lapack fails the testsuite on ppc64el when built with -O3

[Matthias Klose]

lapack fails the testsuite on ppc64el when built with -O3. works with -O2

see https://launchpad.net/ubuntu/+source/lapack/3.7.1-1ubuntu2/+build/13199126

[Joel Stanley (shenki)]

The failing tests:

 ******* FATAL ERROR - COMPUTED RESULT IS LESS THAN HALF ACCURATE *******
                       EXPECTED RESULT COMPUTED RESULT
       1 ( 0.277223 , -0.348651 ) ( 0.110137E+13, 0.164627E+13)
       2 ( 0.806693 , -0.492507 ) ( -0.940210E+09, 0.547188E+12)
       3 ( 0.966533 , 0.442557 ) ( -0.275106E+12, -0.136729E+10)
       4 ( 0.00000 , 0.00000 ) ( -0.452662E+20, -0.498356E+20)
       5 ( 0.926573 , 0.106893 ) ( 0.197802E+20, -0.154845E+20)
       6 ( 0.956543 , -0.100899 ) ( 0.239256E+09, -0.503443E+10)
       7 ( 0.686813 , -0.156843 ) ( 0.176324E+10, 0.214785E+09)
       8 ( 0.247253 , -0.292707 ) ( 0.247253 , -0.292707 )
       9 ( 0.774226E-01, 0.989011E-01) ( 0.774226E-01, 0.989011E-01)
 ******* CTRSV FAILED ON CALL NUMBER:
    195: CTRSV ('U','N','U', 9, A, 10, X, 2) .

 CTBSV PASSED THE TESTS OF ERROR-EXITS

 CTBSV PASSED THE COMPUTATIONAL TESTS ( 961 CALLS)

 CTPSV PASSED THE TESTS OF ERROR-EXITS

 ******* FATAL ERROR - COMPUTED RESULT IS LESS THAN HALF ACCURATE *******
                       EXPECTED RESULT COMPUTED RESULT
       1 ( 0.277223 , -0.348651 ) ( 0.110137E+13, 0.164627E+13)
       2 ( 0.806693 , -0.492507 ) ( -0.940210E+09, 0.547188E+12)
       3 ( 0.966533 , 0.442557 ) ( -0.275106E+12, -0.136729E+10)
       4 ( 0.00000 , 0.00000 ) ( -0.452662E+20, -0.498356E+20)
       5 ( 0.926573 , 0.106893 ) ( 0.197802E+20, -0.154845E+20)
       6 ( 0.956543 , -0.100899 ) ( 0.239256E+09, -0.503443E+10)
       7 ( 0.686813 , -0.156843 ) ( 0.176324E+10, 0.214785E+09)
       8 ( 0.247253 , -0.292707 ) ( 0.247253 , -0.292707 )
       9 ( 0.774226E-01, 0.989011E-01) ( 0.774226E-01, 0.989011E-01)
 ******* CTPSV FAILED ON CALL NUMBER:
    195: CTPSV ('U','N','U', 9, AP, X, 2) .