https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68649
Bug ID: 68649 Summary: note: code may be misoptimized unless -fno-strict-aliasing is used Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end Assignee: unassigned at gcc dot gnu.org Reporter: Joost.VandeVondele at mat dot ethz.ch Target Milestone: --- Today's trunk produces a lot of warnings / notes all referring to functions from libgfortran, when compiling CP2K with LTO. I'm looking at generating a reduced testcase, but the first obvious tries didn't work. /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/dbcsr_lib/dbcsr_block_access_c.F:709:0: note: ‘_gfortran_reshape_c4’ was previously declared here data_block%p(:,:) = RESHAPE (block, (/row_size, col_size/)) /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/dbcsr_lib/dbcsr_block_access_c.F:709:0: note: code may be misoptimized unless -fno-strict-aliasing is used /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/helium_methods.F:1071:0: warning: type of ‘_gfortran_unpack1’ does not match original declaration [-Wlto-type-mismatch] helium%pos(:,:,:) = UNPACK(message(offset+1:offset+msglen), MASK=m, FIELD=f ) /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/helium_methods.F:1699:0: warning: type of ‘_gfortran_unpack1’ does not match original declaration [-Wlto-type-mismatch] helium%rho_rstr(:,:,:,:) = UNPACK(message(1:msglen), MASK=m, FIELD=f) /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/helium_methods.F:1547:0: note: ‘_gfortran_unpack1’ was previously declared here ig(:,:) = UNPACK(message(offset+33:offset+38), MASK=m, FIELD=f ) /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/helium_methods.F:1547:0: note: code may be misoptimized unless -fno-strict-aliasing is used /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/dbcsr_lib/dbcsr_block_access_s.F:709:0: warning: type of ‘_gfortran_reshape_r4’ does not match original declaration [-Wlto-type-mismatch] data_block%p(:,:) = RESHAPE (block, (/row_size, col_size/)) /data/vjoost/gnu/cp2k/cp2k/makefiles/../src/dbcsr_lib/dbcsr_block_access_s.F:709:0: warning: type of ‘_gfortran_reshape_r4’ does not match original declaration [-Wlto-type-mismatch]