[all-commits] [llvm/llvm-project] bfec91: Scalar: Don't visit constants in findInnerReductio...

[Duncan P. N. Exon Smith via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bfec9148a042c8fd6093ae0d54c784211a295c6c
      https://github.com/llvm/llvm-project/commit/bfec9148a042c8fd6093ae0d54c784211a295c6c
  Author: Anton Rapetov <willir29 at gmail.com>
  Date:   2021-01-21 (Thu, 21 Jan 2021)

  Changed paths:
    M llvm/lib/Transforms/Scalar/LoopInterchange.cpp
    M llvm/test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll

  Log Message:
  -----------
  Scalar: Don't visit constants in findInnerReductionPhi in LoopInterchange

In LoopInterchange, `findInnerReductionPhi()` looks for reduction
variables, which cannot be constants. Update it to return early in that
case.

This also addresses a blocker for removing use-lists from ConstantData,
whose users could be spread across arbitrary modules in the same
LLVMContext.

Differential Revision: https://reviews.llvm.org/D94712