Raising: rewrite pointer induction to indexed accesses - #3011
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A loop that walks a pointer forward by a constant stride each iteration (mfem's y[i] accumulation loops) carries it as an iter arg no tensor can stand for. The pointer is a pure function of the induction variable, so accesses through it rebase onto the init pointer at orig + k*stride and the loop rebuilds without the pointer iter args. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016zErYp7upmqr4NHfhod9UD
Extends the rewrite to the shapes rotated do-while lowerings produce: - a used final pointer materializes as the init advanced by the whole trip; statically known trips fold to a constant so downstream users stay affine - the advance stride may be a loop-invariant runtime value (an inner loop's materialized whole-trip advance); its computation chain is cloned above the loop when it lives inside the body - a dead-in-body iter arg that re-yields another induction's advance (a lagging copy) is dropped; its used result becomes select(trip>0, base final, own init), or the base final alone when the init is poison - static strides compose into the affine access map instead of degrading the access to an arith-indexed memref.load Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016zErYp7upmqr4NHfhod9UD
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Stacks on #3006.
A loop that walks a pointer forward by a constant stride each iteration (mfem's
*y++ += ...accumulation loops inhybridization_ext.cpp) carries the pointer as an iter arg no tensor can stand for. The pointer is a pure function of the induction variable, so accesses through it rebase onto the init pointer atorig + k*stride(with the byte stride converted into the view's element units) and the loop rebuilds without the pointer iter args; dead carried pointers drop with it.Part of #2968.
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https://claude.ai/code/session_016zErYp7upmqr4NHfhod9UD