[cfe-dev] food for optimizer developers

[Robert Purves]

Chris Lattner wrote:

>> My wild guess is that this is a failure because we don't have TBAA yet, which isn't being worked on.  What flags are you passing to the compiler?  Anything like -ffast-math?  Note that ifort defaults to "fast and loose" numerics iirc.
> 
> Rather, "which *is* being worked on".  You can quickly verify this assumption by seeing if gcc generates similar code to llvm when you pass -fno-strict-aliasing to gcc.

Passing -fno-strict-aliasing makes no difference to the code generated by g++. It is still twice the speed of code from clang.

Robert P.