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	The save area is twice as big and there is no struct return slot. The stack pointer is always 16-byte aligned (after adding the bias). Also eliminate the stack adjustment instructions around calls when the function has a reserved stack frame. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179083 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			109 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			109 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===-- SparcFrameLowering.cpp - Sparc Frame Information ------------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file contains the Sparc implementation of TargetFrameLowering class.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "SparcFrameLowering.h"
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| #include "SparcInstrInfo.h"
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| #include "SparcMachineFunctionInfo.h"
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| #include "llvm/CodeGen/MachineFrameInfo.h"
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| #include "llvm/CodeGen/MachineFunction.h"
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| #include "llvm/CodeGen/MachineInstrBuilder.h"
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| #include "llvm/CodeGen/MachineModuleInfo.h"
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| #include "llvm/CodeGen/MachineRegisterInfo.h"
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| #include "llvm/IR/DataLayout.h"
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| #include "llvm/IR/Function.h"
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| #include "llvm/Support/CommandLine.h"
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| #include "llvm/Target/TargetOptions.h"
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| 
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| using namespace llvm;
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| 
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| void SparcFrameLowering::emitPrologue(MachineFunction &MF) const {
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|   MachineBasicBlock &MBB = MF.front();
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|   MachineFrameInfo *MFI = MF.getFrameInfo();
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|   const SparcInstrInfo &TII =
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|     *static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
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|   MachineBasicBlock::iterator MBBI = MBB.begin();
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|   DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
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| 
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|   // Get the number of bytes to allocate from the FrameInfo
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|   int NumBytes = (int) MFI->getStackSize();
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| 
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|   if (SubTarget.is64Bit()) {
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|     // All 64-bit stack frames must be 16-byte aligned, and must reserve space
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|     // for spilling the 16 window registers at %sp+BIAS..%sp+BIAS+128.
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|     NumBytes += 128;
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|     // Frames with calls must also reserve space for 6 outgoing arguments
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|     // whether they are used or not. LowerCall_64 takes care of that.
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|     assert(NumBytes % 16 == 0 && "Stack size not 16-byte aligned");
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|   } else {
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|     // Emit the correct save instruction based on the number of bytes in
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|     // the frame. Minimum stack frame size according to V8 ABI is:
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|     //   16 words for register window spill
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|     //    1 word for address of returned aggregate-value
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|     // +  6 words for passing parameters on the stack
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|     // ----------
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|     //   23 words * 4 bytes per word = 92 bytes
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|     NumBytes += 92;
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| 
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|     // Round up to next doubleword boundary -- a double-word boundary
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|     // is required by the ABI.
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|     NumBytes = RoundUpToAlignment(NumBytes, 8);
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|   }
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|   NumBytes = -NumBytes;
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| 
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|   if (NumBytes >= -4096) {
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|     BuildMI(MBB, MBBI, dl, TII.get(SP::SAVEri), SP::O6)
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|       .addReg(SP::O6).addImm(NumBytes);
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|   } else {
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|     // Emit this the hard way.  This clobbers G1 which we always know is
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|     // available here.
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|     unsigned OffHi = (unsigned)NumBytes >> 10U;
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|     BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
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|     // Emit G1 = G1 + I6
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|     BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1)
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|       .addReg(SP::G1).addImm(NumBytes & ((1 << 10)-1));
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|     BuildMI(MBB, MBBI, dl, TII.get(SP::SAVErr), SP::O6)
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|       .addReg(SP::O6).addReg(SP::G1);
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|   }
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| }
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| 
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| void SparcFrameLowering::
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| eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
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|                               MachineBasicBlock::iterator I) const {
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|   if (!hasReservedCallFrame(MF)) {
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|     MachineInstr &MI = *I;
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|     DebugLoc DL = MI.getDebugLoc();
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|     int Size = MI.getOperand(0).getImm();
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|     if (MI.getOpcode() == SP::ADJCALLSTACKDOWN)
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|       Size = -Size;
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|     const SparcInstrInfo &TII =
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|       *static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
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|     if (Size)
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|       BuildMI(MBB, I, DL, TII.get(SP::ADDri), SP::O6).addReg(SP::O6)
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|         .addImm(Size);
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|   }
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|   MBB.erase(I);
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| }
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| 
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| 
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| void SparcFrameLowering::emitEpilogue(MachineFunction &MF,
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|                                   MachineBasicBlock &MBB) const {
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|   MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
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|   const SparcInstrInfo &TII =
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|     *static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
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|   DebugLoc dl = MBBI->getDebugLoc();
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|   assert(MBBI->getOpcode() == SP::RETL &&
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|          "Can only put epilog before 'retl' instruction!");
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|   BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
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|     .addReg(SP::G0);
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| }
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