[Bug tree-optimization/45578] [4.6 Regression] The polyhedron test mdbx is miscompiled with -O2 -ftree-vectorize at revision 163915

["dominiq at lps dot ens dot fr" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #3 from dominiq at lps dot ens dot fr  2010-09-07 14:25 -------
If I replace the loop

      DO i = 1 , MOLsa
         X0(1,i) = X0(1,i) - cm1
         X0(2,i) = X0(2,i) - cm2
         X0(3,i) = X0(3,i) - cm3
         XIN(1,i) = XIN(1,i) - cm1
         XIN(2,i) = XIN(2,i) - cm2
         XIN(3,i) = XIN(3,i) - cm3
      ENDDO

with

      X0(1,1) = X0(1,1) - cm1
      X0(2,1) = X0(2,1) - cm2
      X0(3,1) = X0(3,1) - cm3
      XIN(1,1) = XIN(1,1) - cm1
      XIN(2,1) = XIN(2,1) - cm2
      XIN(3,1) = XIN(3,1) - cm3
      DO i = 2 , MOLsa
         X0(1,i) = X0(1,i) - cm1
         X0(2,i) = X0(2,i) - cm2
         X0(3,i) = X0(3,i) - cm3
         XIN(1,i) = XIN(1,i) - cm1
         XIN(2,i) = XIN(2,i) - cm2
         XIN(3,i) = XIN(3,i) - cm3
      ENDDO

the code is correctly compiled.


-- 

dominiq at lps dot ens dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.6 Regression] The        |[4.6 Regression] The
                   |polyhedron test mdbx is     |polyhedron test mdbx is
                   |miscompiled with -O2 -ftree-|miscompiled with -O2 -ftree-
                   |vectorize at revision 163940|vectorize at revision 163915


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45578