LRA Vs match_scratch

[Claudiu Zissulescu]

Hi guys,

I am trying to get LRA fully working for ARC, but I've got an issue.
Whenever, LRA analyses an instruction having (clobber
(match_scratch:SI 3 "=X, ...)) in its pattern I hit the assert in
lra-constraints.c:4101, and it seems it has to do with the scratch's
'X' constraint.
Do I miss something? Is there any limitation between LRA and scratch
operands having in their alternative 'X' constraint?

Any help appreciated,
Claudiu