diff --git a/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp b/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
index d995333971b..d6d9907be7e 100644
--- a/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
+++ b/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
@@ -300,12 +300,50 @@ bool AtomicExpandLoadLinked::expandAtomicCmpXchg(AtomicCmpXchgInst *CI) {
       StoreSuccess, ConstantInt::get(Type::getInt32Ty(Ctx), 0), "success");
   Builder.CreateCondBr(TryAgain, LoopBB, BarrierBB);
 
-  // Finally, make sure later instructions don't get reordered with a fence if
-  // necessary.
+  // Make sure later instructions don't get reordered with a fence if necessary.
   Builder.SetInsertPoint(BarrierBB);
   insertTrailingFence(Builder, SuccessOrder);
   Builder.CreateBr(ExitBB);
 
+  // Finally, we have control-flow based knowledge of whether the cmpxchg
+  // succeeded or not. We expose this to later passes by converting any
+  // subsequent "icmp eq/ne %loaded, %oldval" into a use of an appropriate PHI.
+
+  // Setup the builder so we can create any PHIs we need.
+  Builder.SetInsertPoint(FailureBB, FailureBB->begin());
+  BasicBlock *SuccessBB = FailureOrder == Monotonic ? BarrierBB : TryStoreBB;
+  PHINode *Success = 0, *Failure = 0;
+
+  // Look for any users of the cmpxchg that are just comparing the loaded value
+  // against the desired one, and replace them with the CFG-derived version.
+  for (auto User : CI->users()) {
+    ICmpInst *ICmp = dyn_cast<ICmpInst>(User);
+    if (!ICmp)
+      continue;
+
+    // Because we know ICmp uses CI, we only need one operand to be the old
+    // value.
+    if (ICmp->getOperand(0) != CI->getCompareOperand() &&
+        ICmp->getOperand(1) != CI->getCompareOperand())
+      continue;
+
+    if (ICmp->getPredicate() == CmpInst::ICMP_EQ) {
+      if (!Success) {
+        Success = Builder.CreatePHI(Type::getInt1Ty(Ctx), 2);
+        Success->addIncoming(ConstantInt::getTrue(Ctx), SuccessBB);
+        Success->addIncoming(ConstantInt::getFalse(Ctx), LoopBB);
+      }
+      ICmp->replaceAllUsesWith(Success);
+    } else if (ICmp->getPredicate() == CmpInst::ICMP_NE) {
+      if (!Failure) {
+        Failure = Builder.CreatePHI(Type::getInt1Ty(Ctx), 2);
+        Failure->addIncoming(ConstantInt::getFalse(Ctx), SuccessBB);
+        Failure->addIncoming(ConstantInt::getTrue(Ctx), LoopBB);
+      }
+      ICmp->replaceAllUsesWith(Failure);
+    }
+  }
+
   CI->replaceAllUsesWith(Loaded);
   CI->eraseFromParent();
 
diff --git a/lib/Target/AArch64/AArch64TargetMachine.cpp b/lib/Target/AArch64/AArch64TargetMachine.cpp
index 0b5dd2f067e..ba301e95538 100644
--- a/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -53,6 +53,12 @@ static cl::opt<bool>
 EnableLoadStoreOpt("aarch64-load-store-opt", cl::desc("Enable the load/store pair"
                    " optimization pass"), cl::init(true), cl::Hidden);
 
+static cl::opt<bool>
+EnableAtomicTidy("aarch64-atomic-cfg-tidy", cl::Hidden,
+                 cl::desc("Run SimplifyCFG after expanding atomic operations"
+                          " to make use of cmpxchg flow-based information"),
+                 cl::init(true));
+
 extern "C" void LLVMInitializeAArch64Target() {
   // Register the target.
   RegisterTargetMachine<AArch64leTargetMachine> X(TheAArch64leTarget);
@@ -113,6 +119,7 @@ public:
     return getTM<AArch64TargetMachine>();
   }
 
+  void addIRPasses()  override;
   bool addPreISel() override;
   bool addInstSelector() override;
   bool addILPOpts() override;
@@ -135,6 +142,20 @@ TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
   return new AArch64PassConfig(this, PM);
 }
 
+void AArch64PassConfig::addIRPasses() {
+  // Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
+  // ourselves.
+  addPass(createAtomicExpandLoadLinkedPass(TM));
+
+  // Cmpxchg instructions are often used with a subsequent comparison to
+  // determine whether it succeeded. We can exploit existing control-flow in
+  // ldrex/strex loops to simplify this, but it needs tidying up.
+  if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
+    addPass(createCFGSimplificationPass());
+
+  TargetPassConfig::addIRPasses();
+}
+
 // Pass Pipeline Configuration
 bool AArch64PassConfig::addPreISel() {
   // Run promote constant before global merge, so that the promoted constants
@@ -146,10 +167,6 @@ bool AArch64PassConfig::addPreISel() {
   if (TM->getOptLevel() != CodeGenOpt::None)
     addPass(createAArch64AddressTypePromotionPass());
 
-  // Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
-  // ourselves.
-  addPass(createAtomicExpandLoadLinkedPass(TM));
-
   return false;
 }
 
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index 887622705ed..6ef2ea4e103 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -28,6 +28,12 @@ DisableA15SDOptimization("disable-a15-sd-optimization", cl::Hidden,
                    cl::desc("Inhibit optimization of S->D register accesses on A15"),
                    cl::init(false));
 
+static cl::opt<bool>
+EnableAtomicTidy("arm-atomic-cfg-tidy", cl::Hidden,
+                 cl::desc("Run SimplifyCFG after expanding atomic operations"
+                          " to make use of cmpxchg flow-based information"),
+                 cl::init(true));
+
 extern "C" void LLVMInitializeARMTarget() {
   // Register the target.
   RegisterTargetMachine<ARMLETargetMachine> X(TheARMLETarget);
@@ -213,6 +219,7 @@ public:
     return *getARMTargetMachine().getSubtargetImpl();
   }
 
+  void addIRPasses() override;
   bool addPreISel() override;
   bool addInstSelector() override;
   bool addPreRegAlloc() override;
@@ -225,11 +232,22 @@ TargetPassConfig *ARMBaseTargetMachine::createPassConfig(PassManagerBase &PM) {
   return new ARMPassConfig(this, PM);
 }
 
-bool ARMPassConfig::addPreISel() {
+void ARMPassConfig::addIRPasses() {
   const ARMSubtarget *Subtarget = &getARMSubtarget();
-  if (Subtarget->hasAnyDataBarrier() && !Subtarget->isThumb1Only())
+  if (Subtarget->hasAnyDataBarrier() && !Subtarget->isThumb1Only()) {
     addPass(createAtomicExpandLoadLinkedPass(TM));
 
+    // Cmpxchg instructions are often used with a subsequent comparison to
+    // determine whether it succeeded. We can exploit existing control-flow in
+    // ldrex/strex loops to simplify this, but it needs tidying up.
+    if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
+      addPass(createCFGSimplificationPass());
+  }
+
+  TargetPassConfig::addIRPasses();
+}
+
+bool ARMPassConfig::addPreISel() {
   if (TM->getOptLevel() != CodeGenOpt::None)
     addPass(createGlobalMergePass(TM));
 
diff --git a/test/CodeGen/AArch64/addsub_ext.ll b/test/CodeGen/AArch64/addsub_ext.ll
index a2266b1d36d..ceea8a08ece 100644
--- a/test/CodeGen/AArch64/addsub_ext.ll
+++ b/test/CodeGen/AArch64/addsub_ext.ll
@@ -1,4 +1,4 @@
-; RUN: llc -verify-machineinstrs %s -o - -mtriple=aarch64-linux-gnu | FileCheck %s
+; RUN: llc -verify-machineinstrs %s -o - -mtriple=aarch64-linux-gnu -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 
 @var8 = global i8 0
 @var16 = global i16 0
diff --git a/test/CodeGen/AArch64/arm64-ands-bad-peephole.ll b/test/CodeGen/AArch64/arm64-ands-bad-peephole.ll
index cf6235570a4..38661a5f38f 100644
--- a/test/CodeGen/AArch64/arm64-ands-bad-peephole.ll
+++ b/test/CodeGen/AArch64/arm64-ands-bad-peephole.ll
@@ -1,4 +1,4 @@
-; RUN: llc %s -o - | FileCheck %s
+; RUN: llc %s -o - -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 ; Check that ANDS (tst) is not merged with ADD when the immediate
 ; is not 0.
 ; <rdar://problem/16693089>
diff --git a/test/CodeGen/AArch64/arm64-cse.ll b/test/CodeGen/AArch64/arm64-cse.ll
index bb14c895504..5d62cfe76a8 100644
--- a/test/CodeGen/AArch64/arm64-cse.ll
+++ b/test/CodeGen/AArch64/arm64-cse.ll
@@ -1,4 +1,4 @@
-; RUN: llc -O3 < %s | FileCheck %s
+; RUN: llc -O3 < %s -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 target triple = "arm64-apple-ios"
 
 ; rdar://12462006
diff --git a/test/CodeGen/AArch64/arm64-early-ifcvt.ll b/test/CodeGen/AArch64/arm64-early-ifcvt.ll
index 17d783a488f..44150c29aeb 100644
--- a/test/CodeGen/AArch64/arm64-early-ifcvt.ll
+++ b/test/CodeGen/AArch64/arm64-early-ifcvt.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -stress-early-ifcvt | FileCheck %s
+; RUN: llc < %s -stress-early-ifcvt -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 target triple = "arm64-apple-macosx"
 
 ; CHECK: mm2
diff --git a/test/CodeGen/AArch64/arm64-fp128.ll b/test/CodeGen/AArch64/arm64-fp128.ll
index 57bbb93e12b..b1d50102aa2 100644
--- a/test/CodeGen/AArch64/arm64-fp128.ll
+++ b/test/CodeGen/AArch64/arm64-fp128.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=arm64-linux-gnu -verify-machineinstrs -mcpu=cyclone < %s | FileCheck %s
+; RUN: llc -mtriple=arm64-linux-gnu -verify-machineinstrs -mcpu=cyclone -aarch64-atomic-cfg-tidy=0 < %s | FileCheck %s
 
 @lhs = global fp128 zeroinitializer, align 16
 @rhs = global fp128 zeroinitializer, align 16
diff --git a/test/CodeGen/AArch64/arm64-frame-index.ll b/test/CodeGen/AArch64/arm64-frame-index.ll
index 4a91ff31d8c..321f3354ca2 100644
--- a/test/CodeGen/AArch64/arm64-frame-index.ll
+++ b/test/CodeGen/AArch64/arm64-frame-index.ll
@@ -1,4 +1,4 @@
-; RUN: llc -march=arm64 -mtriple=arm64-apple-ios < %s | FileCheck %s
+; RUN: llc -march=arm64 -mtriple=arm64-apple-ios -aarch64-atomic-cfg-tidy=0 < %s | FileCheck %s
 ; rdar://11935841
 
 define void @t1() nounwind ssp {
diff --git a/test/CodeGen/AArch64/arm64-xaluo.ll b/test/CodeGen/AArch64/arm64-xaluo.ll
index 6cffbdeef8a..0c300de802b 100644
--- a/test/CodeGen/AArch64/arm64-xaluo.ll
+++ b/test/CodeGen/AArch64/arm64-xaluo.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=arm64 | FileCheck %s
+; RUN: llc < %s -march=arm64 -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 
 ;
 ; Get the actual value of the overflow bit.
diff --git a/test/CodeGen/AArch64/atomic-ops.ll b/test/CodeGen/AArch64/atomic-ops.ll
index 58b5d1d078c..36d0eda1e12 100644
--- a/test/CodeGen/AArch64/atomic-ops.ll
+++ b/test/CodeGen/AArch64/atomic-ops.ll
@@ -889,8 +889,7 @@ define i8 @test_atomic_cmpxchg_i8(i8 %wanted, i8 %new) nounwind {
   ;  function there.
 ; CHECK-NEXT: cmp w[[OLD]], w0
 ; CHECK-NEXT: b.ne [[GET_OUT:.LBB[0-9]+_[0-9]+]]
-  ; As above, w1 is a reasonable guess.
-; CHECK: stxrb [[STATUS:w[0-9]+]], w1, [x[[ADDR]]]
+; CHECK: stxrb [[STATUS:w[0-9]+]], {{w[0-9]+}}, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz [[STATUS]], [[STARTAGAIN]]
 ; CHECK-NOT: dmb
 
@@ -911,8 +910,7 @@ define i16 @test_atomic_cmpxchg_i16(i16 %wanted, i16 %new) nounwind {
   ;  function there.
 ; CHECK-NEXT: cmp w[[OLD]], w0
 ; CHECK-NEXT: b.ne [[GET_OUT:.LBB[0-9]+_[0-9]+]]
-  ; As above, w1 is a reasonable guess.
-; CHECK: stlxrh [[STATUS:w[0-9]+]], w1, [x[[ADDR]]]
+; CHECK: stlxrh [[STATUS:w[0-9]+]], {{w[0-9]+}}, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz [[STATUS]], [[STARTAGAIN]]
 ; CHECK-NOT: dmb
 
@@ -933,8 +931,7 @@ define i32 @test_atomic_cmpxchg_i32(i32 %wanted, i32 %new) nounwind {
   ;  function there.
 ; CHECK-NEXT: cmp w[[OLD]], w0
 ; CHECK-NEXT: b.ne [[GET_OUT:.LBB[0-9]+_[0-9]+]]
-  ; As above, w1 is a reasonable guess.
-; CHECK: stlxr [[STATUS:w[0-9]+]], w1, [x[[ADDR]]]
+; CHECK: stlxr [[STATUS:w[0-9]+]], {{w[0-9]+}}, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz [[STATUS]], [[STARTAGAIN]]
 ; CHECK-NOT: dmb
 
diff --git a/test/CodeGen/AArch64/blockaddress.ll b/test/CodeGen/AArch64/blockaddress.ll
index 1eec4cc7f4e..3a5dbdc945c 100644
--- a/test/CodeGen/AArch64/blockaddress.ll
+++ b/test/CodeGen/AArch64/blockaddress.ll
@@ -1,5 +1,5 @@
-; RUN: llc -mtriple=aarch64-none-linux-gnu -verify-machineinstrs < %s | FileCheck %s
-; RUN: llc -code-model=large -mtriple=aarch64-none-linux-gnu -verify-machineinstrs < %s | FileCheck --check-prefix=CHECK-LARGE %s
+; RUN: llc -mtriple=aarch64-none-linux-gnu -aarch64-atomic-cfg-tidy=0 -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -code-model=large -mtriple=aarch64-none-linux-gnu -aarch64-atomic-cfg-tidy=0 -verify-machineinstrs < %s | FileCheck --check-prefix=CHECK-LARGE %s
 
 @addr = global i8* null
 
diff --git a/test/CodeGen/AArch64/breg.ll b/test/CodeGen/AArch64/breg.ll
index 591f48303e2..952404495ce 100644
--- a/test/CodeGen/AArch64/breg.ll
+++ b/test/CodeGen/AArch64/breg.ll
@@ -1,4 +1,4 @@
-; RUN: llc -verify-machineinstrs -o - %s -mtriple=aarch64-linux-gnu | FileCheck %s
+; RUN: llc -verify-machineinstrs -o - %s -mtriple=aarch64-linux-gnu -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 
 @stored_label = global i8* null
 
diff --git a/test/CodeGen/AArch64/cmpxchg-idioms.ll b/test/CodeGen/AArch64/cmpxchg-idioms.ll
new file mode 100644
index 00000000000..a6b96af99dd
--- /dev/null
+++ b/test/CodeGen/AArch64/cmpxchg-idioms.ll
@@ -0,0 +1,89 @@
+; RUN: llc -mtriple=aarch64-apple-ios7.0 -o - %s | FileCheck %s
+
+define i32 @test_return(i32* %p, i32 %oldval, i32 %newval) {
+; CHECK-LABEL: test_return:
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldaxr [[LOADED:w[0-9]+]], [x0]
+; CHECK: cmp [[LOADED]], w1
+; CHECK: b.ne [[FAILED:LBB[0-9]+_[0-9]+]]
+
+; CHECK: stlxr [[STATUS:w[0-9]+]], {{w[0-9]+}}, [x0]
+; CHECK: cbnz [[STATUS]], [[LOOP]]
+
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: orr w0, wzr, #0x1
+; CHECK: ret
+
+; CHECK: [[FAILED]]:
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: mov w0, wzr
+; CHECK: ret
+
+  %loaded = cmpxchg i32* %p, i32 %oldval, i32 %newval seq_cst seq_cst
+  %success = icmp eq i32 %loaded, %oldval
+  %conv = zext i1 %success to i32
+  ret i32 %conv
+}
+
+define i1 @test_return_bool(i8* %value, i8 %oldValue, i8 %newValue) {
+; CHECK-LABEL: test_return_bool:
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldaxrb [[LOADED:w[0-9]+]], [x0]
+; CHECK: cmp [[LOADED]], w1, uxtb
+; CHECK: b.ne [[FAILED:LBB[0-9]+_[0-9]+]]
+
+; CHECK: stlxrb [[STATUS:w[0-9]+]], {{w[0-9]+}}, [x0]
+; CHECK: cbnz [[STATUS]], [[LOOP]]
+
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: mov w0, wzr
+; CHECK: ret
+
+; CHECK: [[FAILED]]:
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: orr w0, wzr, #0x1
+; CHECK: ret
+
+  %loaded = cmpxchg i8* %value, i8 %oldValue, i8 %newValue acq_rel monotonic
+  %failure = icmp ne i8 %loaded, %oldValue
+  ret i1 %failure
+}
+
+define void @test_conditional(i32* %p, i32 %oldval, i32 %newval) {
+; CHECK-LABEL: test_conditional:
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldaxr [[LOADED:w[0-9]+]], [x0]
+; CHECK: cmp [[LOADED]], w1
+; CHECK: b.ne [[FAILED:LBB[0-9]+_[0-9]+]]
+
+; CHECK: stlxr [[STATUS:w[0-9]+]], w2, [x0]
+; CHECK: cbnz [[STATUS]], [[LOOP]]
+
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: b _bar
+
+; CHECK: [[FAILED]]:
+; CHECK-NOT: cmp {{w[0-9]+}}, {{w[0-9]+}}
+; CHECK: b _baz
+
+  %loaded = cmpxchg i32* %p, i32 %oldval, i32 %newval seq_cst seq_cst
+  %success = icmp eq i32 %loaded, %oldval
+  br i1 %success, label %true, label %false
+
+true:
+  tail call void @bar() #2
+  br label %end
+
+false:
+  tail call void @baz() #2
+  br label %end
+
+end:
+  ret void
+}
+
+declare void @bar()
+declare void @baz()
diff --git a/test/CodeGen/AArch64/directcond.ll b/test/CodeGen/AArch64/directcond.ll
index 1b519284846..fbea4a6e583 100644
--- a/test/CodeGen/AArch64/directcond.ll
+++ b/test/CodeGen/AArch64/directcond.ll
@@ -1,5 +1,5 @@
-; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 | FileCheck %s --check-prefix=CHECK
-; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mattr=-fp-armv8 | FileCheck --check-prefix=CHECK-NOFP %s
+; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 -aarch64-atomic-cfg-tidy=0 | FileCheck %s --check-prefix=CHECK
+; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mattr=-fp-armv8 -aarch64-atomic-cfg-tidy=0 | FileCheck --check-prefix=CHECK-NOFP %s
 
 define i32 @test_select_i32(i1 %bit, i32 %a, i32 %b) {
 ; CHECK-LABEL: test_select_i32:
diff --git a/test/CodeGen/AArch64/flags-multiuse.ll b/test/CodeGen/AArch64/flags-multiuse.ll
index c9b0b9ff7d8..77bbcddc492 100644
--- a/test/CodeGen/AArch64/flags-multiuse.ll
+++ b/test/CodeGen/AArch64/flags-multiuse.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=aarch64-none-linux-gnu -verify-machineinstrs -o - %s | FileCheck %s
+; RUN: llc -mtriple=aarch64-none-linux-gnu -aarch64-atomic-cfg-tidy=0 -verify-machineinstrs -o - %s | FileCheck %s
 
 ; LLVM should be able to cope with multiple uses of the same flag-setting
 ; instruction at different points of a routine. Either by rematerializing the
diff --git a/test/CodeGen/AArch64/jump-table.ll b/test/CodeGen/AArch64/jump-table.ll
index 1dfb789ac8e..69fbd9972b8 100644
--- a/test/CodeGen/AArch64/jump-table.ll
+++ b/test/CodeGen/AArch64/jump-table.ll
@@ -1,6 +1,6 @@
-; RUN: llc -verify-machineinstrs -o - %s -mtriple=aarch64-none-linux-gnu | FileCheck %s
-; RUN: llc -code-model=large -verify-machineinstrs -o - %s -mtriple=aarch64-none-linux-gnu | FileCheck --check-prefix=CHECK-LARGE %s
-; RUN: llc -mtriple=aarch64-none-linux-gnu -verify-machineinstrs -relocation-model=pic -o - %s | FileCheck --check-prefix=CHECK-PIC %s
+; RUN: llc -verify-machineinstrs -o - %s -mtriple=aarch64-none-linux-gnu -aarch64-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc -code-model=large -verify-machineinstrs -o - %s -mtriple=aarch64-none-linux-gnu -aarch64-atomic-cfg-tidy=0 | FileCheck --check-prefix=CHECK-LARGE %s
+; RUN: llc -mtriple=aarch64-none-linux-gnu -verify-machineinstrs -relocation-model=pic -aarch64-atomic-cfg-tidy=0 -o - %s | FileCheck --check-prefix=CHECK-PIC %s
 
 define i32 @test_jumptable(i32 %in) {
 ; CHECK: test_jumptable
diff --git a/test/CodeGen/AArch64/ldst-opt.ll b/test/CodeGen/AArch64/ldst-opt.ll
index 5518db3275e..a0de6342cb8 100644
--- a/test/CodeGen/AArch64/ldst-opt.ll
+++ b/test/CodeGen/AArch64/ldst-opt.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=aarch64-linux-gnu -verify-machineinstrs -o - %s | FileCheck %s
+; RUN: llc -mtriple=aarch64-linux-gnu -aarch64-atomic-cfg-tidy=0 -verify-machineinstrs -o - %s | FileCheck %s
 
 ; This file contains tests for the AArch64 load/store optimizer.
 
diff --git a/test/CodeGen/AArch64/tst-br.ll b/test/CodeGen/AArch64/tst-br.ll
index 8a2fe26803e..5dc7b5df475 100644
--- a/test/CodeGen/AArch64/tst-br.ll
+++ b/test/CodeGen/AArch64/tst-br.ll
@@ -1,4 +1,4 @@
-; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 | FileCheck %s
+; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 -aarch64-atomic-cfg-tidy=0 | FileCheck %s
 
 ; We've got the usual issues with LLVM reordering blocks here. The
 ; tests are correct for the current order, but who knows when that
diff --git a/test/CodeGen/ARM/2009-11-02-NegativeLane.ll b/test/CodeGen/ARM/2009-11-02-NegativeLane.ll
index ca5ae8b62e8..2597b413ec7 100644
--- a/test/CodeGen/ARM/2009-11-02-NegativeLane.ll
+++ b/test/CodeGen/ARM/2009-11-02-NegativeLane.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mcpu=cortex-a8 < %s | FileCheck %s
+; RUN: llc -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 < %s | FileCheck %s
 target datalayout = "e-p:32:32:32-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"
 target triple = "armv7-eabi"
 
diff --git a/test/CodeGen/ARM/2009-11-07-SubRegAsmPrinting.ll b/test/CodeGen/ARM/2009-11-07-SubRegAsmPrinting.ll
index 4fb2be02ce9..38eb0ea2c89 100644
--- a/test/CodeGen/ARM/2009-11-07-SubRegAsmPrinting.ll
+++ b/test/CodeGen/ARM/2009-11-07-SubRegAsmPrinting.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mcpu=cortex-a8 -mattr=-neonfp < %s | FileCheck %s
+; RUN: llc -mcpu=cortex-a8 -mattr=-neonfp -arm-atomic-cfg-tidy=0 < %s | FileCheck %s
 ; PR5423
 
 target datalayout = "e-p:32:32:32-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"
diff --git a/test/CodeGen/ARM/2010-10-25-ifcvt-ldm.ll b/test/CodeGen/ARM/2010-10-25-ifcvt-ldm.ll
index 60379984fab..e7e0580179c 100644
--- a/test/CodeGen/ARM/2010-10-25-ifcvt-ldm.ll
+++ b/test/CodeGen/ARM/2010-10-25-ifcvt-ldm.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=armv6-apple-darwin -mcpu=arm1136jf-s | FileCheck %s
+; RUN: llc < %s -mtriple=armv6-apple-darwin -mcpu=arm1136jf-s -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; Radar 8589805: Counting the number of microcoded operations, such as for an
 ; LDM instruction, was causing an assertion failure because the microop count
 ; was being treated as an instruction count.
diff --git a/test/CodeGen/ARM/2011-02-04-AntidepMultidef.ll b/test/CodeGen/ARM/2011-02-04-AntidepMultidef.ll
index 1bbb7b47a95..3950c9e081f 100644
--- a/test/CodeGen/ARM/2011-02-04-AntidepMultidef.ll
+++ b/test/CodeGen/ARM/2011-02-04-AntidepMultidef.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -asm-verbose=false -O3 -mtriple=armv6-apple-darwin -relocation-model=pic  -mcpu=arm1136jf-s | FileCheck %s
+; RUN: llc < %s -asm-verbose=false -O3 -mtriple=armv6-apple-darwin -relocation-model=pic  -mcpu=arm1136jf-s -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; rdar://8959122 illegal register operands for UMULL instruction
 ;   in cfrac nightly test.
 ; Armv6 generates a umull that must write to two distinct destination regs.
diff --git a/test/CodeGen/ARM/2012-11-14-subs_carry.ll b/test/CodeGen/ARM/2012-11-14-subs_carry.ll
index 8df295a2f65..33083303a3d 100644
--- a/test/CodeGen/ARM/2012-11-14-subs_carry.ll
+++ b/test/CodeGen/ARM/2012-11-14-subs_carry.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 ;CHECK-LABEL: foo:
 ;CHECK: adds
diff --git a/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll b/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll
index a438c1f4556..05a4ef05e95 100644
--- a/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll
+++ b/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; ModuleID = 'bugpoint-reduced-simplified.bc'
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:64:128-a0:0:64-n32-S64"
 target triple = "armv7--linux-gnueabi"
diff --git a/test/CodeGen/ARM/arm-and-tst-peephole.ll b/test/CodeGen/ARM/arm-and-tst-peephole.ll
index bf827d6b66e..14eef832e69 100644
--- a/test/CodeGen/ARM/arm-and-tst-peephole.ll
+++ b/test/CodeGen/ARM/arm-and-tst-peephole.ll
@@ -1,8 +1,8 @@
-; RUN: llc -mtriple=arm-eabi %s -o - | FileCheck -check-prefix=ARM %s
-; RUN: llc -mtriple=thumb-eabi %s -o - | FileCheck -check-prefix=THUMB %s
-; RUN: llc -mtriple=thumb-eabi -mcpu=arm1156t2-s -mattr=+thumb2 %s -o - \
+; RUN: llc -mtriple=arm-eabi -arm-atomic-cfg-tidy=0 %s -o - | FileCheck -check-prefix=ARM %s
+; RUN: llc -mtriple=thumb-eabi -arm-atomic-cfg-tidy=0 %s -o - | FileCheck -check-prefix=THUMB %s
+; RUN: llc -mtriple=thumb-eabi -arm-atomic-cfg-tidy=0 -mcpu=arm1156t2-s -mattr=+thumb2 %s -o - \
 ; RUN:   | FileCheck -check-prefix=T2 %s
-; RUN: llc -mtriple=thumbv8-eabi %s -o - | FileCheck -check-prefix=V8 %s
+; RUN: llc -mtriple=thumbv8-eabi -arm-atomic-cfg-tidy=0 %s -o - | FileCheck -check-prefix=V8 %s
 
 ; FIXME: The -march=thumb test doesn't change if -disable-peephole is specified.
 
diff --git a/test/CodeGen/ARM/atomic-64bit.ll b/test/CodeGen/ARM/atomic-64bit.ll
index 9913f30712b..db092de3875 100644
--- a/test/CodeGen/ARM/atomic-64bit.ll
+++ b/test/CodeGen/ARM/atomic-64bit.ll
@@ -189,9 +189,9 @@ define i64 @test7(i64* %ptr, i64 %val1, i64 %val2) {
 ; CHECK-THUMB: ldrexd [[REG1:[a-z0-9]+]], [[REG2:[a-z0-9]+]]
 ; CHECK-THUMB-LE-DAG: eor.w     [[MISMATCH_LO:[a-z0-9]+]], [[REG1]], r2
 ; CHECK-THUMB-LE-DAG: eor.w     [[MISMATCH_HI:[a-z0-9]+]], [[REG2]], r3
-; CHECK-THUMB-BE-DAG: eor.w     [[MISMATCH_HI:[a-z0-9]+]], [[REG1]]
-; CHECK-THUMB-BE-DAG: eor.w     [[MISMATCH_LO:[a-z0-9]+]], [[REG2]]
-; CHECK-THUMB: orrs    [[MISMATCH_HI]], [[MISMATCH_LO]]
+; CHECK-THUMB-BE-DAG: eor.w     [[MISMATCH_HI:[a-z0-9]+]], [[REG1]], r2
+; CHECK-THUMB-BE-DAG: eor.w     [[MISMATCH_LO:[a-z0-9]+]], [[REG2]], r3
+; CHECK-THUMB-LE: orrs    [[MISMATCH_HI]], [[MISMATCH_LO]]
 ; CHECK-THUMB: bne
 ; CHECK-THUMB: strexd {{[a-z0-9]+}}, {{[a-z0-9]+}}, {{[a-z0-9]+}}
 ; CHECK-THUMB: cmp
diff --git a/test/CodeGen/ARM/call-tc.ll b/test/CodeGen/ARM/call-tc.ll
index 40694bfca5c..a35fd747646 100644
--- a/test/CodeGen/ARM/call-tc.ll
+++ b/test/CodeGen/ARM/call-tc.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -mtriple=armv6-apple-ios5.0 -mattr=+vfp2 | FileCheck %s -check-prefix=CHECKV6
-; RUN: llc < %s -mtriple=thumbv7-apple-ios5.0 | FileCheck %s -check-prefix=CHECKT2D
-; RUN: llc < %s -mtriple=armv6-linux-gnueabi -relocation-model=pic -mattr=+vfp2 \
+; RUN: llc < %s -mtriple=armv6-apple-ios5.0 -mattr=+vfp2 -arm-atomic-cfg-tidy=0 | FileCheck %s -check-prefix=CHECKV6
+; RUN: llc < %s -mtriple=thumbv7-apple-ios5.0 -arm-atomic-cfg-tidy=0 | FileCheck %s -check-prefix=CHECKT2D
+; RUN: llc < %s -mtriple=armv6-linux-gnueabi -relocation-model=pic -mattr=+vfp2 -arm-atomic-cfg-tidy=0 \
 ; RUN:    | FileCheck %s -check-prefix=CHECKELF
 
 ; Enable tailcall optimization for iOS 5.0
diff --git a/test/CodeGen/ARM/cmpxchg-idioms.ll b/test/CodeGen/ARM/cmpxchg-idioms.ll
new file mode 100644
index 00000000000..a4f853450b3
--- /dev/null
+++ b/test/CodeGen/ARM/cmpxchg-idioms.ll
@@ -0,0 +1,101 @@
+; RUN: llc -mtriple=thumbv7s-apple-ios7.0 -o - %s | FileCheck %s
+
+define i32 @test_return(i32* %p, i32 %oldval, i32 %newval) {
+; CHECK-LABEL: test_return:
+
+; CHECK: dmb ishst
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldrex [[LOADED:r[0-9]+]], [r0]
+; CHECK: cmp [[LOADED]], r1
+; CHECK: bne [[FAILED:LBB[0-9]+_[0-9]+]]
+
+; CHECK: strex [[STATUS:r[0-9]+]], {{r[0-9]+}}, [r0]
+; CHECK: cmp [[STATUS]], #0
+; CHECK: bne [[LOOP]]
+
+; CHECK-NOT: cmp {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK: movs r0, #1
+; CHECK: dmb ish
+; CHECK: bx lr
+
+; CHECK: [[FAILED]]:
+; CHECK-NOT: cmp {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK: movs r0, #0
+; CHECK: dmb ish
+; CHECK: bx lr
+
+  %loaded = cmpxchg i32* %p, i32 %oldval, i32 %newval seq_cst seq_cst
+  %success = icmp eq i32 %loaded, %oldval
+  %conv = zext i1 %success to i32
+  ret i32 %conv
+}
+
+define i1 @test_return_bool(i8* %value, i8 %oldValue, i8 %newValue) {
+; CHECK-LABEL: test_return_bool:
+
+; CHECK: uxtb [[OLDBYTE:r[0-9]+]], r1
+; CHECK: dmb ishst
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldrexb [[LOADED:r[0-9]+]], [r0]
+; CHECK: cmp [[LOADED]], [[OLDBYTE]]
+
+; CHECK: itt ne
+; CHECK: movne r0, #1
+; CHECK: bxne lr
+
+; CHECK: strexb [[STATUS:r[0-9]+]], {{r[0-9]+}}, [r0]
+; CHECK: cmp [[STATUS]], #0
+; CHECK: bne [[LOOP]]
+
+; CHECK-NOT: cmp {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK: movs r0, #0
+; CHECK: bx lr
+
+  %loaded = cmpxchg i8* %value, i8 %oldValue, i8 %newValue acq_rel monotonic
+  %failure = icmp ne i8 %loaded, %oldValue
+  ret i1 %failure
+}
+
+define void @test_conditional(i32* %p, i32 %oldval, i32 %newval) {
+; CHECK-LABEL: test_conditional:
+
+; CHECK: dmb ishst
+
+; CHECK: [[LOOP:LBB[0-9]+_[0-9]+]]:
+; CHECK: ldrex [[LOADED:r[0-9]+]], [r0]
+; CHECK: cmp [[LOADED]], r1
+; CHECK: bne [[FAILED:LBB[0-9]+_[0-9]+]]
+
+; CHECK: strex [[STATUS:r[0-9]+]], r2, [r0]
+; CHECK: cmp [[STATUS]], #0
+; CHECK: bne [[LOOP]]
+
+; CHECK-NOT: cmp {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK: dmb ish
+; CHECK: b.w _bar
+
+; CHECK: [[FAILED]]:
+; CHECK-NOT: cmp {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK: dmb ish
+; CHECK: b.w _baz
+
+  %loaded = cmpxchg i32* %p, i32 %oldval, i32 %newval seq_cst seq_cst
+  %success = icmp eq i32 %loaded, %oldval
+  br i1 %success, label %true, label %false
+
+true:
+  tail call void @bar() #2
+  br label %end
+
+false:
+  tail call void @baz() #2
+  br label %end
+
+end:
+  ret void
+}
+
+declare void @bar()
+declare void @baz()
diff --git a/test/CodeGen/ARM/data-in-code-annotations.ll b/test/CodeGen/ARM/data-in-code-annotations.ll
index da70178225e..5eb81b24de0 100644
--- a/test/CodeGen/ARM/data-in-code-annotations.ll
+++ b/test/CodeGen/ARM/data-in-code-annotations.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=armv7-apple-darwin | FileCheck %s
+; RUN: llc < %s -mtriple=armv7-apple-darwin -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 define double @f1() nounwind {
 ; CHECK-LABEL: f1:
diff --git a/test/CodeGen/ARM/fptoint.ll b/test/CodeGen/ARM/fptoint.ll
index c7217560f48..f50d0b96fe9 100644
--- a/test/CodeGen/ARM/fptoint.ll
+++ b/test/CodeGen/ARM/fptoint.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=arm-eabi -mattr=+v6,+vfp2 %s -o - | FileCheck %s
+; RUN: llc -mtriple=arm-eabi -arm-atomic-cfg-tidy=0 -mattr=+v6,+vfp2 %s -o - | FileCheck %s
 
 @i = weak global i32 0		; <i32*> [#uses=2]
 @u = weak global i32 0		; <i32*> [#uses=2]
diff --git a/test/CodeGen/ARM/ifcvt-branch-weight.ll b/test/CodeGen/ARM/ifcvt-branch-weight.ll
index cd8a5613862..a994d3d01ae 100644
--- a/test/CodeGen/ARM/ifcvt-branch-weight.ll
+++ b/test/CodeGen/ARM/ifcvt-branch-weight.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv8 -print-machineinstrs=if-converter -o /dev/null 2>&1 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8 -print-machineinstrs=if-converter -arm-atomic-cfg-tidy=0 -o /dev/null 2>&1 | FileCheck %s
 
 %struct.S = type { i8* (i8*)*, [1 x i8] }
 define internal zeroext i8 @bar(%struct.S* %x, %struct.S* nocapture %y) nounwind readonly {
diff --git a/test/CodeGen/ARM/ifcvt10.ll b/test/CodeGen/ARM/ifcvt10.ll
index 26c72723b28..509c182fc97 100644
--- a/test/CodeGen/ARM/ifcvt10.ll
+++ b/test/CodeGen/ARM/ifcvt10.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=arm-apple-ios -mcpu=cortex-a9 | FileCheck %s
+; RUN: llc < %s -mtriple=arm-apple-ios -arm-atomic-cfg-tidy=0 -mcpu=cortex-a9 | FileCheck %s
 ; rdar://8402126
 ; Make sure if-converter is not predicating vldmia and ldmia. These are
 ; micro-coded and would have long issue latency even if predicated on
diff --git a/test/CodeGen/ARM/indirectbr-3.ll b/test/CodeGen/ARM/indirectbr-3.ll
index 5a9c45902ed..291fedb8110 100644
--- a/test/CodeGen/ARM/indirectbr-3.ll
+++ b/test/CodeGen/ARM/indirectbr-3.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 ; If ARMBaseInstrInfo::AnalyzeBlocks returns the wrong value, which was possible
 ; for blocks with indirect branches, the IfConverter could end up deleting
diff --git a/test/CodeGen/ARM/lsr-unfolded-offset.ll b/test/CodeGen/ARM/lsr-unfolded-offset.ll
index 1dafa0067b5..3ad60d47b53 100644
--- a/test/CodeGen/ARM/lsr-unfolded-offset.ll
+++ b/test/CodeGen/ARM/lsr-unfolded-offset.ll
@@ -1,4 +1,4 @@
-; RUN: llc -regalloc=greedy < %s | FileCheck %s
+; RUN: llc -regalloc=greedy -arm-atomic-cfg-tidy=0 < %s | FileCheck %s
 
 ; LSR shouldn't introduce more induction variables than needed, increasing
 ; register pressure and therefore spilling. There is more room for improvement
diff --git a/test/CodeGen/ARM/misched-copy-arm.ll b/test/CodeGen/ARM/misched-copy-arm.ll
index 26adf0c2ad0..bb2d42ca9ed 100644
--- a/test/CodeGen/ARM/misched-copy-arm.ll
+++ b/test/CodeGen/ARM/misched-copy-arm.ll
@@ -1,5 +1,5 @@
 ; REQUIRES: asserts
-; RUN: llc -mtriple=thumb-eabi -mcpu=swift -pre-RA-sched=source -join-globalcopies -enable-misched -verify-misched -debug-only=misched %s -o - 2>&1 | FileCheck %s
+; RUN: llc -mtriple=thumb-eabi -mcpu=swift -pre-RA-sched=source -join-globalcopies -enable-misched -verify-misched -debug-only=misched -arm-atomic-cfg-tidy=0 %s -o - 2>&1 | FileCheck %s
 ;
 ; Loop counter copies should be eliminated.
 ; There is also a MUL here, but we don't care where it is scheduled.
diff --git a/test/CodeGen/ARM/reg_sequence.ll b/test/CodeGen/ARM/reg_sequence.ll
index b245674c3c9..feed5ad2830 100644
--- a/test/CodeGen/ARM/reg_sequence.ll
+++ b/test/CodeGen/ARM/reg_sequence.ll
@@ -1,5 +1,5 @@
-; RUN: llc < %s -mtriple=arm-apple-ios -mcpu=cortex-a8 | FileCheck %s
-; RUN: llc < %s -mtriple=arm-apple-ios -mcpu=cortex-a8 -regalloc=basic | FileCheck %s
+; RUN: llc < %s -mtriple=arm-apple-ios -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=arm-apple-ios -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 -regalloc=basic | FileCheck %s
 ; Implementing vld / vst as REG_SEQUENCE eliminates the extra vmov's.
 
 %struct.int16x8_t = type { <8 x i16> }
diff --git a/test/CodeGen/ARM/spill-q.ll b/test/CodeGen/ARM/spill-q.ll
index b9246635e40..4fa97ea5b68 100644
--- a/test/CodeGen/ARM/spill-q.ll
+++ b/test/CodeGen/ARM/spill-q.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=armv7-elf -mattr=+neon | FileCheck %s
+; RUN: llc < %s -mtriple=armv7-elf -mattr=+neon -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; PR4789
 
 %bar = type { float, float, float }
diff --git a/test/CodeGen/ARM/struct-byval-frame-index.ll b/test/CodeGen/ARM/struct-byval-frame-index.ll
index 465ee1218fd..0fd55ec6c94 100644
--- a/test/CodeGen/ARM/struct-byval-frame-index.ll
+++ b/test/CodeGen/ARM/struct-byval-frame-index.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mcpu=cortex-a15 -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -mcpu=cortex-a15 -verify-machineinstrs -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 ; Check a spill right after a function call with large struct byval is correctly
 ; generated.
diff --git a/test/CodeGen/ARM/twoaddrinstr.ll b/test/CodeGen/ARM/twoaddrinstr.ll
index 8da875fef27..01df3b42d10 100644
--- a/test/CodeGen/ARM/twoaddrinstr.ll
+++ b/test/CodeGen/ARM/twoaddrinstr.ll
@@ -1,5 +1,5 @@
 ; Tests for the two-address instruction pass.
-; RUN: llc -mtriple=arm-eabi -mcpu=cortex-a9 %s -o - | FileCheck %s
+; RUN: llc -mtriple=arm-eabi -mcpu=cortex-a9 -arm-atomic-cfg-tidy=0 %s -o - | FileCheck %s
 
 define void @PR13378() nounwind {
 ; This was orriginally a crasher trying to schedule the instructions.
diff --git a/test/CodeGen/ARM/vldm-sched-a9.ll b/test/CodeGen/ARM/vldm-sched-a9.ll
index d0a9ac6d2b5..f2e5eb9b7e0 100644
--- a/test/CodeGen/ARM/vldm-sched-a9.ll
+++ b/test/CodeGen/ARM/vldm-sched-a9.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=arm -mtriple=armv7-linux-gnueabihf -float-abi=hard -mcpu=cortex-a9 -O3 | FileCheck %s
+; RUN: llc < %s -march=arm -mtriple=armv7-linux-gnueabihf -arm-atomic-cfg-tidy=0 -float-abi=hard -mcpu=cortex-a9 -O3 | FileCheck %s
 
 target datalayout = "e-p:32:32:32-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-n32-S64"
 
diff --git a/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll b/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
index e0144531454..09e0ed1ead6 100644
--- a/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
+++ b/test/CodeGen/Thumb2/2009-08-01-WrongLDRBOpc.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 @csize = external global [100 x [20 x [4 x i8]]]		; <[100 x [20 x [4 x i8]]]*> [#uses=1]
 @vsize = external global [100 x [20 x [4 x i8]]]		; <[100 x [20 x [4 x i8]]]*> [#uses=1]
diff --git a/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll b/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
index 940cfd15e08..c8eac8d4d09 100644
--- a/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
+++ b/test/CodeGen/Thumb2/2009-08-06-SpDecBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-none-linux-gnueabi | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-none-linux-gnueabi -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; PR4659
 ; PR4682
 
diff --git a/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll b/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
index 52066d3f86a..a9a2478e403 100644
--- a/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
+++ b/test/CodeGen/Thumb2/2009-09-28-ITBlockBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -disable-cgp-branch-opts | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -disable-cgp-branch-opts -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 %struct.pix_pos = type { i32, i32, i32, i32, i32, i32 }
 
diff --git a/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll b/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
index 1b8bdb1c19b..8beb5b1c894 100644
--- a/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
+++ b/test/CodeGen/Thumb2/2010-04-15-DynAllocBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -O3 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 -O3 | FileCheck %s
 ; rdar://7493908
 
 ; Make sure the result of the first dynamic_alloc isn't copied back to sp more
diff --git a/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll b/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
index 810bfb79020..f3046e1fcb8 100644
--- a/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
+++ b/test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -O3 -relocation-model=pic | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -O3 -relocation-model=pic -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; rdar://8115404
 ; Tail merging must not split an IT block.
 
diff --git a/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll b/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
index 75f5439b98c..3d89390d04c 100644
--- a/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
+++ b/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll
@@ -1,5 +1,5 @@
 ; rdar://8465407
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 %struct.buf = type opaque
 
diff --git a/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll b/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
index b1ce3bb935e..240df83252c 100644
--- a/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
+++ b/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=thumbv7-apple-darwin10 < %s | FileCheck %s
+; RUN: llc -mtriple=thumbv7-apple-darwin10 -arm-atomic-cfg-tidy=0 < %s | FileCheck %s
 
 %struct.op = type { %struct.op*, %struct.op*, %struct.op* ()*, i32, i16, i16, i8, i8 }
 
diff --git a/test/CodeGen/Thumb2/buildvector-crash.ll b/test/CodeGen/Thumb2/buildvector-crash.ll
index 8a3c895bbe5..16e2298522f 100644
--- a/test/CodeGen/Thumb2/buildvector-crash.ll
+++ b/test/CodeGen/Thumb2/buildvector-crash.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -O3 -mtriple=thumbv7-apple-ios -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -O3 -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 -mcpu=cortex-a8 | FileCheck %s
 ; Formerly crashed, 3573915.
 
 define void @RotateStarsFP_Vec() nounwind {
diff --git a/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll b/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
index a9f948cf717..88c7f0f17ab 100644
--- a/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
+++ b/test/CodeGen/Thumb2/cross-rc-coalescing-2.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin9 -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
 
 define void @fht(float* nocapture %fz, i16 signext %n) nounwind {
 ; CHECK-LABEL: fht:
diff --git a/test/CodeGen/Thumb2/ldr-str-imm12.ll b/test/CodeGen/Thumb2/ldr-str-imm12.ll
index 36544d16d6f..d20eef0c8bb 100644
--- a/test/CodeGen/Thumb2/ldr-str-imm12.ll
+++ b/test/CodeGen/Thumb2/ldr-str-imm12.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 -mcpu=cortex-a8 -relocation-model=pic -disable-fp-elim | FileCheck %s
 ; rdar://7352504
 ; Make sure we use "str r9, [sp, #+28]" instead of "sub.w r4, r7, #256" followed by "str r9, [r4, #-32]".
 
diff --git a/test/CodeGen/Thumb2/thumb2-branch.ll b/test/CodeGen/Thumb2/thumb2-branch.ll
index a00b22d8502..332ed50ede6 100644
--- a/test/CodeGen/Thumb2/thumb2-branch.ll
+++ b/test/CodeGen/Thumb2/thumb2-branch.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mattr=+thumb2 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mattr=+thumb2 -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; If-conversion defeats the purpose of this test, which is to check
 ; conditional branch generation, so a call to make sure it doesn't
 ; happen and we get actual branches.
diff --git a/test/CodeGen/Thumb2/thumb2-cbnz.ll b/test/CodeGen/Thumb2/thumb2-cbnz.ll
index 893bd0fdaef..f0f79168c90 100644
--- a/test/CodeGen/Thumb2/thumb2-cbnz.ll
+++ b/test/CodeGen/Thumb2/thumb2-cbnz.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; rdar://7354379
 
 declare double @foo(double) nounwind readnone
diff --git a/test/CodeGen/Thumb2/thumb2-ifcvt2.ll b/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
index 403cd48035b..a861912fe11 100644
--- a/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
+++ b/test/CodeGen/Thumb2/thumb2-ifcvt2.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-ios | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-default-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8-apple-ios -arm-no-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-ios -arm-atomic-cfg-tidy=0 -arm-default-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8-apple-ios -arm-atomic-cfg-tidy=0 -arm-no-restrict-it | FileCheck %s
 
 define void @foo(i32 %X, i32 %Y) {
 entry:
diff --git a/test/CodeGen/Thumb2/thumb2-ifcvt3.ll b/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
index a71aa3fb613..79667d43b95 100644
--- a/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
+++ b/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-default-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8-apple-darwin -arm-no-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-atomic-cfg-tidy=0 -arm-default-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8-apple-darwin -arm-atomic-cfg-tidy=0 -arm-no-restrict-it | FileCheck %s
 
 ; There shouldn't be a unconditional branch at end of bb52.
 ; rdar://7184787
diff --git a/test/CodeGen/Thumb2/thumb2-spill-q.ll b/test/CodeGen/Thumb2/thumb2-spill-q.ll
index 52c10634491..94f472593b3 100644
--- a/test/CodeGen/Thumb2/thumb2-spill-q.ll
+++ b/test/CodeGen/Thumb2/thumb2-spill-q.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-elf -mattr=+neon | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-elf -mattr=+neon -arm-atomic-cfg-tidy=0 | FileCheck %s
 ; PR4789
 
 %bar = type { float, float, float }
diff --git a/test/CodeGen/Thumb2/v8_IT_3.ll b/test/CodeGen/Thumb2/v8_IT_3.ll
index 4dca24629b0..a028deebc8e 100644
--- a/test/CodeGen/Thumb2/v8_IT_3.ll
+++ b/test/CodeGen/Thumb2/v8_IT_3.ll
@@ -1,7 +1,7 @@
-; RUN: llc < %s -mtriple=thumbv8 | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv8 -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it -relocation-model=pic | FileCheck %s --check-prefix=CHECK-PIC
 
 %struct.FF = type { i32 (i32*)*, i32 (i32*, i32*, i32, i32, i32, i32)*, i32 (i32, i32, i8*)*, void ()*, i32 (i32, i8*, i32*)*, i32 ()* }
 %struct.BD = type { %struct.BD*, i32, i32, i32, i32, i64, i32 (%struct.BD*, i8*, i64, i32)*, i32 (%struct.BD*, i8*, i32, i32)*, i32 (%struct.BD*, i8*, i64, i32)*, i32 (%struct.BD*, i8*, i32, i32)*, i32 (%struct.BD*, i64, i32)*, [16 x i8], i64, i64 }
diff --git a/test/CodeGen/Thumb2/v8_IT_5.ll b/test/CodeGen/Thumb2/v8_IT_5.ll
index 2f352d6d5f1..2da75ad2143 100644
--- a/test/CodeGen/Thumb2/v8_IT_5.ll
+++ b/test/CodeGen/Thumb2/v8_IT_5.ll
@@ -1,5 +1,5 @@
-; RUN: llc < %s -mtriple=thumbv8 | FileCheck %s
-; RUN: llc < %s -mtriple=thumbv7 -arm-restrict-it | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8 -arm-atomic-cfg-tidy=0 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7 -arm-atomic-cfg-tidy=0 -arm-restrict-it | FileCheck %s
 ; CHECK: it	ne
 ; CHECK-NEXT: cmpne
 ; CHECK-NEXT: bne [[JUMPTARGET:.LBB[0-9]+_[0-9]+]]
diff --git a/test/Transforms/LoopStrengthReduce/ARM/2012-06-15-lsr-noaddrmode.ll b/test/Transforms/LoopStrengthReduce/ARM/2012-06-15-lsr-noaddrmode.ll
index 756ea82f37f..1d56ddea244 100644
--- a/test/Transforms/LoopStrengthReduce/ARM/2012-06-15-lsr-noaddrmode.ll
+++ b/test/Transforms/LoopStrengthReduce/ARM/2012-06-15-lsr-noaddrmode.ll
@@ -1,4 +1,4 @@
-; RUN: llc -O3 -mtriple=thumb-eabi -mcpu=cortex-a8 %s -o - | FileCheck %s
+; RUN: llc -O3 -mtriple=thumb-eabi -mcpu=cortex-a8 %s -o - -arm-atomic-cfg-tidy=0 | FileCheck %s
 ;
 ; LSR should only check for valid address modes when the IV user is a
 ; memory address.