stretch mask - bit manipulation

Question

I want to stretch a mask in which every bit represents 4 bits of stretched mask. I am looking for an elegant bit manipulation to stretch using c++ and systemC

for example:

input:

mask (32 bits) = 0x0000CF00

output:

stretched mask (128 bits) = 0x00000000 00000000 FF00FFFF 00000000

and just to clarify the example let's look at the the byte C:

0xC = 1100 after stretching: 1111111100000000 = 0xFF00

Answer 1

Do this in a elegant form is not easy. The simple mode maybe is create a loop with shift bit

sc_biguint<128> result = 0;
for(int i = 0; i < 32; i++){
    if(bit_test(var, i)){
        result +=0x0F;
    }
    result << 4;
}