Index: lib/Target/AMDGPU/SIMachineFunctionInfo.h
===================================================================
--- lib/Target/AMDGPU/SIMachineFunctionInfo.h
+++ lib/Target/AMDGPU/SIMachineFunctionInfo.h
@@ -675,9 +675,6 @@
     llvm_unreachable("unexpected dimension");
   }
 
-  /// \returns VGPR used for \p Dim' work item ID.
-  unsigned getWorkItemIDVGPR(unsigned Dim) const;
-
   unsigned getLDSWaveSpillSize() const {
     return LDSWaveSpillSize;
   }
Index: lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
===================================================================
--- lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
+++ lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
@@ -300,23 +300,6 @@
     MFI.setStackID(i, 0);
 }
 
-
-/// \returns VGPR used for \p Dim' work item ID.
-unsigned SIMachineFunctionInfo::getWorkItemIDVGPR(unsigned Dim) const {
-  switch (Dim) {
-  case 0:
-    assert(hasWorkItemIDX());
-    return AMDGPU::VGPR0;
-  case 1:
-    assert(hasWorkItemIDY());
-    return AMDGPU::VGPR1;
-  case 2:
-    assert(hasWorkItemIDZ());
-    return AMDGPU::VGPR2;
-  }
-  llvm_unreachable("unexpected dimension");
-}
-
 MCPhysReg SIMachineFunctionInfo::getNextUserSGPR() const {
   assert(NumSystemSGPRs == 0 && "System SGPRs must be added after user SGPRs");
   return AMDGPU::SGPR0 + NumUserSGPRs;