New PowerPC 7400 Code

[Brendan Younger]

Hi,
I've improved the mpn_lshift code for the PowerPC 7400 class of 
processors.  Note that this code is specific to Motorola's G4 (7400, 
7410, 7450, 7455, and up) processors and will not work on a generic 
PowerPC.  It takes advantage of the AltiVec instructions to give a 
speedup of 2x for non-bandwidth bound operations and a speedup of about 
30-40% for bandwidth bound operations.  The two files I'm sending are 
the C-code for the function and the assembler version.  On gcc 3.1, the 
C-code is just as fast as the assembler when the size of the arguments 
is fairly small and only slightly slower (10-15%) when the arguments 
are large.  Please note that I'm not a terribly good assembly 
programmer so there might be some speed gains of about 15% to be had 
from going over my code and tweaking it as necessary.  If you have any 
questions or requests, you can reach me at address@hidden

Brendan Younger

mpn_lshift.c
Description: Text document

mpn_lshift.s
Description: Binary data