llvm/llvm/test/Transforms/InstCombine/volatile_store.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

@x = weak global i32 0

define void @self_assign_1() {
; CHECK-LABEL: @self_assign_1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TMP:%.*]] = load volatile i32, ptr @x, align 4
; CHECK-NEXT:    store volatile i32 [[TMP]], ptr @x, align 4
; CHECK-NEXT:    br label [[RETURN:%.*]]
; CHECK:       return:
; CHECK-NEXT:    ret void
;
entry:
  %tmp = load volatile i32, ptr @x
  store volatile i32 %tmp, ptr @x
  br label %return

return:
  ret void
}

define void @volatile_store_before_unreachable(i1 %c, ptr %p) {
; CHECK-LABEL: @volatile_store_before_unreachable(
; CHECK-NEXT:    br i1 [[C:%.*]], label [[TRUE:%.*]], label [[FALSE:%.*]]
; CHECK:       true:
; CHECK-NEXT:    store volatile i8 0, ptr [[P:%.*]], align 1
; CHECK-NEXT:    unreachable
; CHECK:       false:
; CHECK-NEXT:    ret void
;
  br i1 %c, label %true, label %false

true:
  store volatile i8 0, ptr %p
  unreachable

false:
  ret void
}