[Bug target/56858] alpha looks for NOTE_INSN_EH_REGION notes that cannot exist

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56858

--- Comment #5 from Richard Henderson <rth at gcc dot gnu.org> 2013-04-08 14:35:03 UTC ---
They did used to exist during mach_reorg; they used to exist at rtl creation
time.  You cannot simply delete the code either, that produces wrong-code wrt
fp exceptions.  Of course, we've got wrong-code now, regressed from the last
rtl exception rewrite.

Uros, testing ev68 wouldn't even have executed this code.  This is intended for
ev4 and ev5, without the precise fp exceptions in ev6.  You can test this code
for ICEs on an ev68 host if you don't actually configure alphaev68-*-*, but you
won't see any potential runtime failures either way.

I briefly looked at what one would have to do with the current state of rtl
exceptions, and I'm thinking that it might be easier to split out the trap
shadow handling from machine_reorg and use the pass manager to insert a new
pass after we've re-converted to eh region notes.