test: use go:noinline consistently

Replace various implementations of inlining prevention with
"go:noinline"

Change-Id: Iac90895c3a62d6f4b7a6c72e11e165d15a0abfa4
Reviewed-on: https://go-review.googlesource.com/16510
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

14 files changed, 44 insertions, 81 deletions

diff --git a/src/runtime/gc_test.go b/src/runtime/gc_test.go
index 61bbc14945..ce61059e85 100644
--- a/src/runtime/gc_test.go
+++ b/src/runtime/gc_test.go
@@ -511,9 +511,11 @@ func TestAssertE2T2Liveness(t *testing.T) {
 	testIfaceEqual(io.EOF)
 }
 
+var a bool
+
+//go:noinline
 func testIfaceEqual(x interface{}) {
 	if x == "abc" {
-		// Prevent inlining
-		panic("")
+		a = true
 	}
 }
diff --git a/src/runtime/pprof/mprof_test.go b/src/runtime/pprof/mprof_test.go
index ebf53dd66b..d14fb5888e 100644
--- a/src/runtime/pprof/mprof_test.go
+++ b/src/runtime/pprof/mprof_test.go
@@ -22,11 +22,8 @@ func allocateTransient1M() {
 	}
 }
 
+//go:noinline
 func allocateTransient2M() {
-	// prevent inlining
-	if memSink == nil {
-		panic("bad")
-	}
 	memSink = make([]byte, 2<<20)
 }
 
@@ -76,18 +73,18 @@ func TestMemoryProfiler(t *testing.T) {
 
 	tests := []string{
 		fmt.Sprintf(`%v: %v \[%v: %v\] @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
-#	0x[0-9,a-f]+	runtime/pprof_test\.allocatePersistent1K\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test\.go:43
-#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test\.go:66
+#	0x[0-9,a-f]+	runtime/pprof_test\.allocatePersistent1K\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test\.go:40
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test\.go:63
 `, 32*memoryProfilerRun, 1024*memoryProfilerRun, 32*memoryProfilerRun, 1024*memoryProfilerRun),
 
 		fmt.Sprintf(`0: 0 \[%v: %v\] @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
 #	0x[0-9,a-f]+	runtime/pprof_test\.allocateTransient1M\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:21
-#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:64
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:61
 `, (1<<10)*memoryProfilerRun, (1<<20)*memoryProfilerRun),
 
 		fmt.Sprintf(`0: 0 \[%v: %v\] @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
-#	0x[0-9,a-f]+	runtime/pprof_test\.allocateTransient2M\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:30
-#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:65
+#	0x[0-9,a-f]+	runtime/pprof_test\.allocateTransient2M\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:27
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestMemoryProfiler\+0x[0-9,a-f]+	.*/runtime/pprof/mprof_test.go:62
 `, memoryProfilerRun, (2<<20)*memoryProfilerRun),
 	}
 
diff --git a/src/runtime/race/testdata/mop_test.go b/src/runtime/race/testdata/mop_test.go
index d7cbc98f95..c96acb9021 100644
--- a/src/runtime/race/testdata/mop_test.go
+++ b/src/runtime/race/testdata/mop_test.go
@@ -1356,14 +1356,8 @@ type InterImpl struct {
 	x, y int
 }
 
+//go:noinline
 func (p InterImpl) Foo(x int) {
-	// prevent inlining
-	z := 42
-	x = 85
-	y := x / z
-	z = y * z
-	x = z * y
-	_, _, _ = x, y, z
 }
 
 type InterImpl2 InterImpl
diff --git a/src/runtime/race/testdata/regression_test.go b/src/runtime/race/testdata/regression_test.go
index d461269d98..6a7802fb02 100644
--- a/src/runtime/race/testdata/regression_test.go
+++ b/src/runtime/race/testdata/regression_test.go
@@ -65,10 +65,8 @@ type Image struct {
 	min, max Rect
 }
 
+//go:noinline
 func NewImage() Image {
-	var pleaseDoNotInlineMe stack
-	pleaseDoNotInlineMe.push(1)
-	_ = pleaseDoNotInlineMe.pop()
 	return Image{}
 }
 
@@ -113,11 +111,8 @@ type RpcChan struct {
 
 var makeChanCalls int
 
+//go:noinline
 func makeChan() *RpcChan {
-	var pleaseDoNotInlineMe stack
-	pleaseDoNotInlineMe.push(1)
-	_ = pleaseDoNotInlineMe.pop()
-
 	makeChanCalls++
 	c := &RpcChan{make(chan bool, 1)}
 	c.c <- true
diff --git a/test/fixedbugs/bug401.go b/test/fixedbugs/bug401.go
index 5589b5b1bb..c58e1ca400 100644
--- a/test/fixedbugs/bug401.go
+++ b/test/fixedbugs/bug401.go
@@ -9,9 +9,8 @@ package main
 
 type T struct{}
 
+//go:noinline
 func (T) cplx() complex128 {
-	for false {
-	} // avoid inlining
 	return complex(1, 0)
 }
 
diff --git a/test/fixedbugs/bug484.go b/test/fixedbugs/bug484.go
index c664b83af3..7025affc2d 100644
--- a/test/fixedbugs/bug484.go
+++ b/test/fixedbugs/bug484.go
@@ -23,20 +23,14 @@ package main
 
 import "runtime"
 
-var c bool
-
+//go:noinline
 func f() interface{} {
-	if c { // disable inlining
-		f()
-	}
 	runtime.GC()
 	return nil
 }
 
+//go:noinline
 func g() {
-	if c { // disable inlining
-		g()
-	}
 	var s interface{}
 	_ = func() {
 		s := f()
@@ -47,31 +41,25 @@ func g() {
 	useiface(s)
 }
 
+//go:noinline
 func useiface(x interface{}) {
-	if c {	// disable inlining
-		useiface(x)
-	}
 }
 
+//go:noinline
 func h() {
-	if c { // disable inlining
-		h()
-	}
 	var x [16]uintptr
 	for i := range x {
 		x[i] = 1
 	}
-	
+
 	useint(x[0])
 	useint(x[1])
 	useint(x[2])
 	useint(x[3])
 }
 
+//go:noinline
 func useint(x uintptr) {
-	if c {	// disable inlining
-		useint(x)
-	}
 }
 
 func main() {
@@ -85,6 +73,6 @@ func main() {
 
 func big(x int) {
 	if x >= 0 {
-		big(x-1)
+		big(x - 1)
 	}
 }
diff --git a/test/fixedbugs/issue10441.go b/test/fixedbugs/issue10441.go
index 25832fac45..9bc4948b15 100644
--- a/test/fixedbugs/issue10441.go
+++ b/test/fixedbugs/issue10441.go
@@ -11,7 +11,7 @@ func bar() {
 	foo(&f)
 }
 
+//go:noinline
 func foo(f *func()) func() {
-	defer func() {}() // prevent inlining of foo
 	return *f
 }
diff --git a/test/fixedbugs/issue12133.go b/test/fixedbugs/issue12133.go
index 0b66c56a51..7b02a47c72 100644
--- a/test/fixedbugs/issue12133.go
+++ b/test/fixedbugs/issue12133.go
@@ -19,8 +19,8 @@ func main() {
 		panic("bad")
 	}
 }
+
+//go:noinline
 func f1(v1 uint) uint {
-	switch {
-	} // prevent inlining
 	return v1 >> ((1 >> v1) + (1 >> v1))
 }
diff --git a/test/fixedbugs/issue4518.go b/test/fixedbugs/issue4518.go
index e64b069bb9..5c3a1782be 100644
--- a/test/fixedbugs/issue4518.go
+++ b/test/fixedbugs/issue4518.go
@@ -10,15 +10,13 @@
 
 package main
 
-func DontInline() {}
-
+//go:noinline
 func F(e interface{}) (int, int) {
-	DontInline()
 	return 3, 7
 }
 
+//go:noinline
 func G() (int, int) {
-	DontInline()
 	return 3, 7
 }
 
diff --git a/test/fixedbugs/issue4964.dir/a.go b/test/fixedbugs/issue4964.dir/a.go
index 2b9e44e351..216f352ca9 100644
--- a/test/fixedbugs/issue4964.dir/a.go
+++ b/test/fixedbugs/issue4964.dir/a.go
@@ -10,16 +10,14 @@ type T struct {
 	Pointer *int
 }
 
-func dontinline() {}
-
+//go:noinline
 func Store(t *T) {
 	global = t.Pointer
-	dontinline()
 }
 
+//go:noinline
 func Store2(t *T) {
 	global2 = t.Pointer
-	dontinline()
 }
 
 func Get() *int {
diff --git a/test/fixedbugs/issue7995b.dir/x1.go b/test/fixedbugs/issue7995b.dir/x1.go
index 075911b921..bafecf52a9 100644
--- a/test/fixedbugs/issue7995b.dir/x1.go
+++ b/test/fixedbugs/issue7995b.dir/x1.go
@@ -4,12 +4,8 @@ import "fmt"
 
 var P int
 
-var b bool
-
+//go:noinline
 func F(x *int) string {
-	if b { // avoid inlining
-		F(x)
-	}
 	P = 50
 	*x = 100
 	return fmt.Sprintln(P, *x)
diff --git a/test/fixedbugs/issue8036.go b/test/fixedbugs/issue8036.go
index f32fde84ab..f052cf9e5c 100644
--- a/test/fixedbugs/issue8036.go
+++ b/test/fixedbugs/issue8036.go
@@ -18,19 +18,19 @@ type T struct {
 
 type TI [3]uintptr
 
+//go:noinline
 func G() (t TI) {
 	t[0] = 1
 	t[1] = 2
 	t[2] = 3
-	runtime.GC() // prevent inlining
 	return
 }
 
+//go:noinline
 func F() (t T) {
 	t.X = newint()
 	t.Y = t.X
 	t.Z = t.Y
-	runtime.GC() // prevent inlining
 	return
 }
 
diff --git a/test/func8.go b/test/func8.go
index 13051802ec..09ca020814 100644
--- a/test/func8.go
+++ b/test/func8.go
@@ -21,16 +21,14 @@ func g() int {
 
 var xy string
 
+//go:noinline
 func x() bool {
-	for false {
-	} // no inlining
 	xy += "x"
 	return false
 }
 
+//go:noinline
 func y() string {
-	for false {
-	} // no inlining
 	xy += "y"
 	return "abc"
 }
diff --git a/test/reorder2.go b/test/reorder2.go
index e56be2bc80..3e87998ffe 100644
--- a/test/reorder2.go
+++ b/test/reorder2.go
@@ -58,9 +58,8 @@ func f(x, y string) {
 	log += "f(" + x + ", " + y + ")"
 }
 
+//go:noinline
 func ff(x, y string) {
-	for false {
-	} // prevent inl
 	log += "ff(" + x + ", " + y + ")"
 }
 
@@ -69,9 +68,8 @@ func h(x string) string {
 	return x
 }
 
+//go:noinline
 func g(x string) string {
-	for false {
-	} // prevent inl
 	log += "g(" + x + ")"
 	return x
 }
@@ -167,7 +165,7 @@ func main() {
 		err++
 	}
 	log = ""
-	
+
 	x := 0
 	switch x {
 	case 0:
@@ -176,7 +174,7 @@ func main() {
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in switch, expecting a(1)b(2)a(2), got ", log)
 			err++
@@ -194,7 +192,7 @@ func main() {
 		}
 		log = ""
 	}
-	
+
 	c := make(chan int, 1)
 	c <- 1
 	select {
@@ -206,7 +204,7 @@ func main() {
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in select1, expecting a(1)b(2)a(2), got ", log)
 			err++
@@ -233,7 +231,7 @@ func main() {
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in select2, expecting a(1)b(2)a(2), got ", log)
 			err++
@@ -255,14 +253,14 @@ func main() {
 	c <- 1
 	select {
 	default:
-	case c<-1:
+	case c <- 1:
 	case <-c:
 		if a("1")("2")("3"); log != "a(1)a(2)a(3)" {
 			println("in select3, expecting a(1)a(2)a(3) , got ", log)
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in select3, expecting a(1)b(2)a(2), got ", log)
 			err++
@@ -290,7 +288,7 @@ func main() {
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in select4, expecting a(1)b(2)a(2), got ", log)
 			err++
@@ -318,7 +316,7 @@ func main() {
 			err++
 		}
 		log = ""
-	
+
 		if t.a("1").a(t.b("2")); log != "a(1)b(2)a(2)" {
 			println("in select5, expecting a(1)b(2)a(2), got ", log)
 			err++