> I was looking at the implementation of floorLog2() in src/base/intmath.hh. I > think this implementation is not the best that can be done. We should use a > GCC builtin __builtin_clz* to implement these functions. I have not carried > out any test to get the execution times for two different implementations. > But I looked at the assembly code generated for the two implementations for > 64-bit version of the function. The ratio of number of instructions is > probably about 1:4 for builtin versus current implementation.
Sounds good, though I think it would be best to use some sort of #ifdef to pick which one of the two should be used. Nate _______________________________________________ m5-dev mailing list m5-dev@m5sim.org http://m5sim.org/mailman/listinfo/m5-dev
