Compute the bitwise AND of 256 bits (representing double-precision (64-bit) floating-point
elements) in a and b, producing an intermediate 256-bit value, return 1 if the sign bit of
each 64-bit element in the intermediate value is zero, otherwise return 0.
In other words, return 1 if a and b don't both have a negative number as the same place.
Compute the bitwise AND of 256 bits (representing double-precision (64-bit) floating-point elements) in a and b, producing an intermediate 256-bit value, return 1 if the sign bit of each 64-bit element in the intermediate value is zero, otherwise return 0. In other words, return 1 if a and b don't both have a negative number as the same place.