[Bug tree-optimization/84969] New: [8 Regression] Wrong code with -ftree-loop-distribute-patterns

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84969

            Bug ID: 84969
           Summary: [8 Regression] Wrong code with
                    -ftree-loop-distribute-patterns
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: amker at gcc dot gnu.org
  Target Milestone: ---

Created attachment 43711
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43711&action=edit
test-case

Starting from r253859 we generate wrong code for:

$ gcc -O2 isolate.c   && ./a.out 
retval: {{{0,1},{2,3}}}

$ gcc -O2 isolate.c -ftree-loop-distribute-patterns  && ./a.out 
retval: {{
Aborted (core dumped)