[X86] Make sure load size is not larger than stack slot

[LuoYuanke]

LGTM.

llvm/lib/Target/X86/X86InstrInfo.cpp

void X86InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
   }
 }
 
 void X86InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
                                         MachineBasicBlock::iterator MI,
                                         Register DestReg, int FrameIdx,
                                         const TargetRegisterClass *RC,
                                         const TargetRegisterInfo *TRI) const {
+  const MachineFunction &MF = *MBB.getParent();
+  const MachineFrameInfo &MFI = MF.getFrameInfo();
+  assert(MFI.getObjectSize(FrameIdx) >= TRI->getSpillSize(*RC) &&
+         "Load size exceeds stack slot");
   if (RC->getID() == X86::TILERegClassID) {
     unsigned Opc = X86::TILELOADD;
     // tileloadd (%sp, %idx), %tmm
     MachineRegisterInfo &RegInfo = MBB.getParent()->getRegInfo();
     Register VirtReg = RegInfo.createVirtualRegister(&X86::GR64_NOSPRegClass);
     MachineInstr *NewMI =
         BuildMI(MBB, MI, DebugLoc(), get(X86::MOV64ri), VirtReg).addImm(64);
     NewMI = addFrameReference(BuildMI(MBB, MI, DebugLoc(), get(Opc), DestReg),
                               FrameIdx);
     MachineOperand &MO = NewMI->getOperand(3);
     MO.setReg(VirtReg);
     MO.setIsKill(true);
   } else if ((RC->getID() == X86::FR16RegClassID ||
               RC->getID() == X86::FR16XRegClassID) &&
              !Subtarget.hasFP16()) {
     unsigned Opc = Subtarget.hasAVX512() ? X86::VMOVSSZrm
                    : Subtarget.hasAVX()  ? X86::VMOVSSrm
                                          : X86::MOVSSrm;
     addFrameReference(BuildMI(MBB, MI, DebugLoc(), get(Opc), DestReg),
                       FrameIdx);
   } else {
-    const MachineFunction &MF = *MBB.getParent();
-    const MachineFrameInfo &MFI = MF.getFrameInfo();
     unsigned Alignment = std::max<uint32_t>(TRI->getSpillSize(*RC), 16);
     bool isAligned =
         (Subtarget.getFrameLowering()->getStackAlign() >= Alignment) ||
         (RI.canRealignStack(MF) && !MFI.isFixedObjectIndex(FrameIdx));
     unsigned Opc = getLoadRegOpcode(DestReg, RC, isAligned, Subtarget);
     addFrameReference(BuildMI(MBB, MI, DebugLoc(), get(Opc), DestReg),
                       FrameIdx);
   }