https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102192
Bug ID: 102192 Summary: Curious '-O2'-only '-Wmaybe-uninitialized' diagnostics for 'libgomp.oacc-fortran/routine-10.f90' Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: tschwinge at gcc dot gnu.org CC: burnus at gcc dot gnu.org Blocks: 24639 Target Milestone: --- The 'libgomp.oacc-fortran/routine-10.f90' test case as originally added in commit 12df77ab6df4b91d4770240bcc4ab443e4bb18b9 shows curious '-Wmaybe-uninitialized' diagnostics. Now, of course this is '-Wmaybe-uninitialized', so may easily be dismissed "don't care", but maybe there's something to be improved here? For standard host compilation (no '-fopenacc'), but only with '-O2', we get diagnosed: libgomp.oacc-fortran/routine-10.f90:28:21: Warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] libgomp.oacc-fortran/routine-10.f90:21:50: note: ‘c’ was declared here libgomp.oacc-fortran/routine-10.f90:46:30: Warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] libgomp.oacc-fortran/routine-10.f90:21:50: note: ‘c’ was declared here Not seeing this with any other '-O[...]' level, and also goes away with '-O2 -fno-inline', for example. Have not quickly been able to reproduce with '-O3' plus various '-fno-[...]. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639 [Bug 24639] [meta-bug] bug to track all Wuninitialized issues