diff --git a/src/cmd/internal/gc/closure.go b/src/cmd/internal/gc/closure.go
index 3155b69a21e..df895441625 100644
--- a/src/cmd/internal/gc/closure.go
+++ b/src/cmd/internal/gc/closure.go
@@ -174,8 +174,7 @@ func closurename(n *Node) *Sym {
 	} else {
 		Fatal("closurename called for %v", Nconv(n, obj.FmtShort))
 	}
-	namebuf = fmt.Sprintf("%s.%s%d", outer, prefix, gen)
-	n.Sym = Lookup(namebuf)
+	n.Sym = Lookupf("%s.%s%d", outer, prefix, gen)
 	return n.Sym
 }
 
@@ -333,9 +332,7 @@ func transformclosure(xfunc *Node) {
 				// we introduce function param &v *T
 				// and v remains PPARAMREF with &v heapaddr
 				// (accesses will implicitly deref &v).
-				namebuf = fmt.Sprintf("&%s", v.Sym.Name)
-
-				addr = newname(Lookup(namebuf))
+				addr = newname(Lookupf("&%s", v.Sym.Name))
 				addr.Type = Ptrto(v.Type)
 				addr.Class = PPARAM
 				v.Heapaddr = addr
@@ -397,9 +394,7 @@ func transformclosure(xfunc *Node) {
 			} else {
 				// Declare variable holding addresses taken from closure
 				// and initialize in entry prologue.
-				namebuf = fmt.Sprintf("&%s", v.Sym.Name)
-
-				addr = newname(Lookup(namebuf))
+				addr = newname(Lookupf("&%s", v.Sym.Name))
 				addr.Ntype = Nod(OIND, typenod(v.Type), nil)
 				addr.Class = PAUTO
 				addr.Used = true
@@ -557,9 +552,8 @@ func makepartialcall(fn *Node, t0 *Type, meth *Node) *Node {
 	var fld *Node
 	var n *Node
 	for t := getinargx(t0).Type; t != nil; t = t.Down {
-		namebuf = fmt.Sprintf("a%d", i)
+		n = newname(Lookupf("a%d", i))
 		i++
-		n = newname(Lookup(namebuf))
 		n.Class = PPARAM
 		xfunc.Dcl = list(xfunc.Dcl, n)
 		callargs = list(callargs, n)
@@ -577,9 +571,8 @@ func makepartialcall(fn *Node, t0 *Type, meth *Node) *Node {
 	l = nil
 	var retargs *NodeList
 	for t := getoutargx(t0).Type; t != nil; t = t.Down {
-		namebuf = fmt.Sprintf("r%d", i)
+		n = newname(Lookupf("r%d", i))
 		i++
-		n = newname(Lookup(namebuf))
 		n.Class = PPARAMOUT
 		xfunc.Dcl = list(xfunc.Dcl, n)
 		retargs = list(retargs, n)
diff --git a/src/cmd/internal/gc/dcl.go b/src/cmd/internal/gc/dcl.go
index 7194c123a25..fa955ba929e 100644
--- a/src/cmd/internal/gc/dcl.go
+++ b/src/cmd/internal/gc/dcl.go
@@ -645,10 +645,8 @@ func funcargs(nt *Node) {
 
 		if n.Left == nil {
 			// Name so that escape analysis can track it. ~r stands for 'result'.
-			namebuf = fmt.Sprintf("~r%d", gen)
+			n.Left = newname(Lookupf("~r%d", gen))
 			gen++
-
-			n.Left = newname(Lookup(namebuf))
 		}
 
 		// TODO: n->left->missing = 1;
@@ -667,9 +665,8 @@ func funcargs(nt *Node) {
 
 			*nn = *n.Left
 			nn.Orig = nn
-			namebuf = fmt.Sprintf("~b%d", gen)
+			nn.Sym = Lookupf("~b%d", gen)
 			gen++
-			nn.Sym = Lookup(namebuf)
 			n.Left = nn
 		}
 
diff --git a/src/cmd/internal/gc/gen.go b/src/cmd/internal/gc/gen.go
index 70c218e667c..3777cc310de 100644
--- a/src/cmd/internal/gc/gen.go
+++ b/src/cmd/internal/gc/gen.go
@@ -590,10 +590,8 @@ func Tempname(nn *Node, t *Type) {
 
 	// give each tmp a different name so that there
 	// a chance to registerizer them
-	namebuf = fmt.Sprintf("autotmp_%.4d", statuniqgen)
-
+	s := Lookupf("autotmp_%.4d", statuniqgen)
 	statuniqgen++
-	s := Lookup(namebuf)
 	n := Nod(ONAME, nil, nil)
 	n.Sym = s
 	s.Def = n
diff --git a/src/cmd/internal/gc/go.go b/src/cmd/internal/gc/go.go
index 348dd833e03..e9412d1ff27 100644
--- a/src/cmd/internal/gc/go.go
+++ b/src/cmd/internal/gc/go.go
@@ -500,8 +500,6 @@ var safemode int
 
 var nolocalimports int
 
-var namebuf string
-
 var lexbuf bytes.Buffer
 var strbuf bytes.Buffer
 
diff --git a/src/cmd/internal/gc/init.go b/src/cmd/internal/gc/init.go
index c57e50b13dc..8aaed8c63c8 100644
--- a/src/cmd/internal/gc/init.go
+++ b/src/cmd/internal/gc/init.go
@@ -4,8 +4,6 @@
 
 package gc
 
-import "fmt"
-
 //	case OADD:
 //		if(n->right->op == OLITERAL) {
 //			v = n->right->vconst;
@@ -31,8 +29,7 @@ var renameinit_initgen int
 
 func renameinit() *Sym {
 	renameinit_initgen++
-	namebuf = fmt.Sprintf("init.%d", renameinit_initgen)
-	return Lookup(namebuf)
+	return Lookupf("init.%d", renameinit_initgen)
 }
 
 /*
@@ -112,18 +109,14 @@ func fninit(n *NodeList) {
 	var r *NodeList
 
 	// (1)
-	namebuf = "initdone·"
-
-	gatevar := newname(Lookup(namebuf))
+	gatevar := newname(Lookup("initdone·"))
 	addvar(gatevar, Types[TUINT8], PEXTERN)
 
 	// (2)
 	Maxarg = 0
 
-	namebuf = "init"
-
 	fn := Nod(ODCLFUNC, nil, nil)
-	initsym := Lookup(namebuf)
+	initsym := Lookup("init")
 	fn.Nname = newname(initsym)
 	fn.Nname.Defn = fn
 	fn.Nname.Ntype = Nod(OTFUNC, nil, nil)
@@ -169,8 +162,7 @@ func fninit(n *NodeList) {
 	// (9)
 	// could check that it is fn of no args/returns
 	for i := 1; ; i++ {
-		namebuf = fmt.Sprintf("init.%d", i)
-		s := Lookup(namebuf)
+		s := Lookupf("init.%d", i)
 		if s.Def == nil {
 			break
 		}
diff --git a/src/cmd/internal/gc/inl.go b/src/cmd/internal/gc/inl.go
index c266f7d7aa3..cdd709ed770 100644
--- a/src/cmd/internal/gc/inl.go
+++ b/src/cmd/internal/gc/inl.go
@@ -859,8 +859,7 @@ func inlvar(var_ *Node) *Node {
 
 // Synthesize a variable to store the inlined function's results in.
 func retvar(t *Type, i int) *Node {
-	namebuf = fmt.Sprintf("~r%d", i)
-	n := newname(Lookup(namebuf))
+	n := newname(Lookupf("~r%d", i))
 	n.Type = t.Type
 	n.Class = PAUTO
 	n.Used = true
@@ -872,8 +871,7 @@ func retvar(t *Type, i int) *Node {
 // Synthesize a variable to store the inlined function's arguments
 // when they come from a multiple return call.
 func argvar(t *Type, i int) *Node {
-	namebuf = fmt.Sprintf("~arg%d", i)
-	n := newname(Lookup(namebuf))
+	n := newname(Lookupf("~arg%d", i))
 	n.Type = t.Type
 	n.Class = PAUTO
 	n.Used = true
@@ -886,8 +884,7 @@ var newlabel_inl_label int
 
 func newlabel_inl() *Node {
 	newlabel_inl_label++
-	namebuf = fmt.Sprintf(".inlret%.6d", newlabel_inl_label)
-	n := newname(Lookup(namebuf))
+	n := newname(Lookupf(".inlret%.6d", newlabel_inl_label))
 	n.Etype = 1 // flag 'safe' for escape analysis (no backjumps)
 	return n
 }
diff --git a/src/cmd/internal/gc/lex.go b/src/cmd/internal/gc/lex.go
index 816e67e89a4..03e874929d6 100644
--- a/src/cmd/internal/gc/lex.go
+++ b/src/cmd/internal/gc/lex.go
@@ -559,25 +559,24 @@ func islocalname(name string) bool {
 		strings.HasPrefix(name, "../") || name == ".."
 }
 
-func findpkg(name string) bool {
+func findpkg(name string) (file string, ok bool) {
 	if islocalname(name) {
 		if safemode != 0 || nolocalimports != 0 {
-			return false
+			return "", false
 		}
 
 		// try .a before .6.  important for building libraries:
 		// if there is an array.6 in the array.a library,
 		// want to find all of array.a, not just array.6.
-		namebuf = fmt.Sprintf("%s.a", name)
-
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s.a", name)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
-		namebuf = fmt.Sprintf("%s.%c", name, Thearch.Thechar)
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s.%c", name, Thearch.Thechar)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
-		return false
+		return "", false
 	}
 
 	// local imports should be canonicalized already.
@@ -587,17 +586,17 @@ func findpkg(name string) bool {
 	_ = q
 	if path.Clean(name) != name {
 		Yyerror("non-canonical import path %q (should be %q)", name, q)
-		return false
+		return "", false
 	}
 
 	for p := idirs; p != nil; p = p.link {
-		namebuf = fmt.Sprintf("%s/%s.a", p.dir, name)
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s/%s.a", p.dir, name)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
-		namebuf = fmt.Sprintf("%s/%s.%c", p.dir, name, Thearch.Thechar)
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s/%s.%c", p.dir, name, Thearch.Thechar)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
 	}
 
@@ -612,17 +611,17 @@ func findpkg(name string) bool {
 			suffix = "race"
 		}
 
-		namebuf = fmt.Sprintf("%s/pkg/%s_%s%s%s/%s.a", goroot, goos, goarch, suffixsep, suffix, name)
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s/pkg/%s_%s%s%s/%s.a", goroot, goos, goarch, suffixsep, suffix, name)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
-		namebuf = fmt.Sprintf("%s/pkg/%s_%s%s%s/%s.%c", goroot, goos, goarch, suffixsep, suffix, name, Thearch.Thechar)
-		if obj.Access(namebuf, 0) >= 0 {
-			return true
+		file = fmt.Sprintf("%s/pkg/%s_%s%s%s/%s.%c", goroot, goos, goarch, suffixsep, suffix, name, Thearch.Thechar)
+		if obj.Access(file, 0) >= 0 {
+			return file, true
 		}
 	}
 
-	return false
+	return "", false
 }
 
 func fakeimport() {
@@ -698,7 +697,8 @@ func importfile(f *Val, line int) {
 		}
 	}
 
-	if !findpkg(path_) {
+	file, found := findpkg(path_)
+	if !found {
 		Yyerror("can't find import: %q", f.U.Sval)
 		errorexit()
 	}
@@ -708,7 +708,6 @@ func importfile(f *Val, line int) {
 	// If we already saw that package, feed a dummy statement
 	// to the lexer to avoid parsing export data twice.
 	if importpkg.Imported != 0 {
-		file := namebuf
 		tag := ""
 		if importpkg.Safe {
 			tag = "safe"
@@ -723,16 +722,13 @@ func importfile(f *Val, line int) {
 
 	var err error
 	var imp *obj.Biobuf
-	imp, err = obj.Bopenr(namebuf)
+	imp, err = obj.Bopenr(file)
 	if err != nil {
 		Yyerror("can't open import: %q: %v", f.U.Sval, err)
 		errorexit()
 	}
 
-	file := namebuf
-
-	n := len(namebuf)
-	if n > 2 && namebuf[n-2] == '.' && namebuf[n-1] == 'a' {
+	if strings.HasSuffix(file, ".a") {
 		if !skiptopkgdef(imp) {
 			Yyerror("import %s: not a package file", file)
 			errorexit()
@@ -757,7 +753,7 @@ func importfile(f *Val, line int) {
 
 	// assume files move (get installed)
 	// so don't record the full path.
-	linehist(file[n-len(path_)-2:], -1, 1) // acts as #pragma lib
+	linehist(file[len(file)-len(path_)-2:], -1, 1) // acts as #pragma lib
 
 	/*
 	 * position the input right
@@ -3162,10 +3158,9 @@ func mkpackage(pkgname string) {
 				p = p[i+1:]
 			}
 		}
-		namebuf = p
-		if i := strings.LastIndex(namebuf, "."); i >= 0 {
-			namebuf = namebuf[:i]
+		if i := strings.LastIndex(p, "."); i >= 0 {
+			p = p[:i]
 		}
-		outfile = fmt.Sprintf("%s.%c", namebuf, Thearch.Thechar)
+		outfile = fmt.Sprintf("%s.%c", p, Thearch.Thechar)
 	}
 }
diff --git a/src/cmd/internal/gc/obj.go b/src/cmd/internal/gc/obj.go
index d59898f2861..077b89b500a 100644
--- a/src/cmd/internal/gc/obj.go
+++ b/src/cmd/internal/gc/obj.go
@@ -101,8 +101,8 @@ func dumpobj() {
 			obj.Bputc(bout, 0)
 		}
 		obj.Bseek(bout, startobj-ArhdrSize, 0)
-		namebuf = fmt.Sprintf("_go_.%c", Thearch.Thechar)
-		formathdr(arhdr[:], namebuf, size)
+		name := fmt.Sprintf("_go_.%c", Thearch.Thechar)
+		formathdr(arhdr[:], name, size)
 		obj.Bwrite(bout, arhdr[:])
 	}
 
@@ -199,22 +199,23 @@ func duintptr(s *Sym, off int, v uint64) int {
 var stringsym_gen int
 
 func stringsym(s string) *Sym {
+	var symname string
 	var pkg *Pkg
 	if len(s) > 100 {
 		// huge strings are made static to avoid long names
 		stringsym_gen++
-		namebuf = fmt.Sprintf(".gostring.%d", stringsym_gen)
+		symname = fmt.Sprintf(".gostring.%d", stringsym_gen)
 
 		pkg = localpkg
 	} else {
 		// small strings get named by their contents,
 		// so that multiple modules using the same string
 		// can share it.
-		namebuf = fmt.Sprintf("%q", s)
+		symname = fmt.Sprintf("%q", s)
 		pkg = gostringpkg
 	}
 
-	sym := Pkglookup(namebuf, pkg)
+	sym := Pkglookup(symname, pkg)
 
 	// SymUniq flag indicates that data is generated already
 	if sym.Flags&SymUniq != 0 {
@@ -252,8 +253,8 @@ func slicebytes(nam *Node, s string, len int) {
 	var m int
 
 	slicebytes_gen++
-	namebuf = fmt.Sprintf(".gobytes.%d", slicebytes_gen)
-	sym := Pkglookup(namebuf, localpkg)
+	symname := fmt.Sprintf(".gobytes.%d", slicebytes_gen)
+	sym := Pkglookup(symname, localpkg)
 	sym.Def = newname(sym)
 
 	off := 0
diff --git a/src/cmd/internal/gc/pgen.go b/src/cmd/internal/gc/pgen.go
index 208ecb80ff0..06239048e2b 100644
--- a/src/cmd/internal/gc/pgen.go
+++ b/src/cmd/internal/gc/pgen.go
@@ -18,9 +18,8 @@ var makefuncdatasym_nsym int32
 func makefuncdatasym(namefmt string, funcdatakind int64) *Sym {
 	var nod Node
 
-	namebuf = fmt.Sprintf(namefmt, makefuncdatasym_nsym)
+	sym := Lookupf(namefmt, makefuncdatasym_nsym)
 	makefuncdatasym_nsym++
-	sym := Lookup(namebuf)
 	pnod := newname(sym)
 	pnod.Class = PEXTERN
 	Nodconst(&nod, Types[TINT32], funcdatakind)
diff --git a/src/cmd/internal/gc/sinit.go b/src/cmd/internal/gc/sinit.go
index c5e006b160f..2dec7572bde 100644
--- a/src/cmd/internal/gc/sinit.go
+++ b/src/cmd/internal/gc/sinit.go
@@ -517,9 +517,8 @@ func staticassign(l *Node, r *Node, out **NodeList) bool {
  * part of the composite literal.
  */
 func staticname(t *Type, ctxt int) *Node {
-	namebuf = fmt.Sprintf("statictmp_%.4d", statuniqgen)
+	n := newname(Lookupf("statictmp_%.4d", statuniqgen))
 	statuniqgen++
-	n := newname(Lookup(namebuf))
 	if ctxt == 0 {
 		n.Readonly = true
 	}
diff --git a/src/cmd/internal/gc/subr.go b/src/cmd/internal/gc/subr.go
index c59b7e6447e..f77d1511fce 100644
--- a/src/cmd/internal/gc/subr.go
+++ b/src/cmd/internal/gc/subr.go
@@ -281,6 +281,10 @@ func Lookup(name string) *Sym {
 	return localpkg.Lookup(name)
 }
 
+func Lookupf(format string, a ...interface{}) *Sym {
+	return Lookup(fmt.Sprintf(format, a...))
+}
+
 func LookupBytes(name []byte) *Sym {
 	return localpkg.LookupBytes(name)
 }
diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index e88b4c28b09..e4abc282c25 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -1109,17 +1109,18 @@ func walkexpr(np **Node, init **NodeList) {
 			if Widthreg >= 8 || (et != TUINT64 && et != TINT64) {
 				goto ret
 			}
+			var fn string
 			if et == TINT64 {
-				namebuf = "int64"
+				fn = "int64"
 			} else {
-				namebuf = "uint64"
+				fn = "uint64"
 			}
 			if n.Op == ODIV {
-				namebuf += "div"
+				fn += "div"
 			} else {
-				namebuf += "mod"
+				fn += "mod"
 			}
-			n = mkcall(namebuf, n.Type, init, conv(n.Left, Types[et]), conv(n.Right, Types[et]))
+			n = mkcall(fn, n.Type, init, conv(n.Left, Types[et]), conv(n.Right, Types[et]))
 
 		default:
 			break
@@ -2882,13 +2883,14 @@ func addstr(n *Node, init **NodeList) *Node {
 		args = list(args, conv(l.N, Types[TSTRING]))
 	}
 
+	var fn string
 	if c <= 5 {
 		// small numbers of strings use direct runtime helpers.
 		// note: orderexpr knows this cutoff too.
-		namebuf = fmt.Sprintf("concatstring%d", c)
+		fn = fmt.Sprintf("concatstring%d", c)
 	} else {
 		// large numbers of strings are passed to the runtime as a slice.
-		namebuf = "concatstrings"
+		fn = "concatstrings"
 
 		t := typ(TARRAY)
 		t.Type = Types[TSTRING]
@@ -2901,7 +2903,7 @@ func addstr(n *Node, init **NodeList) *Node {
 		slice.Esc = EscNone
 	}
 
-	cat := syslook(namebuf, 1)
+	cat := syslook(fn, 1)
 	r := Nod(OCALL, cat, nil)
 	r.List = args
 	typecheck(&r, Erv)