argv := make([]uintptr32, argc)
		argvBuf := make([]byte, argvBufLen)
		if args_get(unsafe.Pointer(&argv[0]), unsafe.Pointer(&argvBuf[0])) != 0 {
			throw("args_get failed")
		}

		for i := range argslice {
			start := argv[i] - uintptr32(uintptr(unsafe.Pointer(&argvBuf[0])))
			end := start
			for argvBuf[end] != 0 {
				end++
			}
			argslice[i] = string(argvBuf[start:end])
		}
	}

	// environment

		// vector of '0', to force carry flag set in each 'sub'
		x = makeWordVec(0, n)
		arg = argVW{z, x, 1, 0}
		testFunVWext(t, "subVW, vector of zero", subVW, subVW_g, arg)
	}
}

type argVU struct {
	d  []Word // d is a Word slice, the input parameters x and z come from this array.
	l  uint   // l is the length of the input parameters x and z.