[Bug rtl-optimization/56912] New: scheduler change breaks linux kernel LTO build with 4.8

[andi-gcc at firstfloor dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56912



             Bug #: 56912

           Summary: scheduler change breaks linux kernel LTO build with

                    4.8

    Classification: Unclassified

           Product: gcc

           Version: unknown

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: rtl-optimization

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: andi-...@firstfloor.org





For the Linux kernel LTO build I get ICEs during LTO (segfaults) with the

recent 4.8 branch. I bisected it down to this patch and reverting fixes it.



No simple test case unfortunately as it is LTO 





            Backport from mainline

            2013-02-25  Andrey Belevantsev  <a...@ispras.ru>

            Alexander Monakov  <amona...@ispras.ru>



            PR middle-end/56077

            * sched-deps.c (sched_analyze_insn): When reg_pending_barrier,

            flush pending lists also on non-jumps.  Adjust comment.







Typical crash:







#7  <signal handler called>

#8  sched_analyze_1 (deps=0x7fff550a5c00, x=0x7fa0311e2ed0,

insn=0x7fa0311f40d8)

    at ../../gcc/gcc/sched-deps.c:2479

#9  0x0000000000b668d5 in sched_analyze_insn (deps=deps@entry=0x7fff550a5c00, 

    x=0x7fa0311e2e70, insn=insn@entry=0x7fa0311f40d8) at

../../gcc/gcc/sched-deps.c:2859

#10 0x0000000000b6859b in deps_analyze_insn (deps=deps@entry=0x7fff550a5c00, 

    insn=insn@entry=0x7fa0311f40d8) at ../../gcc/gcc/sched-deps.c:3505

#11 0x0000000000b689c3 in sched_analyze (deps=0x7fff550a5c00, head=<optimized

out>, 

    tail=0x7fa0311f8c18) at ../../gcc/gcc/sched-deps.c:3653

#12 0x000000000070b635 in compute_block_dependences (bb=0) at

../../gcc/gcc/sched-rgn.c:2702

#13 sched_rgn_compute_dependencies (rgn=rgn@entry=5) at

../../gcc/gcc/sched-rgn.c:3140

#14 0x000000000070df84 in schedule_region (rgn=5) at

../../gcc/gcc/sched-rgn.c:2915

#15 schedule_insns () at ../../gcc/gcc/sched-rgn.c:3299

#16 schedule_insns () at ../../gcc/gcc/sched-rgn.c:3278

#17 0x000000000070e3b1 in rest_of_handle_sched2 () at

../../gcc/gcc/sched-rgn.c:3523

#18 0x00000000006b534e in execute_one_pass (pass=pass@entry=0x112e240

<pass_sched2>)

    at ../../gcc/gcc/passes.c:2084

#19 0x00000000006b56bd in execute_pass_list (pass=0x112e240 <pass_sched2>)

    at ../../gcc/gcc/passes.c:2139

#20 0x00000000006b56cf in execute_pass_list (pass=0x112d840 <pass_postreload>)

    at ../../gcc/gcc/passes.c:2140

#21 0x00000000006b56cf in execute_pass_list (pass=0x112d8a0

<pass_rest_of_compilation>)

    at ../../gcc/gcc/passes.c:2140

#22 0x0000000000792043 in tree_rest_of_compilation (fndecl=0x7fa03f899700)

    at ../../gcc/gcc/tree-optimize.c:422

#23 0x0000000000536f7b in cgraph_expand_function (node=0x7fa03c49b5a0)