diff --git a/src/cmd/compile/internal/gc/gen.go b/src/cmd/compile/internal/gc/gen.go
index 6390818e16..4ff4f7a2c8 100644
--- a/src/cmd/compile/internal/gc/gen.go
+++ b/src/cmd/compile/internal/gc/gen.go
@@ -853,7 +853,7 @@ func gen(n *Node) {
 		cgen_dcl(n.Left)
 
 	case OAS:
-		if gen_as_init(n) {
+		if gen_as_init(n, false) {
 			break
 		}
 		Cgen_as(n.Left, n.Right)
diff --git a/src/cmd/compile/internal/gc/sinit.go b/src/cmd/compile/internal/gc/sinit.go
index 7875d16380..099c10a8bc 100644
--- a/src/cmd/compile/internal/gc/sinit.go
+++ b/src/cmd/compile/internal/gc/sinit.go
@@ -1236,6 +1236,7 @@ func getlit(lit *Node) int {
 	return -1
 }
 
+// stataddr sets nam to the static address of n and reports whether it succeeeded.
 func stataddr(nam *Node, n *Node) bool {
 	if n == nil {
 		return false
@@ -1408,7 +1409,9 @@ func entry(p *InitPlan) *InitEntry {
 	return &p.E[len(p.E)-1]
 }
 
-func gen_as_init(n *Node) bool {
+// gen_as_init attempts to emit static data for n and reports whether it succeeded.
+// If reportOnly is true, it does not emit static data and does not modify the AST.
+func gen_as_init(n *Node, reportOnly bool) bool {
 	var nr *Node
 	var nl *Node
 	var nam Node
@@ -1457,7 +1460,9 @@ func gen_as_init(n *Node) bool {
 	case OSLICEARR:
 		if nr.Right.Op == OKEY && nr.Right.Left == nil && nr.Right.Right == nil {
 			nr = nr.Left
-			gused(nil) // in case the data is the dest of a goto
+			if !reportOnly {
+				gused(nil) // in case the data is the dest of a goto
+			}
 			nl := nr
 			if nr == nil || nr.Op != OADDR {
 				goto no
@@ -1472,16 +1477,18 @@ func gen_as_init(n *Node) bool {
 				goto no
 			}
 
-			nam.Xoffset += int64(Array_array)
-			gdata(&nam, nl, int(Types[Tptr].Width))
+			if !reportOnly {
+				nam.Xoffset += int64(Array_array)
+				gdata(&nam, nl, int(Types[Tptr].Width))
 
-			nam.Xoffset += int64(Array_nel) - int64(Array_array)
-			var nod1 Node
-			Nodconst(&nod1, Types[TINT], nr.Type.Bound)
-			gdata(&nam, &nod1, Widthint)
+				nam.Xoffset += int64(Array_nel) - int64(Array_array)
+				var nod1 Node
+				Nodconst(&nod1, Types[TINT], nr.Type.Bound)
+				gdata(&nam, &nod1, Widthint)
 
-			nam.Xoffset += int64(Array_cap) - int64(Array_nel)
-			gdata(&nam, &nod1, Widthint)
+				nam.Xoffset += int64(Array_cap) - int64(Array_nel)
+				gdata(&nam, &nod1, Widthint)
+			}
 
 			return true
 		}
@@ -1512,13 +1519,19 @@ func gen_as_init(n *Node) bool {
 		TPTR64,
 		TFLOAT32,
 		TFLOAT64:
-		gdata(&nam, nr, int(nr.Type.Width))
+		if !reportOnly {
+			gdata(&nam, nr, int(nr.Type.Width))
+		}
 
 	case TCOMPLEX64, TCOMPLEX128:
-		gdatacomplex(&nam, nr.Val().U.(*Mpcplx))
+		if !reportOnly {
+			gdatacomplex(&nam, nr.Val().U.(*Mpcplx))
+		}
 
 	case TSTRING:
-		gdatastring(&nam, nr.Val().U.(string))
+		if !reportOnly {
+			gdatastring(&nam, nr.Val().U.(string))
+		}
 	}
 
 	return true
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index b6b345f205..29b6a141a5 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -462,6 +462,17 @@ func (s *state) stmt(n *Node) {
 		addEdge(b, lab.target)
 
 	case OAS, OASWB:
+		// Check whether we can generate static data rather than code.
+		// If so, ignore n and defer data generation until codegen.
+		// Failure to do this causes writes to readonly symbols.
+		if gen_as_init(n, true) {
+			var data []*Node
+			if s.f.StaticData != nil {
+				data = s.f.StaticData.([]*Node)
+			}
+			s.f.StaticData = append(data, n)
+			return
+		}
 		s.assign(n.Op, n.Left, n.Right)
 
 	case OIF:
@@ -1484,6 +1495,15 @@ func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
 
 	Pc.As = obj.ARET // overwrite AEND
 
+	// Emit static data
+	if f.StaticData != nil {
+		for _, n := range f.StaticData.([]*Node) {
+			if !gen_as_init(n, false) {
+				Fatal("non-static data marked as static: %v\n\n", n, f)
+			}
+		}
+	}
+
 	// TODO: liveness
 	// TODO: gcargs
 	// TODO: gclocals
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index 34d2780104..e0f7c9ff60 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -9,13 +9,14 @@ import "sync"
 // A Func represents a Go func declaration (or function literal) and
 // its body.  This package compiles each Func independently.
 type Func struct {
-	Config *Config  // architecture information
-	Name   string   // e.g. bytes·Compare
-	Type   Type     // type signature of the function.
-	Blocks []*Block // unordered set of all basic blocks (note: not indexable by ID)
-	Entry  *Block   // the entry basic block
-	bid    idAlloc  // block ID allocator
-	vid    idAlloc  // value ID allocator
+	Config     *Config     // architecture information
+	Name       string      // e.g. bytes·Compare
+	Type       Type        // type signature of the function.
+	StaticData interface{} // associated static data, untouched by the ssa package
+	Blocks     []*Block    // unordered set of all basic blocks (note: not indexable by ID)
+	Entry      *Block      // the entry basic block
+	bid        idAlloc     // block ID allocator
+	vid        idAlloc     // value ID allocator
 
 	// when register allocation is done, maps value ids to locations
 	RegAlloc []Location