[Bug middle-end/57192] New: [4.9 Regression] miscompilation at -O3

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57192



             Bug #: 57192

           Summary: [4.9 Regression] miscompilation at -O3

    Classification: Unclassified

           Product: gcc

           Version: 4.9.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: middle-end

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: joost.vandevond...@mat.ethz.ch





Created attachment 30045

  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30045

testcase, reproduce with 'gfortran  -g -O3 orbital_pointers.f90  ; valgrind

./a.out'



For the attached testcase, recently 4.9 trunk started generating the following

error under valgrind:





gfortran  -g -O3 orbital_pointers.f90  ; valgrind ./a.out





==61245== Invalid write of size 4

==61245==    at 0x400EED: __orbital_pointers_MOD_init_orbital_pointers

(orbital_pointers.f90:102)

==61245==    by 0x401B71: main (orbital_pointers.f90:214)

==61245==  Address 0x4da2ee4 is not stack'd, malloc'd or (recently) free'd



when compiled at -O3 . Compiling with 4.8 branch, or 4.9 and -O2 doesn't cause

this behavior. 



It has been reduced from CP2K after observing that CP2K segfaults due to a

change made between rev198568 and rev198590 (but I'm not yet 100% sure this

testcase is the root cause).