On K, 2005-05-18 at 10:24 +0300, Hannu Krosing wrote: > On T, 2005-05-17 at 22:37 -0400, Tom Lane wrote: > > Bruce Momjian <pgman@candle.pha.pa.us> writes: > > > I don't understand why we are testing 64-bit CRC when I thought we > > > agreed that 32-bit was good enough for our purposes. > > > > Well, we need to understand exactly what is going on here. I'd not > > like to think that we dropped back from 64 to 32 bit because of one > > possibly-minor optimization bug in one compiler on one platform. > > Even if that compiler+platform is 90% of the market. > > There are cases where 32bit is about 20% slower. > > I tried to send the folowing yesterday, but for some reason the mails I > send from home where To: is Tom Lane get errors from > "RCPT:[EMAIL PROTECTED] " and fail to go through to other destinations > (like pgsql-hackers) after that :( > -----
the same difference between 32bit and 64bit CRC when compiled as 64bit exe is there also on ibms own compiler (vac xlc 7.0) [EMAIL PROTECTED] ~]$ c99 -O5 -qarch=pwr5 -qtune=pwr5 -qsmp=omp -qunroll=yes -q64 crctest64.c -o crctest64_c99_64 [EMAIL PROTECTED] ~]$ ./crctest64_c99_64 Result of CRC64 (10000 runs): 782104059a01660 in time 0.545042 s [EMAIL PROTECTED] ~]$ c99 -O5 -qarch=pwr5 -qtune=pwr5 -qsmp=omp -qunroll=yes\ -q64 crctest.c -o crctest_c99_64 [EMAIL PROTECTED] ~]$ ./crctest_c99_64 Result of CRC64 (10000 runs): 7821040 (high), 59a01660 (low) in time 0.644319 s > -- Hannu Krosing <[EMAIL PROTECTED]> ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
