Add macros that implement the vec_extract4b and vec_insert4b functionality.
vector unsigned long long vec_extract4b (vector unsigned char, const int)
Extracts a word from a vector at a byte position.
The first doubleword element of the result contains the zero-extended extracted word from ARG1. The second doubleword is set to 0. ARG2 specifies the least-significant byte number (0 - 12) of the word to be extracted
vector unsigned char vec_insert4b (vector signed int, vector unsigned char, const int)
vector unsigned char vec_insert4b (vector unsigned int, vector unsigned char, const int)
Inserts a word into a vector at a byte position.
The contents of word element 1 of the first argument are extracted and placed into argument 2. The word is inserted into argument 2 starting at the byte offset indicated by the third argument.