On 8/17/21 7:50 PM, Alex Murray wrote:
How about letting the compiler choose which prime to use? - something like the
following:
#define H15_PRIME (unsigned long long)5381
#define H32_PRIME (unsigned long long)3657500101
#define H64_PRIME (unsigned long long)4123221751654370051
size_t h = H64_PRIME <= SIZE_MAX ? H64_PRIME : H32_PRIME <= SIZE_MAX ?
H32_PRIME : H15_PRIME;
That's equivalent to the patch I suggested; on my platform it even
generates the same machine code. It's better to avoid macros when that's
easy, as is the case here.
I installed the patch, except with uint_fast64_t instead of unsigned
long long int as that's a better type for the 64-bit constants in
question. (In case you're wondering what that "_fast" is doing there,
POSIX and the C standard guarantee the existence of uint_fast64_t but
not of uint64_t, as a concession to Unisys mainframes where long long is
72 bits.)
