[all-commits] [llvm/llvm-project] 2b7fa7: [LV] Iterate over recipes in VPlan to fix PHI (NFC).

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2b7fa7f7442ba342c4098556a962c1d8ffedc1f4
      https://github.com/llvm/llvm-project/commit/2b7fa7f7442ba342c4098556a962c1d8ffedc1f4
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2021-05-03 (Mon, 03 May 2021)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/lib/Transforms/Vectorize/VPlan.h

  Log Message:
  -----------
  [LV] Iterate over recipes in VPlan to fix PHI (NFC).

As we gradually move more elements of LV to VPlan, we are trying to
reduce the number of places that still has to check IR of the original
loop.

This patch adjusts the code to fix cross iteration phis to get the PHIs
to fix directly from the VPlan that is executed. We still need the
original PHI to check for first-order recurrences, but we can get rid of
that once we model that explicitly in VPlan as well.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D99293