llvm/llvm/test/Transforms/DeadStoreElimination/atomic-todo.ll

; XFAIL: *
; RUN: opt -passes=dse -S < %s | FileCheck %s

target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-macosx10.7.0"

; Basic correctness tests for atomic stores.
; Note that it turns out essentially every transformation DSE does is legal on
; atomic ops, just some transformations are not allowed across release-acquire pairs.

@x = common global i32 0, align 4
@y = common global i32 0, align 4

; DSE across monotonic load (allowed as long as the eliminated store isUnordered)
define i32 @test9() {
; CHECK-LABEL: test9
; CHECK-NOT: store i32 0
; CHECK: store i32 1
  store i32 0, ptr @x
  %x = load atomic i32, ptr @y monotonic, align 4
  store i32 1, ptr @x
  ret i32 %x
}