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Doing hweight16() and checking whether the lsb is set is functionally equivalent to what bitwise_xor_bits() does. In addition, it results in better generated code as before gcc would inline the function 4 times. With hweight16(), the resulting code boils down to 2 instructions - POPCNT and AND, and all relevant CPUs support POPCNT. An alternative would have been to use the __builtin_parity() function provided by both Clang/GCC, however under some circumstances the compiler can choose not to inline it but generate a library call which is unsupported in the kernel. No functional changes. [ bp: Massage commit message. ] Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20251124142517.1708451-1-nik.borisov@suse.com