cmd/compile: avoid one symbol lookup for qualified identifiers

For -newparser only.

Change-Id: I0eaa05035df11734e2bda7ad456b9b30485d9465
Reviewed-on: https://go-review.googlesource.com/31718
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
index 65f39b3506377ccb9c54d9a485cf4670ef7d32c8..11fdde1bbccf1dc629273cdac0615f967221486d 100644 (file)
--- a/src/cmd/compile/internal/gc/noder.go
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -373,13 +373,11 @@ func (p *noder) expr(expr syntax.Expr) *Node {
        case *syntax.SelectorExpr:
                // parser.new_dotname
                obj := p.expr(expr.X)
-               sel := p.name(expr.Sel)
                if obj.Op == OPACK {
-                       s := restrictlookup(sel.Name, obj.Name.Pkg)
                        obj.Used = true
-                       return oldname(s)
+                       return oldname(restrictlookup(expr.Sel.Value, obj.Name.Pkg))
                }
-               return p.setlineno(expr, nodSym(OXDOT, obj, sel))
+               return p.setlineno(expr, nodSym(OXDOT, obj, p.name(expr.Sel)))
        case *syntax.IndexExpr:
                return p.nod(expr, OINDEX, p.expr(expr.X), p.expr(expr.Index))
        case *syntax.SliceExpr:
@@ -535,7 +533,6 @@ func (p *noder) packname(expr syntax.Expr) *Sym {
                return name
        case *syntax.SelectorExpr:
                name := p.name(expr.X.(*syntax.Name))
-               s := p.name(expr.Sel)
                var pkg *Pkg
                if name.Def == nil || name.Def.Op != OPACK {
                        yyerror("%v is not a package", name)
@@ -544,7 +541,7 @@ func (p *noder) packname(expr syntax.Expr) *Sym {
                        name.Def.Used = true
                        pkg = name.Def.Name.Pkg
                }
-               return restrictlookup(s.Name, pkg)
+               return restrictlookup(expr.Sel.Value, pkg)
        }
        panic(fmt.Sprintf("unexpected packname: %#v", expr))
 }