tests/qht-bench: Adjust threshold computation
In
06c4cc3660b3, we split the multiplication in two parts to avoid
a clang warning. But because double still rounds to 53 bits, this
does not provide additional precision beyond multiplication by
nextafter(0x1p64, 0), the largest representable value smaller
than 2**64.
However, since we have eliminated 1.0, mutiplying by 2**64 produces
a better distribution of input values to the output values.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <
20200626200950.
1015121-3-richard.henderson@linaro.org>