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the729
Journeyman III

Register Addressing Modes

About relative addressing, sr, etc.

From the document 'Evergreen-Family ISA Instructions and Microcode' page 2-23~2-24, I find that INDEX_MODE supports 4 modes. My question is, how to utilize these features in IL respectively? To be more specific:

INDEX_AR_X, use ar.x for indexing. As far as I know, we can use indexed array x[] to utilize this feature. Is there any other way?

INDEX_LOOP, use loop index. Actually, I do not really use this feature.

INDEX_GLOBAL, treat GPR address as absolute. We can declare sr in IL. However, the number of SR is limited to 32 (am I right?). It is certainly not a limit of the ISA microcode. Is this a hardware limit?

INDEX_GLOBAL_AR_X, absolute GPR address and us ar.x for indexing. Is there any way to use this feature in IL?

BIG THANKS!

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the729,
Only what is exposed in IL is available from the ISA. If the feature is not directly exposed in the IL doc, then there is no way to use it. The indexing modes are not exposed in IL directly.
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