[Bug rtl-optimization/33257] New: guaranteed-true test not optimized away when input values later used

[raeburn at raeburn dot org]

I wrote a simple test of division and remainder results that should always be
true ((a/b)*b+(a%b)==a, with a hardcoded constant for b).  In testing a current
source tree (trunk rev 127954), I found that the test properly went away...
unless I later printed out the quotient and remainder values.  If I passed them
to printf, the test is still performed, even though it can't fail, and its
intermediate values are not used.


-- 
           Summary: guaranteed-true test not optimized away when input
                    values later used
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raeburn at raeburn dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33257