cmd/compile/internal: some janitoring

Nicer swaps, loops (removed tmp variables). Use of bool instead of int.

This change passes go build -toolexec 'toolstash -cmp' -a std.

Change-Id: I541904c74b57297848decc51a8a4913a8eca4af3
Reviewed-on: https://go-review.googlesource.com/14316
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/compile/internal/amd64/ggen.go

@@ -187,13 +187,13 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	t := nl.Type
 
 	t0 := t
-	check := 0
+	check := false
 	if gc.Issigned[t.Etype] {
-		check = 1
+		check = true
 		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -(1<<uint64(t.Width*8-1)) {
-			check = 0
+			check = false
 		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
-			check = 0
+			check = false
 		}
 	}
 
@@ -203,7 +203,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 		} else {
 			t = gc.Types[gc.TUINT32]
 		}
-		check = 0
+		check = false
 	}
 
 	a := optoas(op, t)
@@ -252,7 +252,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	}
 
 	var p2 *obj.Prog
-	if check != 0 {
+	if check {
 		gc.Nodconst(&n4, t, -1)
 		gins(optoas(gc.OCMP, t), &n3, &n4)
 		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
@@ -289,7 +289,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 		gmove(&dx, res)
 	}
 	restx(&dx, &olddx)
-	if check != 0 {
+	if check {
 		gc.Patch(p2, gc.Pc)
 	}
 	restx(&ax, &oldax)
@@ -340,9 +340,7 @@ func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	t := nl.Type
 	a := optoas(gc.OHMUL, t)
 	if nl.Ullman < nr.Ullman {
-		tmp := nl
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	var n1 gc.Node
@@ -500,9 +498,7 @@ func cgen_bmul(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) bool {
 
 	// largest ullman on left.
 	if nl.Ullman < nr.Ullman {
-		tmp := nl
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	// generate operands in "8-bit" registers.
@@ -564,12 +560,7 @@ func clearfat(nl *gc.Node) {
 		n1.Op = gc.OINDREG
 		var z gc.Node
 		gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
-		for {
-			tmp14 := q
-			q--
-			if tmp14 <= 0 {
-				break
-			}
+		for ; q > 0; q-- {
 			n1.Type = z.Type
 			gins(x86.AMOVQ, &z, &n1)
 			n1.Xoffset += 8
@@ -584,12 +575,7 @@ func clearfat(nl *gc.Node) {
 		}
 
 		gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
-		for {
-			tmp15 := c
-			c--
-			if tmp15 <= 0 {
-				break
-			}
+		for ; c > 0; c-- {
 			n1.Type = z.Type
 			gins(x86.AMOVB, &z, &n1)
 			n1.Xoffset++

src/cmd/compile/internal/arm/cgen.go

@@ -205,12 +205,7 @@ func blockcopy(n, res *gc.Node, osrc, odst, w int64) {
 		gc.Regfree(&nend)
 	} else {
 		var p *obj.Prog
-		for {
-			tmp14 := c
-			c--
-			if tmp14 <= 0 {
-				break
-			}
+		for ; c > 0; c-- {
 			p = gins(op, &src, &tmp)
 			p.From.Type = obj.TYPE_MEM
 			p.From.Offset = int64(dir)

src/cmd/compile/internal/arm/ggen.go

@@ -120,9 +120,7 @@ func appendpp(p *obj.Prog, as int, ftype int, freg int, foffset int32, ttype int
  */
 func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	if nl.Ullman < nr.Ullman {
-		tmp := nl
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	t := nl.Type

src/cmd/compile/internal/arm64/cgen.go

@@ -132,13 +132,7 @@ func blockcopy(n, res *gc.Node, osrc, odst, w int64) {
 		// ADDs.  That will produce shorter, more
 		// pipeline-able code.
 		var p *obj.Prog
-		for {
-			tmp14 := c
-			c--
-			if tmp14 <= 0 {
-				break
-			}
-
+		for ; c > 0; c-- {
 			p = gins(op, &src, &tmp)
 			p.From.Type = obj.TYPE_MEM
 			p.From.Offset = int64(dir)

src/cmd/compile/internal/arm64/ggen.go

@@ -151,13 +151,13 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	t := nl.Type
 
 	t0 := t
-	check := 0
+	check := false
 	if gc.Issigned[t.Etype] {
-		check = 1
+		check = true
 		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -(1<<uint64(t.Width*8-1)) {
-			check = 0
+			check = false
 		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
-			check = 0
+			check = false
 		}
 	}
 
@@ -167,7 +167,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 		} else {
 			t = gc.Types[gc.TUINT64]
 		}
-		check = 0
+		check = false
 	}
 
 	a := optoas(gc.ODIV, t)
@@ -206,7 +206,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	gc.Patch(p1, gc.Pc)
 
 	var p2 *obj.Prog
-	if check != 0 {
+	if check {
 		var nm1 gc.Node
 		gc.Nodconst(&nm1, t, -1)
 		gcmp(optoas(gc.OCMP, t), &tr, &nm1)
@@ -250,7 +250,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	}
 
 	gc.Regfree(&tl)
-	if check != 0 {
+	if check {
 		gc.Patch(p2, gc.Pc)
 	}
 }
@@ -262,9 +262,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	// largest ullman on left.
 	if nl.Ullman < nr.Ullman {
-		tmp := (*gc.Node)(nl)
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	t := (*gc.Type)(nl.Type)

src/cmd/compile/internal/gc/cgen.go

@@ -705,9 +705,7 @@ func cgen_wb(n, res *Node, wb bool) {
 	 */
 sbop: // symmetric binary
 	if nl.Ullman < nr.Ullman || (nl.Ullman == nr.Ullman && (Smallintconst(nl) || (nr.Op == OLITERAL && !Smallintconst(nr)))) {
-		r := nl
-		nl = nr
-		nr = r
+		nl, nr = nr, nl
 	}
 
 abop: // asymmetric binary

src/cmd/compile/internal/gc/plive.go

@@ -1685,15 +1685,13 @@ func livenessprintdebug(lv *Liveness) {
 				for j = 0; j < len(lv.vars); j++ {
 					n = lv.vars[j]
 					if islive(n, args, locals) {
-						tmp9 := printed
-						printed++
-						if tmp9 != 0 {
+						if printed != 0 {
 							fmt.Printf(",")
 						}
 						fmt.Printf("%v", n)
+						printed++
 					}
 				}
-
 				fmt.Printf("\n")
 			}
 

src/cmd/compile/internal/gc/subr.go

@@ -665,12 +665,7 @@ func sortinter(t *Type) *Type {
 		i++
 	}
 	sort.Sort(methcmp(a[:i]))
-	for {
-		tmp11 := i
-		i--
-		if tmp11 <= 0 {
-			break
-		}
+	for i--; i >= 0; i-- {
 		a[i].Down = f
 		f = a[i]
 	}

src/cmd/compile/internal/gc/typecheck.go

@@ -3073,11 +3073,10 @@ func typecheckcomplit(np **Node) {
 				setlineno(ll.N)
 				typecheck(&ll.N, Erv)
 				if f == nil {
-					tmp12 := bad
-					bad++
-					if tmp12 == 0 {
+					if bad == 0 {
 						Yyerror("too many values in struct initializer")
 					}
+					bad++
 					continue
 				}
 
@@ -3110,11 +3109,10 @@ func typecheckcomplit(np **Node) {
 				l = ll.N
 				setlineno(l)
 				if l.Op != OKEY {
-					tmp13 := bad
-					bad++
-					if tmp13 == 0 {
+					if bad == 0 {
 						Yyerror("mixture of field:value and value initializers")
 					}
+					bad++
 					typecheck(&ll.N, Erv)
 					continue
 				}

src/cmd/compile/internal/ppc64/cgen.go

@@ -126,13 +126,7 @@ func blockcopy(n, res *gc.Node, osrc, odst, w int64) {
 		// ADDs.  That will produce shorter, more
 		// pipeline-able code.
 		var p *obj.Prog
-		for {
-			tmp14 := c
-			c--
-			if tmp14 <= 0 {
-				break
-			}
-
+		for ; c > 0; c-- {
 			p = gins(op, &src, &tmp)
 			p.From.Type = obj.TYPE_MEM
 			p.From.Offset = int64(dir)

src/cmd/compile/internal/ppc64/ggen.go

@@ -141,13 +141,13 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	t := nl.Type
 
 	t0 := t
-	check := 0
+	check := false
 	if gc.Issigned[t.Etype] {
-		check = 1
+		check = true
 		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -(1<<uint64(t.Width*8-1)) {
-			check = 0
+			check = false
 		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
-			check = 0
+			check = false
 		}
 	}
 
@@ -157,7 +157,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 		} else {
 			t = gc.Types[gc.TUINT64]
 		}
-		check = 0
+		check = false
 	}
 
 	a := optoas(gc.ODIV, t)
@@ -198,7 +198,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	gc.Patch(p1, gc.Pc)
 
 	var p2 *obj.Prog
-	if check != 0 {
+	if check {
 		var nm1 gc.Node
 		gc.Nodconst(&nm1, t, -1)
 		gins(optoas(gc.OCMP, t), &tr, &nm1)
@@ -242,7 +242,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	}
 
 	gc.Regfree(&tl)
-	if check != 0 {
+	if check {
 		gc.Patch(p2, gc.Pc)
 	}
 }
@@ -254,9 +254,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
 func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
 	// largest ullman on left.
 	if nl.Ullman < nr.Ullman {
-		tmp := (*gc.Node)(nl)
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	t := (*gc.Type)(nl.Type)

src/cmd/compile/internal/x86/ggen.go

@@ -133,24 +133,14 @@ func clearfat(nl *gc.Node) {
 		n1.Op = gc.OINDREG
 		var z gc.Node
 		gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
-		for {
-			tmp14 := q
-			q--
-			if tmp14 <= 0 {
-				break
-			}
+		for ; q > 0; q-- {
 			n1.Type = z.Type
 			gins(x86.AMOVL, &z, &n1)
 			n1.Xoffset += 4
 		}
 
 		gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
-		for {
-			tmp15 := c
-			c--
-			if tmp15 <= 0 {
-				break
-			}
+		for ; c > 0; c-- {
 			n1.Type = z.Type
 			gins(x86.AMOVB, &z, &n1)
 			n1.Xoffset++
@@ -213,13 +203,13 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node, ax *gc.Node, dx *gc.N
 	t := nl.Type
 
 	t0 := t
-	check := 0
+	check := false
 	if gc.Issigned[t.Etype] {
-		check = 1
+		check = true
 		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -1<<uint64(t.Width*8-1) {
-			check = 0
+			check = false
 		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
-			check = 0
+			check = false
 		}
 	}
 
@@ -229,7 +219,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node, ax *gc.Node, dx *gc.N
 		} else {
 			t = gc.Types[gc.TUINT32]
 		}
-		check = 0
+		check = false
 	}
 
 	var t1 gc.Node
@@ -278,7 +268,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node, ax *gc.Node, dx *gc.N
 		gc.Patch(p1, gc.Pc)
 	}
 
-	if check != 0 {
+	if check {
 		gc.Nodconst(&n4, t, -1)
 		gins(optoas(gc.OCMP, t), &n1, &n4)
 		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
@@ -313,7 +303,7 @@ func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node, ax *gc.Node, dx *gc.N
 	} else {
 		gmove(dx, res)
 	}
-	if check != 0 {
+	if check {
 		gc.Patch(p2, gc.Pc)
 	}
 }
@@ -513,9 +503,7 @@ func cgen_bmul(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) bool {
 
 	// largest ullman on left.
 	if nl.Ullman < nr.Ullman {
-		tmp := nl
-		nl = nr
-		nr = tmp
+		nl, nr = nr, nl
 	}
 
 	var nt gc.Node
@@ -705,9 +693,7 @@ func cgen_floatsse(n *gc.Node, res *gc.Node) {
 
 sbop: // symmetric binary
 	if nl.Ullman < nr.Ullman || nl.Op == gc.OLITERAL {
-		r := nl
-		nl = nr
-		nr = r
+		nl, nr = nr, nl
 	}
 
 abop: // asymmetric binary