pc    uint64     // program counter
	cpsr  uint32     // current program status register
	__pad uint32
}

type neonstate64 struct {
	v    [64]uint64 // actually [32]uint128
	fpsr uint32
	fpcr uint32
}

type mcontext64 struct {
	es exceptionstate64
	ss regs64
	ns neonstate64
}

type ucontext struct {
	uc_onstack  int32
	uc_sigmask  uint32
	uc_stack    stackt

type context struct {
	contextflags uint32
	cpsr         uint32
	x            [31]uint64 // fp is x[29], lr is x[30]
	xsp          uint64
	pc           uint64
	v            [32]neon128
	fpcr         uint32
	fpsr         uint32
	bcr          [8]uint32
	bvr          [8]uint64
	wcr          [2]uint32
	wvr          [2]uint64
}

func (c *context) ip() uintptr { return uintptr(c.pc) }

}

type Sigset_t struct {
	Val [4]uint32
}

type Reg struct {
	R    [13]uint32
	Sp   uint32
	Lr   uint32
	Pc   uint32
	Cpsr uint32
}

type FpReg struct {
	Fpsr uint32
	Fpr  [8]FpExtendedPrecision
}

type FpExtendedPrecision struct {
	Exponent    uint32
	Mantissa_hi uint32
	Mantissa_lo uint32
}

type PtraceIoDesc struct {
	Op   int32