Confirm constraint on `save`ing `a`.
Chris Pressey
3 years ago
| 784 | 784 | baton = batons.pop() |
| 785 | 785 | context.re_introduce(baton) |
| 786 | 786 | |
| 787 | # FIXME check if A needs to be the outer thing that is saved, I think it does. | |
| 787 | # We do this check outside the loop, because A is only preserved | |
| 788 | # if it is the outermost thing being `save`d. | |
| 788 | 789 | if location == REG_A: |
| 789 | 790 | pass |
| 790 | 791 | else: |
| 2120 | 2120 | | } |
| 2121 | 2121 | = ok |
| 2122 | 2122 | |
| 2123 | `a` is only preserved if it is the outermost thing `save`d. | |
| 2124 | ||
| 2125 | | routine main | |
| 2126 | | inputs a | |
| 2127 | | outputs a | |
| 2128 | | trashes z, n | |
| 2129 | | { | |
| 2130 | | save x, a { | |
| 2131 | | ld a, 0 | |
| 2132 | | ld x, 1 | |
| 2133 | | } | |
| 2134 | | } | |
| 2135 | ? UnmeaningfulOutputError: a | |
| 2136 | ||
| 2123 | 2137 | Not just registers, but also user-defined locations can be saved. |
| 2124 | 2138 | |
| 2125 | 2139 | | byte foo |