[Bug tree-optimization/95627] [11 Regression] ICE in rs6000_density_test at rs6000.c:4992 since r11-1181-g371cc683371bedb0e53ebcee0c0e89604a1e74b1

["rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95627

--- Comment #2 from rguenther at suse dot de <rguenther at suse dot de> ---
On June 10, 2020 9:54:39 PM GMT+02:00, "marxin at gcc dot gnu.org"
<gcc-bugzilla@gcc.gnu.org> wrote:
>https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95627
>
>            Bug ID: 95627
>           Summary: [11 Regression] ICE in rs6000_density_test at
>                    rs6000.c:4992 since
>                    r11-1181-g371cc683371bedb0e53ebcee0c0e89604a1e74b1
>           Product: gcc
>           Version: 11.0
>            Status: UNCONFIRMED
>          Keywords: ice-on-valid-code
>          Severity: normal
>          Priority: P3
>         Component: tree-optimization
>          Assignee: unassigned at gcc dot gnu.org
>          Reporter: marxin at gcc dot gnu.org
>                CC: rguenth at gcc dot gnu.org
>  Target Milestone: ---
>              Host: x86_64-linux-gnu
>            Target: ppc64le-linux-gnu
>
>Since the revision I see:
>
>$ ./xgcc -B.
>/home/mliska/Programming/gcc/gcc/testsuite/gcc.c-torture/compile/20070520-1.c
>-fvar-tracking-assignments-toggle -ftree-loop-vectorize -O2
>during GIMPLE pass: vect
>/home/mliska/Programming/gcc/gcc/testsuite/gcc.c-torture/compile/20070520-1.c:
>In function ‘ff_pred8x8_plane_c’:
>/home/mliska/Programming/gcc/gcc/testsuite/gcc.c-torture/compile/20070520-1.c:4:6:
>internal compiler error: Segmentation fault
>    4 | void ff_pred8x8_plane_c(uint8_t *src, int stride){
>      |      ^~~~~~~~~~~~~~~~~~
>0xe7e38f crash_signal
>        ../../gcc/toplev.c:328
>0x1259ce4 rs6000_density_test
>        ../../gcc/config/rs6000/rs6000.c:4992
>0x125a00c rs6000_finish_cost
>        ../../gcc/config/rs6000/rs6000.c:5102
>0x1150170 finish_cost
>        ../../gcc/tree-vectorizer.h:1400
>0x1153821 vect_compute_single_scalar_iteration_cost
>        ../../gcc/tree-vect-loop.c:1134
>0x11568fb vect_analyze_loop_2
>        ../../gcc/tree-vect-loop.c:2041
>0x11586ef vect_analyze_loop(loop*, vec_info_shared*)
>        ../../gcc/tree-vect-loop.c:2583
>0x119131c try_vectorize_loop_1
>        ../../gcc/tree-vectorizer.c:894
>0x1191d69 vectorize_loops()
>        ../../gcc/tree-vectorizer.c:1128
>Please submit a full bug report,
>with preprocessed source if appropriate.
>Please include the complete backtrace with any bug report.
>See <https://gcc.gnu.org/bugs/> for instructions.

Just skip debug stmts in the IL walk in the backend or deal with NULL stmt info
result for lookup of those. I have public holidays today.