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7274c73974
llvm-mirror/lib/Target/MBlaze/MBlazeISelLowering.cpp
Wesley Peck 7274c73974 1. Change MBlaze indirect branches to use absolute branch BRALD instead of pc relative branch BRLD. 
2. Make sure that the MBlaze stack is aligned to 4-byte boundaries.
3. Determine frame indexes that should be placed in the callers stack frame, as per the MBlaze ABI, and place them in the correct locations.

llvm-svn: 121639
2010-12-12 20:52:31 +00:00

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//===-- MBlazeISelLowering.cpp - MBlaze DAG Lowering Implementation -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that MBlaze uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mblaze-lower"
#include "MBlazeISelLowering.h"
#include "MBlazeMachineFunction.h"
#include "MBlazeTargetMachine.h"
#include "MBlazeTargetObjectFile.h"
#include "MBlazeSubtarget.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/CallingConv.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static bool CC_MBlaze_AssignReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State);
const char *MBlazeTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
case MBlazeISD::JmpLink : return "MBlazeISD::JmpLink";
case MBlazeISD::GPRel : return "MBlazeISD::GPRel";
case MBlazeISD::Wrap : return "MBlazeISD::Wrap";
case MBlazeISD::ICmp : return "MBlazeISD::ICmp";
case MBlazeISD::Ret : return "MBlazeISD::Ret";
case MBlazeISD::Select_CC : return "MBlazeISD::Select_CC";
default : return NULL;
}
}
MBlazeTargetLowering::MBlazeTargetLowering(MBlazeTargetMachine &TM)
: TargetLowering(TM, new MBlazeTargetObjectFile()) {
Subtarget = &TM.getSubtarget<MBlazeSubtarget>();
// MBlaze does not have i1 type, so use i32 for
// setcc operations results (slt, sgt, ...).
setBooleanContents(ZeroOrOneBooleanContent);
// Set up the register classes
addRegisterClass(MVT::i32, MBlaze::GPRRegisterClass);
if (Subtarget->hasFPU()) {
addRegisterClass(MVT::f32, MBlaze::GPRRegisterClass);
setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
}
// Floating point operations which are not supported
setOperationAction(ISD::FREM, MVT::f32, Expand);
setOperationAction(ISD::UINT_TO_FP, MVT::i8, Expand);
setOperationAction(ISD::UINT_TO_FP, MVT::i16, Expand);
setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
setOperationAction(ISD::FP_ROUND, MVT::f32, Expand);
setOperationAction(ISD::FP_ROUND, MVT::f64, Expand);
setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
setOperationAction(ISD::FSIN, MVT::f32, Expand);
setOperationAction(ISD::FCOS, MVT::f32, Expand);
setOperationAction(ISD::FPOWI, MVT::f32, Expand);
setOperationAction(ISD::FPOW, MVT::f32, Expand);
setOperationAction(ISD::FLOG, MVT::f32, Expand);
setOperationAction(ISD::FLOG2, MVT::f32, Expand);
setOperationAction(ISD::FLOG10, MVT::f32, Expand);
setOperationAction(ISD::FEXP, MVT::f32, Expand);
// Load extented operations for i1 types must be promoted
setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
// Sign extended loads must be expanded
setLoadExtAction(ISD::SEXTLOAD, MVT::i8, Expand);
setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand);
// MBlaze has no REM or DIVREM operations.
setOperationAction(ISD::UREM, MVT::i32, Expand);
setOperationAction(ISD::SREM, MVT::i32, Expand);
setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
// If the processor doesn't support multiply then expand it
if (!Subtarget->hasMul()) {
setOperationAction(ISD::MUL, MVT::i32, Expand);
}
// If the processor doesn't support 64-bit multiply then expand
if (!Subtarget->hasMul() || !Subtarget->hasMul64()) {
setOperationAction(ISD::MULHS, MVT::i32, Expand);
setOperationAction(ISD::MULHS, MVT::i64, Expand);
setOperationAction(ISD::MULHU, MVT::i32, Expand);
setOperationAction(ISD::MULHU, MVT::i64, Expand);
}
// If the processor doesn't support division then expand
if (!Subtarget->hasDiv()) {
setOperationAction(ISD::UDIV, MVT::i32, Expand);
setOperationAction(ISD::SDIV, MVT::i32, Expand);
}
// Expand unsupported conversions
setOperationAction(ISD::BITCAST, MVT::f32, Expand);
setOperationAction(ISD::BITCAST, MVT::i32, Expand);
// Expand SELECT_CC
setOperationAction(ISD::SELECT_CC, MVT::Other, Expand);
// MBlaze doesn't have MUL_LOHI
setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
// Used by legalize types to correctly generate the setcc result.
// Without this, every float setcc comes with a AND/OR with the result,
// we don't want this, since the fpcmp result goes to a flag register,
// which is used implicitly by brcond and select operations.
AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
AddPromotedToType(ISD::SELECT, MVT::i1, MVT::i32);
AddPromotedToType(ISD::SELECT_CC, MVT::i1, MVT::i32);
// MBlaze Custom Operations
setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
setOperationAction(ISD::JumpTable, MVT::i32, Custom);
setOperationAction(ISD::ConstantPool, MVT::i32, Custom);
// Variable Argument support
setOperationAction(ISD::VASTART, MVT::Other, Custom);
setOperationAction(ISD::VAEND, MVT::Other, Expand);
setOperationAction(ISD::VAARG, MVT::Other, Expand);
setOperationAction(ISD::VACOPY, MVT::Other, Expand);
// Operations not directly supported by MBlaze.
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
setOperationAction(ISD::BR_JT, MVT::Other, Expand);
setOperationAction(ISD::BR_CC, MVT::Other, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
setOperationAction(ISD::ROTL, MVT::i32, Expand);
setOperationAction(ISD::ROTR, MVT::i32, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::CTLZ, MVT::i32, Expand);
setOperationAction(ISD::CTTZ, MVT::i32, Expand);
setOperationAction(ISD::CTPOP, MVT::i32, Expand);
setOperationAction(ISD::BSWAP, MVT::i32, Expand);
// We don't have line number support yet.
setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
// Use the default for now
setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
// MBlaze doesn't have extending float->double load/store
setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
setTruncStoreAction(MVT::f64, MVT::f32, Expand);
setStackPointerRegisterToSaveRestore(MBlaze::R1);
computeRegisterProperties();
}
MVT::SimpleValueType MBlazeTargetLowering::getSetCCResultType(EVT VT) const {
return MVT::i32;
}
/// getFunctionAlignment - Return the Log2 alignment of this function.
unsigned MBlazeTargetLowering::getFunctionAlignment(const Function *) const {
return 2;
}
SDValue MBlazeTargetLowering::LowerOperation(SDValue Op,
SelectionDAG &DAG) const {
switch (Op.getOpcode())
{
case ISD::ConstantPool: return LowerConstantPool(Op, DAG);
case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG);
case ISD::JumpTable: return LowerJumpTable(Op, DAG);
case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG);
case ISD::VASTART: return LowerVASTART(Op, DAG);
}
return SDValue();
}
//===----------------------------------------------------------------------===//
// Lower helper functions
//===----------------------------------------------------------------------===//
MachineBasicBlock*
MBlazeTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *BB) const {
const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
DebugLoc dl = MI->getDebugLoc();
switch (MI->getOpcode()) {
default: assert(false && "Unexpected instr type to insert");
case MBlaze::ShiftRL:
case MBlaze::ShiftRA:
case MBlaze::ShiftL: {
// To "insert" a shift left instruction, we actually have to insert a
// simple loop. The incoming instruction knows the destination vreg to
// set, the source vreg to operate over and the shift amount.
const BasicBlock *LLVM_BB = BB->getBasicBlock();
MachineFunction::iterator It = BB;
++It;
// start:
// andi samt, samt, 31
// beqid samt, finish
// add dst, src, r0
// loop:
// addik samt, samt, -1
// sra dst, dst
// bneid samt, loop
// nop
// finish:
MachineFunction *F = BB->getParent();
MachineRegisterInfo &R = F->getRegInfo();
MachineBasicBlock *loop = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *finish = F->CreateMachineBasicBlock(LLVM_BB);
F->insert(It, loop);
F->insert(It, finish);
// Update machine-CFG edges by transfering adding all successors and
// remaining instructions from the current block to the new block which
// will contain the Phi node for the select.
finish->splice(finish->begin(), BB,
llvm::next(MachineBasicBlock::iterator(MI)),
BB->end());
finish->transferSuccessorsAndUpdatePHIs(BB);
// Add the true and fallthrough blocks as its successors.
BB->addSuccessor(loop);
BB->addSuccessor(finish);
// Next, add the finish block as a successor of the loop block
loop->addSuccessor(finish);
loop->addSuccessor(loop);
unsigned IAMT = R.createVirtualRegister(MBlaze::GPRRegisterClass);
BuildMI(BB, dl, TII->get(MBlaze::ANDI), IAMT)
.addReg(MI->getOperand(2).getReg())
.addImm(31);
unsigned IVAL = R.createVirtualRegister(MBlaze::GPRRegisterClass);
BuildMI(BB, dl, TII->get(MBlaze::ADDI), IVAL)
.addReg(MI->getOperand(1).getReg())
.addImm(0);
BuildMI(BB, dl, TII->get(MBlaze::BEQID))
.addReg(IAMT)
.addMBB(finish);
unsigned DST = R.createVirtualRegister(MBlaze::GPRRegisterClass);
unsigned NDST = R.createVirtualRegister(MBlaze::GPRRegisterClass);
BuildMI(loop, dl, TII->get(MBlaze::PHI), DST)
.addReg(IVAL).addMBB(BB)
.addReg(NDST).addMBB(loop);
unsigned SAMT = R.createVirtualRegister(MBlaze::GPRRegisterClass);
unsigned NAMT = R.createVirtualRegister(MBlaze::GPRRegisterClass);
BuildMI(loop, dl, TII->get(MBlaze::PHI), SAMT)
.addReg(IAMT).addMBB(BB)
.addReg(NAMT).addMBB(loop);
if (MI->getOpcode() == MBlaze::ShiftL)
BuildMI(loop, dl, TII->get(MBlaze::ADD), NDST).addReg(DST).addReg(DST);
else if (MI->getOpcode() == MBlaze::ShiftRA)
BuildMI(loop, dl, TII->get(MBlaze::SRA), NDST).addReg(DST);
else if (MI->getOpcode() == MBlaze::ShiftRL)
BuildMI(loop, dl, TII->get(MBlaze::SRL), NDST).addReg(DST);
else
llvm_unreachable("Cannot lower unknown shift instruction");
BuildMI(loop, dl, TII->get(MBlaze::ADDI), NAMT)
.addReg(SAMT)
.addImm(-1);
BuildMI(loop, dl, TII->get(MBlaze::BNEID))
.addReg(NAMT)
.addMBB(loop);
BuildMI(*finish, finish->begin(), dl,
TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
.addReg(IVAL).addMBB(BB)
.addReg(NDST).addMBB(loop);
// The pseudo instruction is no longer needed so remove it
MI->eraseFromParent();
return finish;
}
case MBlaze::Select_FCC:
case MBlaze::Select_CC: {
// To "insert" a SELECT_CC instruction, we actually have to insert the
// diamond control-flow pattern. The incoming instruction knows the
// destination vreg to set, the condition code register to branch on, the
// true/false values to select between, and a branch opcode to use.
const BasicBlock *LLVM_BB = BB->getBasicBlock();
MachineFunction::iterator It = BB;
++It;
// thisMBB:
// ...
// TrueVal = ...
// setcc r1, r2, r3
// bNE r1, r0, copy1MBB
// fallthrough --> copy0MBB
MachineFunction *F = BB->getParent();
MachineBasicBlock *flsBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *dneBB = F->CreateMachineBasicBlock(LLVM_BB);
unsigned Opc;
switch (MI->getOperand(4).getImm()) {
default: llvm_unreachable("Unknown branch condition");
case MBlazeCC::EQ: Opc = MBlaze::BEQID; break;
case MBlazeCC::NE: Opc = MBlaze::BNEID; break;
case MBlazeCC::GT: Opc = MBlaze::BGTID; break;
case MBlazeCC::LT: Opc = MBlaze::BLTID; break;
case MBlazeCC::GE: Opc = MBlaze::BGEID; break;
case MBlazeCC::LE: Opc = MBlaze::BLEID; break;
}
F->insert(It, flsBB);
F->insert(It, dneBB);
// Transfer the remainder of BB and its successor edges to dneBB.
dneBB->splice(dneBB->begin(), BB,
llvm::next(MachineBasicBlock::iterator(MI)),
BB->end());
dneBB->transferSuccessorsAndUpdatePHIs(BB);
BB->addSuccessor(flsBB);
BB->addSuccessor(dneBB);
flsBB->addSuccessor(dneBB);
BuildMI(BB, dl, TII->get(Opc))
.addReg(MI->getOperand(3).getReg())
.addMBB(dneBB);
// sinkMBB:
// %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
// ...
//BuildMI(dneBB, dl, TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
// .addReg(MI->getOperand(1).getReg()).addMBB(flsBB)
// .addReg(MI->getOperand(2).getReg()).addMBB(BB);
BuildMI(*dneBB, dneBB->begin(), dl,
TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
.addReg(MI->getOperand(2).getReg()).addMBB(flsBB)
.addReg(MI->getOperand(1).getReg()).addMBB(BB);
MI->eraseFromParent(); // The pseudo instruction is gone now.
return dneBB;
}
}
}
//===----------------------------------------------------------------------===//
// Misc Lower Operation implementation
//===----------------------------------------------------------------------===//
//
SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op,
SelectionDAG &DAG) const {
SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
SDValue TrueVal = Op.getOperand(2);
SDValue FalseVal = Op.getOperand(3);
DebugLoc dl = Op.getDebugLoc();
unsigned Opc;
SDValue CompareFlag;
if (LHS.getValueType() == MVT::i32) {
Opc = MBlazeISD::Select_CC;
CompareFlag = DAG.getNode(MBlazeISD::ICmp, dl, MVT::i32, LHS, RHS)
.getValue(1);
} else {
llvm_unreachable("Cannot lower select_cc with unknown type");
}
return DAG.getNode(Opc, dl, TrueVal.getValueType(), TrueVal, FalseVal,
CompareFlag);
}
SDValue MBlazeTargetLowering::
LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
// FIXME there isn't actually debug info here
DebugLoc dl = Op.getDebugLoc();
const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32);
return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, GA);
}
SDValue MBlazeTargetLowering::
LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
llvm_unreachable("TLS not implemented for MicroBlaze.");
return SDValue(); // Not reached
}
SDValue MBlazeTargetLowering::
LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
SDValue ResNode;
SDValue HiPart;
// FIXME there isn't actually debug info here
DebugLoc dl = Op.getDebugLoc();
EVT PtrVT = Op.getValueType();
JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, 0);
return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, JTI);
}
SDValue MBlazeTargetLowering::
LowerConstantPool(SDValue Op, SelectionDAG &DAG) const {
SDValue ResNode;
ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
const Constant *C = N->getConstVal();
DebugLoc dl = Op.getDebugLoc();
SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(),
N->getOffset(), 0);
return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, CP);
}
SDValue MBlazeTargetLowering::LowerVASTART(SDValue Op,
SelectionDAG &DAG) const {
MachineFunction &MF = DAG.getMachineFunction();
MBlazeFunctionInfo *FuncInfo = MF.getInfo<MBlazeFunctionInfo>();
DebugLoc dl = Op.getDebugLoc();
SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
getPointerTy());
// vastart just stores the address of the VarArgsFrameIndex slot into the
// memory location argument.
const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
return DAG.getStore(Op.getOperand(0), dl, FI, Op.getOperand(1),
MachinePointerInfo(SV),
false, false, 0);
}
//===----------------------------------------------------------------------===//
// Calling Convention Implementation
//===----------------------------------------------------------------------===//
#include "MBlazeGenCallingConv.inc"
static bool CC_MBlaze_AssignReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State) {
static const unsigned ArgRegs[] = {
MBlaze::R5, MBlaze::R6, MBlaze::R7,
MBlaze::R8, MBlaze::R9, MBlaze::R10
};
const unsigned NumArgRegs = array_lengthof(ArgRegs);
unsigned Reg = State.AllocateReg(ArgRegs, NumArgRegs);
if (!Reg) return false;
unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
State.AllocateStack(SizeInBytes, SizeInBytes);
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return true;
}
//===----------------------------------------------------------------------===//
// Call Calling Convention Implementation
//===----------------------------------------------------------------------===//
/// LowerCall - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: isVarArg, isTailCall.
SDValue MBlazeTargetLowering::
LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv,
bool isVarArg, bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
// MBlaze does not yet support tail call optimization
isTailCall = false;
// The MBlaze requires stack slots for arguments passed to var arg
// functions even if they are passed in registers.
bool needsRegArgSlots = isVarArg;
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
*DAG.getContext());
CCInfo.AnalyzeCallOperands(Outs, CC_MBlaze);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
// Variable argument function calls require a minimum of 24-bytes of stack
if (isVarArg && NumBytes < 24) NumBytes = 24;
Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
MVT RegVT = VA.getLocVT();
SDValue Arg = OutVals[i];
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt:
Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, RegVT, Arg);
break;
case CCValAssign::ZExt:
Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, RegVT, Arg);
break;
case CCValAssign::AExt:
Arg = DAG.getNode(ISD::ANY_EXTEND, dl, RegVT, Arg);
break;
}
// Arguments that can be passed on register must be kept at
// RegsToPass vector
if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
} else {
// Register can't get to this point...
assert(VA.isMemLoc());
// Since we are alread passing values on the stack we don't
// need to worry about creating additional slots for the
// values passed via registers.
needsRegArgSlots = false;
// Create the frame index object for this incoming parameter
unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
unsigned StackLoc = VA.getLocMemOffset() + 4;
int FI = MFI->CreateFixedObject(ArgSize, StackLoc, true);
SDValue PtrOff = DAG.getFrameIndex(FI,getPointerTy());
// emit ISD::STORE whichs stores the
// parameter value to a stack Location
MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
MachinePointerInfo(),
false, false, 0));
}
}
// If we need to reserve stack space for the arguments passed via registers
// then create a fixed stack object at the beginning of the stack.
if (needsRegArgSlots && TFI.hasReservedCallFrame(MF))
MFI->CreateFixedObject(28,0,true);
// Transform all store nodes into one single node because all store
// nodes are independent of each other.
if (!MemOpChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&MemOpChains[0], MemOpChains.size());
// Build a sequence of copy-to-reg nodes chained together with token
// chain and flag operands which copy the outgoing args into registers.
// The InFlag in necessary since all emited instructions must be
// stuck together.
SDValue InFlag;
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
RegsToPass[i].second, InFlag);
InFlag = Chain.getValue(1);
}
// 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.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
getPointerTy(), 0, 0);
else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(S->getSymbol(),
getPointerTy(), 0);
// MBlazeJmpLink = #chain, #target_address, #opt_in_flags...
// = Chain, Callee, Reg#1, Reg#2, ...
//
// Returns a chain & a flag for retval copy to use.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Flag);
SmallVector<SDValue, 8> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
// Add argument registers to the end of the list so that they are
// known live into the call.
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Ops.push_back(DAG.getRegister(RegsToPass[i].first,
RegsToPass[i].second.getValueType()));
}
if (InFlag.getNode())
Ops.push_back(InFlag);
Chain = DAG.getNode(MBlazeISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
InFlag = Chain.getValue(1);
// Create the CALLSEQ_END node.
Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
DAG.getIntPtrConstant(0, true), InFlag);
if (!Ins.empty())
InFlag = Chain.getValue(1);
// Handle result values, copying them out of physregs into vregs that we
// return.
return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
Ins, dl, DAG, InVals);
}
/// LowerCallResult - Lower the result values of a call into the
/// appropriate copies out of appropriate physical registers.
SDValue MBlazeTargetLowering::
LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv,
bool isVarArg, const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
RVLocs, *DAG.getContext());
CCInfo.AnalyzeCallResult(Ins, RetCC_MBlaze);
// Copy all of the result registers out of their specified physreg.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(),
RVLocs[i].getValVT(), InFlag).getValue(1);
InFlag = Chain.getValue(2);
InVals.push_back(Chain.getValue(0));
}
return Chain;
}
//===----------------------------------------------------------------------===//
// Formal Arguments Calling Convention Implementation
//===----------------------------------------------------------------------===//
/// LowerFormalArguments - transform physical registers into
/// virtual registers and generate load operations for
/// arguments places on the stack.
SDValue MBlazeTargetLowering::
LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
unsigned StackReg = MF.getTarget().getRegisterInfo()->getFrameRegister(MF);
MBlazeFI->setVarArgsFrameIndex(0);
// Used with vargs to acumulate store chains.
std::vector<SDValue> OutChains;
// Keep track of the last register used for arguments
unsigned ArgRegEnd = 0;
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
ArgLocs, *DAG.getContext());
CCInfo.AnalyzeFormalArguments(Ins, CC_MBlaze);
SDValue StackPtr;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
// Arguments stored on registers
if (VA.isRegLoc()) {
MVT RegVT = VA.getLocVT();
ArgRegEnd = VA.getLocReg();
TargetRegisterClass *RC = 0;
if (RegVT == MVT::i32)
RC = MBlaze::GPRRegisterClass;
else if (RegVT == MVT::f32)
RC = MBlaze::GPRRegisterClass;
else
llvm_unreachable("RegVT not supported by LowerFormalArguments");
// Transform the arguments stored on
// physical registers into virtual ones
unsigned Reg = MF.addLiveIn(ArgRegEnd, RC);
SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
// If this is an 8 or 16-bit value, it has been passed promoted
// to 32 bits. Insert an assert[sz]ext to capture this, then
// truncate to the right size. If if is a floating point value
// then convert to the correct type.
if (VA.getLocInfo() != CCValAssign::Full) {
unsigned Opcode = 0;
if (VA.getLocInfo() == CCValAssign::SExt)
Opcode = ISD::AssertSext;
else if (VA.getLocInfo() == CCValAssign::ZExt)
Opcode = ISD::AssertZext;
if (Opcode)
ArgValue = DAG.getNode(Opcode, dl, RegVT, ArgValue,
DAG.getValueType(VA.getValVT()));
ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
}
InVals.push_back(ArgValue);
} else { // VA.isRegLoc()
// sanity check
assert(VA.isMemLoc());
// The last argument is not a register
ArgRegEnd = 0;
// The stack pointer offset is relative to the caller stack frame.
// Since the real stack size is unknown here, a negative SPOffset
// is used so there's a way to adjust these offsets when the stack
// size get known (on EliminateFrameIndex). A dummy SPOffset is
// used instead of a direct negative address (which is recorded to
// be used on emitPrologue) to avoid mis-calc of the first stack
// offset on PEI::calculateFrameObjectOffsets.
// Arguments are always 32-bit.
unsigned ArgSize = VA.getLocVT().getSizeInBits()/8;
unsigned StackLoc = VA.getLocMemOffset() + 4;
int FI = MFI->CreateFixedObject(ArgSize, 0, true);
MBlazeFI->recordLoadArgsFI(FI, -StackLoc);
MBlazeFI->recordLiveIn(FI);
// Create load nodes to retrieve arguments from the stack
SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
MachinePointerInfo::getFixedStack(FI),
false, false, 0));
}
}
// To meet ABI, when VARARGS are passed on registers, the registers
// must have their values written to the caller stack frame. If the last
// argument was placed in the stack, there's no need to save any register.
if ((isVarArg) && ArgRegEnd) {
if (StackPtr.getNode() == 0)
StackPtr = DAG.getRegister(StackReg, getPointerTy());
// The last register argument that must be saved is MBlaze::R10
TargetRegisterClass *RC = MBlaze::GPRRegisterClass;
unsigned Begin = MBlazeRegisterInfo::getRegisterNumbering(MBlaze::R5);
unsigned Start = MBlazeRegisterInfo::getRegisterNumbering(ArgRegEnd+1);
unsigned End = MBlazeRegisterInfo::getRegisterNumbering(MBlaze::R10);
unsigned StackLoc = Start - Begin + 1;
for (; Start <= End; ++Start, ++StackLoc) {
unsigned Reg = MBlazeRegisterInfo::getRegisterFromNumbering(Start);
unsigned LiveReg = MF.addLiveIn(Reg, RC);
SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, LiveReg, MVT::i32);
int FI = MFI->CreateFixedObject(4, 0, true);
MBlazeFI->recordStoreVarArgsFI(FI, -(StackLoc*4));
SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy());
OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
MachinePointerInfo(),
false, false, 0));
// Record the frame index of the first variable argument
// which is a value necessary to VASTART.
if (!MBlazeFI->getVarArgsFrameIndex())
MBlazeFI->setVarArgsFrameIndex(FI);
}
}
// All stores are grouped in one node to allow the matching between
// the size of Ins and InVals. This only happens when on varg functions
if (!OutChains.empty()) {
OutChains.push_back(Chain);
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&OutChains[0], OutChains.size());
}
return Chain;
}
//===----------------------------------------------------------------------===//
// Return Value Calling Convention Implementation
//===----------------------------------------------------------------------===//
SDValue MBlazeTargetLowering::
LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl, SelectionDAG &DAG) const {
// CCValAssign - represent the assignment of
// the return value to a location
SmallVector<CCValAssign, 16> RVLocs;
// CCState - Info about the registers and stack slot.
CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
RVLocs, *DAG.getContext());
// Analize return values.
CCInfo.AnalyzeReturn(Outs, RetCC_MBlaze);
// If this is the first return lowered for this function, add
// the regs to the liveout set for the function.
if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
for (unsigned i = 0; i != RVLocs.size(); ++i)
if (RVLocs[i].isRegLoc())
DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
}
SDValue Flag;
// Copy the result values into the output registers.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &VA = RVLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
OutVals[i], Flag);
// guarantee that all emitted copies are
// stuck together, avoiding something bad
Flag = Chain.getValue(1);
}
// Return on MBlaze is always a "rtsd R15, 8"
if (Flag.getNode())
return DAG.getNode(MBlazeISD::Ret, dl, MVT::Other,
Chain, DAG.getRegister(MBlaze::R15, MVT::i32), Flag);
else // Return Void
return DAG.getNode(MBlazeISD::Ret, dl, MVT::Other,
Chain, DAG.getRegister(MBlaze::R15, MVT::i32));
}
//===----------------------------------------------------------------------===//
// MBlaze Inline Assembly Support
//===----------------------------------------------------------------------===//
/// getConstraintType - Given a constraint letter, return the type of
/// constraint it is for this target.
MBlazeTargetLowering::ConstraintType MBlazeTargetLowering::
getConstraintType(const std::string &Constraint) const
{
// MBlaze specific constrainy
//
// 'd' : An address register. Equivalent to r.
// 'y' : Equivalent to r; retained for
// backwards compatibility.
// 'f' : Floating Point registers.
if (Constraint.size() == 1) {
switch (Constraint[0]) {
default : break;
case 'd':
case 'y':
case 'f':
return C_RegisterClass;
break;
}
}
return TargetLowering::getConstraintType(Constraint);
}
/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
MBlazeTargetLowering::getSingleConstraintMatchWeight(
AsmOperandInfo &info, const char *constraint) const {
ConstraintWeight weight = CW_Invalid;
Value *CallOperandVal = info.CallOperandVal;
// If we don't have a value, we can't do a match,
// but allow it at the lowest weight.
if (CallOperandVal == NULL)
return CW_Default;
const Type *type = CallOperandVal->getType();
// Look at the constraint type.
switch (*constraint) {
default:
weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
break;
case 'd':
case 'y':
if (type->isIntegerTy())
weight = CW_Register;
break;
case 'f':
if (type->isFloatTy())
weight = CW_Register;
break;
}
return weight;
}
/// getRegClassForInlineAsmConstraint - Given a constraint letter (e.g. "r"),
/// return a list of registers that can be used to satisfy the constraint.
/// This should only be used for C_RegisterClass constraints.
std::pair<unsigned, const TargetRegisterClass*> MBlazeTargetLowering::
getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const {
if (Constraint.size() == 1) {
switch (Constraint[0]) {
case 'r':
return std::make_pair(0U, MBlaze::GPRRegisterClass);
case 'f':
if (VT == MVT::f32)
return std::make_pair(0U, MBlaze::GPRRegisterClass);
}
}
return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
}
/// Given a register class constraint, like 'r', if this corresponds directly
/// to an LLVM register class, return a register of 0 and the register class
/// pointer.
std::vector<unsigned> MBlazeTargetLowering::
getRegClassForInlineAsmConstraint(const std::string &Constraint, EVT VT) const {
if (Constraint.size() != 1)
return std::vector<unsigned>();
switch (Constraint[0]) {
default : break;
case 'r':
// GCC MBlaze Constraint Letters
case 'd':
case 'y':
case 'f':
return make_vector<unsigned>(
MBlaze::R3, MBlaze::R4, MBlaze::R5, MBlaze::R6,
MBlaze::R7, MBlaze::R9, MBlaze::R10, MBlaze::R11,
MBlaze::R12, MBlaze::R19, MBlaze::R20, MBlaze::R21,
MBlaze::R22, MBlaze::R23, MBlaze::R24, MBlaze::R25,
MBlaze::R26, MBlaze::R27, MBlaze::R28, MBlaze::R29,
MBlaze::R30, MBlaze::R31, 0);
}
return std::vector<unsigned>();
}
bool MBlazeTargetLowering::
isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
// The MBlaze target isn't yet aware of offsets.
return false;
}
bool MBlazeTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
return VT != MVT::f32;
}
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