Hi Samba
I noticed that the crc32 function in lib/crc32.c is somewhat
inefficient. This little patch will reduce the inner loop from 10
instructions to 8 instructions on x86 with gcc. gcc can't figure
out this simple optimization by itself on x86.
Further optimization is possible by using the impl. in the linux 2.5 kernel, but
I don't know if it is worth it. Is crc32 common in samba? What would the
typical
buffer len be?
Jocke
Patch against 2_2_8 CVS:
--- lib/crc32.c Sat Oct 20 23:23:35 2001
+++ lib/crc32.c.new Tue May 13 14:45:31 2003
@@ -60,7 +60,7 @@
uint32 crc=0xffffffff;
int i;
for(i=0;i<count;i++)
- crc = (crc>>8) ^ CRCTable[(buffer[i] ^ crc) & 0xff];
+ crc = CRCTable[(buffer[i] ^ crc) & 0xff] ^ (crc>>8);
crc^=0xffffffff;
DEBUG(10,("crc32_calc_buffer: %x\n", crc));
dump_data(100, buffer, count);