{"ast_node_type":"other","tokens":[{"end":240,"kind":"keyword","start":0,"text":"|MSP430"}]}
|MSP430        | `r0`, `r2`, `r3`                        | These are the program counter, status register, and constant generator respectively. Neither the status register nor constant generator can be written to.                          |
| AVR          | `r0`, `r1`, `r1r0`                      | Due to an issue in LLVM, the `r0` and `r1` registers cannot be used as inputs or outputs.  If modified, they must be restored to their original values before the end of the block. |
| M68k         | `a4`, `a5`                              | Used internally by LLVM for the base pointer and global base pointer. |