diff --git a/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp b/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
index 2ad7fab8142..0a0b993778c 100644
--- a/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
+++ b/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
@@ -1928,7 +1928,7 @@ bool AMDGPUDAGToDAGISel::SelectScratchSAddr(SDNode *N,
   if (!TII->isLegalFLATOffset(COffsetVal, AMDGPUAS::PRIVATE_ADDRESS, true)) {
     int64_t RemainderOffset = COffsetVal;
     int64_t ImmField = 0;
-    const unsigned NumBits = TII->getNumFlatOffsetBits(true);
+    const unsigned NumBits = AMDGPU::getNumFlatOffsetBits(*Subtarget, true);
     // Use signed division by a power of two to truncate towards 0.
     int64_t D = 1LL << (NumBits - 1);
     RemainderOffset = (COffsetVal / D) * D;
diff --git a/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp b/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
index 22c32400ecb..1fd6c2cca6d 100644
--- a/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
+++ b/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
@@ -3646,22 +3646,20 @@ bool AMDGPUAsmParser::validateFlatOffset(const MCInst &Inst,
     return false;
   }
 
-  // Address offset is 12-bit signed for GFX10, 13-bit for GFX9.
   // For FLAT segment the offset must be positive;
   // MSB is ignored and forced to zero.
-  unsigned OffsetSize = isGFX9() ? 13 : 12;
   if (TSFlags & (SIInstrFlags::IsFlatGlobal | SIInstrFlags::IsFlatScratch)) {
+    unsigned OffsetSize = AMDGPU::getNumFlatOffsetBits(getSTI(), true);
     if (!isIntN(OffsetSize, Op.getImm())) {
       Error(getFlatOffsetLoc(Operands),
-            isGFX9() ? "expected a 13-bit signed offset" :
-                       "expected a 12-bit signed offset");
+            Twine("expected a ") + Twine(OffsetSize) + "-bit signed offset");
       return false;
     }
   } else {
-    if (!isUIntN(OffsetSize - 1, Op.getImm())) {
+    unsigned OffsetSize = AMDGPU::getNumFlatOffsetBits(getSTI(), false);
+    if (!isUIntN(OffsetSize, Op.getImm())) {
       Error(getFlatOffsetLoc(Operands),
-            isGFX9() ? "expected a 12-bit unsigned offset" :
-                       "expected an 11-bit unsigned offset");
+            Twine("expected a ") + Twine(OffsetSize) + "-bit unsigned offset");
       return false;
     }
   }
diff --git a/lib/Target/AMDGPU/SIInstrInfo.cpp b/lib/Target/AMDGPU/SIInstrInfo.cpp
index 01721595d55..889908bce90 100644
--- a/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -7053,13 +7053,6 @@ bool SIInstrInfo::isBufferSMRD(const MachineInstr &MI) const {
   return RI.getRegClass(RCID)->hasSubClassEq(&AMDGPU::SGPR_128RegClass);
 }
 
-unsigned SIInstrInfo::getNumFlatOffsetBits(bool Signed) const {
-  if (ST.getGeneration() >= AMDGPUSubtarget::GFX10)
-    return Signed ? 12 : 11;
-
-  return Signed ? 13 : 12;
-}
-
 bool SIInstrInfo::isLegalFLATOffset(int64_t Offset, unsigned AddrSpace,
                                     bool Signed) const {
   // TODO: Should 0 be special cased?
@@ -7069,10 +7062,8 @@ bool SIInstrInfo::isLegalFLATOffset(int64_t Offset, unsigned AddrSpace,
   if (ST.hasFlatSegmentOffsetBug() && AddrSpace == AMDGPUAS::FLAT_ADDRESS)
     return false;
 
-  if (ST.getGeneration() >= AMDGPUSubtarget::GFX10)
-    return Signed ? isInt<12>(Offset) : isUInt<11>(Offset);
-
-  return Signed ? isInt<13>(Offset) :isUInt<12>(Offset);
+  unsigned N = AMDGPU::getNumFlatOffsetBits(ST, Signed);
+  return Signed ? isIntN(N, Offset) : isUIntN(N, Offset);
 }
 
 std::pair<int64_t, int64_t> SIInstrInfo::splitFlatOffset(int64_t COffsetVal,
@@ -7080,7 +7071,7 @@ std::pair<int64_t, int64_t> SIInstrInfo::splitFlatOffset(int64_t COffsetVal,
                                                          bool IsSigned) const {
   int64_t RemainderOffset = COffsetVal;
   int64_t ImmField = 0;
-  const unsigned NumBits = getNumFlatOffsetBits(IsSigned);
+  const unsigned NumBits = AMDGPU::getNumFlatOffsetBits(ST, IsSigned);
   if (IsSigned) {
     // Use signed division by a power of two to truncate towards 0.
     int64_t D = 1LL << (NumBits - 1);
diff --git a/lib/Target/AMDGPU/SIInstrInfo.h b/lib/Target/AMDGPU/SIInstrInfo.h
index 39b512a967e..4625cefa1e3 100644
--- a/lib/Target/AMDGPU/SIInstrInfo.h
+++ b/lib/Target/AMDGPU/SIInstrInfo.h
@@ -1042,8 +1042,6 @@ public:
     return isUInt<12>(Imm);
   }
 
-  unsigned getNumFlatOffsetBits(bool Signed) const;
-
   /// Returns if \p Offset is legal for the subtarget as the offset to a FLAT
   /// encoded instruction. If \p Signed, this is for an instruction that
   /// interprets the offset as signed.
diff --git a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
index b5a0d43645d..c0c5c683c1f 100644
--- a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
+++ b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
@@ -1526,6 +1526,14 @@ Optional<int64_t> getSMRDEncodedLiteralOffset32(const MCSubtargetInfo &ST,
   return isUInt<32>(EncodedOffset) ? Optional<int64_t>(EncodedOffset) : None;
 }
 
+unsigned getNumFlatOffsetBits(const MCSubtargetInfo &ST, bool Signed) {
+  // Address offset is 12-bit signed for GFX10, 13-bit for GFX9.
+  if (AMDGPU::isGFX10(ST))
+    return Signed ? 12 : 11;
+
+  return Signed ? 13 : 12;
+}
+
 // Given Imm, split it into the values to put into the SOffset and ImmOffset
 // fields in an MUBUF instruction. Return false if it is not possible (due to a
 // hardware bug needing a workaround).
diff --git a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
index 297ed3e2200..c65acfc558e 100644
--- a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
+++ b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
@@ -742,6 +742,13 @@ Optional<int64_t> getSMRDEncodedOffset(const MCSubtargetInfo &ST,
 Optional<int64_t> getSMRDEncodedLiteralOffset32(const MCSubtargetInfo &ST,
                                                 int64_t ByteOffset);
 
+/// For FLAT segment the offset must be positive;
+/// MSB is ignored and forced to zero.
+///
+/// \return The number of bits available for the offset field in flat
+/// instructions.
+unsigned getNumFlatOffsetBits(const MCSubtargetInfo &ST, bool Signed);
+
 /// \returns true if this offset is small enough to fit in the SMRD
 /// offset field.  \p ByteOffset should be the offset in bytes and
 /// not the encoded offset.
diff --git a/test/MC/AMDGPU/flat-gfx10.s b/test/MC/AMDGPU/flat-gfx10.s
index b8975cdaf3c..97ab93d5a98 100644
--- a/test/MC/AMDGPU/flat-gfx10.s
+++ b/test/MC/AMDGPU/flat-gfx10.s
@@ -5,13 +5,13 @@ flat_load_dword v1, v[3:4]
 // GFX10: encoding: [0x00,0x00,0x30,0xdc,0x03,0x00,0x7d,0x01]
 
 flat_load_dword v1, v[3:4] offset:-1
-// GFX10-ERR: :28: error: expected an 11-bit unsigned offset
+// GFX10-ERR: :28: error: expected a 11-bit unsigned offset
 
 flat_load_dword v1, v[3:4] offset:2047
 // GFX10: encoding: [0xff,0x07,0x30,0xdc,0x03,0x00,0x7d,0x01]
 
 flat_load_dword v1, v[3:4] offset:2048
-// GFX10-ERR: error: expected an 11-bit unsigned offset
+// GFX10-ERR: error: expected a 11-bit unsigned offset
 
 flat_load_dword v1, v[3:4] offset:4 glc
 // GFX10: encoding: [0x04,0x00,0x31,0xdc,0x03,0x00,0x7d,0x01]
diff --git a/test/MC/AMDGPU/gfx10_err_pos.s b/test/MC/AMDGPU/gfx10_err_pos.s
index 1d4e52d6c64..013dba64100 100644
--- a/test/MC/AMDGPU/gfx10_err_pos.s
+++ b/test/MC/AMDGPU/gfx10_err_pos.s
@@ -387,7 +387,7 @@ ds_swizzle_b32 v8, v2 offset:SWZ(QUAD_PERM, 0, 1, 2, 3)
 // expected an 11-bit unsigned offset
 
 flat_atomic_cmpswap v0, v[1:2], v[3:4] offset:4095 glc
-// CHECK: error: expected an 11-bit unsigned offset
+// CHECK: error: expected a 11-bit unsigned offset
 // CHECK-NEXT:{{^}}flat_atomic_cmpswap v0, v[1:2], v[3:4] offset:4095 glc
 // CHECK-NEXT:{{^}}                                       ^