[pull] master from phate:master#628
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pull[bot] merged 1 commit intoEECS-NTNU:masterfrom Feb 10, 2026
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This PR extends the ScalarEvolution implementation by adding support for computing recurrences for `GetElementPtr` operations. It does this by adding a few new cases to the `GetOrCreateSCEVForOutput()` method, particularly for `GetElementPtr`, `Load`, `IOBarrier` and `SExt` operations. The SCEV for the GetElementPtr operation is computed recursively to support an arbitrary number of indexes, and supports both _array_ and _struct_ GEPs. This PR also adds two simple tests for the two types of GEPs. Since the value of a GEP is not directly tied to the update of an induction variable (passes through a _load_ from memory), some changes were needed in the way recurrences are computed. Particularly, we now compute recurrences for all _valid_ SCEVs as opposed to computing the recurrences for just the loop variables. By valid we mean that the dependencies for the RVSDG output the SCEV corresponds to passes the three requirements. These being: - No more than one self-dependency in the dependency graph (indicates a self-dependent variable) - No cyclic dependencies (A depends on B and B depends on A) - No dependencies via multiplication (results in a geometric update sequence, which we treat as an invalid induction variable) This change means that we end up with a larger amount of chain recurrences at the end of the analysis, some of which can be seen as "junk" or "noise". For the analysis itself this makes no difference, however for measuring the results, we should probably filter most of these out.
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