r187606 - in /trunk/gcc: ChangeLog jump.c

[davem at gcc dot gnu dot org]

Author: davem
Date: Wed May 16 20:11:46 2012
New Revision: 187606

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187606
Log:
Fix var tracking ICE due to reorg.

If during reorg we delete a code label, and as a result we decide to
delete all the code following that label, we hit this condition in
jump.c:delete_related_insns():

  if (was_code_label && prev && BARRIER_P (prev))                                

which passes and then we proceed to delete insns until we hit a
non-deleted code label.

During this traversal, we can end up deleting a CALL, but in doing so
we will leave the var tracking note for the call arguments around.

Later in dwarf2_var_location() we will ICE, because we can't find the
CALL when we search backwards for it.

The note searching scheme in the fix below is cribbed from code in
try_split() which has to handle a similar problem.

gcc/

	* jump.c (delete_related_insns): If we remove a CALL, make sure
	we delete it's NOTE_INSN_CALL_ARG_LOCATION note too.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/jump.c