[Bug debug/100523] New: [11/12 Regression] armv8.1-m.main -fcompare-debug failure with -O -fmodulo-sched -mtune=cortex-a53

[acoplan at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100523

            Bug ID: 100523
           Summary: [11/12 Regression] armv8.1-m.main -fcompare-debug
                    failure with -O -fmodulo-sched -mtune=cortex-a53
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: acoplan at gcc dot gnu.org
  Target Milestone: ---

The following fails:

$ cat test.c
int main_j;
int main() {
  long crc;
  for (; main_j; main_j--)
    if (crc)
      crc = crc >> 1 ^ 20;
}
$ ./arm-eabi-gcc -c test.c -fcompare-debug -O -fmodulo-sched
-march=armv8.1-m.main -mfloat-abi=soft -mtune=cortex-a53
arm-eabi-gcc: error: test.c: '-fcompare-debug' failure

Obviously the choice of scheduling isn't sensible for this -march, but it
reveals a bug in any case.