cmd/compile: mark closure structs as Noalg

Avoids generating useless equality and hash functions.

Shrinks cmd/go executable size on linux/amd64 by ~17kB.

Change-Id: Ifde5315cc5cbceb3a7260195c8803cace952359f
Reviewed-on: https://go-review.googlesource.com/66650
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

diff --git a/src/cmd/compile/internal/gc/closure.go b/src/cmd/compile/internal/gc/closure.go
index afb6805337704046c3e4411389008e0a8a42674b..93997b069a873ca55889ca38c6a8ad64901c9318 100644 (file)
--- a/src/cmd/compile/internal/gc/closure.go
+++ b/src/cmd/compile/internal/gc/closure.go
@@ -480,28 +480,30 @@ func walkclosure(func_ *Node, init *Nodes) *Node {
        // the struct is unnamed so that closures in multiple packages with the
        // same struct type can share the descriptor.
 
-       typ := nod(OTSTRUCT, nil, nil)
-
-       typ.List.Set1(namedfield(".F", types.Types[TUINTPTR]))
+       fields := []*Node{
+               namedfield(".F", types.Types[TUINTPTR]),
+       }
        for _, v := range func_.Func.Cvars.Slice() {
                if v.Op == OXXX {
                        continue
                }
-               typ1 := typenod(v.Type)
+               typ := v.Type
                if !v.Name.Byval() {
-                       typ1 = nod(OIND, typ1, nil)
+                       typ = types.NewPtr(typ)
                }
-               typ.List.Append(nod(ODCLFIELD, newname(v.Sym), typ1))
+               fields = append(fields, symfield(v.Sym, typ))
        }
+       typ := tostruct(fields)
+       typ.SetNoalg(true)
+       typ.SetLocal(true)
 
-       clos := nod(OCOMPLIT, nil, nod(OIND, typ, nil))
+       clos := nod(OCOMPLIT, nil, nod(OIND, typenod(typ), nil))
        clos.Esc = func_.Esc
        clos.Right.SetImplicit(true)
        clos.List.Set(append([]*Node{nod(OCFUNC, func_.Func.Closure.Func.Nname, nil)}, func_.Func.Enter.Slice()...))
 
        // Force type conversion from *struct to the func type.
        clos = nod(OCONVNOP, clos, nil)
-
        clos.Type = func_.Type
 
        clos = typecheck(clos, Erv)
@@ -682,11 +684,14 @@ func walkpartialcall(n *Node, init *Nodes) *Node {
                checknil(n.Left, init)
        }
 
-       typ := nod(OTSTRUCT, nil, nil)
-       typ.List.Set1(namedfield("F", types.Types[TUINTPTR]))
-       typ.List.Append(namedfield("R", n.Left.Type))
+       typ := tostruct([]*Node{
+               namedfield("F", types.Types[TUINTPTR]),
+               namedfield("R", n.Left.Type),
+       })
+       typ.SetNoalg(true)
+       typ.SetLocal(true)
 
-       clos := nod(OCOMPLIT, nil, nod(OIND, typ, nil))
+       clos := nod(OCOMPLIT, nil, nod(OIND, typenod(typ), nil))
        clos.Esc = n.Esc
        clos.Right.SetImplicit(true)
        clos.List.Set1(nod(OCFUNC, n.Func.Nname, nil))
@@ -694,7 +699,6 @@ func walkpartialcall(n *Node, init *Nodes) *Node {
 
        // Force type conversion from *struct to the func type.
        clos = nod(OCONVNOP, clos, nil)
-
        clos.Type = n.Type
 
        clos = typecheck(clos, Erv)

diff --git a/src/cmd/compile/internal/gc/dcl.go b/src/cmd/compile/internal/gc/dcl.go
index cf91f537099b28fe8dd6a35659be93807ab1fd70..37d281d10641f5d26395ff782dc0eb742271e404 100644 (file)
--- a/src/cmd/compile/internal/gc/dcl.go
+++ b/src/cmd/compile/internal/gc/dcl.go
@@ -254,7 +254,11 @@ func anonfield(typ *types.Type) *Node {
 }
 
 func namedfield(s string, typ *types.Type) *Node {
-       return nod(ODCLFIELD, newname(lookup(s)), typenod(typ))
+       return symfield(lookup(s), typ)
+}
+
+func symfield(s *types.Sym, typ *types.Type) *Node {
+       return nod(ODCLFIELD, newname(s), typenod(typ))
 }
 
 // oldname returns the Node that declares symbol s in the current scope.