HomePhabricator

[PowerPC] Implement probing for dynamic stack allocation

Authored by lkail on Jul 2 2020, 10:27 PM.

Description

[PowerPC] Implement probing for dynamic stack allocation

This patch is part of supporting -fstack-clash-protection. Mainly do
such things compared to existing lowerDynamicAlloc

  • Added a new pseudo instruction PPC::PREPARE_PROBED_ALLOC to get actual frame pointer and final stack pointer.
  • Synthesize a loop to probe by blocks.
  • Use DYNAREAOFFSET to get MaxCallFrameSize which is calculated in prologepilog.

Differential Revision: https://reviews.llvm.org/D81358