cmd/internal/gc: more int to bool cleanups

- make paramoutheap return a bool
- convert Node.Assigned to a bool
- convert Node.Captured to a bool
- convert Node.Byval to a bool
- convert Node.Dupok to a bool
- convert Node.Wrapper to a bool
- convert Node.Reslice to a bool

Change-Id: I5b57c019f936c31d53db4db14459fb2b0aa72305
Reviewed-on: https://go-review.googlesource.com/7030
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>

src/cmd/internal/gc/closure.go

@@ -84,8 +84,8 @@ func typecheckclosure(func_ *Node, top int) {
 
 	for l := func_.Cvars; l != nil; l = l.Next {
 		n = l.N.Closure
-		if n.Captured == 0 {
-			n.Captured = 1
+		if !n.Captured {
+			n.Captured = true
 			if n.Decldepth == 0 {
 				Fatal("typecheckclosure: var %v does not have decldepth assigned", Nconv(n, obj.FmtShort))
 			}
@@ -93,7 +93,7 @@ func typecheckclosure(func_ *Node, top int) {
 			// Ignore assignments to the variable in straightline code
 			// preceding the first capturing by a closure.
 			if n.Decldepth == decldepth {
-				n.Assigned = 0
+				n.Assigned = false
 			}
 		}
 	}
@@ -254,8 +254,8 @@ func capturevars(xfunc *Node) {
 		v.Outerexpr = nil
 
 		// out parameters will be assigned to implicitly upon return.
-		if outer.Class != PPARAMOUT && !v.Closure.Addrtaken && v.Closure.Assigned == 0 && v.Type.Width <= 128 {
-			v.Byval = 1
+		if outer.Class != PPARAMOUT && !v.Closure.Addrtaken && !v.Closure.Assigned && v.Type.Width <= 128 {
+			v.Byval = true
 		} else {
 			v.Closure.Addrtaken = true
 			outer = Nod(OADDR, outer, nil)
@@ -267,10 +267,10 @@ func capturevars(xfunc *Node) {
 				name = v.Curfn.Nname.Sym
 			}
 			how := "ref"
-			if v.Byval != 0 {
+			if v.Byval {
 				how = "value"
 			}
-			Warnl(int(v.Lineno), "%v capturing by %s: %v (addr=%d assign=%d width=%d)", Sconv(name, 0), how, Sconv(v.Sym, 0), v.Closure.Addrtaken, v.Closure.Assigned, int32(v.Type.Width))
+			Warnl(int(v.Lineno), "%v capturing by %s: %v (addr=%v assign=%v width=%d)", Sconv(name, 0), how, Sconv(v.Sym, 0), v.Closure.Addrtaken, v.Closure.Assigned, int32(v.Type.Width))
 		}
 
 		typecheck(&outer, Erv)
@@ -322,7 +322,7 @@ func transformclosure(xfunc *Node) {
 			}
 			fld = typ(TFIELD)
 			fld.Funarg = 1
-			if v.Byval != 0 {
+			if v.Byval {
 				// If v is captured by value, we merely downgrade it to PPARAM.
 				v.Class = PPARAM
 
@@ -378,14 +378,14 @@ func transformclosure(xfunc *Node) {
 			cv = Nod(OCLOSUREVAR, nil, nil)
 
 			cv.Type = v.Type
-			if v.Byval == 0 {
+			if !v.Byval {
 				cv.Type = Ptrto(v.Type)
 			}
 			offset = Rnd(offset, int64(cv.Type.Align))
 			cv.Xoffset = offset
 			offset += cv.Type.Width
 
-			if v.Byval != 0 && v.Type.Width <= int64(2*Widthptr) && Thearch.Thechar == '6' {
+			if v.Byval && v.Type.Width <= int64(2*Widthptr) && Thearch.Thechar == '6' {
 				//  If it is a small variable captured by value, downgrade it to PAUTO.
 				// This optimization is currently enabled only for amd64, see:
 				// https://github.com/golang/go/issues/9865
@@ -406,7 +406,7 @@ func transformclosure(xfunc *Node) {
 				addr.Curfn = xfunc
 				xfunc.Dcl = list(xfunc.Dcl, addr)
 				v.Heapaddr = addr
-				if v.Byval != 0 {
+				if v.Byval {
 					cv = Nod(OADDR, cv, nil)
 				}
 				body = list(body, Nod(OAS, addr, cv))
@@ -453,7 +453,7 @@ func walkclosure(func_ *Node, init **NodeList) *Node {
 			continue
 		}
 		typ1 = typenod(v.Type)
-		if v.Byval == 0 {
+		if !v.Byval {
 			typ1 = Nod(OIND, typ1, nil)
 		}
 		typ.List = list(typ.List, Nod(ODCLFIELD, newname(v.Sym), typ1))
@@ -588,7 +588,7 @@ func makepartialcall(fn *Node, t0 *Type, meth *Node) *Node {
 
 	xtype.Rlist = l
 
-	xfunc.Dupok = 1
+	xfunc.Dupok = true
 	xfunc.Nname = newname(sym)
 	xfunc.Nname.Sym.Flags |= SymExported // disable export
 	xfunc.Nname.Ntype = xtype

src/cmd/internal/gc/esc.go

@@ -719,7 +719,7 @@ func esc(e *EscState, n *Node, up *Node) {
 				continue
 			}
 			a = v.Closure
-			if v.Byval == 0 {
+			if !v.Byval {
 				a = Nod(OADDR, a, nil)
 				a.Lineno = v.Lineno
 				a.Escloopdepth = e.loopdepth

src/cmd/internal/gc/fmt.go

@@ -285,7 +285,7 @@ func Jconv(n *Node, flag int) string {
 		fp += " addrtaken"
 	}
 
-	if n.Assigned != 0 {
+	if n.Assigned {
 		fp += " assigned"
 	}
 

src/cmd/internal/gc/pgen.go

@@ -442,10 +442,10 @@ func compile(fn *Node) {
 		nam = nil
 	}
 	ptxt = Thearch.Gins(obj.ATEXT, nam, &nod1)
-	if fn.Dupok != 0 {
+	if fn.Dupok {
 		ptxt.From3.Offset |= obj.DUPOK
 	}
-	if fn.Wrapper != 0 {
+	if fn.Wrapper {
 		ptxt.From3.Offset |= obj.WRAPPER
 	}
 	if fn.Needctxt {

src/cmd/internal/gc/popt.go

@@ -893,7 +893,7 @@ func mergetemp(firstp *obj.Prog) {
 		for j = nfree; j < len(var_); j++ {
 			v1 = inuse[j]
 			if debugmerge > 0 && Debug['v'] != 0 {
-				fmt.Printf("consider %v: maybe %v: type=%v,%v addrtaken=%d,%d\n", Nconv(v.node, obj.FmtSharp), Nconv(v1.node, obj.FmtSharp), Tconv(t, 0), Tconv(v1.node.Type, 0), v.node.Addrtaken, v1.node.Addrtaken)
+				fmt.Printf("consider %v: maybe %v: type=%v,%v addrtaken=%v,%v\n", Nconv(v.node, obj.FmtSharp), Nconv(v1.node, obj.FmtSharp), Tconv(t, 0), Tconv(v1.node.Type, 0), v.node.Addrtaken, v1.node.Addrtaken)
 			}
 
 			// Require the types to match but also require the addrtaken bits to match.

src/cmd/internal/gc/subr.go

@@ -2474,7 +2474,7 @@ func genwrapper(rcvr *Type, method *Type, newnam *Sym, iface int) {
 		n.Left = newname(methodsym(method.Sym, methodrcvr, 0))
 		fn.Nbody = list(fn.Nbody, n)
 	} else {
-		fn.Wrapper = 1 // ignore frame for panic+recover matching
+		fn.Wrapper = true // ignore frame for panic+recover matching
 		call := Nod(OCALL, dot, nil)
 		call.List = args
 		call.Isddd = uint8(isddd)
@@ -2496,7 +2496,7 @@ func genwrapper(rcvr *Type, method *Type, newnam *Sym, iface int) {
 
 	// wrappers where T is anonymous (struct or interface) can be duplicated.
 	if rcvr.Etype == TSTRUCT || rcvr.Etype == TINTER || Isptr[rcvr.Etype] && rcvr.Type.Etype == TSTRUCT {
-		fn.Dupok = 1
+		fn.Dupok = true
 	}
 	typecheck(&fn, Etop)
 	typechecklist(fn.Nbody, Etop)
@@ -2751,7 +2751,7 @@ func genhash(sym *Sym, t *Type) {
 
 	funcbody(fn)
 	Curfn = fn
-	fn.Dupok = 1
+	fn.Dupok = true
 	typecheck(&fn, Etop)
 	typechecklist(fn.Nbody, Etop)
 	Curfn = nil
@@ -2971,7 +2971,7 @@ func geneq(sym *Sym, t *Type) {
 
 	funcbody(fn)
 	Curfn = fn
-	fn.Dupok = 1
+	fn.Dupok = true
 	typecheck(&fn, Etop)
 	typechecklist(fn.Nbody, Etop)
 	Curfn = nil

src/cmd/internal/gc/syntax.go

@@ -47,18 +47,18 @@ type Node struct {
 	Isddd          uint8
 	Readonly       bool
 	Implicit       uint8
-	Addrtaken      bool  // address taken, even if not moved to heap
-	Assigned       uint8 // is the variable ever assigned to
-	Captured       uint8 // is the variable captured by a closure
-	Byval          uint8 // is the variable captured by value or by reference
-	Dupok          uint8 // duplicate definitions ok (for func)
-	Wrapper        uint8 // is method wrapper (for func)
-	Reslice        uint8 // this is a reslice x = x[0:y] or x = append(x, ...)
-	Likely         int8  // likeliness of if statement
-	Hasbreak       bool  // has break statement
-	Needzero       bool  // if it contains pointers, needs to be zeroed on function entry
-	Needctxt       bool  // function uses context register (has closure variables)
-	Esc            uint  // EscXXX
+	Addrtaken      bool // address taken, even if not moved to heap
+	Assigned       bool // is the variable ever assigned to
+	Captured       bool // is the variable captured by a closure
+	Byval          bool // is the variable captured by value or by reference
+	Dupok          bool // duplicate definitions ok (for func)
+	Wrapper        bool // is method wrapper (for func)
+	Reslice        bool // this is a reslice x = x[0:y] or x = append(x, ...)
+	Likely         int8 // likeliness of if statement
+	Hasbreak       bool // has break statement
+	Needzero       bool // if it contains pointers, needs to be zeroed on function entry
+	Needctxt       bool // function uses context register (has closure variables)
+	Esc            uint // EscXXX
 	Funcdepth      int
 
 	// most nodes

src/cmd/internal/gc/typecheck.go

@@ -3258,15 +3258,15 @@ func checkassign(stmt *Node, n *Node) {
 		r := outervalue(n)
 		var l *Node
 		for l = n; l != r; l = l.Left {
-			l.Assigned = 1
+			l.Assigned = true
 			if l.Closure != nil {
-				l.Closure.Assigned = 1
+				l.Closure.Assigned = true
 			}
 		}
 
-		l.Assigned = 1
+		l.Assigned = true
 		if l.Closure != nil {
-			l.Closure.Assigned = 1
+			l.Closure.Assigned = true
 		}
 	}
 
@@ -3370,7 +3370,7 @@ func typecheckas(n *Node) {
 			OSLICE3,
 			OSLICESTR:
 			if false && samesafeexpr(n.Left, n.Right.Left) && (n.Right.Right.Left == nil || iszero(n.Right.Right.Left)) {
-				n.Right.Reslice = 1
+				n.Right.Reslice = true
 			}
 
 			// For x = append(x, ...), x can be updated in place when there is capacity,
@@ -3379,7 +3379,7 @@ func typecheckas(n *Node) {
 		// TODO(rsc): Reenable once the emitted code does update the pointer.
 		case OAPPEND:
 			if false && n.Right.List != nil && samesafeexpr(n.Left, n.Right.List.N) {
-				n.Right.Reslice = 1
+				n.Right.Reslice = true
 			}
 		}
 	}

src/cmd/internal/gc/walk.go

@@ -91,21 +91,21 @@ func samelist(a *NodeList, b *NodeList) bool {
 	return a == b
 }
 
-func paramoutheap(fn *Node) int {
+func paramoutheap(fn *Node) bool {
 	for l := fn.Dcl; l != nil; l = l.Next {
 		switch l.N.Class {
 		case PPARAMOUT,
 			PPARAMOUT | PHEAP:
-			return bool2int(l.N.Addrtaken)
+			return l.N.Addrtaken
 
 			// stop early - parameters are over
 		case PAUTO,
 			PAUTO | PHEAP:
-			return 0
+			return false
 		}
 	}
 
-	return 0
+	return false
 }
 
 // adds "adjust" to all the argument locations for the call n.
@@ -284,7 +284,7 @@ func walkstmt(np **Node) {
 		if n.List == nil {
 			break
 		}
-		if (Curfn.Type.Outnamed != 0 && count(n.List) > 1) || paramoutheap(Curfn) != 0 {
+		if (Curfn.Type.Outnamed != 0 && count(n.List) > 1) || paramoutheap(Curfn) {
 			// assign to the function out parameters,
 			// so that reorder3 can fix up conflicts
 			var rl *NodeList
@@ -2174,7 +2174,7 @@ func needwritebarrier(l *Node, r *Node) bool {
 	// generate the write barrier directly in that case.
 	// (It does not yet, but the cost of the write barrier will be
 	// small compared to the cost of the allocation.)
-	if r.Reslice != 0 {
+	if r.Reslice {
 		switch r.Op {
 		case OSLICE,
 			OSLICE3,