7 nov 2010 kl. 22.50 skrev Justin Lebar: >> check_for_temporal_macros could stop searching if both macros have been >> found? >> I cannot tell if doing that would make any real difference. > > We could certainly do that, although I don't think it would help much. > If your code has lots of __TIME__s, you're screwed anyway. :) >
Right! > On Sun, Nov 7, 2010 at 1:47 PM, Anders Furuhed > <anders.furu...@pantor.com> wrote: >> Hi, >> >> check_for_temporal_macros could stop searching if both macros have been >> found? >> I cannot tell if doing that would make any real difference. >> >> Regards, >> Anders >> >> 7 nov 2010 kl. 22.13 skrev Justin Lebar: >> >>> This patch is a followup to the discussion in "Questions about two hot >>> functions in ccache". >>> >>> On my machine, the patch speeds up direct mode cache hits by about a >>> factor of 1.7 for the c++_includes.cc test file. My benchmark of >>> |make clean && time make| in Mozilla's docshell/base went from 1.04s >>> (git master) to 0.64s, a 1.63x speedup. >>> >>> Full output from ../perf.py on c++_includes.cc is included below. >>> >>> I suspect we could use the fast_hash function for preprocessor mode >>> without much work. I also suspect that switching to a smarter >>> algorithm for searching for "#include" would decrease the cost of >>> cache misses. But I haven't profiled either of these cases. >>> >>> I'm a bit concerned about the fact that I had to change the reported >>> file lengths in the manifest test (in test.sh). I'm not sure what's >>> going on here; I may well have messed something up. Hopefully not. >>> :) >>> >>> -Justin >>> >>> $ ../perf.py -n10 --hit-factor=10 --ccache=../ccache gcc-4.5 c++_includes.cc >>> Compilation command: gcc-4.5 c++_includes.cc -c -o c++_includes.o >>> Compilercheck: mtime >>> Compression: off >>> Hardlink: off >>> Nostats: off >>> >>> * git master (9cdd1154) >>> Without ccache: 3.55 s (100.00 %) ( 1.00 x) >>> With ccache, preprocessor mode, cache miss: 4.16 s (117.10 %) ( 0.85 x) >>> With ccache, preprocessor mode, cache hit: 0.87 s ( 24.51 %) ( 4.08 x) >>> With ccache, direct mode, cache miss: 4.22 s (118.98 %) ( 0.84 x) >>> With ccache, direct mode, cache hit: 0.15 s ( 4.36 %) (22.92 x) >>> >>> * patched >>> Without ccache: 3.53 s (100.00 %) ( 1.00 x) >>> With ccache, preprocessor mode, cache miss: 4.13 s (116.90 %) ( 0.86 x) >>> With ccache, preprocessor mode, cache hit: 0.86 s ( 24.25 %) ( 4.12 x) >>> With ccache, direct mode, cache miss: 4.15 s (117.55 %) ( 0.85 x) >>> With ccache, direct mode, cache hit: 0.09 s ( 2.47 %) (40.43 x) >>> >>> * Speedup: = .15 / .09 = 1.7x >>> <diff>_______________________________________________ >>> ccache mailing list >>> ccache@lists.samba.org >>> https://lists.samba.org/mailman/listinfo/ccache >> >> Anders Furuhed >> Pantor Engineering AB >> +46 8 412 9781 >> >> Anders Furuhed Pantor Engineering AB +46 8 412 9781 _______________________________________________ ccache mailing list ccache@lists.samba.org https://lists.samba.org/mailman/listinfo/ccache