On Wed, Aug 31, 2022 at 05:33:28PM +0800, Kewen.Lin wrote: > Test case bswap64-4.c suffers the issue as its comments: > > /* On some versions of dejagnu this test will fail when > biarch testing with RUNTESTFLAGS="--target_board=unix > '{-m64,-m32}'" due to -m32 being added on the command > line after the dg-options -mpowerpc64. > common/config/rs6000/rs6000-common.c: > rs6000_handle_option disables -mpowerpc64 for -m32. */ > > As tested, on test machine with dejaGnu 1.6.2, the compilation > option order looks like: -m32 ... -mpowerpc64, option > -mpowerpc64 still takes effect; While on test machine with > dejaGnu 1.5.1, the option order looks like: -mpowerpc64 ... -m32, > option -mpowerpc64 is disabled by -m32, then the case fails.
*Should* -mpowerpc64 be disabled by -m32? Should *any* explicit command line flag ever be disabled like that? (Not talking about things like -m32 -m64, this should be supported for convenience). -mpowerpc64 -m32 should always mean the same as -m32 -mpowerpc64, that's the principle of least surprise. Where then dg-options is placed does not matter in this testcase, both -m32 -mno-powerpc64 and -m32 -mpowerpc64 are ilp32. Segher