stack-guard-reassign.mir

# RUN: llc -mtriple=arm64-apple-ios -start-before=localstackalloc -stop-after=prologepilog -o - %s | FileCheck %s

--- |
  @__stack_chk_guard = external global i8*
  define i32 @main(i32, i8**) {
    %StackGuardSlot = alloca i8*
    unreachable
  }
...
---
name:            main
tracksRegLiveness: true
frameInfo:
# CHECK: stackSize: 544
  stackProtector:  '%stack.0.StackGuardSlot'
stack:
  - { id: 0, name: StackGuardSlot, size: 8, alignment: 8, stack-id: default }
# Verify that the offset assigned to the stack protector is at the top of the
# frame, covering the locals.
# CHECK:       - { id: 0, name: StackGuardSlot, type: default, offset: -24, size: 8,
# CHECK-NEXT:      alignment: 8, stack-id: default, callee-saved-register: '', callee-saved-restored: true,
# CHECK-NEXT:      local-offset: -8, debug-info-variable: '', debug-info-expression: '',
# CHECK-NEXT:      debug-info-location: '' }
  - { id: 1, size: 512, alignment: 1, stack-id: default }
  - { id: 2, size: 4, alignment: 4, stack-id: default }
body:             |
  bb.0:
    %25:gpr64common = LOAD_STACK_GUARD :: (dereferenceable invariant load 8 from @__stack_chk_guard)
    STRXui killed %25, %stack.0.StackGuardSlot, 0 :: (volatile store 8 into %stack.0.StackGuardSlot)
    %28:gpr64 = LDRXui %stack.0.StackGuardSlot, 0 :: (volatile load 8 from %stack.0.StackGuardSlot)
    %29:gpr64common = LOAD_STACK_GUARD :: (dereferenceable invariant load 8 from @__stack_chk_guard)
    RET_ReallyLR implicit undef $w0, implicit killed %28, implicit killed %29

...