The obvious improvement is to make your asserts use __builtin_unreachable in "release" mode. So you have something like this: #ifdef DEBUG #define assert(expr) \ if (!(expr)) assertFailed(__FILE__, __LINE__) #else #define assert(expr) \ if (!(expr)) __builtin_unreachable() #endif mvh., David On 23/04/14 19:10, Agustin Perez Paladini wrote: > Hi Jonathan, > Yes, that should work, assuming that the compiler will understand what > I'm trying to say! > > Thanks a lot! I will try that and see if there are any improvement. > Regards > > 2014-04-23 13:56 GMT-03:00 Jonathan Wakely <jwakely.gcc@xxxxxxxxx>: >> On 23 April 2014 17:50, Jonathan Wakely wrote: >>> On 23 April 2014 17:24, Agustin Perez Paladini wrote: >>>> Basically I was thinking in something like asserts, but that are only >>>> visible for the compiler and don't affect the code. Something like >>>> >>>> __builtin_assume(x > 0); >>>> __builtin_assume(x < 10); >>>> >>>> where x is a variable. That way the compiler can do better optimizations. >>> >>> You can use __buitlin_expect and __builtin_unreachable to do that. >> >> Or just __builtin_unreachable alone >> >> #define ASSUME(X) if (!(X)) __builtin_unreachable() >> >> This tells the compiler X is always true. Isn't that what you want? >
