1 //===-- XCoreISelDAGToDAG.cpp - A dag to dag inst selector for XCore ------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines an instruction selector for the XCore target. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "XCore.h" 15 #include "XCoreTargetMachine.h" 16 #include "llvm/CodeGen/MachineFrameInfo.h" 17 #include "llvm/CodeGen/MachineFunction.h" 18 #include "llvm/CodeGen/MachineInstrBuilder.h" 19 #include "llvm/CodeGen/MachineRegisterInfo.h" 20 #include "llvm/CodeGen/SelectionDAG.h" 21 #include "llvm/CodeGen/SelectionDAGISel.h" 22 #include "llvm/IR/CallingConv.h" 23 #include "llvm/IR/Constants.h" 24 #include "llvm/IR/DerivedTypes.h" 25 #include "llvm/IR/Function.h" 26 #include "llvm/IR/Intrinsics.h" 27 #include "llvm/IR/LLVMContext.h" 28 #include "llvm/Support/Compiler.h" 29 #include "llvm/Support/Debug.h" 30 #include "llvm/Support/ErrorHandling.h" 31 #include "llvm/Support/raw_ostream.h" 32 #include "llvm/Target/TargetLowering.h" 33 using namespace llvm; 34 35 /// XCoreDAGToDAGISel - XCore specific code to select XCore machine 36 /// instructions for SelectionDAG operations. 37 /// 38 namespace { 39 class XCoreDAGToDAGISel : public SelectionDAGISel { 40 const XCoreTargetLowering &Lowering; 41 const XCoreSubtarget &Subtarget; 42 43 public: 44 XCoreDAGToDAGISel(XCoreTargetMachine &TM, CodeGenOpt::Level OptLevel) 45 : SelectionDAGISel(TM, OptLevel), 46 Lowering(*TM.getTargetLowering()), 47 Subtarget(*TM.getSubtargetImpl()) { } 48 49 SDNode *Select(SDNode *N); 50 SDNode *SelectBRIND(SDNode *N); 51 52 /// getI32Imm - Return a target constant with the specified value, of type 53 /// i32. 54 inline SDValue getI32Imm(unsigned Imm) { 55 return CurDAG->getTargetConstant(Imm, MVT::i32); 56 } 57 58 inline bool immMskBitp(SDNode *inN) const { 59 ConstantSDNode *N = cast<ConstantSDNode>(inN); 60 uint32_t value = (uint32_t)N->getZExtValue(); 61 if (!isMask_32(value)) { 62 return false; 63 } 64 int msksize = 32 - CountLeadingZeros_32(value); 65 return (msksize >= 1 && msksize <= 8) || 66 msksize == 16 || msksize == 24 || msksize == 32; 67 } 68 69 // Complex Pattern Selectors. 70 bool SelectADDRspii(SDValue Addr, SDValue &Base, SDValue &Offset); 71 bool SelectADDRdpii(SDValue Addr, SDValue &Base, SDValue &Offset); 72 bool SelectADDRcpii(SDValue Addr, SDValue &Base, SDValue &Offset); 73 74 virtual const char *getPassName() const { 75 return "XCore DAG->DAG Pattern Instruction Selection"; 76 } 77 78 // Include the pieces autogenerated from the target description. 79 #include "XCoreGenDAGISel.inc" 80 }; 81 } // end anonymous namespace 82 83 /// createXCoreISelDag - This pass converts a legalized DAG into a 84 /// XCore-specific DAG, ready for instruction scheduling. 85 /// 86 FunctionPass *llvm::createXCoreISelDag(XCoreTargetMachine &TM, 87 CodeGenOpt::Level OptLevel) { 88 return new XCoreDAGToDAGISel(TM, OptLevel); 89 } 90 91 bool XCoreDAGToDAGISel::SelectADDRspii(SDValue Addr, SDValue &Base, 92 SDValue &Offset) { 93 FrameIndexSDNode *FIN = 0; 94 if ((FIN = dyn_cast<FrameIndexSDNode>(Addr))) { 95 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32); 96 Offset = CurDAG->getTargetConstant(0, MVT::i32); 97 return true; 98 } 99 if (Addr.getOpcode() == ISD::ADD) { 100 ConstantSDNode *CN = 0; 101 if ((FIN = dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) 102 && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) 103 && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) { 104 // Constant positive word offset from frame index 105 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32); 106 Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32); 107 return true; 108 } 109 } 110 return false; 111 } 112 113 bool XCoreDAGToDAGISel::SelectADDRdpii(SDValue Addr, SDValue &Base, 114 SDValue &Offset) { 115 if (Addr.getOpcode() == XCoreISD::DPRelativeWrapper) { 116 Base = Addr.getOperand(0); 117 Offset = CurDAG->getTargetConstant(0, MVT::i32); 118 return true; 119 } 120 if (Addr.getOpcode() == ISD::ADD) { 121 ConstantSDNode *CN = 0; 122 if ((Addr.getOperand(0).getOpcode() == XCoreISD::DPRelativeWrapper) 123 && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) 124 && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) { 125 // Constant word offset from a object in the data region 126 Base = Addr.getOperand(0).getOperand(0); 127 Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32); 128 return true; 129 } 130 } 131 return false; 132 } 133 134 bool XCoreDAGToDAGISel::SelectADDRcpii(SDValue Addr, SDValue &Base, 135 SDValue &Offset) { 136 if (Addr.getOpcode() == XCoreISD::CPRelativeWrapper) { 137 Base = Addr.getOperand(0); 138 Offset = CurDAG->getTargetConstant(0, MVT::i32); 139 return true; 140 } 141 if (Addr.getOpcode() == ISD::ADD) { 142 ConstantSDNode *CN = 0; 143 if ((Addr.getOperand(0).getOpcode() == XCoreISD::CPRelativeWrapper) 144 && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) 145 && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) { 146 // Constant word offset from a object in the data region 147 Base = Addr.getOperand(0).getOperand(0); 148 Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32); 149 return true; 150 } 151 } 152 return false; 153 } 154 155 SDNode *XCoreDAGToDAGISel::Select(SDNode *N) { 156 DebugLoc dl = N->getDebugLoc(); 157 switch (N->getOpcode()) { 158 default: break; 159 case ISD::Constant: { 160 uint64_t Val = cast<ConstantSDNode>(N)->getZExtValue(); 161 if (immMskBitp(N)) { 162 // Transformation function: get the size of a mask 163 // Look for the first non-zero bit 164 SDValue MskSize = getI32Imm(32 - CountLeadingZeros_32(Val)); 165 return CurDAG->getMachineNode(XCore::MKMSK_rus, dl, 166 MVT::i32, MskSize); 167 } 168 else if (!isUInt<16>(Val)) { 169 SDValue CPIdx = 170 CurDAG->getTargetConstantPool(ConstantInt::get( 171 Type::getInt32Ty(*CurDAG->getContext()), Val), 172 TLI.getPointerTy()); 173 SDNode *node = CurDAG->getMachineNode(XCore::LDWCP_lru6, dl, MVT::i32, 174 MVT::Other, CPIdx, 175 CurDAG->getEntryNode()); 176 MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1); 177 MemOp[0] = MF->getMachineMemOperand( 178 MachinePointerInfo::getConstantPool(), MachineMemOperand::MOLoad, 4, 4); 179 cast<MachineSDNode>(node)->setMemRefs(MemOp, MemOp + 1); 180 return node; 181 } 182 break; 183 } 184 case XCoreISD::LADD: { 185 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), 186 N->getOperand(2) }; 187 return CurDAG->getMachineNode(XCore::LADD_l5r, dl, MVT::i32, MVT::i32, 188 Ops, 3); 189 } 190 case XCoreISD::LSUB: { 191 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), 192 N->getOperand(2) }; 193 return CurDAG->getMachineNode(XCore::LSUB_l5r, dl, MVT::i32, MVT::i32, 194 Ops, 3); 195 } 196 case XCoreISD::MACCU: { 197 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), 198 N->getOperand(2), N->getOperand(3) }; 199 return CurDAG->getMachineNode(XCore::MACCU_l4r, dl, MVT::i32, MVT::i32, 200 Ops, 4); 201 } 202 case XCoreISD::MACCS: { 203 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), 204 N->getOperand(2), N->getOperand(3) }; 205 return CurDAG->getMachineNode(XCore::MACCS_l4r, dl, MVT::i32, MVT::i32, 206 Ops, 4); 207 } 208 case XCoreISD::LMUL: { 209 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), 210 N->getOperand(2), N->getOperand(3) }; 211 return CurDAG->getMachineNode(XCore::LMUL_l6r, dl, MVT::i32, MVT::i32, 212 Ops, 4); 213 } 214 case XCoreISD::CRC8: { 215 SDValue Ops[] = { N->getOperand(0), N->getOperand(1), N->getOperand(2) }; 216 return CurDAG->getMachineNode(XCore::CRC8_l4r, dl, MVT::i32, MVT::i32, 217 Ops, 3); 218 } 219 case ISD::BRIND: 220 if (SDNode *ResNode = SelectBRIND(N)) 221 return ResNode; 222 break; 223 // Other cases are autogenerated. 224 } 225 return SelectCode(N); 226 } 227 228 /// Given a chain return a new chain where any appearance of Old is replaced 229 /// by New. There must be at most one instruction between Old and Chain and 230 /// this instruction must be a TokenFactor. Returns an empty SDValue if 231 /// these conditions don't hold. 232 static SDValue 233 replaceInChain(SelectionDAG *CurDAG, SDValue Chain, SDValue Old, SDValue New) 234 { 235 if (Chain == Old) 236 return New; 237 if (Chain->getOpcode() != ISD::TokenFactor) 238 return SDValue(); 239 SmallVector<SDValue, 8> Ops; 240 bool found = false; 241 for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i) { 242 if (Chain->getOperand(i) == Old) { 243 Ops.push_back(New); 244 found = true; 245 } else { 246 Ops.push_back(Chain->getOperand(i)); 247 } 248 } 249 if (!found) 250 return SDValue(); 251 return CurDAG->getNode(ISD::TokenFactor, Chain->getDebugLoc(), MVT::Other, 252 &Ops[0], Ops.size()); 253 } 254 255 SDNode *XCoreDAGToDAGISel::SelectBRIND(SDNode *N) { 256 DebugLoc dl = N->getDebugLoc(); 257 // (brind (int_xcore_checkevent (addr))) 258 SDValue Chain = N->getOperand(0); 259 SDValue Addr = N->getOperand(1); 260 if (Addr->getOpcode() != ISD::INTRINSIC_W_CHAIN) 261 return 0; 262 unsigned IntNo = cast<ConstantSDNode>(Addr->getOperand(1))->getZExtValue(); 263 if (IntNo != Intrinsic::xcore_checkevent) 264 return 0; 265 SDValue nextAddr = Addr->getOperand(2); 266 SDValue CheckEventChainOut(Addr.getNode(), 1); 267 if (!CheckEventChainOut.use_empty()) { 268 // If the chain out of the checkevent intrinsic is an operand of the 269 // indirect branch or used in a TokenFactor which is the operand of the 270 // indirect branch then build a new chain which uses the chain coming into 271 // the checkevent intrinsic instead. 272 SDValue CheckEventChainIn = Addr->getOperand(0); 273 SDValue NewChain = replaceInChain(CurDAG, Chain, CheckEventChainOut, 274 CheckEventChainIn); 275 if (!NewChain.getNode()) 276 return 0; 277 Chain = NewChain; 278 } 279 // Enable events on the thread using setsr 1 and then disable them immediately 280 // after with clrsr 1. If any resources owned by the thread are ready an event 281 // will be taken. If no resource is ready we branch to the address which was 282 // the operand to the checkevent intrinsic. 283 SDValue constOne = getI32Imm(1); 284 SDValue Glue = 285 SDValue(CurDAG->getMachineNode(XCore::SETSR_branch_u6, dl, MVT::Glue, 286 constOne, Chain), 0); 287 Glue = 288 SDValue(CurDAG->getMachineNode(XCore::CLRSR_branch_u6, dl, MVT::Glue, 289 constOne, Glue), 0); 290 if (nextAddr->getOpcode() == XCoreISD::PCRelativeWrapper && 291 nextAddr->getOperand(0)->getOpcode() == ISD::TargetBlockAddress) { 292 return CurDAG->SelectNodeTo(N, XCore::BRFU_lu6, MVT::Other, 293 nextAddr->getOperand(0), Glue); 294 } 295 return CurDAG->SelectNodeTo(N, XCore::BAU_1r, MVT::Other, nextAddr, Glue); 296 } 297
