cmd/compile: cleanup ir.Package

Decls used to contain initializer statement for package-level
variables, but now it only contains ir.Funcs. So we might as well
rename it to Funcs and tighten its type to []*ir.Func.

Similarly, Externs always contains *ir.Names, so its type can be
constrained too.

Change-Id: I85b833e2f83d9d3559ab0ef8ab5d8324f4bc37b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/517855
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

16 files changed, 117 insertions, 144 deletions

diff --git a/src/cmd/compile/internal/coverage/cover.go b/src/cmd/compile/internal/coverage/cover.go
index b5ac72d404..d17940fd40 100644
--- a/src/cmd/compile/internal/coverage/cover.go
+++ b/src/cmd/compile/internal/coverage/cover.go
@@ -53,11 +53,7 @@ func FixupVars() Names {
 		}
 	}
 
-	for _, n := range typecheck.Target.Externs {
-		nm, ok := n.(*ir.Name)
-		if !ok {
-			continue
-		}
+	for _, nm := range typecheck.Target.Externs {
 		s := nm.Sym()
 		switch s.Name {
 		case metaVarName:
@@ -108,8 +104,8 @@ func FixupVars() Names {
 // fixup. It adds calls to the pkg init function as appropriate to
 // register coverage-related variables with the runtime.
 func FixupInit(cnames Names) {
-	for _, n := range typecheck.Target.Decls {
-		if fn, ok := n.(*ir.Func); ok && ir.FuncName(fn) == "init" {
+	for _, fn := range typecheck.Target.Funcs {
+		if ir.FuncName(fn) == "init" {
 			cnames.InitFn = fn
 			break
 		}
diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go
index f17ac13fe8..bd80fc5832 100644
--- a/src/cmd/compile/internal/escape/escape.go
+++ b/src/cmd/compile/internal/escape/escape.go
@@ -115,7 +115,7 @@ type escape struct {
 	loopDepth int
 }
 
-func Funcs(all []ir.Node) {
+func Funcs(all []*ir.Func) {
 	ir.VisitFuncsBottomUp(all, Batch)
 }
 
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index e9af8aa325..39505a37b1 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -233,7 +233,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	// We compute Addrtaken in bulk here.
 	// After this phase, we maintain Addrtaken incrementally.
 	if typecheck.DirtyAddrtaken {
-		typecheck.ComputeAddrtaken(typecheck.Target.Decls)
+		typecheck.ComputeAddrtaken(typecheck.Target.Funcs)
 		typecheck.DirtyAddrtaken = false
 	}
 	typecheck.IncrementalAddrtaken = true
@@ -254,7 +254,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 		// TODO(prattmic): No need to use bottom-up visit order. This
 		// is mirroring the PGO IRGraph visit order, which also need
 		// not be bottom-up.
-		ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
+		ir.VisitFuncsBottomUp(typecheck.Target.Funcs, func(list []*ir.Func, recursive bool) {
 			for _, fn := range list {
 				devirtualize.ProfileGuided(fn, profile)
 			}
@@ -271,11 +271,9 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	// Devirtualize and get variable capture right in for loops
 	var transformed []loopvar.VarAndLoop
-	for _, n := range typecheck.Target.Decls {
-		if n.Op() == ir.ODCLFUNC {
-			devirtualize.Static(n.(*ir.Func))
-			transformed = append(transformed, loopvar.ForCapture(n.(*ir.Func))...)
-		}
+	for _, n := range typecheck.Target.Funcs {
+		devirtualize.Static(n)
+		transformed = append(transformed, loopvar.ForCapture(n)...)
 	}
 	ir.CurFunc = nil
 
@@ -297,7 +295,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	// Large values are also moved off stack in escape analysis;
 	// because large values may contain pointers, it must happen early.
 	base.Timer.Start("fe", "escapes")
-	escape.Funcs(typecheck.Target.Decls)
+	escape.Funcs(typecheck.Target.Funcs)
 
 	loopvar.LogTransformations(transformed)
 
@@ -315,15 +313,14 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	// Don't use range--walk can add functions to Target.Decls.
 	base.Timer.Start("be", "compilefuncs")
 	fcount := int64(0)
-	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		if fn, ok := typecheck.Target.Decls[i].(*ir.Func); ok {
-			// Don't try compiling dead hidden closure.
-			if fn.IsDeadcodeClosure() {
-				continue
-			}
-			enqueueFunc(fn)
-			fcount++
+	for i := 0; i < len(typecheck.Target.Funcs); i++ {
+		fn := typecheck.Target.Funcs[i]
+		// Don't try compiling dead hidden closure.
+		if fn.IsDeadcodeClosure() {
+			continue
 		}
+		enqueueFunc(fn)
+		fcount++
 	}
 	base.Timer.AddEvent(fcount, "funcs")
 
diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index e895c452f2..a246177aa5 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -111,7 +111,7 @@ func dumpCompilerObj(bout *bio.Writer) {
 
 func dumpdata() {
 	numExterns := len(typecheck.Target.Externs)
-	numDecls := len(typecheck.Target.Decls)
+	numDecls := len(typecheck.Target.Funcs)
 	dumpglobls(typecheck.Target.Externs)
 	reflectdata.CollectPTabs()
 	numExports := len(typecheck.Target.Exports)
@@ -131,15 +131,14 @@ func dumpdata() {
 	// In the typical case, we loop 0 or 1 times.
 	// It was not until issue 24761 that we found any code that required a loop at all.
 	for {
-		for i := numDecls; i < len(typecheck.Target.Decls); i++ {
-			if n, ok := typecheck.Target.Decls[i].(*ir.Func); ok {
-				enqueueFunc(n)
-			}
+		for i := numDecls; i < len(typecheck.Target.Funcs); i++ {
+			fn := typecheck.Target.Funcs[i]
+			enqueueFunc(fn)
 		}
-		numDecls = len(typecheck.Target.Decls)
+		numDecls = len(typecheck.Target.Funcs)
 		compileFunctions()
 		reflectdata.WriteRuntimeTypes()
-		if numDecls == len(typecheck.Target.Decls) {
+		if numDecls == len(typecheck.Target.Funcs) {
 			break
 		}
 	}
@@ -201,7 +200,7 @@ func dumpGlobal(n *ir.Name) {
 	base.Ctxt.DwarfGlobal(base.Ctxt.Pkgpath, types.TypeSymName(n.Type()), n.Linksym())
 }
 
-func dumpGlobalConst(n ir.Node) {
+func dumpGlobalConst(n *ir.Name) {
 	// only export typed constants
 	t := n.Type()
 	if t == nil {
@@ -229,12 +228,12 @@ func dumpGlobalConst(n ir.Node) {
 	base.Ctxt.DwarfIntConst(base.Ctxt.Pkgpath, n.Sym().Name, types.TypeSymName(t), ir.IntVal(t, v))
 }
 
-func dumpglobls(externs []ir.Node) {
+func dumpglobls(externs []*ir.Name) {
 	// add globals
 	for _, n := range externs {
 		switch n.Op() {
 		case ir.ONAME:
-			dumpGlobal(n.(*ir.Name))
+			dumpGlobal(n)
 		case ir.OLITERAL:
 			dumpGlobalConst(n)
 		}
@@ -336,7 +335,7 @@ func dumpembeds() {
 	}
 }
 
-func addsignats(dcls []ir.Node) {
+func addsignats(dcls []*ir.Name) {
 	// copy types from dcl list to signatset
 	for _, n := range dcls {
 		if n.Op() == ir.OTYPE {
diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 414129d937..28cd870a54 100644
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -78,7 +78,7 @@ var (
 )
 
 // pgoInlinePrologue records the hot callsites from ir-graph.
-func pgoInlinePrologue(p *pgo.Profile, decls []ir.Node) {
+func pgoInlinePrologue(p *pgo.Profile, funcs []*ir.Func) {
 	if base.Debug.PGOInlineCDFThreshold != "" {
 		if s, err := strconv.ParseFloat(base.Debug.PGOInlineCDFThreshold, 64); err == nil && s >= 0 && s <= 100 {
 			inlineCDFHotCallSiteThresholdPercent = s
@@ -161,7 +161,7 @@ func InlinePackage(p *pgo.Profile) {
 		p = nil
 	}
 
-	InlineDecls(p, typecheck.Target.Decls, true)
+	InlineDecls(p, typecheck.Target.Funcs, true)
 
 	// Perform a garbage collection of hidden closures functions that
 	// are no longer reachable from top-level functions following
@@ -174,9 +174,9 @@ func InlinePackage(p *pgo.Profile) {
 }
 
 // InlineDecls applies inlining to the given batch of declarations.
-func InlineDecls(p *pgo.Profile, decls []ir.Node, doInline bool) {
+func InlineDecls(p *pgo.Profile, funcs []*ir.Func, doInline bool) {
 	if p != nil {
-		pgoInlinePrologue(p, decls)
+		pgoInlinePrologue(p, funcs)
 	}
 
 	doCanInline := func(n *ir.Func, recursive bool, numfns int) {
@@ -192,7 +192,7 @@ func InlineDecls(p *pgo.Profile, decls []ir.Node, doInline bool) {
 		}
 	}
 
-	ir.VisitFuncsBottomUp(decls, func(list []*ir.Func, recursive bool) {
+	ir.VisitFuncsBottomUp(funcs, func(list []*ir.Func, recursive bool) {
 		numfns := numNonClosures(list)
 		// We visit functions within an SCC in fairly arbitrary order,
 		// so by computing inlinability for all functions in the SCC
@@ -235,33 +235,31 @@ func garbageCollectUnreferencedHiddenClosures() {
 		})
 	}
 
-	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		if fn, ok := typecheck.Target.Decls[i].(*ir.Func); ok {
-			if fn.IsHiddenClosure() {
-				continue
-			}
-			markLiveFuncs(fn)
+	for i := 0; i < len(typecheck.Target.Funcs); i++ {
+		fn := typecheck.Target.Funcs[i]
+		if fn.IsHiddenClosure() {
+			continue
 		}
+		markLiveFuncs(fn)
 	}
 
-	for i := 0; i < len(typecheck.Target.Decls); i++ {
-		if fn, ok := typecheck.Target.Decls[i].(*ir.Func); ok {
-			if !fn.IsHiddenClosure() {
-				continue
-			}
-			if fn.IsDeadcodeClosure() {
-				continue
-			}
-			if liveFuncs[fn] {
-				continue
-			}
-			fn.SetIsDeadcodeClosure(true)
-			if base.Flag.LowerM > 2 {
-				fmt.Printf("%v: unreferenced closure %v marked as dead\n", ir.Line(fn), fn)
-			}
-			if fn.Inl != nil && fn.LSym == nil {
-				ir.InitLSym(fn, true)
-			}
+	for i := 0; i < len(typecheck.Target.Funcs); i++ {
+		fn := typecheck.Target.Funcs[i]
+		if !fn.IsHiddenClosure() {
+			continue
+		}
+		if fn.IsDeadcodeClosure() {
+			continue
+		}
+		if liveFuncs[fn] {
+			continue
+		}
+		fn.SetIsDeadcodeClosure(true)
+		if base.Flag.LowerM > 2 {
+			fmt.Printf("%v: unreferenced closure %v marked as dead\n", ir.Line(fn), fn)
+		}
+		if fn.Inl != nil && fn.LSym == nil {
+			ir.InitLSym(fn, true)
 		}
 	}
 }
diff --git a/src/cmd/compile/internal/ir/func.go b/src/cmd/compile/internal/ir/func.go
index 5c41893fc6..a232c0fb70 100644
--- a/src/cmd/compile/internal/ir/func.go
+++ b/src/cmd/compile/internal/ir/func.go
@@ -462,7 +462,7 @@ func UseClosure(clo *ClosureExpr, pkg *Package) Node {
 	}
 
 	if pkg != nil {
-		pkg.Decls = append(pkg.Decls, fn)
+		pkg.Funcs = append(pkg.Funcs, fn)
 	}
 
 	if false && IsTrivialClosure(clo) {
diff --git a/src/cmd/compile/internal/ir/package.go b/src/cmd/compile/internal/ir/package.go
index 26d4b1ece3..6efdfb5e1f 100644
--- a/src/cmd/compile/internal/ir/package.go
+++ b/src/cmd/compile/internal/ir/package.go
@@ -19,11 +19,13 @@ type Package struct {
 	// Init functions, listed in source order.
 	Inits []*Func
 
-	// Top-level declarations.
-	Decls []Node
+	// Funcs contains all (instantiated) functions, methods, and
+	// function literals to be compiled.
+	Funcs []*Func
 
-	// Extern (package global) declarations.
-	Externs []Node
+	// Externs holds constants, (non-generic) types, and variables
+	// declared at package scope.
+	Externs []*Name
 
 	// Assembly function declarations.
 	Asms []*Name
diff --git a/src/cmd/compile/internal/ir/scc.go b/src/cmd/compile/internal/ir/scc.go
index b222939a1e..a640f4fc16 100644
--- a/src/cmd/compile/internal/ir/scc.go
+++ b/src/cmd/compile/internal/ir/scc.go
@@ -49,16 +49,13 @@ type bottomUpVisitor struct {
 // If recursive is false, the list consists of only a single function and its closures.
 // If recursive is true, the list may still contain only a single function,
 // if that function is itself recursive.
-func VisitFuncsBottomUp(list []Node, analyze func(list []*Func, recursive bool)) {
+func VisitFuncsBottomUp(list []*Func, analyze func(list []*Func, recursive bool)) {
 	var v bottomUpVisitor
 	v.analyze = analyze
 	v.nodeID = make(map[*Func]uint32)
 	for _, n := range list {
-		if n.Op() == ODCLFUNC {
-			n := n.(*Func)
-			if !n.IsHiddenClosure() {
-				v.visit(n)
-			}
+		if !n.IsHiddenClosure() {
+			v.visit(n)
 		}
 	}
 }
diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go
index a92a890437..0f936b4764 100644
--- a/src/cmd/compile/internal/noder/reader.go
+++ b/src/cmd/compile/internal/noder/reader.go
@@ -3015,7 +3015,14 @@ func (r *reader) tempCopy(pos src.XPos, expr ir.Node, init *ir.Nodes) *ir.Name {
 		assign.Def = true
 		tmp.Defn = assign
 
-		typecheck.Target.Decls = append(typecheck.Target.Decls, typecheck.Stmt(assign))
+		// TODO(mdempsky): This code doesn't work anymore, because we now
+		// rely on types2 to compute InitOrder. If it's going to be used
+		// for testing again, the assignment here probably needs to be
+		// added to typecheck.Target.InitOrder somewhere.
+		//
+		// Probably just easier to address the escape analysis limitation.
+		//
+		// typecheck.Target.Decls = append(typecheck.Target.Decls, typecheck.Stmt(assign))
 
 		return tmp
 	}
@@ -3353,14 +3360,14 @@ func (r *reader) pkgDecls(target *ir.Package) {
 		case declFunc:
 			names := r.pkgObjs(target)
 			assert(len(names) == 1)
-			target.Decls = append(target.Decls, names[0].Func)
+			target.Funcs = append(target.Funcs, names[0].Func)
 
 		case declMethod:
 			typ := r.typ()
 			_, sym := r.selector()
 
 			method := typecheck.Lookdot1(nil, sym, typ, typ.Methods(), 0)
-			target.Decls = append(target.Decls, method.Nname.(*ir.Name).Func)
+			target.Funcs = append(target.Funcs, method.Nname.(*ir.Name).Func)
 
 		case declVar:
 			names := r.pkgObjs(target)
@@ -3629,7 +3636,7 @@ func expandInline(fn *ir.Func, pri pkgReaderIndex) {
 	// with the same information some other way.
 
 	fndcls := len(fn.Dcl)
-	topdcls := len(typecheck.Target.Decls)
+	topdcls := len(typecheck.Target.Funcs)
 
 	tmpfn := ir.NewFunc(fn.Pos())
 	tmpfn.Nname = ir.NewNameAt(fn.Nname.Pos(), fn.Sym())
@@ -3661,7 +3668,7 @@ func expandInline(fn *ir.Func, pri pkgReaderIndex) {
 	// typecheck.Stmts may have added function literals to
 	// typecheck.Target.Decls. Remove them again so we don't risk trying
 	// to compile them multiple times.
-	typecheck.Target.Decls = typecheck.Target.Decls[:topdcls]
+	typecheck.Target.Funcs = typecheck.Target.Funcs[:topdcls]
 }
 
 // usedLocals returns a set of local variables that are used within body.
@@ -3925,7 +3932,7 @@ func finishWrapperFunc(fn *ir.Func, target *ir.Package) {
 		}
 	})
 
-	target.Decls = append(target.Decls, fn)
+	target.Funcs = append(target.Funcs, fn)
 }
 
 // newWrapperType returns a copy of the given signature type, but with
diff --git a/src/cmd/compile/internal/noder/unified.go b/src/cmd/compile/internal/noder/unified.go
index 0afa505550..3e5ab2ec39 100644
--- a/src/cmd/compile/internal/noder/unified.go
+++ b/src/cmd/compile/internal/noder/unified.go
@@ -91,27 +91,17 @@ func unified(m posMap, noders []*noder) {
 	r := localPkgReader.newReader(pkgbits.RelocMeta, pkgbits.PrivateRootIdx, pkgbits.SyncPrivate)
 	r.pkgInit(types.LocalPkg, target)
 
-	// Type-check any top-level assignments. We ignore non-assignments
-	// here because other declarations are typechecked as they're
-	// constructed.
-	for i, ndecls := 0, len(target.Decls); i < ndecls; i++ {
-		switch n := target.Decls[i]; n.Op() {
-		case ir.OAS, ir.OAS2:
-			target.Decls[i] = typecheck.Stmt(n)
-		}
-	}
-
 	readBodies(target, false)
 
 	// Check that nothing snuck past typechecking.
-	for _, n := range target.Decls {
-		if n.Typecheck() == 0 {
-			base.FatalfAt(n.Pos(), "missed typecheck: %v", n)
+	for _, fn := range target.Funcs {
+		if fn.Typecheck() == 0 {
+			base.FatalfAt(fn.Pos(), "missed typecheck: %v", fn)
 		}
 
 		// For functions, check that at least their first statement (if
 		// any) was typechecked too.
-		if fn, ok := n.(*ir.Func); ok && len(fn.Body) != 0 {
+		if len(fn.Body) != 0 {
 			if stmt := fn.Body[0]; stmt.Typecheck() == 0 {
 				base.FatalfAt(stmt.Pos(), "missed typecheck: %v", stmt)
 			}
@@ -120,11 +110,9 @@ func unified(m posMap, noders []*noder) {
 
 	// For functions originally came from package runtime,
 	// mark as norace to prevent instrumenting, see issue #60439.
-	for _, n := range target.Decls {
-		if fn, ok := n.(*ir.Func); ok {
-			if !base.Flag.CompilingRuntime && types.IsRuntimePkg(fn.Sym().Pkg) {
-				fn.Pragma |= ir.Norace
-			}
+	for _, fn := range target.Funcs {
+		if !base.Flag.CompilingRuntime && types.IsRuntimePkg(fn.Sym().Pkg) {
+			fn.Pragma |= ir.Norace
 		}
 	}
 
@@ -138,7 +126,7 @@ func unified(m posMap, noders []*noder) {
 // necessary on instantiations of imported generic functions, so their
 // inlining costs can be computed.
 func readBodies(target *ir.Package, duringInlining bool) {
-	var inlDecls []ir.Node
+	var inlDecls []*ir.Func
 
 	// Don't use range--bodyIdx can add closures to todoBodies.
 	for {
@@ -175,7 +163,7 @@ func readBodies(target *ir.Package, duringInlining bool) {
 				if duringInlining && canSkipNonGenericMethod {
 					inlDecls = append(inlDecls, fn)
 				} else {
-					target.Decls = append(target.Decls, fn)
+					target.Funcs = append(target.Funcs, fn)
 				}
 			}
 
@@ -208,7 +196,7 @@ func readBodies(target *ir.Package, duringInlining bool) {
 		base.Flag.LowerM = oldLowerM
 
 		for _, fn := range inlDecls {
-			fn.(*ir.Func).Body = nil // free memory
+			fn.Body = nil // free memory
 		}
 	}
 }
diff --git a/src/cmd/compile/internal/pgo/irgraph.go b/src/cmd/compile/internal/pgo/irgraph.go
index 074f4a5a2f..01ffc8e867 100644
--- a/src/cmd/compile/internal/pgo/irgraph.go
+++ b/src/cmd/compile/internal/pgo/irgraph.go
@@ -261,7 +261,7 @@ func (p *Profile) processprofileGraph(g *graph.Graph) error {
 // of a package.
 func (p *Profile) initializeIRGraph() {
 	// Bottomup walk over the function to create IRGraph.
-	ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
+	ir.VisitFuncsBottomUp(typecheck.Target.Funcs, func(list []*ir.Func, recursive bool) {
 		for _, fn := range list {
 			p.VisitIR(fn)
 		}
@@ -467,7 +467,7 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
 
 	// List of functions in this package.
 	funcs := make(map[string]struct{})
-	ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
+	ir.VisitFuncsBottomUp(typecheck.Target.Funcs, func(list []*ir.Func, recursive bool) {
 		for _, f := range list {
 			name := ir.LinkFuncName(f)
 			funcs[name] = struct{}{}
@@ -511,7 +511,7 @@ func (p *Profile) PrintWeightedCallGraphDOT(edgeThreshold float64) {
 		}
 	}
 	// Print edges.
-	ir.VisitFuncsBottomUp(typecheck.Target.Decls, func(list []*ir.Func, recursive bool) {
+	ir.VisitFuncsBottomUp(typecheck.Target.Funcs, func(list []*ir.Func, recursive bool) {
 		for _, f := range list {
 			name := ir.LinkFuncName(f)
 			if n, ok := p.WeightedCG.IRNodes[name]; ok {
diff --git a/src/cmd/compile/internal/pkginit/init.go b/src/cmd/compile/internal/pkginit/init.go
index 9703436673..dbd88dcda9 100644
--- a/src/cmd/compile/internal/pkginit/init.go
+++ b/src/cmd/compile/internal/pkginit/init.go
@@ -56,7 +56,7 @@ func MakeInit() {
 	ir.WithFunc(fn, func() {
 		typecheck.Stmts(nf)
 	})
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+	typecheck.Target.Funcs = append(typecheck.Target.Funcs, fn)
 	if base.Debug.WrapGlobalMapDbg > 1 {
 		fmt.Fprintf(os.Stderr, "=-= len(newfuncs) is %d for %v\n",
 			len(newfuncs), fn)
@@ -65,7 +65,7 @@ func MakeInit() {
 		if base.Debug.WrapGlobalMapDbg > 1 {
 			fmt.Fprintf(os.Stderr, "=-= add to target.decls %v\n", nfn)
 		}
-		typecheck.Target.Decls = append(typecheck.Target.Decls, ir.Node(nfn))
+		typecheck.Target.Funcs = append(typecheck.Target.Funcs, nfn)
 	}
 
 	// Prepend to Inits, so it runs first, before any user-declared init
@@ -150,7 +150,7 @@ func Task() *ir.Name {
 			typecheck.Stmts(fnInit.Body)
 			ir.CurFunc = nil
 
-			typecheck.Target.Decls = append(typecheck.Target.Decls, fnInit)
+			typecheck.Target.Funcs = append(typecheck.Target.Funcs, fnInit)
 			typecheck.Target.Inits = append(typecheck.Target.Inits, fnInit)
 		}
 	}
diff --git a/src/cmd/compile/internal/reflectdata/alg.go b/src/cmd/compile/internal/reflectdata/alg.go
index 69de685ca0..4489f59c26 100644
--- a/src/cmd/compile/internal/reflectdata/alg.go
+++ b/src/cmd/compile/internal/reflectdata/alg.go
@@ -242,7 +242,7 @@ func hashFunc(t *types.Type) *ir.Func {
 	})
 
 	fn.SetNilCheckDisabled(true)
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+	typecheck.Target.Funcs = append(typecheck.Target.Funcs, fn)
 
 	return fn
 }
@@ -630,7 +630,7 @@ func eqFunc(t *types.Type) *ir.Func {
 	// neither of which can be nil, and our comparisons
 	// are shallow.
 	fn.SetNilCheckDisabled(true)
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+	typecheck.Target.Funcs = append(typecheck.Target.Funcs, fn)
 	return fn
 }
 
diff --git a/src/cmd/compile/internal/ssagen/abi.go b/src/cmd/compile/internal/ssagen/abi.go
index c97d60b996..2b08d5a63b 100644
--- a/src/cmd/compile/internal/ssagen/abi.go
+++ b/src/cmd/compile/internal/ssagen/abi.go
@@ -125,11 +125,7 @@ func (s *SymABIs) GenABIWrappers() {
 	// This may generate new decls for the wrappers, but we
 	// specifically *don't* want to visit those, lest we create
 	// wrappers for wrappers.
-	for _, fn := range typecheck.Target.Decls {
-		if fn.Op() != ir.ODCLFUNC {
-			continue
-		}
-		fn := fn.(*ir.Func)
+	for _, fn := range typecheck.Target.Funcs {
 		nam := fn.Nname
 		if ir.IsBlank(nam) {
 			continue
@@ -332,7 +328,7 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
 	ir.CurFunc = fn
 	typecheck.Stmts(fn.Body)
 
-	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+	typecheck.Target.Funcs = append(typecheck.Target.Funcs, fn)
 
 	// Restore previous context.
 	base.Pos = savepos
diff --git a/src/cmd/compile/internal/ssagen/nowb.go b/src/cmd/compile/internal/ssagen/nowb.go
index 9de1b9ae36..8a020611df 100644
--- a/src/cmd/compile/internal/ssagen/nowb.go
+++ b/src/cmd/compile/internal/ssagen/nowb.go
@@ -56,11 +56,8 @@ func newNowritebarrierrecChecker() *nowritebarrierrecChecker {
 	// important to handle it for this check, so we model it
 	// directly. This has to happen before transforming closures in walk since
 	// it's a lot harder to work out the argument after.
-	for _, n := range typecheck.Target.Decls {
-		if n.Op() != ir.ODCLFUNC {
-			continue
-		}
-		c.curfn = n.(*ir.Func)
+	for _, n := range typecheck.Target.Funcs {
+		c.curfn = n
 		if c.curfn.ABIWrapper() {
 			// We only want "real" calls to these
 			// functions, not the generated ones within
@@ -139,12 +136,7 @@ func (c *nowritebarrierrecChecker) check() {
 	// q is the queue of ODCLFUNC Nodes to visit in BFS order.
 	var q ir.NameQueue
 
-	for _, n := range typecheck.Target.Decls {
-		if n.Op() != ir.ODCLFUNC {
-			continue
-		}
-		fn := n.(*ir.Func)
-
+	for _, fn := range typecheck.Target.Funcs {
 		symToFunc[fn.LSym] = fn
 
 		// Make nowritebarrierrec functions BFS roots.
diff --git a/src/cmd/compile/internal/typecheck/subr.go b/src/cmd/compile/internal/typecheck/subr.go
index 011cb3c7cf..18b93ba0ad 100644
--- a/src/cmd/compile/internal/typecheck/subr.go
+++ b/src/cmd/compile/internal/typecheck/subr.go
@@ -96,25 +96,26 @@ var IncrementalAddrtaken = false
 // have not yet been marked as Addrtaken.
 var DirtyAddrtaken = false
 
-func ComputeAddrtaken(top []ir.Node) {
-	for _, n := range top {
-		var doVisit func(n ir.Node)
-		doVisit = func(n ir.Node) {
-			if n.Op() == ir.OADDR {
-				if x := ir.OuterValue(n.(*ir.AddrExpr).X); x.Op() == ir.ONAME {
-					x.Name().SetAddrtaken(true)
-					if x.Name().IsClosureVar() {
-						// Mark the original variable as Addrtaken so that capturevars
-						// knows not to pass it by value.
-						x.Name().Defn.Name().SetAddrtaken(true)
-					}
+func ComputeAddrtaken(funcs []*ir.Func) {
+	var doVisit func(n ir.Node)
+	doVisit = func(n ir.Node) {
+		if n.Op() == ir.OADDR {
+			if x := ir.OuterValue(n.(*ir.AddrExpr).X); x.Op() == ir.ONAME {
+				x.Name().SetAddrtaken(true)
+				if x.Name().IsClosureVar() {
+					// Mark the original variable as Addrtaken so that capturevars
+					// knows not to pass it by value.
+					x.Name().Defn.Name().SetAddrtaken(true)
 				}
 			}
-			if n.Op() == ir.OCLOSURE {
-				ir.VisitList(n.(*ir.ClosureExpr).Func.Body, doVisit)
-			}
 		}
-		ir.Visit(n, doVisit)
+		if n.Op() == ir.OCLOSURE {
+			ir.VisitList(n.(*ir.ClosureExpr).Func.Body, doVisit)
+		}
+	}
+
+	for _, fn := range funcs {
+		ir.Visit(fn, doVisit)
 	}
 }