OK thanks, indeed Clang is able to generate better assembly using __restrict__. And -O3 generates the same assembly as -O3 -fstrict-aliasing (which is not as good as __restrict__).
I wish there was a C/C++ compiler flag for treating all pointers as __restrict__. However I guess that C/C++ standard libraries wouldn't work with this compiler option (and therefore this compiler option wouldn't be useful in practice).
I wish there was a C/C++ compiler flag for treating all pointers as __restrict__. However I guess that C/C++ standard libraries wouldn't work with this compiler option (and therefore this compiler option wouldn't be useful in practice).