Byte Permute Doubleword
Returns the result of a bit permutation operation.
long long __bpermd (long long bit_selector, long long source);
Eight bits are returned, each corresponding to a bit within source, and were selected by a byte of bit_selector. If byte i of bit_selector is less than 64, the permuted bit i is set to the bit of source specified by byte i of bit_selector; otherwise the permuted bit i is set to 0. The permuted bits are placed in the least-significant byte of the result value and the remaining bits are filled with 0s.
Valid only when -qarch is set to target POWER7 processors in 64-bit mode.