{name: "REV", argLength: 1, reg: gp11, asm: "REV"},                                    // byte reverse, 64-bit
		{name: "REVW", argLength: 1, reg: gp11, asm: "REVW"},                                  // byte reverse, 32-bit
		{name: "REV16", argLength: 1, reg: gp11, asm: "REV16"},                                // byte reverse in each 16-bit halfword, 64-bit

		{name: "RISBGZ", argLength: 1, reg: gp11, asm: "RISBGZ", aux: "S390XRotateParams", clobberFlags: true},                   // rotate then insert selected bits [into zero]

		// unary ops
		{name: "NEG", argLength: 1, reg: gp11, asm: "NEG", clobberFlags: true},   // -arg0
		{name: "NEGW", argLength: 1, reg: gp11, asm: "NEGW", clobberFlags: true}, // -arg0

		{name: "NOT", argLength: 1, reg: gp11, resultInArg0: true, clobberFlags: true},  // ^arg0

// goroutine that is coordinating the goroutine profile (running on its own
// stack), or from the scheduler in preparation to execute gp1 (running on the
// system stack).
func doRecordGoroutineProfile(gp1 *g, pcbuf []uintptr) {
	if readgstatus(gp1) == _Grunning {
		print("doRecordGoroutineProfile gp1=", gp1.goid, "\n")
		throw("cannot read stack of running goroutine")
	}

	offset := int(goroutineProfile.offset.Add(1)) - 1