Question about `seq_exec` compiler optimizations

[yencal]

Question about `seq_exec` compiler optimizations

[rhornung67]

I believe that the compiler sees essentially the same source code whether written as a C-style for-loop or using a RAJA kernel exec method with a seq_exec policy. https://github.com/LLNL/RAJA/blob/develop/include/RAJA/policy/sequential/forall.hpp#L65

That is, there are no pragmas or other annotations applied in RAJA internals. That said, we often observe cases where RAJA code runs faster than native C-style code, but it is not clear why. However, 4x faster seems extraordinary. Have you compared the assembly code for the two versions?

[yencal]

Ok, I will check the assembly code and ensure the cmake flags are propagated accordingly. Thanks