https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100866
--- Comment #7 from Jens Seifert <jens.seifert at de dot ibm.com> --- Regarding vec_revb for vector unsigned int. I agree that revb: .LFB0: .cfi_startproc vspltish %v1,8 vspltisw %v0,-16 vrlh %v2,%v2,%v1 vrlw %v2,%v2,%v0 blr works. But in this case, I would prefer the vperm approach assuming that the loaded constant for the permute vector can be re-used multiple times. But please get rid of the xxlnor 32,32,32. That does not make sense after loading a constant. Change the constant that need to be loaded.