for i := 0; i < 8; i++ {
		lSSE.add("MOVUPS", fmt.Sprintf("X%d", i), 16)
	}

	p("ADJSP $%d", lSSE.stack)
	p("NOP SP")
	l.save()
	p("#ifndef %s", softfloat)
	lSSE.save()
	p("#endif")
	p("CALL ·asyncPreempt2(SB)")
	p("#ifndef %s", softfloat)
	lSSE.restore()
	p("#endif")
	l.restore()
	p("ADJSP $%d", -lSSE.stack)

	p("POPFL")
	p("RET")
}

func genAMD64() {
	// Assign stack offsets.

}

//go:generate go run mkpreempt.go

// asyncPreempt saves all user registers and calls asyncPreempt2.
//
// When stack scanning encounters an asyncPreempt frame, it scans that
// frame and its parent frame conservatively.
//
// asyncPreempt is implemented in assembly.
func asyncPreempt()

//go:nosplit
func asyncPreempt2() {
	gp := getg()
	gp.asyncSafePoint = true
	if gp.preemptStop {

	// won't get to see who faulted.)
	// Also don't push a sigpanic frame if the faulting PC
	// is the entry of asyncPreempt. In this case, we suspended
	// the thread right between the fault and the exception handler
	// starting to run, and we have pushed an asyncPreempt call.
	// The exception is not from asyncPreempt, so not to push a
	// sigpanic call to make it look like that. Instead, just
	// overwrite the PC. (See issue #35773)

	gp := gFromSP(mp, c.sp())
	if gp != nil && wantAsyncPreempt(gp) {
		if ok, newpc := isAsyncSafePoint(gp, c.ip(), c.sp(), c.lr()); ok {
			// Inject call to asyncPreempt
			targetPC := abi.FuncPCABI0(asyncPreempt)
			switch GOARCH {
			default:
				throw("unsupported architecture")
			case "386", "amd64":
				// Make it look like the thread called targetPC.
				sp := c.sp()

	// preempt.
	if wantAsyncPreempt(gp) {
		if ok, newpc := isAsyncSafePoint(gp, ctxt.sigpc(), ctxt.sigsp(), ctxt.siglr()); ok {
			// Adjust the PC and inject a call to asyncPreempt.
			ctxt.pushCall(abi.FuncPCABI0(asyncPreempt), newpc)
		}
	}

	// Acknowledge the preemption.
	gp.m.preemptGen.Add(1)
	gp.m.signalPending.Store(0)

	if GOOS == "darwin" || GOOS == "ios" {

	"F15",
	"F16",
	"F17",
	"F18",
	"F19",
	"F20",
	"F21",
	"F22",
	"F23",
	"F24",
	"F25",
	"F26",
	"F27",
	"F28",
	"F29",
	"F30",
	"F31",

	// If you add registers, update asyncPreempt in runtime.

	// pseudo-registers
	"SB",
}

func init() {
	// Make map from reg names to reg integers.
	if len(regNamesLOONG64) > 64 {
		panic("too many registers")
	}

	"F23",
	"F24",
	"F25",
	"F26",
	"F27",
	"F28",
	"F29",
	"F30",
	"F31",

	"HI", // high bits of multiplication
	"LO", // low bits of multiplication

	// If you add registers, update asyncPreempt in runtime.

	// pseudo-registers
	"SB",
}

func init() {
	// Make map from reg names to reg integers.
	if len(regNamesMIPS64) > 64 {
		panic("too many registers")
	}

	"F14",
	"F16",
	"F18",
	"F20",
	"F22",
	"F24",
	"F26",
	"F28",
	"F30",

	"HI", // high bits of multiplication
	"LO", // low bits of multiplication

	// If you add registers, update asyncPreempt in runtime.

	// pseudo-registers
	"SB",
}

func init() {
	// Make map from reg names to reg integers.
	if len(regNamesMIPS) > 64 {
		panic("too many registers")
	}
	num := map[string]int{}

}

func TestAsyncPreempt(t *testing.T) {
	if !runtime.PreemptMSupported {
		t.Skip("asynchronous preemption not supported on this platform")
	}
	output := runTestProg(t, "testprog", "AsyncPreempt")
	want := "OK\n"
	if output != want {
		t.Fatalf("want %s, got %s\n", want, output)
	}
}

func TestGCFairness(t *testing.T) {
	output := runTestProg(t, "testprog", "GCFairness")
	want := "OK\n"

var regNames386 = []string{
	"AX",
	"CX",
	"DX",
	"BX",
	"SP",
	"BP",
	"SI",
	"DI",
	"X0",
	"X1",
	"X2",
	"X3",
	"X4",
	"X5",
	"X6",
	"X7",

	// If you add registers, update asyncPreempt in runtime

	// pseudo-registers
	"SB",
}

func init() {
	// Make map from reg names to reg integers.
	if len(regNames386) > 64 {
		panic("too many registers")
	}
	num := map[string]int{}