[Bug tree-optimization/31029] New: missed otimization

[jv244 at cam dot ac dot uk]

the following is tiny missed optimization, as it fails to link at -O3

read(5,*) igmin
DO ig=igmin,0
   ig2=1-ig
   if (ig.EQ.ig2) CALL link_error()
ENDDO
END

since ig can only have values in the interval [-huge,0], ig2 can only have
values in [1,huge] and so ig can never be equal to ig2. Code similar to this
appears in PR 31021


-- 
           Summary: missed otimization
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jv244 at cam dot ac dot uk


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31029