How to detect bit 1 in a series of bit from left to right? (in normalization matissa)

[Nhan95]

I design a floating point multiplication. After multiplying the mantissa of multiplicand and multiplier is the normalize step. I need to detect the first bit 1 from left to right of a 48-bit series.
For example:
01 01010110000000000000000 0000000000000000000000
from left to right, i detect bit 1 and get 23 bit behind to achive the mantissa of result is:
01010110000000000000000
How do I do that by combination logic circuit ? thanks so much

 

[FvM]

Write a behavioral description and make the synthesis tool do the work for you.

The combinational shift will end up in a huge mux array anyway.