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      1 //===-- XCoreMachineFunctionInfo.cpp - XCore machine function info --------===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8 
      9 #include "XCoreMachineFunctionInfo.h"
     10 #include "XCoreInstrInfo.h"
     11 #include "llvm/CodeGen/TargetSubtargetInfo.h"
     12 #include "llvm/IR/Function.h"
     13 
     14 using namespace llvm;
     15 
     16 void XCoreFunctionInfo::anchor() { }
     17 
     18 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 
     34 int XCoreFunctionInfo::createLRSpillSlot(MachineFunction &MF) {
     35   if (LRSpillSlotSet) {
     36     return LRSpillSlot;
     37   }
     38   const TargetRegisterClass &RC = XCore::GRRegsRegClass;
     39   const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo();
     40   MachineFrameInfo &MFI = MF.getFrameInfo();
     41   if (! MF.getFunction().isVarArg()) {
     42     // A fixed offset of 0 allows us to save / restore LR using entsp / retsp.
     43     LRSpillSlot = MFI.CreateFixedObject(TRI.getSpillSize(RC), 0, true);
     44   } else {
     45     LRSpillSlot = MFI.CreateStackObject(TRI.getSpillSize(RC),
     46                                         TRI.getSpillAlign(RC), true);
     47   }
     48   LRSpillSlotSet = true;
     49   return LRSpillSlot;
     50 }
     51 
     52 int XCoreFunctionInfo::createFPSpillSlot(MachineFunction &MF) {
     53   if (FPSpillSlotSet) {
     54     return FPSpillSlot;
     55   }
     56   const TargetRegisterClass &RC = XCore::GRRegsRegClass;
     57   const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo();
     58   MachineFrameInfo &MFI = MF.getFrameInfo();
     59   FPSpillSlot =
     60       MFI.CreateStackObject(TRI.getSpillSize(RC), TRI.getSpillAlign(RC), true);
     61   FPSpillSlotSet = true;
     62   return FPSpillSlot;
     63 }
     64 
     65 const int* XCoreFunctionInfo::createEHSpillSlot(MachineFunction &MF) {
     66   if (EHSpillSlotSet) {
     67     return EHSpillSlot;
     68   }
     69   const TargetRegisterClass &RC = XCore::GRRegsRegClass;
     70   const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo();
     71   MachineFrameInfo &MFI = MF.getFrameInfo();
     72   unsigned Size = TRI.getSpillSize(RC);
     73   Align Alignment = TRI.getSpillAlign(RC);
     74   EHSpillSlot[0] = MFI.CreateStackObject(Size, Alignment, true);
     75   EHSpillSlot[1] = MFI.CreateStackObject(Size, Alignment, true);
     76   EHSpillSlotSet = true;
     77   return EHSpillSlot;
     78 }
     79 
     80