On Wednesday 01 November 2006 17:39, Richard Sandiford wrote: > Can a register be used more than once in an insn if one of those uses is > an auto-modification? I've looked at this several times in the past and > never come to a conclusion. doc/rtl.texi says:
We have a related problem on ARM. The ISA does not allow the base of a automodify address to be used as a source register. ie. (set (mem (post_inc (reg X)) (reg Y)) Is not valid when X == Y. Currently there is no way of expressing this, which leads to invalid asm being generated in some obscure cases. Paul
