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Position Independent Code (PIC) support [3]

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42780 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bruno Cardoso Lopes 2007-10-09 03:15:11 +00:00
parent 0a6040063f
commit 8262df3aa4
3 changed files with 51 additions and 20 deletions
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51
lib/Target/Mips/MipsISelLowering.cpp
View File

@ -44,6 +44,7 @@ getTargetNodeName(unsigned Opcode) const
case MipsISD::Lo : return "MipsISD::Lo";
case MipsISD::Ret : return "MipsISD::Ret";
case MipsISD::Add : return "MipsISD::Add";
case MipsISD::LoadAddr : return "MipsISD::LoadAddr";
default : return NULL;
}
}
@ -146,18 +147,25 @@ AddLiveIn(MachineFunction &MF, unsigned PReg, TargetRegisterClass *RC)
SDOperand MipsTargetLowering::
LowerGlobalAddress(SDOperand Op, SelectionDAG &DAG)
{
SDOperand ResNode;
GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
SDOperand GA = DAG.getTargetGlobalAddress(GV, MVT::i32);
const MVT::ValueType *VTs = DAG.getNodeValueTypes(MVT::i32, MVT::Flag);
SDOperand Ops[] = { GA };
// On PIC code global addresses are loaded with "la" instruction
if (!(getTargetMachine().getRelocationModel() == Reloc::PIC_)) {
const MVT::ValueType *VTs = DAG.getNodeValueTypes(MVT::i32, MVT::Flag);
SDOperand Ops[] = { GA };
SDOperand Hi = DAG.getNode(MipsISD::Hi, VTs, 2, Ops, 1);
SDOperand Lo = DAG.getNode(MipsISD::Lo, MVT::i32, GA);
SDOperand Hi = DAG.getNode(MipsISD::Hi, VTs, 2, Ops, 1);
SDOperand Lo = DAG.getNode(MipsISD::Lo, MVT::i32, GA);
SDOperand InFlag = Hi.getValue(1);
return DAG.getNode(MipsISD::Add, MVT::i32, Lo, Hi, InFlag);
SDOperand InFlag = Hi.getValue(1);
ResNode = DAG.getNode(MipsISD::Add, MVT::i32, Lo, Hi, InFlag);
} else
ResNode = DAG.getNode(MipsISD::LoadAddr, MVT::i32, GA);
return ResNode;
}
SDOperand MipsTargetLowering::
@ -236,6 +244,7 @@ LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC)
SmallVector<SDOperand, 8> MemOpChains;
SDOperand StackPtr;
unsigned LastStackLoc=0;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
@ -273,8 +282,9 @@ LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC)
// Create the frame index object for this incoming parameter
// This guarantees that when allocating Local Area the firsts
// 16 bytes which are alwayes reserved won't be overwritten.
LastStackLoc = (16 + VA.getLocMemOffset());
int FI = MFI->CreateFixedObject(MVT::getSizeInBits(VA.getValVT())/8,
(16 + VA.getLocMemOffset()));
LastStackLoc);
SDOperand PtrOff = DAG.getFrameIndex(FI,getPointerTy());
@ -284,6 +294,14 @@ LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC)
}
}
// Create a stack location to hold GP when PIC is used
if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
LastStackLoc = (!LastStackLoc) ? (16) : (LastStackLoc+4);
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
MFI->CreateFixedObject(4, LastStackLoc);
MipsFI->setGPStackOffset(LastStackLoc);
}
// Transform all store nodes into one single node because
// all store nodes are independent of each other.
if (!MemOpChains.empty())
@ -301,13 +319,13 @@ LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG, unsigned CC)
InFlag = Chain.getValue(1);
}
// If the callee is a GlobalAddress node (quite common, every direct
// call is) turn it into a TargetGlobalAddress node so that legalize
// doesn't hack it.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
// If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
// direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
// node so that legalize doesn't hack it. Otherwise we have an indirect call,
// if PIC is used, the call must use register GP
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), getPointerTy());
} else
if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy());
// MipsJmpLink = #chain, #target_address, #opt_in_flags...
@ -543,8 +561,7 @@ LowerRET(SDOperand Op, SelectionDAG &DAG)
// ISD::RET => ret chain, (regnum1,val1), ...
// So i*2+1 index only the regnums
Chain = DAG.getCopyToReg(Chain, VA.getLocReg(),
Op.getOperand(i*2+1), Flag);
Chain = DAG.getCopyToReg(Chain, VA.getLocReg(), Op.getOperand(i*2+1), Flag);
// guarantee that all emitted copies are
// stuck together, avoiding something bad
@ -554,10 +571,10 @@ LowerRET(SDOperand Op, SelectionDAG &DAG)
// Return on Mips is always a "jr $ra"
if (Flag.Val)
return DAG.getNode(MipsISD::Ret, MVT::Other,
Chain, DAG.getRegister(Mips::RA, MVT::i32), Flag);
Chain, DAG.getRegister(Mips::RA, MVT::i32), Flag);
else // Return Void
return DAG.getNode(MipsISD::Ret, MVT::Other,
Chain, DAG.getRegister(Mips::RA, MVT::i32));
Chain, DAG.getRegister(Mips::RA, MVT::i32));
}
//===----------------------------------------------------------------------===//

5
lib/Target/Mips/MipsISelLowering.h
View File

@ -41,7 +41,10 @@ namespace llvm {
Ret,
// Need to support addition with a input flag
Add
Add,
// Used on PIC Code to load global addresses
LoadAddr
};
}

15
lib/Target/Mips/MipsRegisterInfo.cpp
View File

@ -369,9 +369,10 @@ emitPrologue(MachineFunction &MF) const
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
MachineBasicBlock::iterator MBBI = MBB.begin();
bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_);
// Replace the dummy '0' SPOffset by the negative offsets, as
// explained on LowerFORMAL_ARGUMENTS
// Replace the dummy '0' SPOffset by the negative
// offsets, as explained on LowerFORMAL_ARGUMENTS
MipsFI->adjustLoadArgsFI(MFI);
MipsFI->adjustStoreVarArgsFI(MFI);
@ -421,6 +422,10 @@ emitPrologue(MachineFunction &MF) const
// Update frame info
MFI->setStackSize(NumBytes);
// PIC speficic function prologue
if (isPIC)
BuildMI(MBB, MBBI, TII.get(Mips::CPLOAD)).addReg(Mips::T9);
// Adjust stack : addi sp, sp, (-imm)
BuildMI(MBB, MBBI, TII.get(Mips::ADDiu), Mips::SP)
.addReg(Mips::SP).addImm(-NumBytes);
@ -443,6 +448,12 @@ emitPrologue(MachineFunction &MF) const
BuildMI(MBB, MBBI, TII.get(Mips::ADDu), Mips::FP)
.addReg(Mips::SP).addReg(Mips::ZERO);
}
// PIC speficic function prologue
if ((isPIC) && (MFI->hasCalls()))
BuildMI(MBB, MBBI, TII.get(Mips::CPRESTORE))
.addImm(MipsFI->getGPStackOffset());
}
void MipsRegisterInfo::