Generated bytecode by dxc has very higher compression ratio

[zuba]

Generated bytecode of dxc has a very higher compression ratio comparing to fxc, for example If I will zip same shaders dxc version is 3 times bigger ( fxc has around 30% compression ratio when dxc has around 80-85%). I’m compiling without debug info and with /O3 argument, do I need to specify anything else? thanks

[BitMD]

We just added better support for /qstrip_reflect but even with that the DXIL size is too high and it does not compress well. We are working on this now.

[pgjb]

Hi @BitMD and @tex3d

I've also recently come across this dxc compression ratio issue and wondered if there was any update? Also if anyone has found improvements by eg. using different compression algorithm? Thanks

[bluespeck]

Hi @BitMD @tex3d, any update on this? Thanks a lot.

[Division]

@BitMD @tex3d
Hi, I'm adding dx12 renderer to pc version of the game and noticed that vulkan shader cache is 3x smaller than dx12 (cache is compressed). At the same time size of a single uncompressed shader in dx12 is smaller. Which makes me think that shader bytecode is already compressed.

On xbox I used __XBOX_DISABLE_SHADER_OBJECT_COMPRESSION macro for dxc to fix the same issue.
Is there a similar parameter for PC dxc?