Index: llvm/lib/Target/AMDGPU/SIISelLowering.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -100,6 +100,11 @@
   cl::desc("Do not align and prefetch loops"),
   cl::init(false));
 
+static cl::opt<bool> VGPRReserveforSGPRSpill(
+  "amdgpu-reserve-vgpr-for-sgpr-spill",
+  cl::desc("Allocates one VGPR for future SGPR Spill"),
+  cl::init(false));
+
 static unsigned findFirstFreeSGPR(CCState &CCInfo) {
   unsigned NumSGPRs = AMDGPU::SGPR_32RegClass.getNumRegs();
   for (unsigned Reg = 0; Reg < NumSGPRs; ++Reg) {
@@ -10745,6 +10750,7 @@
   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
   const SIRegisterInfo *TRI = Subtarget->getRegisterInfo();
 
+
   if (Info->isEntryFunction()) {
     // Callable functions have fixed registers used for stack access.
     reservePrivateMemoryRegs(getTargetMachine(), MF, *TRI, *Info);
@@ -10790,6 +10796,15 @@
   }
 
   TargetLoweringBase::finalizeLowering(MF);
+
+  // Allocate a VGPR for future SGPR Spill if
+  // "amdgpu-reserve-vgpr-for-sgpr-spill" option is used
+  if (VGPRReserveforSGPRSpill) {
+    int fi = MF.getFrameInfo().CreateStackObject(4,4,false, nullptr, TargetStackID::SGPRSpill);
+    Info->allocateSGPRSpillToVGPR(MF, fi);
+    MF.getFrameInfo().RemoveStackObject(fi);
+  }
+
 }
 
 void SITargetLowering::computeKnownBitsForFrameIndex(const SDValue Op,