https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68649
Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hubicka at gcc dot gnu.org,
| |Joost.VandeVondele at mat dot
ethz
| |.ch
Summary|note: code may be |[6 Regression] note: code
|misoptimized unless |may be misoptimized unless
|-fno-strict-aliasing is |-fno-strict-aliasing is
|used |used
--- Comment #1 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch>
---
testcase
> cat foo.f90
SUBROUTINE s8(a8,b8)
REAL*8 :: a8(16),b8(4,4)
a8=RESHAPE(b8,(/16/))
b8=RESHAPE(a8,(/4,4/))
END SUBROUTINE
REAL*8 :: a8(16),b8(4,4)
CALL RANDOM_NUMBER(b8)
CALL s8(a8,b8)
WRITE(6,*) MAXVAL(a8),MAXVAL(b8)
END
> gfortran -flto -O3 foo.f90
foo.f90:3:0: warning: type of ‘_gfortran_reshape_r8’ does not match original
declaration [-Wlto-type-mismatch]
a8=RESHAPE(b8,(/16/))
foo.f90:4:0: note: ‘_gfortran_reshape_r8’ was previously declared here
b8=RESHAPE(a8,(/4,4/))
foo.f90:4:0: note: code may be misoptimized unless -fno-strict-aliasing is used
