//===----------------------------------------------------------------------===//
#include "MSP430.h"
-#include "MSP430ISelLowering.h"
#include "MSP430TargetMachine.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Target/TargetLowering.h"
-#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/Statistic.h"
-
using namespace llvm;
-#ifndef NDEBUG
-static cl::opt<bool>
-ViewRMWDAGs("view-msp430-rmw-dags", cl::Hidden,
- cl::desc("Pop up a window to show isel dags after RMW preprocess"));
-#else
-static const bool ViewRMWDAGs = false;
-#endif
-
-STATISTIC(NumLoadMoved, "Number of loads moved below TokenFactor");
-
-
namespace {
struct MSP430ISelAddressMode {
enum {
} Base;
int16_t Disp;
- GlobalValue *GV;
- Constant *CP;
- BlockAddress *BlockAddr;
+ const GlobalValue *GV;
+ const Constant *CP;
+ const BlockAddress *BlockAddr;
const char *ES;
int JT;
unsigned Align; // CP alignment.
return GV != 0 || CP != 0 || ES != 0 || JT != -1;
}
- bool hasBaseReg() const {
- return Base.Reg.getNode() != 0;
- }
-
- void setBaseReg(SDValue Reg) {
- BaseType = RegBase;
- Base.Reg = Reg;
- }
-
void dump() {
errs() << "MSP430ISelAddressMode " << this << '\n';
- if (Base.Reg.getNode() != 0) {
+ if (BaseType == RegBase && Base.Reg.getNode() != 0) {
errs() << "Base.Reg ";
Base.Reg.getNode()->dump();
- } else {
+ } else if (BaseType == FrameIndexBase) {
errs() << " Base.FrameIndex " << Base.FrameIndex << '\n';
}
errs() << " Disp " << Disp << '\n';
///
namespace {
class MSP430DAGToDAGISel : public SelectionDAGISel {
- MSP430TargetLowering &Lowering;
+ const MSP430TargetLowering &Lowering;
const MSP430Subtarget &Subtarget;
public:
Lowering(*TM.getTargetLowering()),
Subtarget(*TM.getSubtargetImpl()) { }
- virtual void InstructionSelect();
-
virtual const char *getPassName() const {
return "MSP430 DAG->DAG Pattern Instruction Selection";
}
bool MatchWrapper(SDValue N, MSP430ISelAddressMode &AM);
bool MatchAddressBase(SDValue N, MSP430ISelAddressMode &AM);
- bool IsLegalAndProfitableToFold(SDNode *N, SDNode *U,
- SDNode *Root) const;
-
virtual bool
SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
std::vector<SDValue> &OutOps);
#include "MSP430GenDAGISel.inc"
private:
- DenseMap<SDNode*, SDNode*> RMWStores;
- void PreprocessForRMW();
- SDNode *Select(SDValue Op);
- bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp);
-
- #ifndef NDEBUG
- unsigned Indent;
- #endif
+ SDNode *Select(SDNode *N);
+ SDNode *SelectIndexedLoad(SDNode *Op);
+ SDNode *SelectIndexedBinOp(SDNode *Op, SDValue N1, SDValue N2,
+ unsigned Opc8, unsigned Opc16);
+
+ bool SelectAddr(SDValue Addr, SDValue &Base, SDValue &Disp);
};
} // end anonymous namespace
}
bool MSP430DAGToDAGISel::MatchAddress(SDValue N, MSP430ISelAddressMode &AM) {
- DebugLoc dl = N.getDebugLoc();
- DEBUG({
- errs() << "MatchAddress: ";
- AM.dump();
- });
+ DEBUG(errs() << "MatchAddress: "; AM.dump());
switch (N.getOpcode()) {
default: break;
/// SelectAddr - returns true if it is able pattern match an addressing mode.
/// It returns the operands which make up the maximal addressing mode it can
/// match by reference.
-bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue N,
+bool MSP430DAGToDAGISel::SelectAddr(SDValue N,
SDValue &Base, SDValue &Disp) {
MSP430ISelAddressMode AM;
AM.Base.Reg;
if (AM.GV)
- Disp = CurDAG->getTargetGlobalAddress(AM.GV, MVT::i16, AM.Disp,
+ Disp = CurDAG->getTargetGlobalAddress(AM.GV, N->getDebugLoc(),
+ MVT::i16, AM.Disp,
0/*AM.SymbolFlags*/);
else if (AM.CP)
Disp = CurDAG->getTargetConstantPool(AM.CP, MVT::i16,
else if (AM.JT != -1)
Disp = CurDAG->getTargetJumpTable(AM.JT, MVT::i16, 0/*AM.SymbolFlags*/);
else if (AM.BlockAddr)
- Disp = CurDAG->getBlockAddress(AM.BlockAddr, DebugLoc()/*MVT::i32*/,
- true /*AM.SymbolFlags*/);
+ Disp = CurDAG->getBlockAddress(AM.BlockAddr, MVT::i32,
+ true, 0/*AM.SymbolFlags*/);
else
Disp = CurDAG->getTargetConstant(AM.Disp, MVT::i16);
switch (ConstraintCode) {
default: return true;
case 'm': // memory
- if (!SelectAddr(Op, Op, Op0, Op1))
+ if (!SelectAddr(Op, Op0, Op1))
return true;
break;
}
return false;
}
-bool MSP430DAGToDAGISel::IsLegalAndProfitableToFold(SDNode *N, SDNode *U,
- SDNode *Root) const {
- if (OptLevel == CodeGenOpt::None) return false;
-
- /// RMW preprocessing creates the following code:
- /// [Load1]
- /// ^ ^
- /// / |
- /// / |
- /// [Load2] |
- /// ^ ^ |
- /// | | |
- /// | \-|
- /// | |
- /// | [Op]
- /// | ^
- /// | |
- /// \ /
- /// \ /
- /// [Store]
- ///
- /// The path Store => Load2 => Load1 is via chain. Note that in general it is
- /// not allowed to fold Load1 into Op (and Store) since it will creates a
- /// cycle. However, this is perfectly legal for the loads moved below the
- /// TokenFactor by PreprocessForRMW. Query the map Store => Load1 (created
- /// during preprocessing) to determine whether it's legal to introduce such
- /// "cycle" for a moment.
- DenseMap<SDNode*, SDNode*>::iterator I = RMWStores.find(Root);
- if (I != RMWStores.end() && I->second == N)
- return true;
+static bool isValidIndexedLoad(const LoadSDNode *LD) {
+ ISD::MemIndexedMode AM = LD->getAddressingMode();
+ if (AM != ISD::POST_INC || LD->getExtensionType() != ISD::NON_EXTLOAD)
+ return false;
- // Proceed to 'generic' cycle finder code
- return SelectionDAGISel::IsLegalAndProfitableToFold(N, U, Root);
-}
+ EVT VT = LD->getMemoryVT();
+ switch (VT.getSimpleVT().SimpleTy) {
+ case MVT::i8:
+ // Sanity check
+ if (cast<ConstantSDNode>(LD->getOffset())->getZExtValue() != 1)
+ return false;
-/// MoveBelowTokenFactor - Replace TokenFactor operand with load's chain operand
-/// and move load below the TokenFactor. Replace store's chain operand with
-/// load's chain result.
-static void MoveBelowTokenFactor(SelectionDAG *CurDAG, SDValue Load,
- SDValue Store, SDValue TF) {
- SmallVector<SDValue, 4> Ops;
- for (unsigned i = 0, e = TF.getNode()->getNumOperands(); i != e; ++i)
- if (Load.getNode() == TF.getOperand(i).getNode())
- Ops.push_back(Load.getOperand(0));
- else
- Ops.push_back(TF.getOperand(i));
- SDValue NewTF = CurDAG->UpdateNodeOperands(TF, &Ops[0], Ops.size());
- SDValue NewLoad = CurDAG->UpdateNodeOperands(Load, NewTF,
- Load.getOperand(1),
- Load.getOperand(2));
- CurDAG->UpdateNodeOperands(Store, NewLoad.getValue(1), Store.getOperand(1),
- Store.getOperand(2), Store.getOperand(3));
-}
+ break;
+ case MVT::i16:
+ // Sanity check
+ if (cast<ConstantSDNode>(LD->getOffset())->getZExtValue() != 2)
+ return false;
-/// MoveBelowTokenFactor2 - Replace TokenFactor operand with load's chain operand
-/// and move load below the TokenFactor. Replace store's chain operand with
-/// load's chain result. This a version which sinks two loads below token factor.
-/// Look into PreprocessForRMW comments for explanation of transform.
-static void MoveBelowTokenFactor2(SelectionDAG *CurDAG,
- SDValue Load1, SDValue Load2,
- SDValue Store, SDValue TF) {
- SmallVector<SDValue, 4> Ops;
- for (unsigned i = 0, e = TF.getNode()->getNumOperands(); i != e; ++i) {
- SDNode* N = TF.getOperand(i).getNode();
- if (Load2.getNode() == N)
- Ops.push_back(Load2.getOperand(0));
- else if (Load1.getNode() != N)
- Ops.push_back(TF.getOperand(i));
+ break;
+ default:
+ return false;
}
- SDValue NewTF = SDValue(CurDAG->MorphNodeTo(TF.getNode(),
- TF.getOpcode(),
- TF.getNode()->getVTList(),
- &Ops[0], Ops.size()), TF.getResNo());
- SDValue NewLoad2 = CurDAG->UpdateNodeOperands(Load2, NewTF,
- Load2.getOperand(1),
- Load2.getOperand(2));
-
- SDValue NewLoad1 = CurDAG->UpdateNodeOperands(Load1, NewLoad2.getValue(1),
- Load1.getOperand(1),
- Load1.getOperand(2));
-
- CurDAG->UpdateNodeOperands(Store,
- NewLoad1.getValue(1),
- Store.getOperand(1),
- Store.getOperand(2), Store.getOperand(3));
+ return true;
}
-/// isAllowedToSink - return true if N a load which can be moved below token
-/// factor. Basically, the load should be non-volatile and has single use.
-static bool isLoadAllowedToSink(SDValue N, SDValue Chain) {
- if (N.getOpcode() == ISD::BIT_CONVERT)
- N = N.getOperand(0);
+SDNode *MSP430DAGToDAGISel::SelectIndexedLoad(SDNode *N) {
+ LoadSDNode *LD = cast<LoadSDNode>(N);
+ if (!isValidIndexedLoad(LD))
+ return NULL;
- LoadSDNode *LD = dyn_cast<LoadSDNode>(N);
- if (!LD || LD->isVolatile())
- return false;
- if (LD->getAddressingMode() != ISD::UNINDEXED)
- return false;
+ MVT VT = LD->getMemoryVT().getSimpleVT();
- ISD::LoadExtType ExtType = LD->getExtensionType();
- if (ExtType != ISD::NON_EXTLOAD && ExtType != ISD::EXTLOAD)
- return false;
+ unsigned Opcode = 0;
+ switch (VT.SimpleTy) {
+ case MVT::i8:
+ Opcode = MSP430::MOV8rm_POST;
+ break;
+ case MVT::i16:
+ Opcode = MSP430::MOV16rm_POST;
+ break;
+ default:
+ return NULL;
+ }
- return (N.hasOneUse() &&
- LD->hasNUsesOfValue(1, 1) &&
- LD->isOperandOf(Chain.getNode()));
+ return CurDAG->getMachineNode(Opcode, N->getDebugLoc(),
+ VT, MVT::i16, MVT::Other,
+ LD->getBasePtr(), LD->getChain());
}
-
-/// isRMWLoad - Return true if N is a load that's part of RMW sub-DAG.
-/// The chain produced by the load must only be used by the store's chain
-/// operand, otherwise this may produce a cycle in the DAG.
-static bool isRMWLoad(SDValue N, SDValue Chain, SDValue Address,
- SDValue &Load) {
- if (isLoadAllowedToSink(N, Chain) &&
- N.getOperand(1) == Address) {
- Load = N;
- return true;
+SDNode *MSP430DAGToDAGISel::SelectIndexedBinOp(SDNode *Op,
+ SDValue N1, SDValue N2,
+ unsigned Opc8, unsigned Opc16) {
+ if (N1.getOpcode() == ISD::LOAD &&
+ N1.hasOneUse() &&
+ IsLegalToFold(N1, Op, Op, OptLevel)) {
+ LoadSDNode *LD = cast<LoadSDNode>(N1);
+ if (!isValidIndexedLoad(LD))
+ return NULL;
+
+ MVT VT = LD->getMemoryVT().getSimpleVT();
+ unsigned Opc = (VT == MVT::i16 ? Opc16 : Opc8);
+ MachineSDNode::mmo_iterator MemRefs0 = MF->allocateMemRefsArray(1);
+ MemRefs0[0] = cast<MemSDNode>(N1)->getMemOperand();
+ SDValue Ops0[] = { N2, LD->getBasePtr(), LD->getChain() };
+ SDNode *ResNode =
+ CurDAG->SelectNodeTo(Op, Opc,
+ VT, MVT::i16, MVT::Other,
+ Ops0, 3);
+ cast<MachineSDNode>(ResNode)->setMemRefs(MemRefs0, MemRefs0 + 1);
+ // Transfer chain.
+ ReplaceUses(SDValue(N1.getNode(), 2), SDValue(ResNode, 2));
+ // Transfer writeback.
+ ReplaceUses(SDValue(N1.getNode(), 1), SDValue(ResNode, 1));
+ return ResNode;
}
- return false;
-}
-
-/// PreprocessForRMW - Preprocess the DAG to make instruction selection better.
-/// This is only run if not in -O0 mode.
-/// This allows the instruction selector to pick more read-modify-write
-/// instructions. This is a common case:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [Load]
-/// ^ ^
-/// | |
-/// / \-
-/// / |
-/// [TokenFactor] [Op]
-/// ^ ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// The fact the store's chain operand != load's chain will prevent the
-/// (store (op (load))) instruction from being selected. We can transform it to:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [TokenFactor]
-/// ^
-/// |
-/// [Load]
-/// ^ ^
-/// | |
-/// | \-
-/// | |
-/// | [Op]
-/// | ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// We also recognize the case where second operand of Op is load as well and
-/// move it below token factor as well creating DAG as follows:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [TokenFactor]
-/// ^
-/// |
-/// [Load1]
-/// ^ ^
-/// / |
-/// / |
-/// [Load2] |
-/// ^ ^ |
-/// | | |
-/// | \-|
-/// | |
-/// | [Op]
-/// | ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// This allows selection of mem-mem instructions. Yay!
-
-void MSP430DAGToDAGISel::PreprocessForRMW() {
- for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
- E = CurDAG->allnodes_end(); I != E; ++I) {
- if (!ISD::isNON_TRUNCStore(I))
- continue;
- SDValue Chain = I->getOperand(0);
-
- if (Chain.getNode()->getOpcode() != ISD::TokenFactor)
- continue;
-
- SDValue N1 = I->getOperand(1);
- SDValue N2 = I->getOperand(2);
- if ((N1.getValueType().isFloatingPoint() &&
- !N1.getValueType().isVector()) ||
- !N1.hasOneUse())
- continue;
-
- unsigned RModW = 0;
- SDValue Load1, Load2;
- unsigned Opcode = N1.getNode()->getOpcode();
- switch (Opcode) {
- case ISD::ADD:
- case ISD::AND:
- case ISD::OR:
- case ISD::XOR:
- case ISD::ADDC:
- case ISD::ADDE: {
- SDValue N10 = N1.getOperand(0);
- SDValue N11 = N1.getOperand(1);
- if (isRMWLoad(N10, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N11, Chain)) {
- Load2 = N11;
- RModW = 2;
- } else
- RModW = 1;
- } else if (isRMWLoad(N11, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N10, Chain)) {
- Load2 = N10;
- RModW = 2;
- } else
- RModW = 1;
- }
- break;
- }
- case ISD::SUB:
- case ISD::SUBC:
- case ISD::SUBE: {
- SDValue N10 = N1.getOperand(0);
- SDValue N11 = N1.getOperand(1);
- if (isRMWLoad(N10, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N11, Chain)) {
- Load2 = N11;
- RModW = 2;
- } else
- RModW = 1;
- }
- break;
- }
- }
- NumLoadMoved += RModW;
- if (RModW == 1)
- MoveBelowTokenFactor(CurDAG, Load1, SDValue(I, 0), Chain);
- else if (RModW == 2) {
- MoveBelowTokenFactor2(CurDAG, Load1, Load2, SDValue(I, 0), Chain);
- SDNode* Store = I;
- RMWStores[Store] = Load2.getNode();
- }
- }
+ return NULL;
}
-/// InstructionSelect - This callback is invoked by
-/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void MSP430DAGToDAGISel::InstructionSelect() {
- std::string BlockName;
- if (ViewRMWDAGs)
- BlockName = MF->getFunction()->getNameStr() + ":" +
- BB->getBasicBlock()->getNameStr();
-
- PreprocessForRMW();
-
- if (ViewRMWDAGs) CurDAG->viewGraph("RMW preprocessed:" + BlockName);
-
- DEBUG(errs() << "Selection DAG after RMW preprocessing:\n");
- DEBUG(CurDAG->dump());
-
- // Codegen the basic block.
- DEBUG(errs() << "===== Instruction selection begins:\n");
- DEBUG(Indent = 0);
- SelectRoot(*CurDAG);
- DEBUG(errs() << "===== Instruction selection ends:\n");
-
- CurDAG->RemoveDeadNodes();
- RMWStores.clear();
-}
-SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
- SDNode *Node = Op.getNode();
- DebugLoc dl = Op.getDebugLoc();
+SDNode *MSP430DAGToDAGISel::Select(SDNode *Node) {
+ DebugLoc dl = Node->getDebugLoc();
// Dump information about the Node being selected
- DEBUG(errs().indent(Indent) << "Selecting: ");
+ DEBUG(errs() << "Selecting: ");
DEBUG(Node->dump(CurDAG));
DEBUG(errs() << "\n");
- DEBUG(Indent += 2);
// If we have a custom node, we already have selected!
if (Node->isMachineOpcode()) {
- DEBUG(errs().indent(Indent-2) << "== ";
+ DEBUG(errs() << "== ";
Node->dump(CurDAG);
errs() << "\n");
- DEBUG(Indent -= 2);
return NULL;
}
switch (Node->getOpcode()) {
default: break;
case ISD::FrameIndex: {
- assert(Op.getValueType() == MVT::i16);
+ assert(Node->getValueType(0) == MVT::i16);
int FI = cast<FrameIndexSDNode>(Node)->getIndex();
SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16);
if (Node->hasOneUse())
return CurDAG->getMachineNode(MSP430::ADD16ri, dl, MVT::i16,
TFI, CurDAG->getTargetConstant(0, MVT::i16));
}
+ case ISD::LOAD:
+ if (SDNode *ResNode = SelectIndexedLoad(Node))
+ return ResNode;
+ // Other cases are autogenerated.
+ break;
+ case ISD::ADD:
+ if (SDNode *ResNode =
+ SelectIndexedBinOp(Node,
+ Node->getOperand(0), Node->getOperand(1),
+ MSP430::ADD8rm_POST, MSP430::ADD16rm_POST))
+ return ResNode;
+ else if (SDNode *ResNode =
+ SelectIndexedBinOp(Node, Node->getOperand(1), Node->getOperand(0),
+ MSP430::ADD8rm_POST, MSP430::ADD16rm_POST))
+ return ResNode;
+
+ // Other cases are autogenerated.
+ break;
+ case ISD::SUB:
+ if (SDNode *ResNode =
+ SelectIndexedBinOp(Node,
+ Node->getOperand(0), Node->getOperand(1),
+ MSP430::SUB8rm_POST, MSP430::SUB16rm_POST))
+ return ResNode;
+
+ // Other cases are autogenerated.
+ break;
+ case ISD::AND:
+ if (SDNode *ResNode =
+ SelectIndexedBinOp(Node,
+ Node->getOperand(0), Node->getOperand(1),
+ MSP430::AND8rm_POST, MSP430::AND16rm_POST))
+ return ResNode;
+ else if (SDNode *ResNode =
+ SelectIndexedBinOp(Node, Node->getOperand(1), Node->getOperand(0),
+ MSP430::AND8rm_POST, MSP430::AND16rm_POST))
+ return ResNode;
+
+ // Other cases are autogenerated.
+ break;
+ case ISD::OR:
+ if (SDNode *ResNode =
+ SelectIndexedBinOp(Node,
+ Node->getOperand(0), Node->getOperand(1),
+ MSP430::OR8rm_POST, MSP430::OR16rm_POST))
+ return ResNode;
+ else if (SDNode *ResNode =
+ SelectIndexedBinOp(Node, Node->getOperand(1), Node->getOperand(0),
+ MSP430::OR8rm_POST, MSP430::OR16rm_POST))
+ return ResNode;
+
+ // Other cases are autogenerated.
+ break;
+ case ISD::XOR:
+ if (SDNode *ResNode =
+ SelectIndexedBinOp(Node,
+ Node->getOperand(0), Node->getOperand(1),
+ MSP430::XOR8rm_POST, MSP430::XOR16rm_POST))
+ return ResNode;
+ else if (SDNode *ResNode =
+ SelectIndexedBinOp(Node, Node->getOperand(1), Node->getOperand(0),
+ MSP430::XOR8rm_POST, MSP430::XOR16rm_POST))
+ return ResNode;
+
+ // Other cases are autogenerated.
+ break;
}
// Select the default instruction
- SDNode *ResNode = SelectCode(Op);
+ SDNode *ResNode = SelectCode(Node);
- DEBUG(errs() << std::string(Indent-2, ' ') << "=> ");
- if (ResNode == NULL || ResNode == Op.getNode())
- DEBUG(Op.getNode()->dump(CurDAG));
+ DEBUG(errs() << "=> ");
+ if (ResNode == NULL || ResNode == Node)
+ DEBUG(Node->dump(CurDAG));
else
DEBUG(ResNode->dump(CurDAG));
DEBUG(errs() << "\n");
- DEBUG(Indent -= 2);
return ResNode;
}