[Bf-committers] Cycles CPU Kernel on MSVC *all versions*

[Jürgen Herrmann]

Hi there,

I think I found one of the reasons why Cycles is slower on CPU when compiled with MSVC.
The compiler flags are not quite right here. We use:

/arch:sse2 /fp:fast

to compile the cpu kernel.

We should tell the compiler to use intrinsics and favor faster binaries with:

/arch:sse2 /fp:fast /Oi /Ot

This gives a slight speedup on my dev machine, I had no time to do a in depth test yet but I will ;)
I have 3 test Systems ready and will file a complete report until Saturday.

/Jürgen