[Bug bootstrap/38591] New: erratic comparison failures on very fast machines

[ebotcazou at gcc dot gnu dot org]

Since we started building the 4.3.x compiler on very fast Linux machines (bi-
quad cores) we have observed erratic but consistent comparison failures, say
a handful of times a month.  The problematic file is always the same:

Comparing stages 2 and 3
Bootstrap comparison failure!
./sparseset.o differs
make[2]: *** [compare] Error 1

The stage 3 object file is not compiled as it should be; in fact, it can be
obtained manually by changing

#define ENABLE_ASSERT_CHECKING 1

to

/* #undef ENABLE_ASSERT_CHECKING */

in gcc/auto-host.h.

so there might be a race condition somewhere in the top-level bootstrap (note
that we have never built 4.2.x on the same machines).


-- 
           Summary: erratic comparison failures on very fast machines
           Product: gcc
           Version: 4.3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ebotcazou at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38591