[all-commits] [llvm/llvm-project] ea475c: [SystemZFrameLowering] Don't overrwrite R1D (backc...

[Jonas Paulsson via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: ea475c77ff9eab1de7d44684c8fb453b39f70081
      https://github.com/llvm/llvm-project/commit/ea475c77ff9eab1de7d44684c8fb453b39f70081
  Author: Jonas Paulsson <paulsson at linux.vnet.ibm.com>
  Date:   2020-12-10 (Thu, 10 Dec 2020)

  Changed paths:
    M llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
    M llvm/test/CodeGen/SystemZ/stack-clash-dynamic-alloca.ll
    M llvm/test/CodeGen/SystemZ/stack-clash-protection.ll

  Log Message:
  -----------
  [SystemZFrameLowering] Don't overrwrite R1D (backchain) when probing.

The loop-based probing done for stack clash protection altered R1D which
corrupted the backchain value to be stored after the probing was done.

By using R0D instead for the loop exit value, R1D is not modified.

Review: Ulrich Weigand.

Differential Revision: https://reviews.llvm.org/D92803