------- Comment #6 from rguenther at suse dot de 2007-12-10 17:13 ------- Subject: Re: non-optimal inlining heuristics pessimizes gzip SPEC score at -O3
On Mon, 10 Dec 2007, ubizjak at gmail dot com wrote: > (In reply to comment #4) > > > Fair enough. It looks that this problem is specific to Core2. > > Here are timings with 'gcc version 4.3.0 20071201 (experimental) [trunk > revision 130554] (GCC)' on > > vendor_id : GenuineIntel > cpu family : 6 > model : 15 > model name : Intel(R) Core(TM)2 CPU X6800 @ 2.93GHz > stepping : 5 > cpu MHz : 2933.389 > cache size : 4096 KB > > -mtune=generic -m32 -O3: 40.763s [*] > -mtune=generic -m32 -O2: 32.170s > -mtune=core2 -m32 -O3 : 36.850s > -mtune=core2 -m32 -O2 : 32.170s > > -mtune=generic -m64 -O3: 28.550s > -mtune=generic -m64 -O2: 28.682s > -mtune=core2 -m64 -O3 : 28.670s > -mtune=core2 -m64 -O2 : 28.714s > > With __attribute__((noinline)) to longest_match(): > > -mtune=generic -m32 -O3: 30.658s > -mtune=generic -m32 -O2: 32.154s > -mtune=core2 -m32 -O3 : 30.690s > -mtune=core2 -m32 -O2 : 32.247s > > And with FC6 system compiler 'gcc version 4.1.1 20061011 (Red Hat 4.1.1-30)': > > -mtune=generic -m32 -O3: 30.154s [**] > -mtune=generic -m32 -O2: 30.275s > > Comparing [*] to [**], it _is_ a regression, at least on Core2. FSF GCC 4.1 does not have -mtune=generic. Richard. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33761