[all-commits] [llvm/llvm-project] 01dc10: [ARM] unwinding .pad instructions missing in execu...

[walkerkd via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 01dc10774eb87bc2f114a0e2d77083dbec62226b
      https://github.com/llvm/llvm-project/commit/01dc10774eb87bc2f114a0e2d77083dbec62226b
  Author: Keith Walker <keith.walker at arm.com>
  Date:   2020-04-07 (Tue, 07 Apr 2020)

  Changed paths:
    M llvm/lib/Target/ARM/ARMAsmPrinter.cpp
    M llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
    M llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
    M llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
    M llvm/test/CodeGen/Thumb/emergency-spill-slot.ll
    A llvm/test/CodeGen/Thumb2/thumb2-execute-only-prologue.ll

  Log Message:
  -----------
  [ARM] unwinding .pad instructions missing in execute-only prologue

If the stack pointer is altered for local variables and we are generating
Thumb2 execute-only code the .pad directive is missing.

Usually the size of the adjustment is stored in a PC-relative location
and loaded into a register which is then added to the stack pointer.
However when we are generating execute-only code code the size of the
adjustment is instead generated using the MOVW/MOVT instruction pair.

As a by product of handling the execute-only case this also fixes an
existing issue that in the none execute-only case the .pad directive was
generated against the load of the constant to a register instruction,
instead of the instruction which adds the register to the stack pointer.

Differential Revision: https://reviews.llvm.org/D76849