On Fri, Mar 25, 2005 at 02:46:04PM -0800, Ed Martini wrote: > Daniel Jacobowitz wrote: > > >On Fri, Mar 25, 2005 at 11:24:05AM -0800, Ed Martini wrote: > > > > > >>1. If the first part of the if were an ifdef instead it would result in > >>a code size reduction as well as a runtime performance gain. > >> > >> > > > >You should spend a little time playing with an optimizing compiler. > >They're capable of working out when a condition will always be false. > > > > > Yes, but in the case where R10000_LLSC_WAR is true, but cpu_has_llsc > returns false there are still two wasted tests, and two blocks of code > that the compiler can't optimize out. Not only is cpu_has_llsc often a constant, R10000_LLSC_WAR will never be true if the CPU does not have LL/SC. -- Daniel Jacobowitz CodeSourcery, LLC
