Wei, Wanxia wrote: > Dear Sir/Madam: > > I am sorry I met a problem when I used gcc to compile my C program and ran the > executables on servers. I compiled my C program with the following two different ways > with different options. > > gcc -m32 -O3 -DNDEBUG -fno-strict-aliasing -static –lm > > gcc -m32 –O3 –lm > > My problem is that the two executables obtained by using the above two ways have the > same performance on some inputs but have different performance on other inputs. I'd expect that. -fno-strict-aliasing has some performance impact. > If two executables with different options should always have the same performance, Certainly not, no, especially when one of the options controls optimization. Andrew.
