diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index 3d1c68f804..f023b269c8 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -174,64 +174,6 @@ newplist(void)
 	return pl;
 }
 
-void
-clearstk(void)
-{
-	Plist *pl;
-	Prog *p, *p1, *p2, *p3;
-	Node dst, end, zero, con;
-
-	if(plast->firstpc->to.offset <= 0)
-		return;
-
-	// reestablish context for inserting code
-	// at beginning of function.
-	pl = plast;
-	p1 = pl->firstpc;
-	p2 = p1->link;
-	pc = mal(sizeof(*pc));
-	clearp(pc);
-	p1->link = pc;
-	
-	// zero stack frame
-
-	// MOVW $4(SP), R1
-	nodreg(&dst, types[tptr], 1);
-	p = gins(AMOVW, N, &dst);
-	p->from.type = D_CONST;
-	p->from.reg = REGSP;
-	p->from.offset = 4;
-
-	// MOVW $n(R1), R2
-	nodreg(&end, types[tptr], 2);
-	p = gins(AMOVW, N, &end);
-	p->from.type = D_CONST;
-	p->from.reg = 1;
-	p->from.offset = p1->to.offset;
-	
-	// MOVW $0, R3
-	nodreg(&zero, types[TUINT32], 3);
-	nodconst(&con, types[TUINT32], 0);
-	gmove(&con, &zero);
-
-	// L:
-	//	MOVW.P R3, 0(R1) +4
-	//	CMP R1, R2
-	//	BNE L
-	p = gins(AMOVW, &zero, &dst);
-	p->to.type = D_OREG;
-	p->to.offset = 4;
-	p->scond |= C_PBIT;
-	p3 = p;
-	p = gins(ACMP, &dst, N);
-	raddr(&end, p);
-	patch(gbranch(ABNE, T, 0), p3);
-
-	// continue with original code.
-	gins(ANOP, N, N)->link = p2;
-	pc = P;
-}	
-
 void
 gused(Node *n)
 {
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index cdc5fdae2e..65d5ad786f 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -172,44 +172,6 @@ newplist(void)
 	return pl;
 }
 
-void
-clearstk(void)
-{
-	Plist *pl;
-	Prog *p1, *p2;
-	Node sp, di, cx, con, ax;
-
-	if((uint32)plast->firstpc->to.offset <= 0)
-		return;
-
-	// reestablish context for inserting code
-	// at beginning of function.
-	pl = plast;
-	p1 = pl->firstpc;
-	p2 = p1->link;
-	pc = mal(sizeof(*pc));
-	clearp(pc);
-	p1->link = pc;
-	
-	// zero stack frame
-	nodreg(&sp, types[tptr], D_SP);
-	nodreg(&di, types[tptr], D_DI);
-	nodreg(&cx, types[TUINT64], D_CX);
-	nodconst(&con, types[TUINT64], (uint32)p1->to.offset / widthptr);
-	gins(ACLD, N, N);
-	gins(AMOVQ, &sp, &di);
-	gins(AMOVQ, &con, &cx);
-	nodconst(&con, types[TUINT64], 0);
-	nodreg(&ax, types[TUINT64], D_AX);
-	gins(AMOVQ, &con, &ax);
-	gins(AREP, N, N);
-	gins(ASTOSQ, N, N);
-
-	// continue with original code.
-	gins(ANOP, N, N)->link = p2;
-	pc = P;
-}	
-
 void
 gused(Node *n)
 {
diff --git a/src/cmd/8g/gsubr.c b/src/cmd/8g/gsubr.c
index 93cea21469..dbea45a201 100644
--- a/src/cmd/8g/gsubr.c
+++ b/src/cmd/8g/gsubr.c
@@ -173,44 +173,6 @@ newplist(void)
 	return pl;
 }
 
-void
-clearstk(void)
-{
-	Plist *pl;
-	Prog *p1, *p2;
-	Node sp, di, cx, con, ax;
-
-	if(plast->firstpc->to.offset <= 0)
-		return;
-
-	// reestablish context for inserting code
-	// at beginning of function.
-	pl = plast;
-	p1 = pl->firstpc;
-	p2 = p1->link;
-	pc = mal(sizeof(*pc));
-	clearp(pc);
-	p1->link = pc;
-	
-	// zero stack frame
-	nodreg(&sp, types[tptr], D_SP);
-	nodreg(&di, types[tptr], D_DI);
-	nodreg(&cx, types[TUINT32], D_CX);
-	nodconst(&con, types[TUINT32], p1->to.offset / widthptr);
-	gins(ACLD, N, N);
-	gins(AMOVL, &sp, &di);
-	gins(AMOVL, &con, &cx);
-	nodconst(&con, types[TUINT32], 0);
-	nodreg(&ax, types[TUINT32], D_AX);
-	gins(AMOVL, &con, &ax);
-	gins(AREP, N, N);
-	gins(ASTOSL, N, N);
-
-	// continue with original code.
-	gins(ANOP, N, N)->link = p2;
-	pc = P;
-}	
-
 void
 gused(Node *n)
 {
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 42319578a8..36bc4b2954 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -937,7 +937,6 @@ EXTERN	int	funcdepth;
 EXTERN	int	typecheckok;
 EXTERN	int	compiling_runtime;
 EXTERN	int	compiling_wrappers;
-EXTERN	int	zerostack_enabled;
 
 EXTERN	int	nointerface;
 EXTERN	int	fieldtrack_enabled;
@@ -1093,7 +1092,6 @@ void	genlist(NodeList *l);
 Node*	sysfunc(char *name);
 void	tempname(Node *n, Type *t);
 Node*	temp(Type*);
-void	clearstk(void);
 
 /*
  *	init.c
diff --git a/src/cmd/gc/lex.c b/src/cmd/gc/lex.c
index 8d6487dea7..eabeaeb646 100644
--- a/src/cmd/gc/lex.c
+++ b/src/cmd/gc/lex.c
@@ -41,7 +41,6 @@ static struct {
 } exper[] = {
 //	{"rune32", &rune32},
 	{"fieldtrack", &fieldtrack_enabled},
-	{"zerostack", &zerostack_enabled},
 	{nil, nil},
 };
 
diff --git a/src/cmd/gc/pgen.c b/src/cmd/gc/pgen.c
index e2cad14398..7be254fff1 100644
--- a/src/cmd/gc/pgen.c
+++ b/src/cmd/gc/pgen.c
@@ -141,9 +141,6 @@ compile(Node *fn)
 	if(0)
 		frame(0);
 
-	if(zerostack_enabled)
-		clearstk();
-
 ret:
 	lineno = lno;
 }