On Sat, Jun 2, 2012 at 6:06 PM, Jan Hubicka <hubi...@ucw.cz> wrote: >> On Sat, Jun 2, 2012 at 2:36 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >> >> Hi, >> >> >> >> This patch adds 4 flags to enable user to type in a list of name >> >> patterns. Compiler will match the function name with the given >> >> patterns, and add "hot", "cold", "likely_hot", "likely_cold" >> >> attributes to function declaration. The static branch prediction >> >> checks if a basic block contains call to a annotated function, and set >> >> the branch probability accordingly. >> >> >> >> Bootstrapped and passed gcc testsuites. >> >> >> >> Ok for google branches? >> > >> > Just out of curiosity, what is main advantage of this over annotating your >> > source? >> > >> >> This is to avoid too much annotation at source level. Some >> applications have good per application knowledge of library functions >> (that are compiled and statically linked in). Another example of its >> -- coarse grain (function level) profile data collected from data >> center can be used to guide branch prediction/estimation. > > Well, perhaps the feature would be more useful with command line option > allowing > to add an attribute instead of having special case command line options for > individual > cases.
Hi, Honza, I'm not sure what you mean by "command line option allowing to add an attribution". But this seems what this patch does: it adds attributes to functions with specified name patterns. > I guess the problem would be also solvable with header included after > the library adding the attributes to the declarations > > typeof (printf) printf __attribute__ ((cold)); Do you mean that for each specific application, we extract a common header file to include all function annotations, and all source files will include this header file? Thanks, Dehao > > Honza >> >> thanks, >> >> David >> > Honza
