1 files changed, 7 insertions, 1 deletions
diff --git a/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp b/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
index b6a982aee6be..adebb8c4a1c5 100644
--- a/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
+++ b/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
@@ -122,9 +122,15 @@ SIMachineFunctionInfo::SIMachineFunctionInfo(const MachineFunction &MF)
   bool MaySpill = ST.isVGPRSpillingEnabled(*F);
   bool HasStackObjects = FrameInfo.hasStackObjects();
 
-  if (HasStackObjects || MaySpill)
+  if (HasStackObjects || MaySpill) {
     PrivateSegmentWaveByteOffset = true;
 
+    // HS and GS always have the scratch wave offset in SGPR5 on GFX9.
+    if (ST.getGeneration() >= AMDGPUSubtarget::GFX9 &&
+        (CC == CallingConv::AMDGPU_HS || CC == CallingConv::AMDGPU_GS))
+      PrivateSegmentWaveByteOffsetSystemSGPR = AMDGPU::SGPR5;
+  }
+
   if (ST.isAmdCodeObjectV2(MF)) {
     if (HasStackObjects || MaySpill)
       PrivateSegmentBuffer = true;