ENOTSOCK        = syscall.Errno(0x26)
	ENOTSUP         = syscall.Errno(0x2d)
	ENOTTY          = syscall.Errno(0x19)
	ENXIO           = syscall.Errno(0x6)
	EOPNOTSUPP      = syscall.Errno(0x66)
	EOVERFLOW       = syscall.Errno(0x54)
	EOWNERDEAD      = syscall.Errno(0x69)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPIPE           = syscall.Errno(0x20)

	ENOTSOCK        = syscall.Errno(0x26)
	ENOTSUP         = syscall.Errno(0x5b)
	ENOTTY          = syscall.Errno(0x19)
	ENXIO           = syscall.Errno(0x6)
	EOPNOTSUPP      = syscall.Errno(0x2d)
	EOVERFLOW       = syscall.Errno(0x57)
	EOWNERDEAD      = syscall.Errno(0x5e)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPIPE           = syscall.Errno(0x20)

	n := (size/goarch.PtrSize + 7) / 8
	x := (*[1 << 30]byte)(persistentalloc(n+1, 1, &memstats.buckhash_sys))[:n+1]
	x[len(x)-1] = 0xa1 // overflow check sentinel
	n = runGCProg(prog, &x[0])
	if x[len(x)-1] != 0xa1 {
		throw("progToPointerMask: overflow")
	}
	return bitvector{int32(n), &x[0]}
}

// Packed GC pointer bitmaps, aka GC programs.
//

	ENOTSOCK        = syscall.Errno(0x26)
	ENOTSUP         = syscall.Errno(0x2d)
	ENOTTY          = syscall.Errno(0x19)
	ENXIO           = syscall.Errno(0x6)
	EOPNOTSUPP      = syscall.Errno(0x2d)
	EOVERFLOW       = syscall.Errno(0x54)
	EOWNERDEAD      = syscall.Errno(0x60)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPIPE           = syscall.Errno(0x20)

	{-99, -1,
		"-933262154439441526816992388562667004907159682643816214685929" +
			"638952175999932299156089414639761565182862536979208272237582" +
			"511852109168640000000000000000000000", // -99!
	},

	// overflow situations
	{math.MaxInt64 - 0, math.MaxInt64, "9223372036854775807"},
	{math.MaxInt64 - 1, math.MaxInt64, "85070591730234615838173535747377725442"},

	ENOTSOCK        = syscall.Errno(0x26)
	ENOTSUP         = syscall.Errno(0x2d)
	ENOTTY          = syscall.Errno(0x19)
	ENXIO           = syscall.Errno(0x6)
	EOPNOTSUPP      = syscall.Errno(0x2d)
	EOVERFLOW       = syscall.Errno(0x54)
	EOWNERDEAD      = syscall.Errno(0x60)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPIPE           = syscall.Errno(0x20)

	ENOTSOCK        = syscall.Errno(0x26)
	ENOTSUP         = syscall.Errno(0x2d)
	ENOTTY          = syscall.Errno(0x19)
	ENXIO           = syscall.Errno(0x6)
	EOPNOTSUPP      = syscall.Errno(0x2d)
	EOVERFLOW       = syscall.Errno(0x54)
	EOWNERDEAD      = syscall.Errno(0x60)
	EPERM           = syscall.Errno(0x1)
	EPFNOSUPPORT    = syscall.Errno(0x2e)
	EPIPE           = syscall.Errno(0x20)

                                 log1p_z_div_lanczos_gamma_plus_one_half);

    // Compute the final result (modulo reflection).  t(z) may be large, and we
    // need to be careful not to overflow to infinity in the first term of
    //
    //   (z + 1/2) * log(t(z)) - t(z).
    //
    // Therefore we compute this as
    //
    //   (z + 1/2 - t(z) / log(t(z))) * log(t(z)).
    //

func (fc flagConstant) Z() bool {
	return fc&2 != 0
}

// C reports whether an unsigned add overflowed (carry), or an
// unsigned subtract did not underflow (borrow).
func (fc flagConstant) C() bool {
	return fc&4 != 0
}

// V reports whether a signed operation overflowed or underflowed.
func (fc flagConstant) V() bool {
	return fc&8 != 0
}

func (fc flagConstant) eq() bool {

		st.fail("missing number")
	}
	val := 0
	for len(st.str) > 0 && isDigit(st.str[0]) {
		// Number picked to ensure we can't overflow with 32-bit int.
		// Any very large number here is bogus.
		if val >= 0x80000000/10-10 {
			st.fail("numeric overflow")
		}
		val = val*10 + int(st.str[0]-'0')
		st.advance(1)
	}
	if neg {
		val = -val
	}
	return val
}