @@ func emitptrargsmap() {
 	for j := 0; int32(j) < bv.n; j += 32 {
 		off = duint32(sym, off, bv.b[j/32])
 	}
-	if Curfn.Type.Outtuple > 0 {
+	if Curfn.Type.Results().NumFields() > 0 {
 		xoffset = 0
 		onebitwalktype1(Curfn.Type.Results(), &xoffset, bv)
 		for j := 0; int32(j) < bv.n; j += 32 {
@@ -503,7 +503,7 @@ func genlegacy(ptxt *obj.Prog, gcargs, gclocals *Sym) {
 		lineno = Curfn.Func.Endlineno
 	}
 
-	if Curfn.Type.Outtuple != 0 {
+	if Curfn.Type.Results().NumFields() != 0 {
 		Ginscall(throwreturn, 0)
 	}
 

src/cmd/compile/internal/gc/reflect.go

@@ -286,7 +286,7 @@ func methods(t *Type) []*Sig {
 	// generating code if necessary.
 	var ms []*Sig
 	for _, f := range mt.AllMethods().Slice() {
-		if f.Type.Etype != TFUNC || f.Type.Thistuple == 0 {
+		if f.Type.Etype != TFUNC || f.Type.Recv() == nil {
 			Fatalf("non-method on %v method %v %v\n", mt, f.Sym, f)
 		}
 		if f.Type.Recv() == nil {
@@ -1041,8 +1041,8 @@ ok:
 		}
 
 		ot = dcommontype(s, ot, t)
-		inCount := t.Thistuple + t.Intuple
-		outCount := t.Outtuple
+		inCount := t.Recvs().NumFields() + t.Params().NumFields()
+		outCount := t.Results().NumFields()
 		if isddd {
 			outCount |= 1 << 15
 		}
@@ -1052,7 +1052,7 @@ ok:
 			ot += 4 // align for *rtype
 		}
 
-		dataAdd := (inCount + t.Outtuple) * Widthptr
+		dataAdd := (inCount + t.Results().NumFields()) * Widthptr
 		ot = dextratype(s, ot, t, dataAdd)
 
 		// Array of rtype pointers follows funcType.

src/cmd/compile/internal/gc/sizeof_test.go

@@ -27,7 +27,7 @@ func TestSizeof(t *testing.T) {
 		{Name{}, 52, 80},
 		{Node{}, 92, 144},
 		{Sym{}, 60, 112},
-		{Type{}, 132, 224},
+		{Type{}, 116, 184},
 	}
 
 	for _, tt := range tests {

src/cmd/compile/internal/gc/subr.go

@@ -1556,7 +1556,7 @@ func lookdot0(s *Sym, t *Type, save **Field, ignorecase bool) int {
 	c := 0
 	if u.Etype == TSTRUCT || u.Etype == TINTER {
 		for _, f := range u.Fields().Slice() {
-			if f.Sym == s || (ignorecase && f.Type.Etype == TFUNC && f.Type.Thistuple > 0 && strings.EqualFold(f.Sym.Name, s.Name)) {
+			if f.Sym == s || (ignorecase && f.Type.Etype == TFUNC && f.Type.Recv() != nil && strings.EqualFold(f.Sym.Name, s.Name)) {
 				if save != nil {
 					*save = f
 				}
@@ -1807,7 +1807,7 @@ func expandmeth(t *Type) {
 		}
 
 		// dotpath may have dug out arbitrary fields, we only want methods.
-		if f.Type.Etype != TFUNC || f.Type.Thistuple == 0 {
+		if f.Type.Etype != TFUNC || f.Type.Recv() == nil {
 			continue
 		}
 
@@ -1981,7 +1981,7 @@ func genwrapper(rcvr *Type, method *Field, newnam *Sym, iface int) {
 		call := Nod(OCALL, dot, nil)
 		call.List.Set(args)
 		call.Isddd = isddd
-		if method.Type.Outtuple > 0 {
+		if method.Type.Results().NumFields() > 0 {
 			n := Nod(ORETURN, nil, nil)
 			n.List.Set1(call)
 			call = n
@@ -2051,7 +2051,7 @@ func ifacelookdot(s *Sym, t *Type, followptr *bool, ignorecase bool) *Field {
 		}
 	}
 
-	if m.Type.Etype != TFUNC || m.Type.Thistuple == 0 {
+	if m.Type.Etype != TFUNC || m.Type.Recv() == nil {
 		Yyerror("%v.%v is a field, not a method", t, s)
 		return nil
 	}

src/cmd/compile/internal/gc/type.go

@@ -112,22 +112,17 @@ type Type struct {
 	Broke       bool // broken type definition.
 	Align       uint8
 	Haspointers uint8 // 0 unknown, 1 no, 2 yes
+	Outnamed    bool  // on TFUNC
 
-	Nod    *Node // canonical OTYPE node
-	Orig   *Type // original type (type literal or predefined type)
-	Lineno int32
-
-	// TFUNC
-	Thistuple int
-	Outtuple  int
-	Intuple   int
-	Outnamed  bool
+	Nod  *Node // canonical OTYPE node
+	Orig *Type // original type (type literal or predefined type)
 
 	methods    Fields
 	allMethods Fields
 
 	Sym    *Sym
 	Vargen int32 // unique name for OTYPE/ONAME
+	Lineno int32
 
 	Nname  *Node
 	Argwid int64

src/cmd/compile/internal/gc/typecheck.go

@@ -845,7 +845,7 @@ OpSwitch:
 				return
 			}
 
-			if n.Type.Etype != TFUNC || n.Type.Thistuple != 1 {
+			if n.Type.Etype != TFUNC || n.Type.Recv() == nil {
 				Yyerror("type %v has no method %v", n.Left.Type, Sconv(n.Right.Sym, FmtShort))
 				n.Type = nil
 				n.Type = nil
@@ -1327,11 +1327,11 @@ OpSwitch:
 
 		typecheckaste(OCALL, n.Left, n.Isddd, t.Params(), n.List, func() string { return fmt.Sprintf("argument to %v", n.Left) })
 		ok |= Etop
-		if t.Outtuple == 0 {
+		if t.Results().NumFields() == 0 {
 			break OpSwitch
 		}
 		ok |= Erv
-		if t.Outtuple == 1 {
+		if t.Results().NumFields() == 1 {
 			n.Type = l.Type.Results().Field(0).Type
 
 			if n.Op == OCALLFUNC && n.Left.Op == ONAME && (compiling_runtime != 0 || n.Left.Sym.Pkg == Runtimepkg) && n.Left.Sym.Name == "getg" {
@@ -1445,8 +1445,8 @@ OpSwitch:
 			}
 
 			t := n.List.First().Left.Type
-			if t.Outtuple != 2 {
-				Yyerror("invalid operation: complex expects two arguments, %v returns %d results", n.List.First(), t.Outtuple)
+			if t.Results().NumFields() != 2 {
+				Yyerror("invalid operation: complex expects two arguments, %v returns %d results", n.List.First(), t.Results().NumFields())
 				n.Type = nil
 				return
 			}
@@ -3957,7 +3957,7 @@ func (n *Node) isterminating() bool {
 }
 
 func checkreturn(fn *Node) {
-	if fn.Type.Outtuple != 0 && len(fn.Nbody.Slice()) != 0 {
+	if fn.Type.Results().NumFields() != 0 && len(fn.Nbody.Slice()) != 0 {
 		markbreaklist(fn.Nbody, nil)
 		if !fn.Nbody.isterminating() {
 			yyerrorl(fn.Func.Endlineno, "missing return at end of function")

src/cmd/compile/internal/gc/universe.go

@@ -387,10 +387,6 @@ func lexinit1() {
 	*f.RecvsP() = rcvr
 	*f.ResultsP() = out
 	*f.ParamsP() = in
-	f.Thistuple = 1
-	f.Intuple = 0
-	f.Outnamed = false
-	f.Outtuple = 1
 
 	t := typ(TINTER)
 	field = newField()

src/cmd/compile/internal/gc/walk.go

@@ -657,7 +657,7 @@ opswitch:
 
 			// Update type of OCALLFUNC node.
 			// Output arguments had not changed, but their offsets could.
-			if n.Left.Type.Outtuple == 1 {
+			if n.Left.Type.Results().NumFields() == 1 {
 				n.Type = n.Left.Type.Results().Field(0).Type
 			} else {
 				n.Type = n.Left.Type.Results()
@@ -2634,11 +2634,11 @@ func vmkcall(fn *Node, t *Type, init *Nodes, va []*Node) *Node {
 		Fatalf("mkcall %v %v", fn, fn.Type)
 	}
 
-	n := fn.Type.Intuple
+	n := fn.Type.Params().NumFields()
 
 	r := Nod(OCALL, fn, nil)
 	r.List.Set(va[:n])
-	if fn.Type.Outtuple > 0 {
+	if fn.Type.Results().NumFields() > 0 {
 		typecheck(&r, Erv|Efnstruct)
 	} else {
 		typecheck(&r, Etop)