Sender: graham AT delorie DOT com Message-ID: <37374C32.4D12565A@home.com> Date: Mon, 10 May 1999 14:14:26 -0700 From: Graham TerMarsch Organization: Internet specialist for hire. X-Mailer: Mozilla 4.51 [en] (X11; I; Linux 2.2.7 i586) X-Accept-Language: en MIME-Version: 1.0 To: pgcc AT delorie DOT com Subject: What types of optimizations are present for the K6? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: pgcc AT delorie DOT com Have been trying out pgcc here on my K6-III system to see if I could actually see any performance improvement out of optimizing my compiles for this processor. I've tried '-mk6' and '-march=k6', but have only found the effect that it actually generates _slower_ code than egcs-1.1.2 does. With 'gzip', pgcc generated code that ran about 5% slower on a 50MB file than the equivalent egcs version. After that, figured that I'd try something more demanding, and recompiled XFree86 under pgcc. Ran 'x11perf' a few times and compared the results to what I had with the egcs-1.1.2 version I had installed before, and found that for some of the tests it was up to 10% faster, but on others it was up to 10% slower. So, uh, wanted to find out a bit more about what types of optimizations we're doing for K6 processors, and find out if anyone had other tips on cmd line args that I can pass to pgcc to try to squeeze every last little ounce out of this machine. FWIW, both the 'gzip' and 'xfree86' compiles were done with '-O2' for both egcs and pgcc compiles. -- Graham TerMarsch // ----------------------------------------------------------------- // A yawn is a silent shout. -- G.K. Chesterton // -----------------------------------------------------------------