[Bug tree-optimization/94167] New: pr71109.c -fcompare-debug failures on x86_64 and powerpc64le

[zhroma at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94167

            Bug ID: 94167
           Summary: pr71109.c -fcompare-debug failures on x86_64 and
                    powerpc64le
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhroma at gcc dot gnu.org
  Target Milestone: ---

Running
gcc -O2 -fcompare-debug gcc/testsuite/gcc.c-torture/compile/pr71109.c
fails with recent master on powerpc64le.
I also checked that same happens on x86 with recent 9.3.0 and old 5.5.0 ubuntu.

On master, first dump file with difference is fixup_cfg3

--
I've compared (on powerpc64le) usual regtest results and '-fcompare-debug'
results and there are like ~10 more failures, two of them already reported as
PR94166.

Certainly, there are actually a lot of cases when -fcompare-debug dumps
differs, but .o files have same code, so that can only be catched "manually"
(e.g. using RUNTESTFLAGS="--target_board=unix/-fcompare-debug" or bootstrapping
--with-build-config=bootstrap-debug-lean).  And I'm not sure how much community
bothers about fixing issues like this one.