[Bug rtl-optimization/80233] [7 Regression] ICE in combine_instructions w/ -O2 (and above)

["segher at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80233

--- Comment #5 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Author: segher
Date: Wed Mar 29 20:53:59 2017
New Revision: 246575

URL: https://gcc.gnu.org/viewcvs?rev=246575&root=gcc&view=rev
Log:
combine: Fix PR80233

If combine has added an unconditional trap there will be a new basic
block as well.  It will then end up considering the NOTE_INSN_BASIC_BLOCK
as the last_combined_insn, but then it tries to take the DF_INSN_LUID
of that and that dereferences a NULL pointer (since such a note is not
an INSN_P).

This fixes it by not taking non-insns as last_combined_insn.


        PR rtl-optimization/80233
        * combine.c (combine_instructions): Only take NONDEBUG_INSN_P insns
        as last_combined_insn.  Do not test for BARRIER_P separately.

gcc/testsuite/
        PR rtl-optimization/80233
        * gcc.c-torture/compile/pr80233.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr80233.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c
    trunk/gcc/testsuite/ChangeLog