[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/swt.go b/src/cmd/internal/gc/swt.go
index 7c25041..81eb56c 100644
--- a/src/cmd/internal/gc/swt.go
+++ b/src/cmd/internal/gc/swt.go
@@ -35,9 +35,7 @@
var C *Case
func dumpcase(c0 *Case) {
- var c *Case
-
- for c = c0; c != nil; c = c.link {
+ for c := c0; c != nil; c = c.link {
switch c.type_ {
case Tdefault:
fmt.Printf("case-default\n")
@@ -104,11 +102,6 @@
}
func exprcmp(c1 *Case, c2 *Case) int {
- var ct int
- var n int
- var n1 *Node
- var n2 *Node
-
// sort non-constants last
if c1.type_ != Texprconst {
return +1
@@ -117,11 +110,11 @@
return -1
}
- n1 = c1.node.Left
- n2 = c2.node.Left
+ n1 := c1.node.Left
+ n2 := c2.node.Left
// sort by type (for switches on interface)
- ct = int(n1.Val.Ctype)
+ ct := int(n1.Val.Ctype)
if ct != int(n2.Val.Ctype) {
return ct - int(n2.Val.Ctype)
@@ -135,7 +128,7 @@
}
// sort by constant value
- n = 0
+ n := 0
switch ct {
case CTFLT:
@@ -181,16 +174,12 @@
}
func csort(l *Case, f func(*Case, *Case) int) *Case {
- var l1 *Case
- var l2 *Case
- var le *Case
-
if l == nil || l.link == nil {
return l
}
- l1 = l
- l2 = l
+ l1 := l
+ l2 := l
for {
l2 = l2.link
if l2 == nil {
@@ -217,7 +206,7 @@
l2 = l2.link
}
- le = l
+ le := l
for {
if l1 == nil {
@@ -270,31 +259,24 @@
* deal with fallthrough, break, unreachable statements
*/
func casebody(sw *Node, typeswvar *Node) {
- var n *Node
- var c *Node
- var last *Node
- var def *Node
- var cas *NodeList
- var stat *NodeList
- var l *NodeList
- var lc *NodeList
- var go_ *Node
- var br *Node
- var lno int32
- var needvar bool
-
if sw.List == nil {
return
}
- lno = setlineno(sw)
+ lno := setlineno(sw)
- cas = nil // cases
- stat = nil // statements
- def = nil // defaults
- br = Nod(OBREAK, nil, nil)
+ cas := (*NodeList)(nil) // cases
+ stat := (*NodeList)(nil) // statements
+ def := (*Node)(nil) // defaults
+ br := Nod(OBREAK, nil, nil)
- for l = sw.List; l != nil; l = l.Next {
+ var c *Node
+ var go_ *Node
+ var needvar bool
+ var lc *NodeList
+ var last *Node
+ var n *Node
+ for l := sw.List; l != nil; l = l.Next {
n = l.N
setlineno(n)
if n.Op != OXCASE {
@@ -333,9 +315,7 @@
stat = list(stat, Nod(OLABEL, go_.Left, nil))
if typeswvar != nil && needvar && n.Nname != nil {
- var l *NodeList
-
- l = list1(Nod(ODCL, n.Nname, nil))
+ l := list1(Nod(ODCL, n.Nname, nil))
l = list(l, Nod(OAS, n.Nname, typeswvar))
typechecklist(l, Etop)
stat = concat(stat, l)
@@ -375,16 +355,12 @@
func mkcaselist(sw *Node, arg int) *Case {
var n *Node
- var c *Case
var c1 *Case
- var c2 *Case
- var l *NodeList
- var ord int
- c = nil
- ord = 0
+ c := (*Case)(nil)
+ ord := 0
- for l = sw.List; l != nil; l = l.Next {
+ for l := sw.List; l != nil; l = l.Next {
n = l.N
c1 = new(Case)
c1.link = c
@@ -444,7 +420,8 @@
switch arg {
case Stype:
c = csort(c, typecmp)
- for c1 = c; c1 != nil; c1 = c1.link {
+ var c2 *Case
+ for c1 := c; c1 != nil; c1 = c1.link {
for c2 = c1.link; c2 != nil && c2.hash == c1.hash; c2 = c2.link {
if c1.type_ == Ttypenil || c1.type_ == Tdefault {
break
@@ -463,7 +440,7 @@
Strue,
Sfalse:
c = csort(c, exprcmp)
- for c1 = c; c1.link != nil; c1 = c1.link {
+ for c1 := c; c1.link != nil; c1 = c1.link {
if exprcmp(c1, c1.link) != 0 {
continue
}
@@ -481,17 +458,12 @@
var exprname *Node
func exprbsw(c0 *Case, ncase int, arg int) *Node {
- var cas *NodeList
- var a *Node
- var n *Node
- var c *Case
- var i int
- var half int
- var lno int
-
- cas = nil
+ cas := (*NodeList)(nil)
if ncase < Ncase {
- for i = 0; i < ncase; i++ {
+ var a *Node
+ var n *Node
+ var lno int
+ for i := 0; i < ncase; i++ {
n = c0.node
lno = int(setlineno(n))
@@ -520,13 +492,13 @@
}
// find the middle and recur
- c = c0
+ c := c0
- half = ncase >> 1
- for i = 1; i < half; i++ {
+ half := ncase >> 1
+ for i := 1; i < half; i++ {
c = c.link
}
- a = Nod(OIF, nil, nil)
+ a := Nod(OIF, nil, nil)
a.Ntest = Nod(OLE, exprname, c.node.Left)
typecheck(&a.Ntest, Erv)
a.Nbody = list1(exprbsw(c0, half, arg))
@@ -539,19 +511,9 @@
* rebuild case statements into if .. goto
*/
func exprswitch(sw *Node) {
- var def *Node
- var cas *NodeList
- var a *Node
- var c0 *Case
- var c *Case
- var c1 *Case
- var t *Type
- var arg int
- var ncase int
-
casebody(sw, nil)
- arg = Snorm
+ arg := Snorm
if Isconst(sw.Ntest, CTBOOL) {
arg = Strue
if sw.Ntest.Val.U.Bval == 0 {
@@ -560,7 +522,7 @@
}
walkexpr(&sw.Ntest, &sw.Ninit)
- t = sw.Type
+ t := sw.Type
if t == nil {
return
}
@@ -570,7 +532,7 @@
*/
exprname = nil
- cas = nil
+ cas := (*NodeList)(nil)
if arg == Strue || arg == Sfalse {
exprname = Nodbool(arg == Strue)
} else if consttype(sw.Ntest) >= 0 {
@@ -582,7 +544,8 @@
typechecklist(cas, Etop)
}
- c0 = mkcaselist(sw, arg)
+ c0 := mkcaselist(sw, arg)
+ var def *Node
if c0 != nil && c0.type_ == Tdefault {
def = c0.node.Right
c0 = c0.link
@@ -590,6 +553,10 @@
def = Nod(OBREAK, nil, nil)
}
+ var c *Case
+ var a *Node
+ var ncase int
+ var c1 *Case
loop:
if c0 == nil {
cas = list(cas, def)
@@ -639,13 +606,8 @@
var boolname *Node
func typeone(t *Node) *Node {
- var init *NodeList
- var a *Node
- var b *Node
- var var_ *Node
-
- var_ = t.Nname
- init = nil
+ var_ := t.Nname
+ init := (*NodeList)(nil)
if var_ == nil {
typecheck(&nblank, Erv|Easgn)
var_ = nblank
@@ -653,9 +615,9 @@
init = list1(Nod(ODCL, var_, nil))
}
- a = Nod(OAS2, nil, nil)
+ a := Nod(OAS2, nil, nil)
a.List = list(list1(var_), boolname) // var,bool =
- b = Nod(ODOTTYPE, facename, nil)
+ b := Nod(ODOTTYPE, facename, nil)
b.Type = t.Left.Type // interface.(type)
a.Rlist = list1(b)
typecheck(&a, Etop)
@@ -669,17 +631,12 @@
}
func typebsw(c0 *Case, ncase int) *Node {
- var cas *NodeList
- var a *Node
- var n *Node
- var c *Case
- var i int
- var half int
-
- cas = nil
+ cas := (*NodeList)(nil)
if ncase < Ncase {
- for i = 0; i < ncase; i++ {
+ var n *Node
+ var a *Node
+ for i := 0; i < ncase; i++ {
n = c0.node
if c0.type_ != Ttypeconst {
Fatal("typebsw")
@@ -696,13 +653,13 @@
}
// find the middle and recur
- c = c0
+ c := c0
- half = ncase >> 1
- for i = 1; i < half; i++ {
+ half := ncase >> 1
+ for i := 1; i < half; i++ {
c = c.link
}
- a = Nod(OIF, nil, nil)
+ a := Nod(OIF, nil, nil)
a.Ntest = Nod(OLE, hashname, Nodintconst(int64(c.hash)))
typecheck(&a.Ntest, Erv)
a.Nbody = list1(typebsw(c0, half))
@@ -716,18 +673,6 @@
* into if statements
*/
func typeswitch(sw *Node) {
- var def *Node
- var cas *NodeList
- var hash *NodeList
- var a *Node
- var n *Node
- var c *Case
- var c0 *Case
- var c1 *Case
- var ncase int
- var t *Type
- var v Val
-
if sw.Ntest == nil {
return
}
@@ -743,7 +688,7 @@
return
}
- cas = nil
+ cas := (*NodeList)(nil)
/*
* predeclare temporary variables
@@ -751,7 +696,7 @@
*/
facename = temp(sw.Ntest.Right.Type)
- a = Nod(OAS, facename, sw.Ntest.Right)
+ a := Nod(OAS, facename, sw.Ntest.Right)
typecheck(&a, Etop)
cas = list(cas, a)
@@ -763,7 +708,7 @@
hashname = temp(Types[TUINT32])
typecheck(&hashname, Erv)
- t = sw.Ntest.Right.Type
+ t := sw.Ntest.Right.Type
if isnilinter(t) {
a = syslook("efacethash", 1)
} else {
@@ -776,7 +721,8 @@
typecheck(&a, Etop)
cas = list(cas, a)
- c0 = mkcaselist(sw, Stype)
+ c0 := mkcaselist(sw, Stype)
+ var def *Node
if c0 != nil && c0.type_ == Tdefault {
def = c0.node.Right
c0 = c0.link
@@ -787,7 +733,9 @@
/*
* insert if statement into each case block
*/
- for c = c0; c != nil; c = c.link {
+ var v Val
+ var n *Node
+ for c := c0; c != nil; c = c.link {
n = c.node
switch c.type_ {
case Ttypenil:
@@ -807,6 +755,10 @@
/*
* generate list of if statements, binary search for constant sequences
*/
+ var ncase int
+ var c1 *Case
+ var hash *NodeList
+ var c *Case
for c0 != nil {
if c0.type_ != Ttypeconst {
n = c0.node
@@ -895,22 +847,11 @@
*/
func typecheckswitch(n *Node) {
var top int
- var lno int
- var ptr int
- var nilonly string
var t *Type
- var badtype *Type
- var missing *Type
- var have *Type
- var l *NodeList
- var ll *NodeList
- var ncase *Node
- var nvar *Node
- var def *Node
- lno = int(lineno)
+ lno := int(lineno)
typechecklist(n.Ninit, Etop)
- nilonly = ""
+ nilonly := ""
if n.Ntest != nil && n.Ntest.Op == OTYPESW {
// type switch
@@ -933,6 +874,7 @@
t = Types[TBOOL]
}
if t != nil {
+ var badtype *Type
if okforeq[t.Etype] == 0 {
Yyerror("cannot switch on %v", Nconv(n.Ntest, obj.FmtLong))
} else if t.Etype == TARRAY && !Isfixedarray(t) {
@@ -951,8 +893,14 @@
n.Type = t
- def = nil
- for l = n.List; l != nil; l = l.Next {
+ def := (*Node)(nil)
+ var ptr int
+ var have *Type
+ var nvar *Node
+ var ll *NodeList
+ var missing *Type
+ var ncase *Node
+ for l := n.List; l != nil; l = l.Next {
ncase = l.N
setlineno(n)
if ncase.List == nil {
