[AMDGPU] Add an AMDGPU specific atomic optimizer.

[sheredom]

Summary

This commit adds a new IR level pass to the AMDGPU backend to perform atomic optimizations. It works by:

• Running through a function and finding atomicrmw add/sub or uses of the atomic buffer intrinsics for add/sub.
• If all arguments except the value to be added/subtracted are uniform, record the value to be optimized.
• Run through the atomic operations we can optimize and, depending on whether the value is uniform/divergent use wavefront wide operations (DPP in the divergent case) to calculate the total amount to be atomically added/subtracted.
• Then let only a single lane of each wavefront perform the atomic operation, reducing the total number of atomic operations in flight.
• Lastly we recombine the result from the single lane to each lane of the wavefront, and calculate our individual lanes offset into the final result.

[sheredom]

Update to include tip LLVM changes (DivergenceAnalysis -> LegacyDivergenceAnalysis, AMDGPUAS is become just an enum now).

[arsenm]

Should include tests running only the IR pass

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

58

This can be dropped

61–62

This needs work, but should preserve the dominator tree

177

No getPrimitiveSizeInBits

208

All the consts are in the wrong place

213–214

I'm pretty sure there's a utility function that deals with what you're trying to do, that will also handle the DominatorTree updates for this

220

You pretty much should never use getPrimitiveSizeInBits directly. Use the DataLayout

230–235

You need to mark this call site as convergent

244–245

CreateIntrinsic

295–296

Can you use enums to derive these values

368–379

The canonical way to do this in IR is lshr x, 32 and truncate

[arsenm]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

380

Checking a different value is suspicious

[arsenm]

test/CodeGen/AMDGPU/atomic_optimizations_buffer.ll

72

Missing -LABELs

[sheredom]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

58

You mean I don't need to include a getPassName at all? I was just including it for consistency with the other AMDGPU level passes (a bunch at least have the method overridden).

208

I ran clang-format -i -style=file AMDGPUAtomicOptimizer.cpp and this is what it did!

244–245

I can't use the IRBuilder's CreateIntrinsic because it will then try and mangle the amdgcn_mbcnt_lo like llvm.amdgcn.mbcnt.lo.i32, whereas we expect the name to be sans-type-suffix.

[nhaehnle]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

244–245

Ugh, this is a bug in CreateIntrinsic. It does:

Function *Fn = Intrinsic::getDeclaration(M, ID, { Args.front()->getType() });

... when in this particular case, the type vector should be empty.

There aren't that many users of CreateIntrinsic -- can you just fix CreateIntrinsic so that it takes an ArrayRef<Type*> like Intrinsic::getDeclaration? (As a separate preparatory patch obviously.)

[sheredom]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

244–245

Just to be clear - do you want me to get the IRBuilder fix in first? Or is it fine to let this patch in as is, and then fixup during the IRBuilder change?

[nhaehnle]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

244–245

I think we should do it right the first time.

[sheredom]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

244–245

See https://reviews.llvm.org/D52087

[sheredom]

Added an interaction with the DominatorTree, so that if its present in the PassManager we can preserve + update it.

[nhaehnle]

This still needs to be adjusted for D52087, and I have one minor comment, but mostly LGTM.

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

341

The last two arguments are defaults, so you can just leave them out.

[arsenm]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

58

Yes. We should be deleting them. I'm not sure why they exist in the first place - they are redundant with the name passed in the macro

[arsenm]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

140–141

You can use I.getPointerOperand/getValOperand

[sheredom]

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

140–141

So I had that originally - but because I am using ValIdx so that I can have a single optimizeAtomic call that works for atomicrmw insts and our atomic intrinsics, I thought this was slightly nicer overall.

[mareko]

What happens if a shader already does "if (threadID == 0) { do_atomic(); }"? Is the optimization skipped in this case?

[sheredom]

In D51969#1244238, @mareko wrote:

What happens if a shader already does "if (threadID == 0) { do_atomic(); }"? Is the optimization skipped in this case?

It is not skipped - the optimization would be applied twice. To be able to skip that kind of thing we need to track a further axis for a given value - we need to know if the value is divergent, uniform, or scalar. A scalar value would be like the one in the if statement of your example, its a value that is known to be only active for a single lane of the wavefront.

That is a much bigger change, and so we deemed it better to get this in as is - even if it will apply the optimization twice if the user had applied it, rather than not doing the optimization at all (which is a much worse performance penalty).

[sheredom]

Rebased ontop of tip to get the IRBuilder change in https://reviews.llvm.org/D52087, and incorporate the requested changes by @nhaehnle resulting from that.

[nhaehnle]

LGTM

lib/Target/AMDGPU/AMDGPU.h

 extern char &AMDGPUMachineCFGStructurizerID;
 
 void initializeAMDGPUAlwaysInlinePass(PassRegistry&);
 
 Pass *createAMDGPUAnnotateKernelFeaturesPass();
 void initializeAMDGPUAnnotateKernelFeaturesPass(PassRegistry &);
 extern char &AMDGPUAnnotateKernelFeaturesID;
 
+FunctionPass *createAMDGPUAtomicOptimizerPass();
+void initializeAMDGPUAtomicOptimizerPass(PassRegistry &);
+extern char &AMDGPUAtomicOptimizerID;
+
 ModulePass *createAMDGPULowerIntrinsicsPass();
 void initializeAMDGPULowerIntrinsicsPass(PassRegistry &);
 extern char &AMDGPULowerIntrinsicsID;
 
 FunctionPass *createAMDGPULowerKernelArgumentsPass();
 void initializeAMDGPULowerKernelArgumentsPass(PassRegistry &);
 extern char &AMDGPULowerKernelArgumentsID;
 

lib/Target/AMDGPU/AMDGPUAtomicOptimizer.cpp

+//===-- AMDGPUAtomicOptimizer.cpp -----------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This pass optimizes atomic operations by using a single lane of a wavefront
+/// to perform the atomic operation, thus reducing contention on that memory
+/// location.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "AMDGPUSubtarget.h"
+#include "llvm/Analysis/LegacyDivergenceAnalysis.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstVisitor.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+
+#define DEBUG_TYPE "amdgpu-atomic-optimizer"
+
+using namespace llvm;
+
+namespace {
+
+enum DPP_CTRL {
+  DPP_ROW_SR1 = 0x111,
+  DPP_ROW_SR2 = 0x112,
+  DPP_ROW_SR4 = 0x114,
+  DPP_ROW_SR8 = 0x118,
+  DPP_WF_SR1 = 0x138,
+  DPP_ROW_BCAST15 = 0x142,
+  DPP_ROW_BCAST31 = 0x143
+};
+
+struct ReplacementInfo {
+  Instruction *I;
+  Instruction::BinaryOps Op;
+  unsigned ValIdx;
+  bool ValDivergent;
+};
+
+class AMDGPUAtomicOptimizer : public FunctionPass,
+                              public InstVisitor<AMDGPUAtomicOptimizer> {
+private:
+  SmallVector<ReplacementInfo, 8> ToReplace;
+  const LegacyDivergenceAnalysis *DA;
+  const DataLayout *DL;
+  DominatorTree *DT;
+  bool HasDPP;
+
+  void optimizeAtomic(Instruction &I, Instruction::BinaryOps Op,
+                      unsigned ValIdx, bool ValDivergent) const;
+
+  void setConvergent(CallInst *const CI) const;
+
+public:
+  static char ID;
+
+  AMDGPUAtomicOptimizer() : FunctionPass(ID) {}
+
+  bool runOnFunction(Function &F) override;
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addPreserved<DominatorTreeWrapperPass>();
+    AU.addRequired<LegacyDivergenceAnalysis>();
+    AU.addRequired<TargetPassConfig>();
+  }
+
+  void visitAtomicRMWInst(AtomicRMWInst &I);
+  void visitIntrinsicInst(IntrinsicInst &I);
+};
+
+} // namespace
+
+char AMDGPUAtomicOptimizer::ID = 0;
+
+char &llvm::AMDGPUAtomicOptimizerID = AMDGPUAtomicOptimizer::ID;
+
+bool AMDGPUAtomicOptimizer::runOnFunction(Function &F) {
+  if (skipFunction(F)) {
+    return false;
+  }
+
+  DA = &getAnalysis<LegacyDivergenceAnalysis>();
+  DL = &F.getParent()->getDataLayout();
+  DominatorTreeWrapperPass *const DTW =
+      getAnalysisIfAvailable<DominatorTreeWrapperPass>();
+  DT = DTW ? &DTW->getDomTree() : nullptr;
+  const TargetPassConfig &TPC = getAnalysis<TargetPassConfig>();
+  const TargetMachine &TM = TPC.getTM<TargetMachine>();
+  const GCNSubtarget &ST = TM.getSubtarget<GCNSubtarget>(F);
+  HasDPP = ST.hasDPP();
+
+  visit(F);
+
+  const bool Changed = !ToReplace.empty();
+
+  for (ReplacementInfo &Info : ToReplace) {
+    optimizeAtomic(*Info.I, Info.Op, Info.ValIdx, Info.ValDivergent);
+  }
+
+  ToReplace.clear();
+
+  return Changed;
+}
+
+void AMDGPUAtomicOptimizer::visitAtomicRMWInst(AtomicRMWInst &I) {
+  // Early exit for unhandled address space atomic instructions.
+  switch (I.getPointerAddressSpace()) {
+  default:
+    return;
+  case AMDGPUAS::GLOBAL_ADDRESS:
+  case AMDGPUAS::LOCAL_ADDRESS:
+    break;
+  }
+
+  Instruction::BinaryOps Op;
+
+  switch (I.getOperation()) {
+  default:
+    return;
+  case AtomicRMWInst::Add:
+    Op = Instruction::Add;
+    break;
+  case AtomicRMWInst::Sub:
+    Op = Instruction::Sub;
+    break;
+  }
+
+  const unsigned PtrIdx = 0;
+  const unsigned ValIdx = 1;
+
+  // If the pointer operand is divergent, then each lane is doing an atomic
+  // operation on a different address, and we cannot optimize that.
+  if (DA->isDivergent(I.getOperand(PtrIdx))) {
+    return;
+  }
+
+  const bool ValDivergent = DA->isDivergent(I.getOperand(ValIdx));
+
+  // If the value operand is divergent, each lane is contributing a different
+  // value to the atomic calculation. We can only optimize divergent values if
+  // we have DPP available on our subtarget, and the atomic operation is 32
+  // bits.
+  if (ValDivergent && (!HasDPP || (DL->getTypeSizeInBits(I.getType()) != 32))) {
+    return;
+  }
+
+  // If we get here, we can optimize the atomic using a single wavefront-wide
+  // atomic operation to do the calculation for the entire wavefront, so
+  // remember the instruction so we can come back to it.
+  const ReplacementInfo Info = {&I, Op, ValIdx, ValDivergent};
+
+  ToReplace.push_back(Info);
+}
+
+void AMDGPUAtomicOptimizer::visitIntrinsicInst(IntrinsicInst &I) {
+  Instruction::BinaryOps Op;
+
+  switch (I.getIntrinsicID()) {
+  default:
+    return;
+  case Intrinsic::amdgcn_buffer_atomic_add:
+  case Intrinsic::amdgcn_struct_buffer_atomic_add:
+  case Intrinsic::amdgcn_raw_buffer_atomic_add:
+    Op = Instruction::Add;
+    break;
+  case Intrinsic::amdgcn_buffer_atomic_sub:
+  case Intrinsic::amdgcn_struct_buffer_atomic_sub:
+  case Intrinsic::amdgcn_raw_buffer_atomic_sub:
+    Op = Instruction::Sub;
+    break;
+  }
+
+  const unsigned ValIdx = 0;
+
+  const bool ValDivergent = DA->isDivergent(I.getOperand(ValIdx));
+
+  // If the value operand is divergent, each lane is contributing a different
+  // value to the atomic calculation. We can only optimize divergent values if
+  // we have DPP available on our subtarget, and the atomic operation is 32
+  // bits.
+  if (ValDivergent && (!HasDPP || (DL->getTypeSizeInBits(I.getType()) != 32))) {
+    return;
+  }
+
+  // If any of the other arguments to the intrinsic are divergent, we can't
+  // optimize the operation.
+  for (unsigned Idx = 1; Idx < I.getNumOperands(); Idx++) {
+    if (DA->isDivergent(I.getOperand(Idx))) {
+      return;
+    }
+  }
+
+  // If we get here, we can optimize the atomic using a single wavefront-wide
+  // atomic operation to do the calculation for the entire wavefront, so
+  // remember the instruction so we can come back to it.
+  const ReplacementInfo Info = {&I, Op, ValIdx, ValDivergent};
+
+  ToReplace.push_back(Info);
+}
+
+void AMDGPUAtomicOptimizer::optimizeAtomic(Instruction &I,
+                                           Instruction::BinaryOps Op,
+                                           unsigned ValIdx,
+                                           bool ValDivergent) const {
+  LLVMContext &Context = I.getContext();
+
+  // Start building just before the instruction.
+  IRBuilder<> B(&I);
+
+  Type *const Ty = I.getType();
+  const unsigned TyBitWidth = DL->getTypeSizeInBits(Ty);
+  Type *const VecTy = VectorType::get(B.getInt32Ty(), 2);
+
+  // This is the value in the atomic operation we need to combine in order to
+  // reduce the number of atomic operations.
+  Value *const V = I.getOperand(ValIdx);
+
+  // We need to know how many lanes are active within the wavefront, and we do
+  // this by getting the exec register, which tells us all the lanes that are
+  // active.
+  MDNode *const RegName =
+      llvm::MDNode::get(Context, llvm::MDString::get(Context, "exec"));
+  Value *const Metadata = llvm::MetadataAsValue::get(Context, RegName);
+  CallInst *const Exec =
+      B.CreateIntrinsic(Intrinsic::read_register, {B.getInt64Ty()}, {Metadata});
+  setConvergent(Exec);
+
+  // We need to know how many lanes are active within the wavefront that are
+  // below us. If we counted each lane linearly starting from 0, a lane is
+  // below us only if its associated index was less than ours. We do this by
+  // using the mbcnt intrinsic.
+  Value *const BitCast = B.CreateBitCast(Exec, VecTy);
+  Value *const ExtractLo = B.CreateExtractElement(BitCast, B.getInt32(0));
+  Value *const ExtractHi = B.CreateExtractElement(BitCast, B.getInt32(1));
+  CallInst *const PartialMbcnt = B.CreateIntrinsic(
+      Intrinsic::amdgcn_mbcnt_lo, {}, {ExtractLo, B.getInt32(0)});
+  CallInst *const Mbcnt = B.CreateIntrinsic(Intrinsic::amdgcn_mbcnt_hi, {},
+                                            {ExtractHi, PartialMbcnt});
+
+  Value *const MbcntCast = B.CreateIntCast(Mbcnt, Ty, false);
+
+  Value *LaneOffset = nullptr;
+  Value *NewV = nullptr;
+
+  // If we have a divergent value in each lane, we need to combine the value
+  // using DPP.
+  if (ValDivergent) {
+    // First we need to set all inactive invocations to 0, so that they can
+    // correctly contribute to the final result.
+    CallInst *const SetInactive = B.CreateIntrinsic(
+        Intrinsic::amdgcn_set_inactive, Ty, {V, B.getIntN(TyBitWidth, 0)});
+    setConvergent(SetInactive);
+    NewV = SetInactive;
+
+    const unsigned Iters = 6;
+    const unsigned DPPCtrl[Iters] = {DPP_ROW_SR1,     DPP_ROW_SR2,
+                                     DPP_ROW_SR4,     DPP_ROW_SR8,
+                                     DPP_ROW_BCAST15, DPP_ROW_BCAST31};
+    const unsigned RowMask[Iters] = {0xf, 0xf, 0xf, 0xf, 0xa, 0xc};
+
+    // This loop performs an inclusive scan across the wavefront, with all lanes
+    // active (by using the WWM intrinsic).
+    for (unsigned Idx = 0; Idx < Iters; Idx++) {
+      CallInst *const DPP = B.CreateIntrinsic(Intrinsic::amdgcn_mov_dpp, Ty,
+                                              {NewV, B.getInt32(DPPCtrl[Idx]),
+                                               B.getInt32(RowMask[Idx]),
+                                               B.getInt32(0xf), B.getFalse()});
+      setConvergent(DPP);
+      Value *const WWM = B.CreateIntrinsic(Intrinsic::amdgcn_wwm, Ty, DPP);
+
+      NewV = B.CreateBinOp(Op, NewV, WWM);
+      NewV = B.CreateIntrinsic(Intrinsic::amdgcn_wwm, Ty, NewV);
+    }
+
+    // NewV has returned the inclusive scan of V, but for the lane offset we
+    // require an exclusive scan. We do this by shifting the values from the
+    // entire wavefront right by 1, and by setting the bound_ctrl (last argument
+    // to the intrinsic below) to true, we can guarantee that 0 will be shifted
+    // into the 0'th invocation.
+    CallInst *const DPP =
+        B.CreateIntrinsic(Intrinsic::amdgcn_mov_dpp, {Ty},
+                          {NewV, B.getInt32(DPP_WF_SR1), B.getInt32(0xf),
+                           B.getInt32(0xf), B.getTrue()});
+    setConvergent(DPP);
+    LaneOffset = B.CreateIntrinsic(Intrinsic::amdgcn_wwm, Ty, DPP);
+
+    // Read the value from the last lane, which has accumlated the values of
+    // each active lane in the wavefront. This will be our new value with which
+    // we will provide to the atomic operation.
+    if (TyBitWidth == 64) {
+      Value *const ExtractLo = B.CreateTrunc(NewV, B.getInt32Ty());
+      Value *const ExtractHi =
+          B.CreateTrunc(B.CreateLShr(NewV, B.getInt64(32)), B.getInt32Ty());
+      CallInst *const ReadLaneLo = B.CreateIntrinsic(
+          Intrinsic::amdgcn_readlane, {}, {ExtractLo, B.getInt32(63)});
+      setConvergent(ReadLaneLo);
+      CallInst *const ReadLaneHi = B.CreateIntrinsic(
+          Intrinsic::amdgcn_readlane, {}, {ExtractHi, B.getInt32(63)});
+      setConvergent(ReadLaneHi);
+      Value *const PartialInsert = B.CreateInsertElement(
+          UndefValue::get(VecTy), ReadLaneLo, B.getInt32(0));
+      Value *const Insert =
+          B.CreateInsertElement(PartialInsert, ReadLaneHi, B.getInt32(1));
+      NewV = B.CreateBitCast(Insert, Ty);
+    } else if (TyBitWidth == 32) {
+      CallInst *const ReadLane = B.CreateIntrinsic(Intrinsic::amdgcn_readlane,
+                                                   {}, {NewV, B.getInt32(63)});
+      setConvergent(ReadLane);
+      NewV = ReadLane;
+    } else {
+      llvm_unreachable("Unhandled atomic bit width");
+    }
+  } else {
+    // Get the total number of active lanes we have by using popcount.
+    Instruction *const Ctpop = B.CreateUnaryIntrinsic(Intrinsic::ctpop, Exec);
+    Value *const CtpopCast = B.CreateIntCast(Ctpop, Ty, false);
+
+    // Calculate the new value we will be contributing to the atomic operation
+    // for the entire wavefront.
+    NewV = B.CreateMul(V, CtpopCast);
+    LaneOffset = B.CreateMul(V, MbcntCast);
+  }
+
+  // We only want a single lane to enter our new control flow, and we do this
+  // by checking if there are any active lanes below us. Only one lane will
+  // have 0 active lanes below us, so that will be the only one to progress.
+  Value *const Cond = B.CreateICmpEQ(MbcntCast, B.getIntN(TyBitWidth, 0));
+
+  // Store I's original basic block before we split the block.
+  BasicBlock *const EntryBB = I.getParent();
+
+  // We need to introduce some new control flow to force a single lane to be
+  // active. We do this by splitting I's basic block at I, and introducing the
+  // new block such that:
+  // entry --> single_lane -\
+  //       \------------------> exit
+  Instruction *const SingleLaneTerminator =
+      SplitBlockAndInsertIfThen(Cond, &I, false, nullptr, DT, nullptr);
+
+  // Move the IR builder into single_lane next.
+  B.SetInsertPoint(SingleLaneTerminator);
+
+  // Clone the original atomic operation into single lane, replacing the
+  // original value with our newly created one.
+  Instruction *const NewI = I.clone();
+  B.Insert(NewI);
+  NewI->setOperand(ValIdx, NewV);
+
+  // Move the IR builder into exit next, and start inserting just before the
+  // original instruction.
+  B.SetInsertPoint(&I);
+
+  // Create a PHI node to get our new atomic result into the exit block.
+  PHINode *const PHI = B.CreatePHI(Ty, 2);
+  PHI->addIncoming(UndefValue::get(Ty), EntryBB);
+  PHI->addIncoming(NewI, SingleLaneTerminator->getParent());
+
+  // We need to broadcast the value who was the lowest active lane (the first
+  // lane) to all other lanes in the wavefront. We use an intrinsic for this,
+  // but have to handle 64-bit broadcasts with two calls to this intrinsic.
+  Value *BroadcastI = nullptr;
+
+  if (TyBitWidth == 64) {
+    Value *const ExtractLo = B.CreateTrunc(PHI, B.getInt32Ty());
+    Value *const ExtractHi =
+        B.CreateTrunc(B.CreateLShr(PHI, B.getInt64(32)), B.getInt32Ty());
+    CallInst *const ReadFirstLaneLo =
+        B.CreateIntrinsic(Intrinsic::amdgcn_readfirstlane, {}, ExtractLo);
+    setConvergent(ReadFirstLaneLo);
+    CallInst *const ReadFirstLaneHi =
+        B.CreateIntrinsic(Intrinsic::amdgcn_readfirstlane, {}, ExtractHi);
+    setConvergent(ReadFirstLaneHi);
+    Value *const PartialInsert = B.CreateInsertElement(
+        UndefValue::get(VecTy), ReadFirstLaneLo, B.getInt32(0));
+    Value *const Insert =
+        B.CreateInsertElement(PartialInsert, ReadFirstLaneHi, B.getInt32(1));
+    BroadcastI = B.CreateBitCast(Insert, Ty);
+  } else if (TyBitWidth == 32) {
+    CallInst *const ReadFirstLane =
+        B.CreateIntrinsic(Intrinsic::amdgcn_readfirstlane, {}, PHI);
+    setConvergent(ReadFirstLane);
+    BroadcastI = ReadFirstLane;
+  } else {
+    llvm_unreachable("Unhandled atomic bit width");
+  }
+
+  // Now that we have the result of our single atomic operation, we need to
+  // get our individual lane's slice into the result. We use the lane offset we
+  // previously calculated combined with the atomic result value we got from the
+  // first lane, to get our lane's index into the atomic result.
+  Value *const Result = B.CreateBinOp(Op, BroadcastI, LaneOffset);
+
+  // Replace the original atomic instruction with the new one.
+  I.replaceAllUsesWith(Result);
+
+  // And delete the original.
+  I.eraseFromParent();
+}
+
+void AMDGPUAtomicOptimizer::setConvergent(CallInst *const CI) const {
+  CI->addAttribute(AttributeList::FunctionIndex, Attribute::Convergent);
+}
+
+INITIALIZE_PASS_BEGIN(AMDGPUAtomicOptimizer, DEBUG_TYPE,
+                      "AMDGPU atomic optimizations", false, false)
+INITIALIZE_PASS_DEPENDENCY(LegacyDivergenceAnalysis)
+INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
+INITIALIZE_PASS_END(AMDGPUAtomicOptimizer, DEBUG_TYPE,
+                    "AMDGPU atomic optimizations", false, false)
+
+FunctionPass *llvm::createAMDGPUAtomicOptimizerPass() {
+  return new AMDGPUAtomicOptimizer();
+}

lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

static cl::opt<bool> EnableLibCallSimplify(
   cl::Hidden);
 
 static cl::opt<bool> EnableLowerKernelArguments(
   "amdgpu-ir-lower-kernel-arguments",
   cl::desc("Lower kernel argument loads in IR pass"),
   cl::init(true),
   cl::Hidden);
 
+// Enable atomic optimization
+static cl::opt<bool> EnableAtomicOptimizations(
+  "amdgpu-atomic-optimizations",
+  cl::desc("Enable atomic optimizations"),
+  cl::init(false),
+  cl::Hidden);
+
 extern "C" void LLVMInitializeAMDGPUTarget() {
   // Register the target
   RegisterTargetMachine<R600TargetMachine> X(getTheAMDGPUTarget());
   RegisterTargetMachine<GCNTargetMachine> Y(getTheGCNTarget());
 
   PassRegistry *PR = PassRegistry::getPassRegistry();
   initializeR600ClauseMergePassPass(*PR);
   initializeR600ControlFlowFinalizerPass(*PR);
extern "C" void LLVMInitializeAMDGPUTarget() {
   initializeSIPeepholeSDWAPass(*PR);
   initializeSIShrinkInstructionsPass(*PR);
   initializeSIOptimizeExecMaskingPreRAPass(*PR);
   initializeSILoadStoreOptimizerPass(*PR);
   initializeAMDGPUAlwaysInlinePass(*PR);
   initializeAMDGPUAnnotateKernelFeaturesPass(*PR);
   initializeAMDGPUAnnotateUniformValuesPass(*PR);
   initializeAMDGPUArgumentUsageInfoPass(*PR);
+  initializeAMDGPUAtomicOptimizerPass(*PR);
   initializeAMDGPULowerKernelArgumentsPass(*PR);
   initializeAMDGPULowerKernelAttributesPass(*PR);
   initializeAMDGPULowerIntrinsicsPass(*PR);
   initializeAMDGPUOpenCLEnqueuedBlockLoweringPass(*PR);
   initializeAMDGPUPromoteAllocaPass(*PR);
   initializeAMDGPUCodeGenPreparePass(*PR);
   initializeAMDGPURewriteOutArgumentsPass(*PR);
   initializeAMDGPUUnifyMetadataPass(*PR);
ScheduleDAGInstrs *GCNPassConfig::createMachineScheduler(
   if (ST.enableSIScheduler())
     return createSIMachineScheduler(C);
   return createGCNMaxOccupancyMachineScheduler(C);
 }
 
 bool GCNPassConfig::addPreISel() {
   AMDGPUPassConfig::addPreISel();
 
+  if (EnableAtomicOptimizations) {
+    addPass(createAMDGPUAtomicOptimizerPass());
+  }
+
   // FIXME: We need to run a pass to propagate the attributes when calls are
   // supported.
   addPass(createAMDGPUAnnotateKernelFeaturesPass());
 
   // Merge divergent exit nodes. StructurizeCFG won't recognize the multi-exit
   // regions formed by them.
   addPass(&AMDGPUUnifyDivergentExitNodesID);
   if (!LateCFGStructurize) {

lib/Target/AMDGPU/CMakeLists.txt

 
 add_llvm_target(AMDGPUCodeGen
   AMDGPUAliasAnalysis.cpp
   AMDGPUAlwaysInlinePass.cpp
   AMDGPUAnnotateKernelFeatures.cpp
   AMDGPUAnnotateUniformValues.cpp
   AMDGPUArgumentUsageInfo.cpp
   AMDGPUAsmPrinter.cpp
+  AMDGPUAtomicOptimizer.cpp
   AMDGPUCallLowering.cpp
   AMDGPUCodeGenPrepare.cpp
   AMDGPUFrameLowering.cpp
   AMDGPUHSAMetadataStreamer.cpp
   AMDGPUInstrInfo.cpp
   AMDGPUInstructionSelector.cpp
   AMDGPUIntrinsicInfo.cpp
   AMDGPUISelDAGToDAG.cpp

test/CodeGen/AMDGPU/atomic_load_add.ll

-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GFX9,FUNC %s
-; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefixes=R600,FUNC %s
+; RUN: llc -march=amdgcn -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GFX9,FUNC %s
+; RUN: llc -march=r600 -mcpu=redwood -amdgpu-atomic-optimizations=false < %s | FileCheck -check-prefixes=R600,FUNC %s
 
 ; FUNC-LABEL: {{^}}atomic_add_local:
 ; SICIVI: s_mov_b32 m0
 ; GFX9-NOT: m0
 ; R600: LDS_ADD *
 ; GCN: ds_add_u32
 define amdgpu_kernel void @atomic_add_local(i32 addrspace(3)* %local) {
    %unused = atomicrmw volatile add i32 addrspace(3)* %local, i32 5 seq_cst

test/CodeGen/AMDGPU/atomic_load_sub.ll

-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9,FUNC %s
-; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -enable-var-scope -check-prefixes=R600,FUNC %s
+; RUN: llc -march=amdgcn -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9,FUNC %s
+; RUN: llc -march=r600 -mcpu=redwood -amdgpu-atomic-optimizations=false < %s | FileCheck -enable-var-scope -check-prefixes=R600,FUNC %s
 
 ; FUNC-LABEL: {{^}}atomic_sub_local:
 ; SICIVI: s_mov_b32 m0
 ; GFX9-NOT: m0
 
 ; R600: LDS_SUB *
 ; GCN: ds_sub_u32
 define amdgpu_kernel void @atomic_sub_local(i32 addrspace(3)* %local) {

test/CodeGen/AMDGPU/atomic_optimizations_buffer.ll

+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX7LESS %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+
+declare i32 @llvm.amdgcn.workitem.id.x()
+declare i32 @llvm.amdgcn.buffer.atomic.add(i32, <4 x i32>, i32, i32, i1)
+declare i32 @llvm.amdgcn.buffer.atomic.sub(i32, <4 x i32>, i32, i32, i1)
+
+; Show that what the atomic optimization pass will do for raw buffers.
+
+; GCN-LABEL: add_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.buffer.atomic.add(i32 5, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %additive) {
+entry:
+  %old = call i32 @llvm.amdgcn.buffer.atomic.add(i32 %additive, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_add v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.buffer.atomic.add(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_add v{{[0-9]+}}
+define amdgpu_kernel void @add_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.buffer.atomic.add(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.buffer.atomic.sub(i32 5, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %subitive) {
+entry:
+  %old = call i32 @llvm.amdgcn.buffer.atomic.sub(i32 %subitive, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_sub v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.buffer.atomic.sub(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_sub v{{[0-9]+}}
+define amdgpu_kernel void @sub_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.buffer.atomic.sub(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i1 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}

test/CodeGen/AMDGPU/atomic_optimizations_global_pointer.ll

+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX7LESS %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+
+declare i32 @llvm.amdgcn.workitem.id.x()
+
+; Show that what the atomic optimization pass will do for global pointers.
+
+; GCN-LABEL: add_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: {{flat|buffer|global}}_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_constant(i32 addrspace(1)* %out, i32 addrspace(1)* %inout) {
+entry:
+  %old = atomicrmw add i32 addrspace(1)* %inout, i32 5 acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: {{flat|buffer|global}}_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_uniform(i32 addrspace(1)* %out, i32 addrspace(1)* %inout, i32 %additive) {
+entry:
+  %old = atomicrmw add i32 addrspace(1)* %inout, i32 %additive acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_add v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_varying(i32 addrspace(1)* %out, i32 addrspace(1)* %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = atomicrmw add i32 addrspace(1)* %inout, i32 %lane acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_hi_u32_u24{{(_e[0-9]+)?}} v[[value_hi:[0-9]+]], s[[popcount]], 5
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value_lo:[0-9]+]], s[[popcount]], 5
+; GCN: {{flat|buffer|global}}_atomic_add_x2 v{{\[}}[[value_lo]]:[[value_hi]]{{\]}}
+define amdgpu_kernel void @add_i64_constant(i64 addrspace(1)* %out, i64 addrspace(1)* %inout) {
+entry:
+  %old = atomicrmw add i64 addrspace(1)* %inout, i64 5 acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s{{[0-9]+}}, s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: {{flat|buffer|global}}_atomic_add_x2 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @add_i64_uniform(i64 addrspace(1)* %out, i64 addrspace(1)* %inout, i64 %additive) {
+entry:
+  %old = atomicrmw add i64 addrspace(1)* %inout, i64 %additive acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_varying:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: {{flat|buffer|global}}_atomic_add_x2 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @add_i64_varying(i64 addrspace(1)* %out, i64 addrspace(1)* %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %zext = zext i32 %lane to i64
+  %old = atomicrmw add i64 addrspace(1)* %inout, i64 %zext acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: {{flat|buffer|global}}_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_constant(i32 addrspace(1)* %out, i32 addrspace(1)* %inout) {
+entry:
+  %old = atomicrmw sub i32 addrspace(1)* %inout, i32 5 acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: {{flat|buffer|global}}_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_uniform(i32 addrspace(1)* %out, i32 addrspace(1)* %inout, i32 %subitive) {
+entry:
+  %old = atomicrmw sub i32 addrspace(1)* %inout, i32 %subitive acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_sub v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_varying(i32 addrspace(1)* %out, i32 addrspace(1)* %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = atomicrmw sub i32 addrspace(1)* %inout, i32 %lane acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_hi_u32_u24{{(_e[0-9]+)?}} v[[value_hi:[0-9]+]], s[[popcount]], 5
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value_lo:[0-9]+]], s[[popcount]], 5
+; GCN: {{flat|buffer|global}}_atomic_sub_x2 v{{\[}}[[value_lo]]:[[value_hi]]{{\]}}
+define amdgpu_kernel void @sub_i64_constant(i64 addrspace(1)* %out, i64 addrspace(1)* %inout) {
+entry:
+  %old = atomicrmw sub i64 addrspace(1)* %inout, i64 5 acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s{{[0-9]+}}, s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: {{flat|buffer|global}}_atomic_sub_x2 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @sub_i64_uniform(i64 addrspace(1)* %out, i64 addrspace(1)* %inout, i64 %subitive) {
+entry:
+  %old = atomicrmw sub i64 addrspace(1)* %inout, i64 %subitive acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_varying:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: {{flat|buffer|global}}_atomic_sub_x2 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @sub_i64_varying(i64 addrspace(1)* %out, i64 addrspace(1)* %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %zext = zext i32 %lane to i64
+  %old = atomicrmw sub i64 addrspace(1)* %inout, i64 %zext acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}

test/CodeGen/AMDGPU/atomic_optimizations_local_pointer.ll

+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX7LESS %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+
+declare i32 @llvm.amdgcn.workitem.id.x()
+
+@local_var32 = addrspace(3) global i32 undef, align 4
+@local_var64 = addrspace(3) global i64 undef, align 8
+
+; Show that what the atomic optimization pass will do for local pointers.
+
+; GCN-LABEL: add_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: ds_add_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @add_i32_constant(i32 addrspace(1)* %out) {
+entry:
+  %old = atomicrmw add i32 addrspace(3)* @local_var32, i32 5 acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: ds_add_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @add_i32_uniform(i32 addrspace(1)* %out, i32 %additive) {
+entry:
+  %old = atomicrmw add i32 addrspace(3)* @local_var32, i32 %additive acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: ds_add_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: ds_add_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @add_i32_varying(i32 addrspace(1)* %out) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = atomicrmw add i32 addrspace(3)* @local_var32, i32 %lane acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_hi_u32_u24{{(_e[0-9]+)?}} v[[value_hi:[0-9]+]], s[[popcount]], 5
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value_lo:[0-9]+]], s[[popcount]], 5
+; GCN: ds_add_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}[[value_lo]]:[[value_hi]]{{\]}}
+define amdgpu_kernel void @add_i64_constant(i64 addrspace(1)* %out) {
+entry:
+  %old = atomicrmw add i64 addrspace(3)* @local_var64, i64 5 acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s{{[0-9]+}}, s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: ds_add_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @add_i64_uniform(i64 addrspace(1)* %out, i64 %additive) {
+entry:
+  %old = atomicrmw add i64 addrspace(3)* @local_var64, i64 %additive acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i64_varying:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: ds_add_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @add_i64_varying(i64 addrspace(1)* %out) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %zext = zext i32 %lane to i64
+  %old = atomicrmw add i64 addrspace(3)* @local_var64, i64 %zext acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: ds_sub_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @sub_i32_constant(i32 addrspace(1)* %out) {
+entry:
+  %old = atomicrmw sub i32 addrspace(3)* @local_var32, i32 5 acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: ds_sub_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @sub_i32_uniform(i32 addrspace(1)* %out, i32 %subitive) {
+entry:
+  %old = atomicrmw sub i32 addrspace(3)* @local_var32, i32 %subitive acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: ds_sub_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: ds_sub_rtn_u32 v{{[0-9]+}}, v{{[0-9]+}}, v[[value]]
+define amdgpu_kernel void @sub_i32_varying(i32 addrspace(1)* %out) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = atomicrmw sub i32 addrspace(3)* @local_var32, i32 %lane acq_rel
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_hi_u32_u24{{(_e[0-9]+)?}} v[[value_hi:[0-9]+]], s[[popcount]], 5
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value_lo:[0-9]+]], s[[popcount]], 5
+; GCN: ds_sub_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}[[value_lo]]:[[value_hi]]{{\]}}
+define amdgpu_kernel void @sub_i64_constant(i64 addrspace(1)* %out) {
+entry:
+  %old = atomicrmw sub i64 addrspace(3)* @local_var64, i64 5 acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s{{[0-9]+}}, s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: ds_sub_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @sub_i64_uniform(i64 addrspace(1)* %out, i64 %subitive) {
+entry:
+  %old = atomicrmw sub i64 addrspace(3)* @local_var64, i64 %subitive acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i64_varying:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: ds_sub_rtn_u64 v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}, v{{[0-9]+}}, v{{\[}}{{[0-9]+}}:{{[0-9]+}}{{\]}}
+define amdgpu_kernel void @sub_i64_varying(i64 addrspace(1)* %out) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %zext = zext i32 %lane to i64
+  %old = atomicrmw sub i64 addrspace(3)* @local_var64, i64 %zext acq_rel
+  store i64 %old, i64 addrspace(1)* %out
+  ret void
+}

test/CodeGen/AMDGPU/atomic_optimizations_raw_buffer.ll

+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX7LESS %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+
+declare i32 @llvm.amdgcn.workitem.id.x()
+declare i32 @llvm.amdgcn.raw.buffer.atomic.add(i32, <4 x i32>, i32, i32, i32)
+declare i32 @llvm.amdgcn.raw.buffer.atomic.sub(i32, <4 x i32>, i32, i32, i32)
+
+; Show that what the atomic optimization pass will do for raw buffers.
+
+; GCN-LABEL: add_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.add(i32 5, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %additive) {
+entry:
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.add(i32 %additive, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_add v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.add(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_add v{{[0-9]+}}
+define amdgpu_kernel void @add_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.add(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.sub(i32 5, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %subitive) {
+entry:
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.sub(i32 %subitive, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_sub v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.sub(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_sub v{{[0-9]+}}
+define amdgpu_kernel void @sub_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.raw.buffer.atomic.sub(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}

test/CodeGen/AMDGPU/atomic_optimizations_struct_buffer.ll

+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX7LESS %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+; RUN: llc -march=amdgcn -mtriple=amdgcn---amdgiz -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=true -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX8MORE %s
+
+declare i32 @llvm.amdgcn.workitem.id.x()
+declare i32 @llvm.amdgcn.struct.buffer.atomic.add(i32, <4 x i32>, i32, i32, i32, i32)
+declare i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32, <4 x i32>, i32, i32, i32, i32)
+
+; Show that what the atomic optimization pass will do for struct buffers.
+
+; GCN-LABEL: add_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.add(i32 5, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %additive) {
+entry:
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.add(i32 %additive, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_add v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_add v[[value]]
+define amdgpu_kernel void @add_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.add(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_vindex:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_add v{{[0-9]+}}
+define amdgpu_kernel void @add_i32_varying_vindex(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.add(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: add_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_add v{{[0-9]+}}
+define amdgpu_kernel void @add_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.add(i32 1, <4 x i32> %inout, i32 0, i32 %lane, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_constant:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: v_mul_u32_u24{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[popcount]], 5
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_constant(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32 5, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_uniform:
+; GCN: s_mov_b64 s{{\[}}[[exec_lo:[0-9]+]]:[[exec_hi:[0-9]+]]{{\]}}, exec
+; GCN: v_mbcnt_lo_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_lo:[0-9]+]], s[[exec_lo]], 0
+; GCN: v_mbcnt_hi_u32_b32{{(_e[0-9]+)?}} v[[mbcnt_hi:[0-9]+]], s[[exec_hi]], v[[mbcnt_lo]]
+; GCN: v_cmp_eq_u32{{(_e[0-9]+)?}} vcc, 0, v[[mbcnt_hi]]
+; GCN: s_bcnt1_i32_b64 s[[popcount:[0-9]+]], s{{\[}}[[exec_lo]]:[[exec_hi]]{{\]}}
+; GCN: s_mul_i32 s[[scalar_value:[0-9]+]], s{{[0-9]+}}, s[[popcount]]
+; GCN: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GCN: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_uniform(i32 addrspace(1)* %out, <4 x i32> %inout, i32 %subitive) {
+entry:
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32 %subitive, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_vdata:
+; GFX7LESS-NOT: v_mbcnt_lo_u32_b32
+; GFX7LESS-NOT: v_mbcnt_hi_u32_b32
+; GFX7LESS-NOT: s_bcnt1_i32_b64
+; GFX7LESS: buffer_atomic_sub v{{[0-9]+}}
+; GFX8MORE: v_readlane_b32 s[[scalar_value:[0-9]+]], v{{[0-9]+}}, 63
+; GFX8MORE: v_mov_b32{{(_e[0-9]+)?}} v[[value:[0-9]+]], s[[scalar_value]]
+; GFX8MORE: buffer_atomic_sub v[[value]]
+define amdgpu_kernel void @sub_i32_varying_vdata(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32 %lane, <4 x i32> %inout, i32 0, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_vindex:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_sub v{{[0-9]+}}
+define amdgpu_kernel void @sub_i32_varying_vindex(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32 1, <4 x i32> %inout, i32 %lane, i32 0, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: sub_i32_varying_offset:
+; GCN-NOT: v_mbcnt_lo_u32_b32
+; GCN-NOT: v_mbcnt_hi_u32_b32
+; GCN-NOT: s_bcnt1_i32_b64
+; GCN: buffer_atomic_sub v{{[0-9]+}}
+define amdgpu_kernel void @sub_i32_varying_offset(i32 addrspace(1)* %out, <4 x i32> %inout) {
+entry:
+  %lane = call i32 @llvm.amdgcn.workitem.id.x()
+  %old = call i32 @llvm.amdgcn.struct.buffer.atomic.sub(i32 1, <4 x i32> %inout, i32 0, i32 %lane, i32 0, i32 0)
+  store i32 %old, i32 addrspace(1)* %out
+  ret void
+}

test/CodeGen/AMDGPU/global_atomics.ll

-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SI,SIVI %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,VI,SIVI %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9 %s
+; RUN: llc -march=amdgcn -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SI,SIVI %s
+; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-atomic-optimizations=false -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,VI,SIVI %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9 %s
 
 ; GCN-LABEL: {{^}}atomic_add_i32_offset:
 ; SIVI: buffer_atomic_add v{{[0-9]+}}, off, s[{{[0-9]+}}:{{[0-9]+}}], 0 offset:16{{$}}
 ; GFX9: global_atomic_add v[{{[0-9]+}}:{{[0-9]+}}], v{{[0-9]+}}, off offset:16{{$}}
 define amdgpu_kernel void @atomic_add_i32_offset(i32 addrspace(1)* %out, i32 %in) {
 entry:
   %gep = getelementptr i32, i32 addrspace(1)* %out, i64 4
   %val = atomicrmw volatile add i32 addrspace(1)* %gep, i32 %in seq_cst

test/CodeGen/AMDGPU/global_atomics_i64.ll

-; RUN: llc -march=amdgcn -mcpu=bonaire -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CI,CIVI %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,VI,CIVI %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9 %s
+; RUN: llc -march=amdgcn -mcpu=bonaire -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CI,CIVI %s
+; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-atomic-optimizations=false -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,VI,CIVI %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9 %s
 
 ; GCN-LABEL: {{^}}atomic_add_i64_offset:
 ; CIVI: buffer_atomic_add_x2 v{{\[[0-9]+:[0-9]+\]}}, off, s[{{[0-9]+}}:{{[0-9]+}}], 0 offset:32{{$}}
 
 ; GFX9: global_atomic_add_x2 v{{\[[0-9]+:[0-9]+\]}}, v[{{[0-9]+}}:{{[0-9]+}}], off offset:32{{$}}
 define amdgpu_kernel void @atomic_add_i64_offset(i64 addrspace(1)* %out, i64 %in) {
 entry:
   %gep = getelementptr i64, i64 addrspace(1)* %out, i64 4

test/CodeGen/AMDGPU/llvm.amdgcn.buffer.atomic.ll

-;RUN: llc < %s -march=amdgcn -mcpu=verde -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
-;RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
+;RUN: llc < %s -march=amdgcn -mcpu=verde -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
+;RUN: llc < %s -march=amdgcn -mcpu=tonga -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
 
 ;CHECK-LABEL: {{^}}test1:
 ;CHECK-NOT: s_waitcnt
 ;CHECK: buffer_atomic_swap v0, off, s[0:3], 0 glc
 ;VI: s_movk_i32 [[SOFS:s[0-9]+]], 0x1ffc
 ;CHECK: s_waitcnt vmcnt(0)
 ;CHECK: buffer_atomic_swap v0, v1, s[0:3], 0 idxen glc
 ;CHECK: s_waitcnt vmcnt(0)

test/CodeGen/AMDGPU/llvm.amdgcn.raw.buffer.atomic.ll

-;RUN: llc < %s -march=amdgcn -mcpu=verde -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
-;RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
+;RUN: llc < %s -march=amdgcn -mcpu=verde -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
+;RUN: llc < %s -march=amdgcn -mcpu=tonga -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
 
 ;CHECK-LABEL: {{^}}test1:
 ;CHECK-NOT: s_waitcnt
 ;CHECK: buffer_atomic_swap v0, off, s[0:3], 0 glc
 ;CHECK: s_movk_i32 [[SOFS:s[0-9]+]], 0x1ffc
 ;CHECK: s_waitcnt vmcnt(0)
 ;CHECK: buffer_atomic_swap v0, v1, s[0:3], 0 offen glc
 ;CHECK: s_waitcnt vmcnt(0)

test/CodeGen/AMDGPU/llvm.amdgcn.struct.buffer.atomic.ll

-;RUN: llc < %s -march=amdgcn -mcpu=verde -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
-;RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
+;RUN: llc < %s -march=amdgcn -mcpu=verde -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
+;RUN: llc < %s -march=amdgcn -mcpu=tonga -amdgpu-atomic-optimizations=false -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
 
 ;CHECK-LABEL: {{^}}test1:
 ;CHECK-NOT: s_waitcnt
 ;CHECK: buffer_atomic_swap v0, {{v[0-9]+}}, s[0:3], 0 idxen glc
 ;CHECK: s_waitcnt vmcnt(0)
 ;CHECK: buffer_atomic_swap v0, {{v[0-9]+}}, s[0:3], 0 idxen glc
 ;CHECK: s_movk_i32 [[SOFS:s[0-9]+]], 0x1ffc
 ;CHECK: s_waitcnt vmcnt(0)

test/CodeGen/AMDGPU/local-atomics.ll

-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SI,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=bonaire -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI,SICIVI,FUNC %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9,FUNC %s
-; RUN: llc -march=r600 -mcpu=redwood -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=EG,FUNC %s
+; RUN: llc -march=amdgcn -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,SI,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=bonaire -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,CIVI,SICIVI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=GCN,GFX9,FUNC %s
+; RUN: llc -march=r600 -mcpu=redwood -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefixes=EG,FUNC %s
 
 ; FUNC-LABEL: {{^}}lds_atomic_xchg_ret_i32:
 ; EG: LDS_WRXCHG_RET *
 
 ; SICIVI-DAG: s_mov_b32 m0
 ; GFX9-NOT: m0
 
 ; GCN-DAG: s_load_dword [[SPTR:s[0-9]+]],

test/CodeGen/AMDGPU/local-atomics64.ll

-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,SI,SICIVI %s
-; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,VI,SICIVI,GFX89 %s
-; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,GFX9,GFX89 %s
+; RUN: llc -march=amdgcn -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,SI,SICIVI %s
+; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,VI,SICIVI,GFX89 %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=-flat-for-global -amdgpu-atomic-optimizations=false -verify-machineinstrs < %s | FileCheck -enable-var-scope -strict-whitespace -check-prefixes=GCN,GFX9,GFX89 %s
 
 ; GCN-LABEL: {{^}}lds_atomic_xchg_ret_i64:
 ; SICIVI: s_mov_b32 m0
 ; GFX9-NOT: m0
 
 ; GCN: ds_wrxchg_rtn_b64
 ; GCN: s_endpgm
 define amdgpu_kernel void @lds_atomic_xchg_ret_i64(i64 addrspace(1)* %out, i64 addrspace(3)* %ptr) nounwind {