generateLen

    fn generateLen(smith: *Smith, will_memset: bool) usize {
        @disableInstrumentation();

        // 1 << 24 indicates to generate an unweighted usize.
        // 1 << 25 indicates to provide a value relative to the maximum usize.
        const len = smith.valueWeightedWithHash(
            u32,
            if (!will_memset) comptime &.{
                // zig fmt: off
                .rangeLessThan(u32, 1      , 1 << 6 , 1 << 15), // 2^21 - 2^4 times below so 16x odds
                .rangeLessThan(u32, 1 <<  6, 1 << 17, 1      ), // 2^17 - 2^4 times below so 16x odds
                .value        (u32, 1 << 24,          1 << 12), // 2^12
                .value        (u32, 1 << 25,          1 << 12), // 2^12
                // zig fmt: on
            } else comptime &.{
                // zig fmt: off
                .rangeLessThan(u32, 1      , 1 <<  6, 1 << 17), // 2^23 - 2^6 times below so 64x odds
                .rangeLessThan(u32, 1 <<  6, 1 << 17, 1      ), // 2^17 - 2^6 times below so 64x odds
                .value        (u32, 1 << 24,          1 << 10), // 2^10
                .value        (u32, 1 << 25,          1 << 10), // 2^10
                // zig fmt: on
            },
            // Give the fuzzer different hashes when the weights used differ
            // so that it does not reuse values from other probabilities.
            if (!will_memset) 0x38a74424 else 0xec581ff0,
        );

        if (len == 1 << 24) return @max(1, smith.value(usize));
        if (len == 1 << 25) return @as(usize, math.maxInt(usize)) - smith.value(u16);
        return len;
    }