util/bufferiszero: Improve scalar variant

Split less-than and greater-than 256 cases.
Use unaligned accesses for head and tail.
Avoid using out-of-bounds pointers in loop boundary conditions.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
1 file changed