[Bug middle-end/70219] [6 Regression] ICE: in delete_move_and_clobber, at lra-constraints.c:5864 with -O2

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70219

--- Comment #4 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #3)
> Created attachment 37953 [details]
> gcc6-pr70219.patch
> 
> Untested fix.  The code had assertion dregno > 0, but I don't see anything
> special on register 0 (%rax on x86_64), assuming Vlad meant >= 0 here (i.e.
> make sure dregno is not negative, which is not a hard register, but has
> special meaning).

Yes,  I meant >=0.   I am really sorry for such obvious mistake.  I was to
distracted to other things.

Jakub, could submit your patch.