[dev.cc] cmd/5g etc: code cleanup: delay var decls and eliminate dead code
Ran rsc.io/grind rev 6f0e601 on the source files.
The cleanups move var declarations as close to the use
as possible, splitting disjoint uses of the var into separate
variables. They also remove dead code (especially in
func sudoaddable), which helps with the var moving.
There's more cleanup to come, but this alone cuts the
time spent compiling html/template on my 2013 MacBook Pro
from 3.1 seconds to 2.3 seconds.
Change-Id: I4de499f47b1dd47a560c310bbcde6b08d425cfd6
Reviewed-on: https://go-review.googlesource.com/5637
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/internal/gc/gen.go b/src/cmd/internal/gc/gen.go
index 9d41b6f..079158a 100644
--- a/src/cmd/internal/gc/gen.go
+++ b/src/cmd/internal/gc/gen.go
@@ -18,9 +18,7 @@
var lastlabel *Label
func Sysfunc(name string) *Node {
- var n *Node
-
- n = newname(Pkglookup(name, Runtimepkg))
+ n := newname(Pkglookup(name, Runtimepkg))
n.Class = PFUNC
return n
}
@@ -31,9 +29,6 @@
* as needing to move to the heap.
*/
func addrescapes(n *Node) {
- var buf string
- var oldfn *Node
-
switch n.Op {
// probably a type error already.
// dump("addrescapes", n);
@@ -84,11 +79,11 @@
n.Xoffset = 0
// create stack variable to hold pointer to heap
- oldfn = Curfn
+ oldfn := Curfn
Curfn = n.Curfn
n.Heapaddr = temp(Ptrto(n.Type))
- buf = fmt.Sprintf("&%v", Sconv(n.Sym, 0))
+ buf := fmt.Sprintf("&%v", Sconv(n.Sym, 0))
n.Heapaddr.Sym = Lookup(buf)
n.Heapaddr.Orig.Sym = n.Heapaddr.Sym
n.Esc = EscHeap
@@ -116,9 +111,7 @@
}
func clearlabels() {
- var l *Label
-
- for l = labellist; l != nil; l = l.Link {
+ for l := labellist; l != nil; l = l.Link {
l.Sym.Label = nil
}
@@ -127,11 +120,8 @@
}
func newlab(n *Node) *Label {
- var s *Sym
- var lab *Label
-
- s = n.Left.Sym
- lab = s.Label
+ s := n.Left.Sym
+ lab := s.Label
if lab == nil {
lab = new(Label)
if lastlabel == nil {
@@ -158,41 +148,33 @@
}
func checkgoto(from *Node, to *Node) {
- var nf int
- var nt int
- var block *Sym
- var dcl *Sym
- var fs *Sym
- var ts *Sym
- var lno int
-
if from.Sym == to.Sym {
return
}
- nf = 0
- for fs = from.Sym; fs != nil; fs = fs.Link {
+ nf := 0
+ for fs := from.Sym; fs != nil; fs = fs.Link {
nf++
}
- nt = 0
- for fs = to.Sym; fs != nil; fs = fs.Link {
+ nt := 0
+ for fs := to.Sym; fs != nil; fs = fs.Link {
nt++
}
- fs = from.Sym
+ fs := from.Sym
for ; nf > nt; nf-- {
fs = fs.Link
}
if fs != to.Sym {
- lno = int(lineno)
+ lno := int(lineno)
setlineno(from)
// decide what to complain about.
// prefer to complain about 'into block' over declarations,
// so scan backward to find most recent block or else dcl.
- block = nil
+ block := (*Sym)(nil)
- dcl = nil
- ts = to.Sym
+ dcl := (*Sym)(nil)
+ ts := to.Sym
for ; nt > nf; nt-- {
if ts.Pkg == nil {
block = ts
@@ -222,10 +204,8 @@
}
func stmtlabel(n *Node) *Label {
- var lab *Label
-
if n.Sym != nil {
- lab = n.Sym.Label
+ lab := n.Sym.Label
if lab != nil {
if lab.Def != nil {
if lab.Def.Defn == n {
@@ -295,8 +275,6 @@
* generate discard of value
*/
func cgen_discard(nr *Node) {
- var tmp Node
-
if nr == nil {
return
}
@@ -342,6 +320,7 @@
// special enough to just evaluate
default:
+ var tmp Node
Tempname(&tmp, nr.Type)
Cgen_as(&tmp, nr)
@@ -353,10 +332,7 @@
* clearslim generates code to zero a slim node.
*/
func Clearslim(n *Node) {
- var z Node
- var zero Mpflt
-
- z = Node{}
+ z := Node{}
z.Op = OLITERAL
z.Type = n.Type
z.Addable = 1
@@ -370,6 +346,7 @@
case TFLOAT32,
TFLOAT64:
+ var zero Mpflt
Mpmovecflt(&zero, 0.0)
z.Val.Ctype = CTFLT
z.Val.U.Fval = &zero
@@ -410,20 +387,17 @@
* n->right is data
*/
func Cgen_eface(n *Node, res *Node) {
- var dst Node
/*
* the right node of an eface may contain function calls that uses res as an argument,
* so it's important that it is done first
*/
- var tmp *Node
-
- tmp = temp(Types[Tptr])
+ tmp := temp(Types[Tptr])
Thearch.Cgen(n.Right, tmp)
Gvardef(res)
- dst = *res
+ dst := *res
dst.Type = Types[Tptr]
dst.Xoffset += int64(Widthptr)
Thearch.Cgen(tmp, &dst)
@@ -442,23 +416,9 @@
* called for OSLICE, OSLICE3, OSLICEARR, OSLICE3ARR, OSLICESTR.
*/
func Cgen_slice(n *Node, res *Node) {
- var src Node
- var dst Node
- var cap *Node
- var len *Node
- var offs *Node
- var add *Node
- var base *Node
- var tmpcap *Node
- var tmplen *Node
- var cmp *Node
- var con Node
- var p1 *obj.Prog
- var p2 *obj.Prog
-
- cap = n.List.N
- len = n.List.Next.N
- offs = nil
+ cap := n.List.N
+ len := n.List.Next.N
+ offs := (*Node)(nil)
if n.List.Next.Next != nil {
offs = n.List.Next.Next.N
}
@@ -470,15 +430,17 @@
// might cause preemption or garbage collection.
// this makes the whole slice update atomic as far as the
// garbage collector can see.
- base = temp(Types[TUINTPTR])
+ base := temp(Types[TUINTPTR])
- tmplen = temp(Types[TINT])
+ tmplen := temp(Types[TINT])
+ var tmpcap *Node
if n.Op != OSLICESTR {
tmpcap = temp(Types[TINT])
} else {
tmpcap = tmplen
}
+ var src Node
if isnil(n.Left) {
Tempname(&src, n.Left.Type)
Thearch.Cgen(n.Left, &src)
@@ -519,16 +481,17 @@
// In essence we are replacing x[i:j:k] where i == j == k
// or x[i:j] where i == j == cap(x) with x[0:0:0].
if offs != nil {
- p1 = gjmp(nil)
- p2 = gjmp(nil)
+ p1 := gjmp(nil)
+ p2 := gjmp(nil)
Patch(p1, Pc)
+ var con Node
Nodconst(&con, tmpcap.Type, 0)
- cmp = Nod(OEQ, tmpcap, &con)
+ cmp := Nod(OEQ, tmpcap, &con)
typecheck(&cmp, Erv)
Thearch.Bgen(cmp, true, -1, p2)
- add = Nod(OADD, base, offs)
+ add := Nod(OADD, base, offs)
typecheck(&add, Erv)
Thearch.Cgen(add, base)
@@ -536,7 +499,7 @@
}
// dst.array = src.array [ + lo *width ]
- dst = *res
+ dst := *res
dst.Xoffset += int64(Array_array)
dst.Type = Types[Tptr]
@@ -616,9 +579,6 @@
* make a new off the books
*/
func Tempname(nn *Node, t *Type) {
- var n *Node
- var s *Sym
-
if Curfn == nil {
Fatal("no curfn for tempname")
}
@@ -633,8 +593,8 @@
namebuf = fmt.Sprintf("autotmp_%.4d", statuniqgen)
statuniqgen++
- s = Lookup(namebuf)
- n = Nod(ONAME, nil, nil)
+ s := Lookup(namebuf)
+ n := Nod(ONAME, nil, nil)
n.Sym = s
s.Def = n
n.Type = t
@@ -651,26 +611,16 @@
}
func temp(t *Type) *Node {
- var n *Node
-
- n = Nod(OXXX, nil, nil)
+ n := Nod(OXXX, nil, nil)
Tempname(n, t)
n.Sym.Def.Used = 1
return n.Orig
}
func gen(n *Node) {
- var lno int32
- var scontin *obj.Prog
- var sbreak *obj.Prog
- var p1 *obj.Prog
- var p2 *obj.Prog
- var p3 *obj.Prog
- var lab *Label
-
//dump("gen", n);
- lno = setlineno(n)
+ lno := setlineno(n)
wasregalloc := Thearch.Anyregalloc()
@@ -708,10 +658,11 @@
break
}
- lab = newlab(n)
+ lab := newlab(n)
// if there are pending gotos, resolve them all to the current pc.
- for p1 = lab.Gotopc; p1 != nil; p1 = p2 {
+ var p2 *obj.Prog
+ for p1 := lab.Gotopc; p1 != nil; p1 = p2 {
p2 = unpatch(p1)
Patch(p1, Pc)
}
@@ -739,7 +690,7 @@
// to the same label. we'll unwind it when we learn the pc
// of the label in the OLABEL case above.)
case OGOTO:
- lab = newlab(n)
+ lab := newlab(n)
if lab.Labelpc != nil {
gjmp(lab.Labelpc)
@@ -749,7 +700,7 @@
case OBREAK:
if n.Left != nil {
- lab = n.Left.Sym.Label
+ lab := n.Left.Sym.Label
if lab == nil {
Yyerror("break label not defined: %v", Sconv(n.Left.Sym, 0))
break
@@ -774,7 +725,7 @@
case OCONTINUE:
if n.Left != nil {
- lab = n.Left.Sym.Label
+ lab := n.Left.Sym.Label
if lab == nil {
Yyerror("continue label not defined: %v", Sconv(n.Left.Sym, 0))
break
@@ -798,14 +749,14 @@
gjmp(continpc)
case OFOR:
- sbreak = breakpc
- p1 = gjmp(nil) // goto test
+ sbreak := breakpc
+ p1 := gjmp(nil) // goto test
breakpc = gjmp(nil) // break: goto done
- scontin = continpc
+ scontin := continpc
continpc = Pc
// define break and continue labels
- lab = stmtlabel(n)
+ lab := stmtlabel(n)
if lab != nil {
lab.Breakpc = breakpc
lab.Continpc = continpc
@@ -825,23 +776,23 @@
}
case OIF:
- p1 = gjmp(nil) // goto test
- p2 = gjmp(nil) // p2: goto else
+ p1 := gjmp(nil) // goto test
+ p2 := gjmp(nil) // p2: goto else
Patch(p1, Pc) // test:
Thearch.Bgen(n.Ntest, false, int(-n.Likely), p2) // if(!test) goto p2
Genlist(n.Nbody) // then
- p3 = gjmp(nil) // goto done
+ p3 := gjmp(nil) // goto done
Patch(p2, Pc) // else:
Genlist(n.Nelse) // else
Patch(p3, Pc) // done:
case OSWITCH:
- sbreak = breakpc
- p1 = gjmp(nil) // goto test
+ sbreak := breakpc
+ p1 := gjmp(nil) // goto test
breakpc = gjmp(nil) // break: goto done
// define break label
- lab = stmtlabel(n)
+ lab := stmtlabel(n)
if lab != nil {
lab.Breakpc = breakpc
}
@@ -855,12 +806,12 @@
}
case OSELECT:
- sbreak = breakpc
- p1 = gjmp(nil) // goto test
+ sbreak := breakpc
+ p1 := gjmp(nil) // goto test
breakpc = gjmp(nil) // break: goto done
// define break label
- lab = stmtlabel(n)
+ lab := stmtlabel(n)
if lab != nil {
lab.Breakpc = breakpc
}
@@ -918,8 +869,6 @@
}
func Cgen_as(nl *Node, nr *Node) {
- var tl *Type
-
if Debug['g'] != 0 {
Dump("cgen_as", nl)
Dump("cgen_as = ", nr)
@@ -940,7 +889,7 @@
return
}
- tl = nl.Type
+ tl := nl.Type
if tl == nil {
return
}
@@ -956,7 +905,7 @@
return
}
- tl = nl.Type
+ tl := nl.Type
if tl == nil {
return
}
@@ -965,19 +914,16 @@
}
func Cgen_callmeth(n *Node, proc int) {
- var n2 Node
- var l *Node
-
// generate a rewrite in n2 for the method call
// (p.f)(...) goes to (f)(p,...)
- l = n.Left
+ l := n.Left
if l.Op != ODOTMETH {
Fatal("cgen_callmeth: not dotmethod: %v")
}
- n2 = *n
+ n2 := *n
n2.Op = OCALLFUNC
n2.Left = l.Right
n2.Left.Type = l.Type
@@ -989,10 +935,9 @@
}
func checklabels() {
- var lab *Label
var l *NodeList
- for lab = labellist; lab != nil; lab = lab.Link {
+ for lab := labellist; lab != nil; lab = lab.Link {
if lab.Def == nil {
for l = lab.Use; l != nil; l = l.Next {
yyerrorl(int(l.N.Lineno), "label %v not defined", Sconv(lab.Sym, 0))
