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authorArnd Bergmann <arnd@arndb.de>2020-06-04 16:50:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-04 19:06:25 -0700
commitbd93f003b7462ae39a43c531abca37fe7073b866 (patch)
treecbeb320e8a47a09b0fc35276576c87a1f7aa18e1 /include
parentc348c16305280fe3e6c1186378f96c8634c149f9 (diff)
downloadlinux-bd93f003b7462ae39a43c531abca37fe7073b866.tar.bz2
include/linux/bitops.h: avoid clang shift-count-overflow warnings
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 <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: http://lkml.kernel.org/r/20200505135513.65265-1-arnd@arndb.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/bitops.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 9acf654f0b19..99f2ac30b1d9 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -72,7 +72,7 @@ static inline int get_bitmask_order(unsigned int count)
static __always_inline unsigned long hweight_long(unsigned long w)
{
- return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
+ return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
}
/**