[all-commits] [llvm/llvm-project] 872ee7: Revert "[ARM] Improve codegen of volatile load/sto...

[Victor Campos via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 872ee78f65f47fae19d4f8db7396eb56d902aef1
      https://github.com/llvm/llvm-project/commit/872ee78f65f47fae19d4f8db7396eb56d902aef1
  Author: Victor Campos <victor.campos at arm.com>
  Date:   2020-05-22 (Fri, 22 May 2020)

  Changed paths:
    M llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
    M llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/lib/Target/ARM/ARMISelLowering.h
    M llvm/lib/Target/ARM/ARMInstrInfo.td
    M llvm/lib/Target/ARM/ARMInstrThumb2.td
    R llvm/test/CodeGen/ARM/i64_volatile_load_store.ll

  Log Message:
  -----------
  Revert "[ARM] Improve codegen of volatile load/store of i64"

This reverts commit 8a12553223180246eeafaa0fa7bfa11e834d34b6.

A bug has been found when generating code for Thumb2. In some very
specific cases, the prologue/epilogue emitter generates erroneous stack
offsets for the new LDRD instructions that access the stack.

This bug does not seem to be caused by the reverted patch though. Likely
the latter has made an undiscovered issue emerge in the
prologue/epilogue emission pass. Nevertheless, this reversion is
necessary since it is blocking users of the ARM backend.