Index: lib/Target/AMDGPU/AMDGPU.td
===================================================================
--- lib/Target/AMDGPU/AMDGPU.td
+++ lib/Target/AMDGPU/AMDGPU.td
@@ -61,6 +61,24 @@
   "Support flat address space"
 >;
 
+def FeatureFlatInstOffsets : SubtargetFeature<"flat-inst-offsets",
+  "FlatInstOffsets",
+  "true",
+  "Flat instructions have immediate offset addressing mode"
+>;
+
+def FeatureFlatGlobalInsts : SubtargetFeature<"flat-global-insts",
+  "FlatGlobalInsts",
+  "true",
+  "Have global_* flat memory instructions"
+>;
+
+def FeatureFlatScratchInsts : SubtargetFeature<"flat-scratch-insts",
+  "FlatScratchInsts",
+  "true",
+  "Have scratch_* flat memory instructions"
+>;
+
 def FeatureUnalignedBufferAccess : SubtargetFeature<"unaligned-buffer-access",
   "UnalignedBufferAccess",
   "true",
@@ -407,7 +425,8 @@
    FeatureGCN3Encoding, FeatureCIInsts, Feature16BitInsts,
    FeatureSMemRealTime, FeatureScalarStores, FeatureInv2PiInlineImm,
    FeatureApertureRegs, FeatureGFX9Insts, FeatureVOP3P, FeatureVGPRIndexMode,
-   FeatureFastFMAF32, FeatureDPP
+   FeatureFastFMAF32, FeatureDPP,
+   FeatureFlatInstOffsets, FeatureFlatGlobalInsts, FeatureFlatScratchInsts
   ]
 >;
 
Index: lib/Target/AMDGPU/AMDGPUSubtarget.h
===================================================================
--- lib/Target/AMDGPU/AMDGPUSubtarget.h
+++ lib/Target/AMDGPU/AMDGPUSubtarget.h
@@ -145,6 +145,9 @@
   bool HasSDWA;
   bool HasDPP;
   bool FlatAddressSpace;
+  bool FlatInstOffsets;
+  bool FlatGlobalInsts;
+  bool FlatScratchInsts;
   bool R600ALUInst;
   bool CaymanISA;
   bool CFALUBug;
@@ -380,6 +383,18 @@
     return FlatAddressSpace;
   }
 
+  bool hasFlatInstOffsets() const {
+    return FlatInstOffsets;
+  }
+
+  bool hasFlatGlobalInsts() const {
+    return FlatGlobalInsts;
+  }
+
+  bool hasFlatScratchInsts() const {
+    return FlatScratchInsts;
+  }
+
   bool isMesaKernel(const MachineFunction &MF) const {
     return isMesa3DOS() && !AMDGPU::isShader(MF.getFunction()->getCallingConv());
   }
Index: lib/Target/AMDGPU/AMDGPUSubtarget.cpp
===================================================================
--- lib/Target/AMDGPU/AMDGPUSubtarget.cpp
+++ lib/Target/AMDGPU/AMDGPUSubtarget.cpp
@@ -125,6 +125,9 @@
     HasSDWA(false),
     HasDPP(false),
     FlatAddressSpace(false),
+    FlatInstOffsets(false),
+    FlatGlobalInsts(false),
+    FlatScratchInsts(false),
 
     R600ALUInst(false),
     CaymanISA(false),