[XCore] Support functions returning more than 4 words.

[oota-llvm.git] / lib / Target / XCore / XCoreMachineFunctionInfo.cpp

diff --git a/lib/Target/XCore/XCoreMachineFunctionInfo.cpp b/lib/Target/XCore/XCoreMachineFunctionInfo.cpp
index 7ca06729120efbe5b3955e654e3000472cd1d90e..9ef9752d0a5b0432075da3ae87f69dbb781663bf 100644 (file)
--- a/lib/Target/XCore/XCoreMachineFunctionInfo.cpp
+++ b/lib/Target/XCore/XCoreMachineFunctionInfo.cpp
@@ -8,7 +8,65 @@
 //===----------------------------------------------------------------------===//
 
 #include "XCoreMachineFunctionInfo.h"
+#include "XCoreInstrInfo.h"
+#include "llvm/IR/Function.h"
 
 using namespace llvm;
 
 void XCoreFunctionInfo::anchor() { }
+
+bool XCoreFunctionInfo::isLargeFrame(const MachineFunction &MF) const {
+  if (CachedEStackSize == -1) {
+    CachedEStackSize = MF.getFrameInfo()->estimateStackSize(MF);
+  }
+  // isLargeFrame() is used when deciding if spill slots should be added to
+  // allow eliminateFrameIndex() to scavenge registers.
+  // This is only required when there is no FP and offsets are greater than
+  // ~256KB (~64Kwords). Thus only for code run on the emulator!
+  //
+  // The arbitrary value of 0xf000 allows frames of up to ~240KB before spill
+  // slots are added for the use of eliminateFrameIndex() register scavenging.
+  // For frames less than 240KB, it is assumed that there will be less than
+  // 16KB of function arguments.
+  return CachedEStackSize > 0xf000;
+}
+
+int XCoreFunctionInfo::createLRSpillSlot(MachineFunction &MF) {
+  if (LRSpillSlotSet) {
+    return LRSpillSlot;
+  }
+  const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  if (! MF.getFunction()->isVarArg()) {
+    // A fixed offset of 0 allows us to save / restore LR using entsp / retsp.
+    LRSpillSlot = MFI->CreateFixedObject(RC->getSize(), 0, true);
+  } else {
+    LRSpillSlot = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
+  }
+  LRSpillSlotSet = true;
+  return LRSpillSlot;
+}
+
+int XCoreFunctionInfo::createFPSpillSlot(MachineFunction &MF) {
+  if (FPSpillSlotSet) {
+    return FPSpillSlot;
+  }
+  const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  FPSpillSlot = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
+  FPSpillSlotSet = true;
+  return FPSpillSlot;
+}
+
+const int* XCoreFunctionInfo::createEHSpillSlot(MachineFunction &MF) {
+  if (EHSpillSlotSet) {
+    return EHSpillSlot;
+  }
+  const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  EHSpillSlot[0] = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
+  EHSpillSlot[1] = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
+  EHSpillSlotSet = true;
+  return EHSpillSlot;
+}
+