[PATCH] D124645: [SCEV] Model simple same base pointer `select`s via `umin_seq`

[Roman Lebedev via Phabricator via llvm-commits]

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We can't model pointer selects (or even fully variable integer selects) in SCEV in their generality.

But, *IFF* we are selecting between pointers with the same base object,
we can instead decompose the pointers into pointer base + integer offset,
try to model the select of said integer offsets, and add the result
to the base pointer, thus modelling the original select,
because we do support limited modelling for partially-variable integer selects.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D124645

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Analysis/ScalarEvolution/pointer-rounding.ll
  llvm/test/Analysis/ScalarEvolution/pointer-select.ll

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