[Bug middle-end/106534] New: [13 Regression][gcn] ICE 'verify_ssa failed' / 'error: definition in block 18 does not dominate use in block 19' during libgfortran bootstrap

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106534

            Bug ID: 106534
           Summary: [13 Regression][gcn] ICE 'verify_ssa failed' / 'error:
                    definition in block 18 does not dominate use in block
                    19' during libgfortran bootstrap
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: build, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
                CC: ams at gcc dot gnu.org
  Target Milestone: ---
            Target: amdgcn-amdhsa

Build of amdgcn-amdhsa (as offloading compiler for/on x86_64-gnu-linux) fails
to build as follows. It did bootstrap successfully a few days back (like Aug 2
or 3):


src/gcc-mainline/libgfortran/io/unit.c: In function 'get_gfc_unit':
src/gcc-mainline/libgfortran/io/unit.c:326:1: error: definition in block 18
does not dominate use in block 19
  326 | get_gfc_unit (int n, int do_create)
      | ^~~~~~~~~~~~
for SSA_NAME: p_47 in statement:
p_30 = PHI <p_47(19), p_47(38)>
PHI argument
p_47
for PHI node
p_30 = PHI <p_47(19), p_47(38)>
during GIMPLE pass: phiopt
/scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/libgfortran/io/unit.c:326:1:
internal compiler error: verify_ssa failed