for g := 0; g < 256; g += 5 {
			for b := 0; b < 256; b += 3 {
				r0, g0, b0 := uint8(r), uint8(g), uint8(b)
				y, cb, cr := RGBToYCbCr(r0, g0, b0)
				r1, g1, b1 := YCbCrToRGB(y, cb, cr)
				if delta(r0, r1) > 2 || delta(g0, g1) > 2 || delta(b0, b1) > 2 {
					t.Fatalf("\nr0, g0, b0 = %d, %d, %d\ny,  cb, cr = %d, %d, %d\nr1, g1, b1 = %d, %d, %d",
						r0, g0, b0, y, cb, cr, r1, g1, b1)
				}
			}
		}
	}
}

		panic(fmt.Sprintf("f2() == %d, %d, want %d, %d", got1, got2, want, want))
	}
}

var x interface {
	g0()
	g1() int
	g2() (int, int)
} = s[int]{a: 7}
var y interface{} = s[int]{a: 7}

func interfaceMethods() {
	x.g0()
	is7(x.g1())
	is77(x.g2())
	y.(interface{ g0() }).g0()
	is7(y.(interface{ g1() int }).g1())
	is77(y.(interface{ g2() (int, int) }).g2())
}

}

var x interface {
	g0()
	g1() int
	g2() (int, int)
} = s[int]{a: 7}
var y interface{} = s[int]{a: 7}

func interfaceMethods() {
	x.g0()
	is7(x.g1())
	is77(x.g2())
	y.(interface{ g0() }).g0()
	is7(y.(interface{ g1() int }).g1())
	is77(y.(interface{ g2() (int, int) }).g2())
}

// Also check for instantiations outside functions.
var gg0 = g0[int]
var gg1 = g1[int]
var gg2 = g2[int]

	g0.stack.lo = 0
	g0.stackguard0 = g0.stack.lo + stackGuard
	g0.stackguard1 = g0.stackguard0

	print("Exception ", hex(info.exceptioncode), " ", hex(info.exceptioninformation[0]), " ", hex(info.exceptioninformation[1]), " ", hex(r.ip()), "\n")

	print("PC=", hex(r.ip()), "\n")
	if g0.m.incgo && gp == g0.m.g0 && g0.m.curg != nil {
		if iscgo {

#include "go_asm.h"
#include "go_tls.h"
#include "funcdata.h"
#include "textflag.h"

TEXT runtime·rt0_go(SB), NOSPLIT|NOFRAME|TOPFRAME, $0
	// save m->g0 = g0
	MOVD $runtime·g0(SB), runtime·m0+m_g0(SB)
	// save m0 to g0->m
	MOVD $runtime·m0(SB), runtime·g0+g_m(SB)
	// set g to g0
	MOVD $runtime·g0(SB), g
	CALLNORESUME runtime·check(SB)
#ifdef GOOS_js
	CALLNORESUME runtime·args(SB)
#endif
	CALLNORESUME runtime·osinit(SB)

		// that is always passing a new M from needm.

		// Stack is bogus, but reset the bounds anyway so we can print.
		hi := g0.stack.hi
		lo := g0.stack.lo
		g0.stack.hi = sp + 1024
		g0.stack.lo = sp - 32*1024
		g0.stackguard0 = g0.stack.lo + stackGuard
		g0.stackguard1 = g0.stackguard0

		print("M ", mp.id, " procid ", mp.procid, " runtime: cgocallback with sp=", hex(sp), " out of bounds [", hex(lo), ", ", hex(hi), "]")

	gp := getg()
	if gp != gp.m.g0 {
		throw("notetsleep not on g0")
	}
	semacreate(gp.m)
	return notetsleep_internal(n, ns, nil, 0)
}

// same as runtime·notetsleep, but called on user g (not g0)
// calls only nosplit functions between entersyscallblock/exitsyscall.
func notetsleepg(n *note, ns int64) bool {
	gp := getg()
	if gp == gp.m.g0 {
		throw("notetsleepg on g0")
	}
	semacreate(gp.m)

        when:
        def g2 = subject.group(2)
        def g0 = subject.group(0)
        def g1 = subject.group(1)

        then:
        subject.allGroups == [g0, g1, g2]
    }

    def 'returns the same group for the same ordinal'() {
        given:
        def subject = new OrdinalGroupFactory()

        when:
        def g0 = subject.group(0)
        def g1 = subject.group(1)

        then:

	MOVD	fakePC+24(FP), R8
	// Save the original return address in a local variable
	MOVD	R30, savedRetAddr-8(SP)

	MOVD	g_m(g), R10

	// Switch to g0 stack.
	MOVD	RSP, R19	// callee-saved, preserved across the CALL
	MOVD	m_g0(R10), R11
	CMP	R11, g
	BEQ	call	// already on g0
	MOVD	(g_sched+gobuf_sp)(R11), R12
	MOVD	R12, RSP
call:
	// Load address of the ret sled into the default register for the return
	// address.

	}
	if go1Dot5Fields {
		g0.Disposal = make([]byte, len(g0.Image))
		for i := range g0.Disposal {
			g0.Disposal[i] = DisposalNone
		}
		g0.Config = image.Config{
			ColorModel: globalColorModel,
			Width:      width,
			Height:     height,
		}
		g0.BackgroundIndex = backgroundIndex
	}

	var buf bytes.Buffer
	if err := EncodeAll(&buf, g0); err != nil {
		t.Fatal("EncodeAll:", err)
	}