[all-commits] [llvm/llvm-project] 793cc5: [PowerPC] Prevent legalization loop from promoting...

[nemanja-ibm via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 793cc518b9428a0b7a40c59d4ecd5939a7bc84f7
      https://github.com/llvm/llvm-project/commit/793cc518b9428a0b7a40c59d4ecd5939a7bc84f7
  Author: Nemanja Ivanovic <nemanjai at ca.ibm.com>
  Date:   2020-05-25 (Mon, 25 May 2020)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCISelLowering.cpp
    A llvm/test/CodeGen/PowerPC/pr45709.ll

  Log Message:
  -----------
  [PowerPC] Prevent legalization loop from promoting SELECT_CC from v4i32 to v4i32

As reported in https://bugs.llvm.org/show_bug.cgi?id=45709 we can hit an
infinite loop in legalization since we set the legalization action for
ISD::SELECT_CC for all fixed length vector types to Promote. Without some
different legalization action for the type being promoted to, the legalizer
simply loops. Since we don't have patterns to match the node, the right
legalization action should be Expand.

Differential revision: https://reviews.llvm.org/D79854