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