https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71961
--- Comment #10 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> --- (In reply to Thomas Koenig from comment #9) > With a test case, it would be OK with me if somebody reverted the > patch. I can then rework it to take care of that particular bug. A revert would be good I think.. this is a small testcase showing the wrong results and the missing warning. I suspect it could be matmul specific. > cat test.f90 REAL, DIMENSION(:,:), POINTER :: a REAL, DIMENSION(:,:), ALLOCATABLE :: b ALLOCATE(a(4,4),b(4,2)) CALL RANDOM_NUMBER(a) CALL RANDOM_NUMBER(b) a(1:4,1:2)=MATMUL(a(1:4,1:4),b(1:4,1:2)) WRITE(6,*) a(1,1) END > gfortran -O0 -Warray-temporaries test.f90 ; ./a.out test.f90:6:11: a(1:4,1:2)=MATMUL(a(1:4,1:4),b(1:4,1:2)) 1 Warning: Creating array temporary at (1) [-Warray-temporaries] 0.770401359 > gfortran -O1 -Warray-temporaries test.f90 ; ./a.out 0.515214324