Hey, 2014-08-25 17:25 GMT+02:00 Óscar Fuentes <[email protected]>: > On a CPU-intensive application, the 64 bit exe runs 40% slower than > its 32 bit counterpart. It's a C++ app with a workload typical of a > compiler. > > Are there known slow spots on the 64 bit runtimes?
Well, there might be some. I can't actual confirm this finding in general. The load you see is often application-specific. I know about a lot of application, which are actual about 30% faster on 64-bit over 32-bit. Mainly caused by wider memory-moves, and use of more registers. So a profiling would be indeed interesting to learn where your application spends cycles over the 32-bit. In general we might have some opportunities to optimize further math for x64. > I'm using latest gcc/runtime as shipped by MSYS2. Tried to profile the > executables but gprof doesn't output any numbers, just the boilerplate. > (Yes, I'm passing -pg to the g++ instance that invokes the linker.) Well, for me profiling works in general for 64-bit. Nevertheless I admit that usage is pretty borged. For upcoming 5.0 there will be new tool available to work with profiling-information more intuitive. Hopeful it will help. Kai ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
