Date: Wed, 19 Jan 2011 08:47:52 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Roman Divacky <rdivacky@freebsd.org> Cc: freebsd-toolchain@freebsd.org Subject: Re: How to build an executable with profiling? Message-ID: <20110119164752.GB13969@troutmask.apl.washington.edu> In-Reply-To: <20110119104448.GA15730@freebsd.org> References: <20110117184411.GA54556@troutmask.apl.washington.edu> <20110118143205.GA34216@freebsd.org> <20110118144313.GO2518@deviant.kiev.zoral.com.ua> <20110118171657.GA68321@freebsd.org> <20110118173517.GA60201@troutmask.apl.washington.edu> <20110118211200.GA3586@freebsd.org> <4D36BA6E.5030202@iae.nl> <20110119104448.GA15730@freebsd.org>
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On Wed, Jan 19, 2011 at 11:44:48AM +0100, Roman Divacky wrote: > On Wed, Jan 19, 2011 at 11:18:22AM +0100, Hans Ottevanger wrote: > > On 01/18/11 22:12, Roman Divacky wrote: > > >On Tue, Jan 18, 2011 at 09:35:17AM -0800, Steve Kargl wrote: > > >>On Tue, Jan 18, 2011 at 06:16:57PM +0100, Roman Divacky wrote: > > >>>On Tue, Jan 18, 2011 at 04:43:13PM +0200, Kostik Belousov wrote: > > >>>>On Tue, Jan 18, 2011 at 03:32:05PM +0100, Roman Divacky wrote: > > >>>>>On Mon, Jan 17, 2011 at 10:44:11AM -0800, Steve Kargl wrote: > > >>>>>>How does one build an executable for profiling with clang? > > >>>>> > > >>>>>LLVM (and thus clang) does not support GPROF profiling. > > >>>>> > > >>>>>>clang -o testf -O2 -march=native -pipe -static -pg > > >>>>>>-I/usr/local/include -I../mp testf.c -L/usr/local/lib -L../mp -lsgk > > >>>>>>-lmpfr -lgmp -L/usr/home/kargl/work/lib -lm_clang_p > > >>>>>>clang: warning: the clang compiler does not support '-pg' > > >>>>>> > > > > If you are really desperate to find the hotspots in your program when > > compiled with clang, you could call clang with -v to find the call to > > /bin/ld. Then append _p to the appropriate libs if still needed and > > replace crt1.o by gcrt1.o while calling ld directly. E.g. > > > > "/usr/bin/ld" -Bstatic -o testcoll /usr/lib/gcrt1.o /usr/lib/crti.o > > /usr/lib/crtbegin.o testcoll.o angle.o apsis.o error.o minmax.o qags.o > > qext.o qk21.o sort.o timint.o zero.o vmol.o -lm_p -lgcc -lgcc_eh -lc_p > > -lgcc -lgcc_eh -t /usr/lib/crtend.o /usr/lib/crtn.o > > > > You will get a profile without the number of calls for the objects > > compiled with clang, but with the time spent. In my case: > > > > granularity: each sample hit covers 4 byte(s) for 0.00% of 6.41 seconds > > > > % cumulative self self total > > time seconds seconds calls ms/call ms/call name > > 30.3 1.94 1.94 0 100.00% f_timint [2] > > 20.2 3.24 1.29 0 100.00% _mcount [3] > > 19.4 4.48 1.24 21900000 0.00 0.00 exp [4] > > 13.2 5.32 0.85 0 40.51% vmol [1] > > 7.3 5.79 0.47 0 100.00% f_angle [5] > > 2.8 5.98 0.18 1000000 0.00 0.00 pow [7] > > 2.7 6.15 0.17 0 48.70% qk21 [6] > > 2.4 6.30 0.15 0 100.00% .mcount (51) > > 0.5 6.33 0.03 0 100.00% zero [8] > > 0.4 6.35 0.02 0 100.00% qext [9] > > 0.4 6.38 0.02 0 100.00% qags [10] > > ... > > hm.. this is interesting. I wonder if it makes sense to teach the > driver about this (it's a trivial change). opinions? > I believe that this does not address the issue. The issue is how does one create libm_p.c and libc_p.c with clang. -- Steve
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