[Bug other/50925] [4.7 Regression][avr] ICE at spill_failure, at reload1.c:2118

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50925

--- Comment #8 from Jeffrey A. Law <law at redhat dot com> 2011-11-14 17:09:04 UTC ---
I'm not going to be able to look at it anytime soon, but just some general
thoughts:

  1. Disabling caller-saves probably isn't appropriate.  Just looking at
codesize isn't the way to evaluate caller-saves either as caller-saves is
tasked with improving performance, possibly at the expense of codesize.

  2. The first thing someone needs to do is provide information as to why that
insn needs reloads.  I don't know enough about the AVR to hazard as guess why
that insn needs reloads.

  3. Find out where insn 172 comes from.  There are restrictions on the insns
created by caller-save.  So if caller-save creates a bogus insn, then that
needs to be investigated.

Anyway, that's where I'd start.  I can't say enough that disabling caller-saves
merely to work around this problem is wrong wrong wrong.