On Tue, May 05, 2020 at 03:54:57PM +0200, Arnd Bergmann wrote: > Clang normally does not warn about certain issues in inline functions when > it only happens in an eliminated code path. However if something else > goes wrong, it does tend to complain about the definition of hweight_long() > on 32-bit targets: > > include/linux/bitops.h:75:41: error: shift count >= width of type > [-Werror,-Wshift-count-overflow] > return sizeof(w) == 4 ? hweight32(w) : hweight64(w); > ^~~~~~~~~~~~ > include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro > 'hweight64' > define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : > __arch_hweight64(w)) > ^~~~~~~~~~~~~~~~~~~~ > include/asm-generic/bitops/const_hweight.h:21:76: note: expanded from macro > '__const_hweight64' > define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> > 32)) > ^ > ~~ > include/asm-generic/bitops/const_hweight.h:20:49: note: expanded from macro > '__const_hweight32' > define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> > 16)) > ^ > include/asm-generic/bitops/const_hweight.h:19:72: note: expanded from macro > '__const_hweight16' > define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> > 8 )) > ^ > include/asm-generic/bitops/const_hweight.h:12:9: note: expanded from macro > '__const_hweight8' > (!!((w) & (1ULL << 2))) + \ > > Adding an explicit cast to __u64 avoids that warning and makes it easier > to read other output. > > Signed-off-by: Arnd Bergmann <a...@arndb.de> > ---
Acked-by: Christian Brauner <christian.brau...@ubuntu.com>
