[hlsl] functions usage

Graphics and GPU Programming Programming

Started by user88 March 09, 2010 07:22 AM

3 comments, last by user88 14 years, 1 month ago

304

Author

March 09, 2010 07:22 AM

Hello everybody! There are places in my hlsl effect file where some code is duplicates. As i know hlsl allow to define functions where i can move duplicated code. Question: will performance decrease with functions usage in compare to use duplicated code snippet?

Adam_42

3,664

March 09, 2010 08:08 AM

Performance should be the same - all functions calls will be inlined at compile time.

If you want to test it to be sure you can use a tool like Nvidia's ShaderPerf or AMD's GPUShaderAnalizer.

user88

304

Author

March 09, 2010 08:41 AM

Thanks for fast answer, Adam. Now i can start move all duplicated code to functions with no any doubt..

MJP

20,295

March 09, 2010 01:24 PM

Quote:Original post by Adam_42
Performance should be the same - all functions calls will be inlined at compile time.

Technically it's possible for the compiler to use a "call" instruction instead of inlining. However, I've never actually seen it happen. If you want to be sure about these things, you should always have a look at the compiled assembly. And of course ShaderPerf + GPUShaderAnalyzer are invaluable tools.

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