[Bf-cycles] OIIO/OSL update performance

Thomas Dinges blender at dingto.org
Sun Mar 1 12:20:51 CET 2015

I spend some time last night, on compiling new OIIO/OSL libs for Windows.
Used versions: OIIO RB-1.5 branch, OSL master branch.

Compiling the libs was pretty easy, I only had to do 2 little tweaks to 
OIIO (http://www.pasteall.org/56978/diff , missing include and 
undeclared "command" variable).
As for compiler flags, I added USE_SIMD to both OIIO/OSL, and compiled 
the libs three times: USE_SIMD=0, USE_SIMD=sse2, USE_SIMD=sse4.2
For OSL I also had to add LINKSTATIC=ON.

Now the weird thing: The new libs (with SIMD enabled), render some files 
significantly slower. Here a file with a Volume + Noise texture 
http://www.pasteall.org/blend/34747. Current OSL renders this in ~21 
seconds, new SIMD one in ~54 seconds. The libs without SIMD seem to do fine.

I post this here, so maybe someone else can give it a try (Linux, Mac?), 
maybe I have done something wrong, maybe Cycles code needs some updates, 
or it's one of these "Windows platform" issues again.

Best regards,

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