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[bs_kl]

I think Fetch4 is a very useful feature for working with single-channel data.

From the GZA, I am able to produce fetch4 IL code from Pixel Shader 4.1, by using the Gather method of the texture object. The ASM for fetch4 is even there (in the GZA).

But trying to use the IL code produced by GZA result in compilation error by CAL CL (1.1 & 1.2).

Trying to assemble the ASM produced by GZA and although the program is able to run, but it returned invalid value.


Or is there other alternative that can achieve the efficiency of fetch4 for single-channel data? What about the SAMPLE_L (in which the doc is lacking in explaining it)?

[MicahVillmow]

bs_kl,
The code generated by GZA uses the Compiler in the catalyst driver. This compiler is not the one that ships with CAL but is the graphics driver compiler, the CAL compiler uses a seperate version of the compiler that only supports a subset of the IL language tailored for Compute and specified in the il.pdf.
The sample_l instruction is the version of sample that guarantee's correctness when used in flow control. This is a known issue that the documentation is sparse in this area and we are working on fixing that.

[bs_kl]

Hi Micah,

Yes I know it's currently limited by CAL and that's why I am posting it as a feature request. Moreover, in the general compute world, single-channel data appears more frequent than the four-channel data usually used in graphics, IMO.

I hope that CAL could really unlock all the powerful features of the Radeon hardware. It is the reason I chose to stick with Radeon and it is the reason I switched from Direct3D/OpenGL to CAL.

Thanks.