warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   238650ef6c7c7cca08e032527329424c9fbd70e5
commit: bc87cbdb952e9223616b839d64bdb4723aa2ed1d powerpc: Enable Rust for ppc64le
date:   7 weeks ago
config: powerpc64-randconfig-r2201-20260917 (https://download.01.org/0day-ci/archive/20260917/202609171549.xeqQabC6-lkp@xxxxxxxxx/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
rustc: rustc 1.96.0 (ac68faa20 2026-05-25)
smatch: v0.5.0-9187-g5189e3fb
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260917/202609171549.xeqQabC6-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Fixes: bc87cbdb952e ("powerpc: Enable Rust for ppc64le")
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609171549.xeqQabC6-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`
   |
   = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
   = help: consider filing a feature request
--
>> warning: unstable feature specified for `-Ctarget-feature`: `vsx`
   |
   = note: this feature is not stably supported; its behavior can change in the future
--
>> warning: unknown and unstable feature specified for `-Ctarget-feature`: `hard-float`
   |
   = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
   = help: consider filing a feature request
--
>> warning: unstable feature specified for `-Ctarget-feature`: `altivec`
   |
   = note: this feature is not stably supported; its behavior can change in the future

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki