[Bug middle-end/92952] New: [10 regression] gfortran.dg/lto/pr87689 FAILs at -O2

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92952

            Bug ID: 92952
           Summary: [10 regression] gfortran.dg/lto/pr87689 FAILs at -O2
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: msebor at gcc dot gnu.org
  Target Milestone: ---

Between 20191213 (r279370) and 20191215 (r279402), gfortran.dg/lto/pr87689
started to FAIL:

+FAIL: gfortran.dg/lto/pr87689 f_lto_pr87689_0.o-f_lto_pr87689_1.o link, -O2
-flto
+FAIL: gfortran.dg/lto/pr87689 f_lto_pr87689_0.o-f_lto_pr87689_1.o link, -O2
-flto -flto-partition=1to1 
+FAIL: gfortran.dg/lto/pr87689 f_lto_pr87689_0.o-f_lto_pr87689_1.o link, -O2
-flto -flto-partition=none 

I'm seeing it on 32 and 64-bit Solaris/SPARC and x86, but according to
gcc-testresults
it happens everywhere.  The link succeeds actually, but there's a warning:

In function ‘MAIN__’,
    inlined from ‘main’ at
/vol/gcc/src/hg/trunk/local/gcc/testsuite/gfortran.dg/lto/pr87689_0.f:13:0:
/vol/gcc/src/hg/trunk/local/gcc/testsuite/gfortran.dg/lto/pr87689_0.f:10:
warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
/vol/gcc/src/hg/trunk/local/gcc/testsuite/gfortran.dg/lto/pr87689_0.f: In
function ‘main’:
/vol/gcc/src/hg/trunk/local/gcc/testsuite/gfortran.dg/lto/pr87689_0.f:7:22:
note: at offset 1 to object ‘c’ with size 1 declared here

during the link step.  It seems plausible that this is due to

2019-12-13  Martin Sebor  <msebor@redhat.com>

        PR middle-end/91582
        PR middle-end/92868