1 //===-- XCoreMachineFunctionInfo.cpp - XCore machine function info --------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "XCoreMachineFunctionInfo.h"
11 #include "XCoreInstrInfo.h"
12 #include "llvm/IR/Function.h"
13 
14 using namespace llvm;
15 
anchor()16 void XCoreFunctionInfo::anchor() { }
17 
isLargeFrame(const MachineFunction & MF) const18 bool XCoreFunctionInfo::isLargeFrame(const MachineFunction &MF) const {
19   if (CachedEStackSize == -1) {
20     CachedEStackSize = MF.getFrameInfo()->estimateStackSize(MF);
21   }
22   // isLargeFrame() is used when deciding if spill slots should be added to
23   // allow eliminateFrameIndex() to scavenge registers.
24   // This is only required when there is no FP and offsets are greater than
25   // ~256KB (~64Kwords). Thus only for code run on the emulator!
26   //
27   // The arbitrary value of 0xf000 allows frames of up to ~240KB before spill
28   // slots are added for the use of eliminateFrameIndex() register scavenging.
29   // For frames less than 240KB, it is assumed that there will be less than
30   // 16KB of function arguments.
31   return CachedEStackSize > 0xf000;
32 }
33 
createLRSpillSlot(MachineFunction & MF)34 int XCoreFunctionInfo::createLRSpillSlot(MachineFunction &MF) {
35   if (LRSpillSlotSet) {
36     return LRSpillSlot;
37   }
38   const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
39   MachineFrameInfo *MFI = MF.getFrameInfo();
40   if (! MF.getFunction()->isVarArg()) {
41     // A fixed offset of 0 allows us to save / restore LR using entsp / retsp.
42     LRSpillSlot = MFI->CreateFixedObject(RC->getSize(), 0, true);
43   } else {
44     LRSpillSlot = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
45   }
46   LRSpillSlotSet = true;
47   return LRSpillSlot;
48 }
49 
createFPSpillSlot(MachineFunction & MF)50 int XCoreFunctionInfo::createFPSpillSlot(MachineFunction &MF) {
51   if (FPSpillSlotSet) {
52     return FPSpillSlot;
53   }
54   const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
55   MachineFrameInfo *MFI = MF.getFrameInfo();
56   FPSpillSlot = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
57   FPSpillSlotSet = true;
58   return FPSpillSlot;
59 }
60 
createEHSpillSlot(MachineFunction & MF)61 const int* XCoreFunctionInfo::createEHSpillSlot(MachineFunction &MF) {
62   if (EHSpillSlotSet) {
63     return EHSpillSlot;
64   }
65   const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
66   MachineFrameInfo *MFI = MF.getFrameInfo();
67   EHSpillSlot[0] = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
68   EHSpillSlot[1] = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), true);
69   EHSpillSlotSet = true;
70   return EHSpillSlot;
71 }
72 
73