[PATCH] Fix SCHED_GROUP_P ICEs on v850

[law@redhat.com]

In message <Pine.LNX.4.44.0301190809100.30567-100000@www.eyesopen.com>, Roger S
ayle writes:
 >
 >The following patch fixes two ICEs building mainline GCC on v850.
 >Both occur building libstdc++-v3/include/bits/istream.tcc:
 >
 >internal compiler error: RTL flag check: SCHED_GROUP_P used with
 >unexpected rtx code `note' in can_schedule_ready_p, at sched-rgn.c:2123
 >
 >The code in question looks like:
 >
 >>	while (SCHED_GROUP_P (insn))
 >>	  insn = PREV_INSN (insn);
 >
 >Examining the other examples of looping over SCHED_GROUP_P in
 >sched-rgn.c, it appears the correct fix it to use prev_nonnote_insn.
 >Making this change, gets us very slightly further:
 >
 >internal compiler error: RTL flag check: SCHED_GROUP_P used with
 >unexpected rtx code `note' in move_insn, at haifa-sched.c:1774
 >
 >This is an identical problem, and can be resolved using the same
 >idiom, replacing PREV_INSN with prev_nonnote_insn.
 >
 >With these two changes I'm able to successfully build a cross-compiler
 >from i686-pc-linux-gnu to v850-elf, and run the testsuite on v850-sim.
 >The patch has also been tested with a complete bootstrap, all languages
 >except Ada and treelang, on i686-pc-linux-gnu, and a full "make -k check"
 >with no new regressions.
 >
 >
 >Could a scheduling expert confirm this is indeed the correct fix?
 >Ok for mainline?
I'd like to know what kinds of notes you're running into.  I'm pretty
sure they all should have been (temporarily) removed from the insn stream
before scheduling.

Jeff