diff --git a/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
--- a/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
@@ -959,8 +959,11 @@
                      FuncInfo->FramePointerSaveIndex)) &&
          "Needed to save FP but didn't save it anywhere");
 
+  // If we allow spilling to AGPRs we may have saved FP but then spill
+  // everything into AGPRs instead of the stack.
   assert((HasFP || (!FuncInfo->SGPRForFPSaveRestoreCopy &&
-                    !FuncInfo->FramePointerSaveIndex)) &&
+                    !FuncInfo->FramePointerSaveIndex) ||
+                   EnableSpillVGPRToAGPR) &&
          "Saved FP but didn't need it");
 
   assert((!HasBP || (FuncInfo->SGPRForBPSaveRestoreCopy ||
diff --git a/llvm/test/CodeGen/AMDGPU/save-fp.ll b/llvm/test/CodeGen/AMDGPU/save-fp.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/save-fp.ll
@@ -0,0 +1,29 @@
+; RUN: llc -march=amdgcn -mcpu=gfx908 -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GFX908 %s
+; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GFX900 %s
+
+define void @foo() {
+bb:
+  ret void
+}
+
+; FIXME: We spill v40 into AGPR, but still save and restore FP
+; which is not needed in this case.
+
+; GCN-LABEL: {{^}}caller:
+
+; GFX900:     s_mov_b32 [[SAVED_FP:s[0-9]+]], s33
+; GFX900:     s_mov_b32 s33, s32
+; GFX908-NOT: s_mov_b32 s33, s32
+; GFX900:     buffer_store_dword
+; GFX908-DAG: s_mov_b32 [[SAVED_FP:s[0-9]+]], s33
+; GFX908-DAG: v_accvgpr_write_b32
+; GCN:        s_swappc_b64
+; GFX900:     buffer_load_dword
+; GFX908:     v_accvgpr_read_b32
+; GCN:        s_mov_b32 s33, [[SAVED_FP]]
+define i64 @caller() {
+bb:
+  call void asm sideeffect "", "~{v40}" ()
+  tail call void @foo()
+  ret i64 0
+}