llvm/llvm/test/CodeGen/AArch64/wineh-frame-predecrement.mir

# RUN: llc -o - %s -mtriple=aarch64-windows -start-before=prologepilog \
# RUN:   -stop-after=prologepilog | FileCheck %s

# Check that the callee-saved registers are saved starting with a STP
# with predecrement, followed by a separate stack adjustment later,
# if the optsize attribute is set.

# CHECK:      early-clobber $sp = frame-setup STPXpre killed $x19, killed $x20, $sp, -2
# CHECK-NEXT: frame-setup SEH_SaveRegP_X 19, 20, -16
# CHECK-NEXT: $sp = frame-setup SUBXri $sp, 16, 0
# CHECK-NEXT: frame-setup SEH_StackAlloc 16
# CHECK-NEXT: frame-setup SEH_PrologEnd

--- |

  define dso_local i32 @func(i32 %a) optsize { ret i32 %a }

...
---
name:            func
alignment:       4
exposesReturnsTwice: false
legalized:       false
regBankSelected: false
selected:        false
failedISel:      false
tracksRegLiveness: true
hasWinCFI:       false
registers:       []
liveins:         []
frameInfo:
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       0
  offsetAdjustment: 0
  maxAlignment:    4
  adjustsStack:    false
  hasCalls:        false
  stackProtector:  ''
  maxCallFrameSize: 0
  cvBytesOfCalleeSavedRegisters: 0
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
  localFrameSize:  4
  savePoint:       ''
  restorePoint:    ''
fixedStack:      []
stack:
  - { id: 0, name: '', type: default, offset: 0, size: 4, alignment: 4,
      stack-id: default, callee-saved-register: '', callee-saved-restored: true,
      local-offset: -4, debug-info-variable: '', debug-info-expression: '',
      debug-info-location: '' }
callSites:       []
constants:       []
machineFunctionInfo: {}
body:             |
  bb.0:
    liveins: $x0, $x19, $x20

    renamable $x8 = ADDXri %stack.0, 0, 0
    $x19 = ADDXrr $x0, $x8
    $x20 = ADDXrr $x19, $x0
    $x0 = ADDXrr $x0, killed $x20

    RET_ReallyLR

...