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llvm-6502/lib/Target/MBlaze/MBlazeISelLowering.cpp
Wesley Peck 4da992aeba Adding initial AsmParser implementation for the MBlaze backend. It is 
mostly based on the ARM AsmParser at this time and is not particularly
functional.

Changed the MBlaze data layout from:
    "E-p:32:32-i8:8:8-i16:16:16-i64:32:32-f64:32:32-v64:32:32-v128:32:32-n32"
to:
    "E-p:32:32:32-i8:8:8-i16:16:16"
because the MicroBlaze doesn't have i64, f64, v64, or v128 data types.

Cleaned up the MBlaze source code:
    1. The floating point register class has been removed. The
       MicroBlaze does not have floating point registers. Floating
       point values are simply stored in integer registers.
    2. Renaming the CPURegs register class to GPR to reflect the
       standard naming.
    3. Removing a lot of stale code from AsmPrinter after
       the conversion to InstPrinter.
    4. Simplified sign extended loads by marking them as
       expanded in ISelLowering.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117054 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-21 19:48:38 +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;
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::BIT_CONVERT, MVT::f32, Expand);
setOperationAction(ISD::BIT_CONVERT, 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::BNEID; break;
case MBlazeCC::NE: Opc = MBlaze::BEQID; break;
case MBlazeCC::GT: Opc = MBlaze::BLEID; break;
case MBlazeCC::LT: Opc = MBlaze::BGEID; break;
case MBlazeCC::GE: Opc = MBlaze::BLTID; break;
case MBlazeCC::LE: Opc = MBlaze::BGTID; 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_MBlaze2(unsigned ValNo, EVT ValVT,
EVT LocVT, CCValAssign::LocInfo LocInfo,
ISD::ArgFlagsTy ArgFlags, CCState &State) {
static const unsigned RegsSize=6;
static const unsigned IntRegs[] = {
MBlaze::R5, MBlaze::R6, MBlaze::R7,
MBlaze::R8, MBlaze::R9, MBlaze::R10
};
unsigned Reg=0;
// Promote i8 and i16
if (LocVT == MVT::i8 || LocVT == MVT::i16) {
LocVT = MVT::i32;
if (ArgFlags.isSExt())
LocInfo = CCValAssign::SExt;
else if (ArgFlags.isZExt())
LocInfo = CCValAssign::ZExt;
else
LocInfo = CCValAssign::AExt;
}
if (ValVT == MVT::i32) {
Reg = State.AllocateReg(IntRegs, RegsSize);
LocVT = MVT::i32;
} else if (ValVT == MVT::f32) {
Reg = State.AllocateReg(IntRegs, RegsSize);
LocVT = MVT::f32;
}
if (!Reg) {
unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
unsigned Offset = State.AllocateStack(SizeInBytes, SizeInBytes);
State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
} else {
unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
State.AllocateStack(SizeInBytes, SizeInBytes);
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
}
return false; // CC must always match
}
//===----------------------------------------------------------------------===//
// 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;
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.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_MBlaze2);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
// First/LastArgStackLoc contains the first/last
// "at stack" argument location.
int LastArgStackLoc = 0;
unsigned FirstStackArgLoc = 0;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
EVT 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());
// Create the frame index object for this incoming parameter
LastArgStackLoc = (FirstStackArgLoc + VA.getLocMemOffset());
int FI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
LastArgStackLoc, 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));
}
}
// 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_MBlaze2);
SDValue StackPtr;
unsigned FirstStackArgLoc = 0;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
// Arguments stored on registers
if (VA.isRegLoc()) {
EVT 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;
int FI = MFI->CreateFixedObject(ArgSize, 0, true);
MBlazeFI->recordLoadArgsFI(FI, -(ArgSize+
(FirstStackArgLoc + VA.getLocMemOffset())));
// 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 = ArgLocs.size()-1 + (Start - Begin);
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, -(4+(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);
}
/// 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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