Index: lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
===================================================================
--- lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
+++ lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
@@ -208,15 +208,14 @@
   bool SelectMUBUFOffset(SDValue Addr, SDValue &SRsrc, SDValue &Soffset,
                          SDValue &Offset) const;
 
+  template <bool IsSigned>
+  bool SelectFlatOffset(SDNode *N, SDValue Addr, SDValue &VAddr,
+                        SDValue &Offset, SDValue &SLC) const;
   bool SelectFlatAtomic(SDNode *N, SDValue Addr, SDValue &VAddr,
                         SDValue &Offset, SDValue &SLC) const;
   bool SelectFlatAtomicSigned(SDNode *N, SDValue Addr, SDValue &VAddr,
                               SDValue &Offset, SDValue &SLC) const;
 
-  template <bool IsSigned>
-  bool SelectFlatOffset(SDNode *N, SDValue Addr, SDValue &VAddr,
-                        SDValue &Offset, SDValue &SLC) const;
-
   bool SelectSMRDOffset(SDValue ByteOffsetNode, SDValue &Offset,
                         bool &Imm) const;
   SDValue Expand32BitAddress(SDValue Addr) const;
@@ -1594,14 +1593,55 @@
   return SelectMUBUFOffset(Addr, SRsrc, Soffset, Offset, GLC, SLC, TFE, DLC);
 }
 
+// Find a load or store from corresponding pattern root.
+// Roots may be build_vector, bitconvert or their combinations.
+static MemSDNode* findMemSDNode(SDNode *N) {
+  N = AMDGPUTargetLowering::stripBitcast(SDValue(N,0)).getNode();
+  if (MemSDNode *MN = dyn_cast<MemSDNode>(N))
+    return MN;
+  assert(isa<BuildVectorSDNode>(N));
+  for (SDValue V : N->op_values())
+    if (MemSDNode *MN =
+          dyn_cast<MemSDNode>(AMDGPUTargetLowering::stripBitcast(V)))
+      return MN;
+  llvm_unreachable("cannot find MemSDNode in the pattern!");
+}
+
 template <bool IsSigned>
 bool AMDGPUDAGToDAGISel::SelectFlatOffset(SDNode *N,
                                           SDValue Addr,
                                           SDValue &VAddr,
                                           SDValue &Offset,
                                           SDValue &SLC) const {
-  return static_cast<const SITargetLowering*>(getTargetLowering())->
-    SelectFlatOffset(IsSigned, *CurDAG, N, Addr, VAddr, Offset, SLC);
+  int64_t OffsetVal = 0;
+
+  if (Subtarget->hasFlatInstOffsets() &&
+      (!Subtarget->hasFlatSegmentOffsetBug() ||
+       findMemSDNode(N)->getAddressSpace() != AMDGPUAS::FLAT_ADDRESS) &&
+      CurDAG->isBaseWithConstantOffset(Addr)) {
+    SDValue N0 = Addr.getOperand(0);
+    SDValue N1 = Addr.getOperand(1);
+    int64_t COffsetVal = cast<ConstantSDNode>(N1)->getSExtValue();
+
+    if (Subtarget->getGeneration() >= AMDGPUSubtarget::GFX10) {
+      if ((IsSigned && isInt<12>(COffsetVal)) ||
+          (!IsSigned && isUInt<11>(COffsetVal))) {
+        Addr = N0;
+        OffsetVal = COffsetVal;
+      }
+    } else {
+      if ((IsSigned && isInt<13>(COffsetVal)) ||
+          (!IsSigned && isUInt<12>(COffsetVal))) {
+        Addr = N0;
+        OffsetVal = COffsetVal;
+      }
+    }
+  }
+
+  VAddr = Addr;
+  Offset = CurDAG->getTargetConstant(OffsetVal, SDLoc(), MVT::i16);
+  SLC = CurDAG->getTargetConstant(0, SDLoc(), MVT::i1);
+  return true;
 }
 
 bool AMDGPUDAGToDAGISel::SelectFlatAtomic(SDNode *N,
@@ -1613,10 +1653,10 @@
 }
 
 bool AMDGPUDAGToDAGISel::SelectFlatAtomicSigned(SDNode *N,
-                                          SDValue Addr,
-                                          SDValue &VAddr,
-                                          SDValue &Offset,
-                                          SDValue &SLC) const {
+                                                SDValue Addr,
+                                                SDValue &VAddr,
+                                                SDValue &Offset,
+                                                SDValue &SLC) const {
   return SelectFlatOffset<true>(N, Addr, VAddr, Offset, SLC);
 }
 
Index: lib/Target/AMDGPU/AMDGPUISelLowering.h
===================================================================
--- lib/Target/AMDGPU/AMDGPUISelLowering.h
+++ lib/Target/AMDGPU/AMDGPUISelLowering.h
@@ -323,10 +323,6 @@
   }
 
   AtomicExpansionKind shouldExpandAtomicRMWInIR(AtomicRMWInst *) const override;
-
-  bool SelectFlatOffset(bool IsSigned, SelectionDAG &DAG, SDNode *N,
-                        SDValue Addr, SDValue &VAddr, SDValue &Offset,
-                        SDValue &SLC) const;
 };
 
 namespace AMDGPUISD {
Index: lib/Target/AMDGPU/AMDGPUISelLowering.cpp
===================================================================
--- lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -2889,61 +2889,6 @@
   return true;
 }
 
-// Find a load or store from corresponding pattern root.
-// Roots may be build_vector, bitconvert or their combinations.
-static MemSDNode* findMemSDNode(SDNode *N) {
-  N = AMDGPUTargetLowering::stripBitcast(SDValue(N,0)).getNode();
-  if (MemSDNode *MN = dyn_cast<MemSDNode>(N))
-    return MN;
-  assert(isa<BuildVectorSDNode>(N));
-  for (SDValue V : N->op_values())
-    if (MemSDNode *MN =
-          dyn_cast<MemSDNode>(AMDGPUTargetLowering::stripBitcast(V)))
-      return MN;
-  llvm_unreachable("cannot find MemSDNode in the pattern!");
-}
-
-bool AMDGPUTargetLowering::SelectFlatOffset(bool IsSigned,
-                                            SelectionDAG &DAG,
-                                            SDNode *N,
-                                            SDValue Addr,
-                                            SDValue &VAddr,
-                                            SDValue &Offset,
-                                            SDValue &SLC) const {
-  const GCNSubtarget &ST =
-        DAG.getMachineFunction().getSubtarget<GCNSubtarget>();
-  int64_t OffsetVal = 0;
-
-  if (ST.hasFlatInstOffsets() &&
-      (!ST.hasFlatSegmentOffsetBug() ||
-       findMemSDNode(N)->getAddressSpace() != AMDGPUAS::FLAT_ADDRESS) &&
-      DAG.isBaseWithConstantOffset(Addr)) {
-    SDValue N0 = Addr.getOperand(0);
-    SDValue N1 = Addr.getOperand(1);
-    int64_t COffsetVal = cast<ConstantSDNode>(N1)->getSExtValue();
-
-    if (ST.getGeneration() >= AMDGPUSubtarget::GFX10) {
-      if ((IsSigned && isInt<12>(COffsetVal)) ||
-          (!IsSigned && isUInt<11>(COffsetVal))) {
-        Addr = N0;
-        OffsetVal = COffsetVal;
-      }
-    } else {
-      if ((IsSigned && isInt<13>(COffsetVal)) ||
-          (!IsSigned && isUInt<12>(COffsetVal))) {
-        Addr = N0;
-        OffsetVal = COffsetVal;
-      }
-    }
-  }
-
-  VAddr = Addr;
-  Offset = DAG.getTargetConstant(OffsetVal, SDLoc(), MVT::i16);
-  SLC = DAG.getTargetConstant(0, SDLoc(), MVT::i1);
-
-  return true;
-}
-
 // Replace load of an illegal type with a store of a bitcast to a friendlier
 // type.
 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,