AMDGPU: Create emergency stack slots during frame lowering

Test has a bogus verifier error which will be fixed by later commits.

llvm-svn: 252327

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
new file mode 100644
index 0000000..a2d8fa1
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
@@ -0,0 +1,33 @@
+//===----------------------- SIFrameLowering.cpp --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//==-----------------------------------------------------------------------===//
+
+#include "SIFrameLowering.h"
+#include "SIRegisterInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+
+using namespace llvm;
+
+void SIFrameLowering::processFunctionBeforeFrameFinalized(
+  MachineFunction &MF,
+  RegScavenger *RS) const {
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  bool MayNeedScavengingEmergencySlot = MFI->hasStackObjects();
+
+  assert((RS || !MayNeedScavengingEmergencySlot) &&
+         "RegScavenger required if spilling");
+
+  if (MayNeedScavengingEmergencySlot) {
+    int ScavengeFI = MFI->CreateSpillStackObject(
+      AMDGPU::SGPR_32RegClass.getSize(),
+      AMDGPU::SGPR_32RegClass.getAlignment());
+    RS->addScavengingFrameIndex(ScavengeFI);
+  }
+}