Matthias-Christian Ott <matthias.christian@tiscali.de> wrote: > And if you think "register" variables are outdated, please remove the > CONFIG_REGPARM option from the Kernel source. Register variables are outdated because they hinder the compiler from optimizing by taking away 1/7 of the usable registers on x86. Use six register variables and you're back to a accumulator-machine. Use -O2 or -Os instead, the compiler is smarter than you. The regparm calling convention will change the load value -> store value on stack -> call sequence into load value -> call -> store if needed Obviously the second form can be better optimized than the first one. Therefore it's a gain instead of a loss. If you really want to help the compiler, look for something like repeated pointer dereference or access to global variables and cache them in block- local variables (pointers, int and uint only, even for caching chars). Beware of volatile variables, and don't forget to look at the assembler code. -- The generation of random numbers is too important to be left to chance. - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Wed Apr 27 04:23:10 2005
This archive was generated by hypermail 2.1.8 : 2005-04-27 04:23:10 EST