As far as I can tell, the following warning is not dependent on my code, as it's inside a function in count-leading-zeros.h. Warning obtained with GCC 7.3.0:
bits_util.c: In function ‘smite_find_msbit’:
../lib/count-leading-zeros.h:39:26: warning: assuming signed overflow does not occur when simplifying conditional to constant [-Wstrict-overflow]
return x ? BUILTIN (x) : CHAR_BIT * sizeof x;
~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
../lib/count-leading-zeros.h:100:3: note: in expansion of macro ‘COUNT_LEADING_ZEROS’
COUNT_LEADING_ZEROS (__builtin_clzl, _BitScanReverse, unsigned long int);
^~~~~~~~~~~~~~~~~~~
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