283 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			283 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- XCoreISelDAGToDAG.cpp - A dag to dag inst selector for XCore ------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file defines an instruction selector for the XCore target.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "XCore.h"
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| #include "XCoreTargetMachine.h"
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| #include "llvm/CodeGen/MachineFrameInfo.h"
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| #include "llvm/CodeGen/MachineFunction.h"
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| #include "llvm/CodeGen/MachineInstrBuilder.h"
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| #include "llvm/CodeGen/MachineRegisterInfo.h"
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| #include "llvm/CodeGen/SelectionDAG.h"
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| #include "llvm/CodeGen/SelectionDAGISel.h"
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| #include "llvm/IR/CallingConv.h"
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| #include "llvm/IR/Constants.h"
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| #include "llvm/IR/DerivedTypes.h"
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| #include "llvm/IR/Function.h"
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| #include "llvm/IR/Intrinsics.h"
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| #include "llvm/IR/LLVMContext.h"
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| #include "llvm/Support/Debug.h"
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| #include "llvm/Support/ErrorHandling.h"
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| #include "llvm/Support/raw_ostream.h"
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| #include "llvm/Target/TargetLowering.h"
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| using namespace llvm;
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| 
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| /// XCoreDAGToDAGISel - XCore specific code to select XCore machine
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| /// instructions for SelectionDAG operations.
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| ///
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| namespace {
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|   class XCoreDAGToDAGISel : public SelectionDAGISel {
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| 
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|   public:
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|     XCoreDAGToDAGISel(XCoreTargetMachine &TM, CodeGenOpt::Level OptLevel)
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|       : SelectionDAGISel(TM, OptLevel) {}
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| 
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|     void Select(SDNode *N) override;
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|     bool tryBRIND(SDNode *N);
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| 
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|     /// getI32Imm - Return a target constant with the specified value, of type
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|     /// i32.
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|     inline SDValue getI32Imm(unsigned Imm, const SDLoc &dl) {
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|       return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
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|     }
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| 
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|     inline bool immMskBitp(SDNode *inN) const {
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|       ConstantSDNode *N = cast<ConstantSDNode>(inN);
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|       uint32_t value = (uint32_t)N->getZExtValue();
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|       if (!isMask_32(value)) {
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|         return false;
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|       }
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|       int msksize = 32 - countLeadingZeros(value);
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|       return (msksize >= 1 && msksize <= 8) ||
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|               msksize == 16 || msksize == 24 || msksize == 32;
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|     }
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| 
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|     // Complex Pattern Selectors.
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|     bool SelectADDRspii(SDValue Addr, SDValue &Base, SDValue &Offset);
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| 
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|     bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
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|                                       std::vector<SDValue> &OutOps) override;
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| 
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|     StringRef getPassName() const override {
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|       return "XCore DAG->DAG Pattern Instruction Selection";
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|     }
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| 
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|     // Include the pieces autogenerated from the target description.
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|   #include "XCoreGenDAGISel.inc"
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|   };
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| }  // end anonymous namespace
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| 
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| /// createXCoreISelDag - This pass converts a legalized DAG into a
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| /// XCore-specific DAG, ready for instruction scheduling.
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| ///
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| FunctionPass *llvm::createXCoreISelDag(XCoreTargetMachine &TM,
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|                                        CodeGenOpt::Level OptLevel) {
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|   return new XCoreDAGToDAGISel(TM, OptLevel);
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| }
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| 
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| bool XCoreDAGToDAGISel::SelectADDRspii(SDValue Addr, SDValue &Base,
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|                                        SDValue &Offset) {
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|   FrameIndexSDNode *FIN = nullptr;
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|   if ((FIN = dyn_cast<FrameIndexSDNode>(Addr))) {
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|     Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
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|     Offset = CurDAG->getTargetConstant(0, SDLoc(Addr), MVT::i32);
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|     return true;
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|   }
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|   if (Addr.getOpcode() == ISD::ADD) {
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|     ConstantSDNode *CN = nullptr;
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|     if ((FIN = dyn_cast<FrameIndexSDNode>(Addr.getOperand(0)))
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|       && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
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|       && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) {
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|       // Constant positive word offset from frame index
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|       Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
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|       Offset = CurDAG->getTargetConstant(CN->getSExtValue(), SDLoc(Addr),
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|                                          MVT::i32);
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|       return true;
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|     }
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|   }
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|   return false;
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| }
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| 
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| bool XCoreDAGToDAGISel::
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| SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
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|                              std::vector<SDValue> &OutOps) {
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|   SDValue Reg;
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|   switch (ConstraintID) {
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|   default: return true;
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|   case InlineAsm::Constraint_m: // Memory.
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|     switch (Op.getOpcode()) {
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|     default: return true;
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|     case XCoreISD::CPRelativeWrapper:
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|       Reg = CurDAG->getRegister(XCore::CP, MVT::i32);
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|       break;
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|     case XCoreISD::DPRelativeWrapper:
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|       Reg = CurDAG->getRegister(XCore::DP, MVT::i32);
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|       break;
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|     }
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|   }
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|   OutOps.push_back(Reg);
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|   OutOps.push_back(Op.getOperand(0));
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|   return false;
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| }
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| 
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| void XCoreDAGToDAGISel::Select(SDNode *N) {
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|   SDLoc dl(N);
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|   switch (N->getOpcode()) {
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|   default: break;
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|   case ISD::Constant: {
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|     uint64_t Val = cast<ConstantSDNode>(N)->getZExtValue();
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|     if (immMskBitp(N)) {
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|       // Transformation function: get the size of a mask
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|       // Look for the first non-zero bit
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|       SDValue MskSize = getI32Imm(32 - countLeadingZeros((uint32_t)Val), dl);
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|       ReplaceNode(N, CurDAG->getMachineNode(XCore::MKMSK_rus, dl,
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|                                             MVT::i32, MskSize));
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|       return;
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|     }
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|     else if (!isUInt<16>(Val)) {
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|       SDValue CPIdx = CurDAG->getTargetConstantPool(
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|           ConstantInt::get(Type::getInt32Ty(*CurDAG->getContext()), Val),
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|           getTargetLowering()->getPointerTy(CurDAG->getDataLayout()));
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|       SDNode *node = CurDAG->getMachineNode(XCore::LDWCP_lru6, dl, MVT::i32,
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|                                             MVT::Other, CPIdx,
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|                                             CurDAG->getEntryNode());
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|       MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1);
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|       MemOp[0] =
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|           MF->getMachineMemOperand(MachinePointerInfo::getConstantPool(*MF),
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|                                    MachineMemOperand::MOLoad, 4, 4);
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|       cast<MachineSDNode>(node)->setMemRefs(MemOp, MemOp + 1);
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|       ReplaceNode(N, node);
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|       return;
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|     }
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|     break;
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|   }
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|   case XCoreISD::LADD: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
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|                         N->getOperand(2) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::LADD_l5r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case XCoreISD::LSUB: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
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|                         N->getOperand(2) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::LSUB_l5r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case XCoreISD::MACCU: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
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|                       N->getOperand(2), N->getOperand(3) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::MACCU_l4r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case XCoreISD::MACCS: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
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|                       N->getOperand(2), N->getOperand(3) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::MACCS_l4r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case XCoreISD::LMUL: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1),
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|                       N->getOperand(2), N->getOperand(3) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::LMUL_l6r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case XCoreISD::CRC8: {
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|     SDValue Ops[] = { N->getOperand(0), N->getOperand(1), N->getOperand(2) };
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|     ReplaceNode(N, CurDAG->getMachineNode(XCore::CRC8_l4r, dl, MVT::i32,
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|                                           MVT::i32, Ops));
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|     return;
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|   }
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|   case ISD::BRIND:
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|     if (tryBRIND(N))
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|       return;
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|     break;
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|   // Other cases are autogenerated.
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|   }
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|   SelectCode(N);
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| }
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| 
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| /// Given a chain return a new chain where any appearance of Old is replaced
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| /// by New. There must be at most one instruction between Old and Chain and
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| /// this instruction must be a TokenFactor. Returns an empty SDValue if
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| /// these conditions don't hold.
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| static SDValue
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| replaceInChain(SelectionDAG *CurDAG, SDValue Chain, SDValue Old, SDValue New)
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| {
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|   if (Chain == Old)
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|     return New;
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|   if (Chain->getOpcode() != ISD::TokenFactor)
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|     return SDValue();
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|   SmallVector<SDValue, 8> Ops;
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|   bool found = false;
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|   for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i) {
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|     if (Chain->getOperand(i) == Old) {
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|       Ops.push_back(New);
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|       found = true;
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|     } else {
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|       Ops.push_back(Chain->getOperand(i));
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|     }
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|   }
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|   if (!found)
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|     return SDValue();
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|   return CurDAG->getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, Ops);
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| }
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| 
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| bool XCoreDAGToDAGISel::tryBRIND(SDNode *N) {
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|   SDLoc dl(N);
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|   // (brind (int_xcore_checkevent (addr)))
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|   SDValue Chain = N->getOperand(0);
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|   SDValue Addr = N->getOperand(1);
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|   if (Addr->getOpcode() != ISD::INTRINSIC_W_CHAIN)
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|     return false;
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|   unsigned IntNo = cast<ConstantSDNode>(Addr->getOperand(1))->getZExtValue();
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|   if (IntNo != Intrinsic::xcore_checkevent)
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|     return false;
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|   SDValue nextAddr = Addr->getOperand(2);
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|   SDValue CheckEventChainOut(Addr.getNode(), 1);
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|   if (!CheckEventChainOut.use_empty()) {
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|     // If the chain out of the checkevent intrinsic is an operand of the
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|     // indirect branch or used in a TokenFactor which is the operand of the
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|     // indirect branch then build a new chain which uses the chain coming into
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|     // the checkevent intrinsic instead.
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|     SDValue CheckEventChainIn = Addr->getOperand(0);
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|     SDValue NewChain = replaceInChain(CurDAG, Chain, CheckEventChainOut,
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|                                       CheckEventChainIn);
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|     if (!NewChain.getNode())
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|       return false;
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|     Chain = NewChain;
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|   }
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|   // Enable events on the thread using setsr 1 and then disable them immediately
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|   // after with clrsr 1. If any resources owned by the thread are ready an event
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|   // will be taken. If no resource is ready we branch to the address which was
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|   // the operand to the checkevent intrinsic.
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|   SDValue constOne = getI32Imm(1, dl);
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|   SDValue Glue =
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|     SDValue(CurDAG->getMachineNode(XCore::SETSR_branch_u6, dl, MVT::Glue,
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|                                    constOne, Chain), 0);
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|   Glue =
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|     SDValue(CurDAG->getMachineNode(XCore::CLRSR_branch_u6, dl, MVT::Glue,
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|                                    constOne, Glue), 0);
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|   if (nextAddr->getOpcode() == XCoreISD::PCRelativeWrapper &&
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|       nextAddr->getOperand(0)->getOpcode() == ISD::TargetBlockAddress) {
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|     CurDAG->SelectNodeTo(N, XCore::BRFU_lu6, MVT::Other,
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|                          nextAddr->getOperand(0), Glue);
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|     return true;
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|   }
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|   CurDAG->SelectNodeTo(N, XCore::BAU_1r, MVT::Other, nextAddr, Glue);
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|   return true;
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| }
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