[Bug tree-optimization/79811] New: ICE verify_flow_info failed with -param vect-epilogues-nomask=1 and -mavx512vbmi

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79811

            Bug ID: 79811
           Summary: ICE verify_flow_info failed with -param
                    vect-epilogues-nomask=1 and -mavx512vbmi
           Product: gcc
           Version: 7.0
            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: hjl.tools at gmail dot com, ysrumyan at gmail dot com
  Target Milestone: ---

Starting from r242501 we ICE on:

$ gcc /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c -O3 --param
vect-epilogues-nomask=1 -mavx512vbmi
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c: In function ‘foo’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: control
flow in the middle of basic block 9
 foo (unsigned char x)
 ^~~
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: control
flow in the middle of basic block 9
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: wrong
outgoing edge flags at end of bb 9
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: control
flow in the middle of basic block 25
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: control
flow in the middle of basic block 25
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: error: wrong
outgoing edge flags at end of bb 25
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr46771.c:9:1: internal
compiler error: verify_flow_info failed
0x7cba99 verify_flow_info()
        ../../gcc/cfghooks.c:260
0xc50214 checking_verify_flow_info
        ../../gcc/cfghooks.h:198
0xc50214 cleanup_tree_cfg_noloop
        ../../gcc/tree-cfgcleanup.c:774
0xc50214 cleanup_tree_cfg()
        ../../gcc/tree-cfgcleanup.c:820
0xb23c14 execute_function_todo
        ../../gcc/passes.c:1919
0xb245a5 execute_todo
        ../../gcc/passes.c:2016