1 //===-- AMDILISelDAGToDAG.cpp - A dag to dag inst selector for AMDIL ------===//
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 AMDIL target.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "AMDGPUInstrInfo.h"
14 #include "AMDGPUISelLowering.h" // For AMDGPUISD
15 #include "AMDGPURegisterInfo.h"
16 #include "AMDILDevices.h"
17 #include "AMDILUtilityFunctions.h"
18 #include "llvm/ADT/ValueMap.h"
19 #include "llvm/CodeGen/PseudoSourceValue.h"
20 #include "llvm/CodeGen/SelectionDAGISel.h"
21 #include "llvm/Support/Compiler.h"
22 #include <list>
23 #include <queue>
24 
25 using namespace llvm;
26 
27 //===----------------------------------------------------------------------===//
28 // Instruction Selector Implementation
29 //===----------------------------------------------------------------------===//
30 
31 //===----------------------------------------------------------------------===//
32 // AMDGPUDAGToDAGISel - AMDGPU specific code to select AMDGPU machine instructions
33 // //for SelectionDAG operations.
34 //
35 namespace {
36 class AMDGPUDAGToDAGISel : public SelectionDAGISel {
37   // Subtarget - Keep a pointer to the AMDGPU Subtarget around so that we can
38   // make the right decision when generating code for different targets.
39   const AMDGPUSubtarget &Subtarget;
40 public:
41   AMDGPUDAGToDAGISel(TargetMachine &TM);
42   virtual ~AMDGPUDAGToDAGISel();
43 
44   SDNode *Select(SDNode *N);
45   virtual const char *getPassName() const;
46 
47 private:
48   inline SDValue getSmallIPtrImm(unsigned Imm);
49 
50   // Complex pattern selectors
51   bool SelectADDRParam(SDValue Addr, SDValue& R1, SDValue& R2);
52   bool SelectADDR(SDValue N, SDValue &R1, SDValue &R2);
53   bool SelectADDR64(SDValue N, SDValue &R1, SDValue &R2);
54 
55   static bool checkType(const Value *ptr, unsigned int addrspace);
56   static const Value *getBasePointerValue(const Value *V);
57 
58   static bool isGlobalStore(const StoreSDNode *N);
59   static bool isPrivateStore(const StoreSDNode *N);
60   static bool isLocalStore(const StoreSDNode *N);
61   static bool isRegionStore(const StoreSDNode *N);
62 
63   static bool isCPLoad(const LoadSDNode *N);
64   static bool isConstantLoad(const LoadSDNode *N, int cbID);
65   static bool isGlobalLoad(const LoadSDNode *N);
66   static bool isPrivateLoad(const LoadSDNode *N);
67   static bool isLocalLoad(const LoadSDNode *N);
68   static bool isRegionLoad(const LoadSDNode *N);
69 
70   bool SelectADDR8BitOffset(SDValue Addr, SDValue& Base, SDValue& Offset);
71   bool SelectADDRReg(SDValue Addr, SDValue& Base, SDValue& Offset);
72   bool SelectADDRVTX_READ(SDValue Addr, SDValue &Base, SDValue &Offset);
73 
74   // Include the pieces autogenerated from the target description.
75 #include "AMDGPUGenDAGISel.inc"
76 };
77 }  // end anonymous namespace
78 
79 // createAMDGPUISelDag - This pass converts a legalized DAG into a AMDGPU-specific
80 // DAG, ready for instruction scheduling.
81 //
createAMDGPUISelDag(TargetMachine & TM)82 FunctionPass *llvm::createAMDGPUISelDag(TargetMachine &TM
83                                        ) {
84   return new AMDGPUDAGToDAGISel(TM);
85 }
86 
AMDGPUDAGToDAGISel(TargetMachine & TM)87 AMDGPUDAGToDAGISel::AMDGPUDAGToDAGISel(TargetMachine &TM
88                                      )
89   : SelectionDAGISel(TM), Subtarget(TM.getSubtarget<AMDGPUSubtarget>())
90 {
91 }
92 
~AMDGPUDAGToDAGISel()93 AMDGPUDAGToDAGISel::~AMDGPUDAGToDAGISel() {
94 }
95 
getSmallIPtrImm(unsigned int Imm)96 SDValue AMDGPUDAGToDAGISel::getSmallIPtrImm(unsigned int Imm) {
97   return CurDAG->getTargetConstant(Imm, MVT::i32);
98 }
99 
SelectADDRParam(SDValue Addr,SDValue & R1,SDValue & R2)100 bool AMDGPUDAGToDAGISel::SelectADDRParam(
101     SDValue Addr, SDValue& R1, SDValue& R2) {
102 
103   if (Addr.getOpcode() == ISD::FrameIndex) {
104     if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
105       R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
106       R2 = CurDAG->getTargetConstant(0, MVT::i32);
107     } else {
108       R1 = Addr;
109       R2 = CurDAG->getTargetConstant(0, MVT::i32);
110     }
111   } else if (Addr.getOpcode() == ISD::ADD) {
112     R1 = Addr.getOperand(0);
113     R2 = Addr.getOperand(1);
114   } else {
115     R1 = Addr;
116     R2 = CurDAG->getTargetConstant(0, MVT::i32);
117   }
118   return true;
119 }
120 
SelectADDR(SDValue Addr,SDValue & R1,SDValue & R2)121 bool AMDGPUDAGToDAGISel::SelectADDR(SDValue Addr, SDValue& R1, SDValue& R2) {
122   if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
123       Addr.getOpcode() == ISD::TargetGlobalAddress) {
124     return false;
125   }
126   return SelectADDRParam(Addr, R1, R2);
127 }
128 
129 
SelectADDR64(SDValue Addr,SDValue & R1,SDValue & R2)130 bool AMDGPUDAGToDAGISel::SelectADDR64(SDValue Addr, SDValue& R1, SDValue& R2) {
131   if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
132       Addr.getOpcode() == ISD::TargetGlobalAddress) {
133     return false;
134   }
135 
136   if (Addr.getOpcode() == ISD::FrameIndex) {
137     if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
138       R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i64);
139       R2 = CurDAG->getTargetConstant(0, MVT::i64);
140     } else {
141       R1 = Addr;
142       R2 = CurDAG->getTargetConstant(0, MVT::i64);
143     }
144   } else if (Addr.getOpcode() == ISD::ADD) {
145     R1 = Addr.getOperand(0);
146     R2 = Addr.getOperand(1);
147   } else {
148     R1 = Addr;
149     R2 = CurDAG->getTargetConstant(0, MVT::i64);
150   }
151   return true;
152 }
153 
Select(SDNode * N)154 SDNode *AMDGPUDAGToDAGISel::Select(SDNode *N) {
155   unsigned int Opc = N->getOpcode();
156   if (N->isMachineOpcode()) {
157     return NULL;   // Already selected.
158   }
159   switch (Opc) {
160   default: break;
161   case ISD::FrameIndex:
162     {
163       if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N)) {
164         unsigned int FI = FIN->getIndex();
165         EVT OpVT = N->getValueType(0);
166         unsigned int NewOpc = AMDGPU::COPY;
167         SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i32);
168         return CurDAG->SelectNodeTo(N, NewOpc, OpVT, TFI);
169       }
170     }
171     break;
172   }
173   return SelectCode(N);
174 }
175 
checkType(const Value * ptr,unsigned int addrspace)176 bool AMDGPUDAGToDAGISel::checkType(const Value *ptr, unsigned int addrspace) {
177   if (!ptr) {
178     return false;
179   }
180   Type *ptrType = ptr->getType();
181   return dyn_cast<PointerType>(ptrType)->getAddressSpace() == addrspace;
182 }
183 
getBasePointerValue(const Value * V)184 const Value * AMDGPUDAGToDAGISel::getBasePointerValue(const Value *V)
185 {
186   if (!V) {
187     return NULL;
188   }
189   const Value *ret = NULL;
190   ValueMap<const Value *, bool> ValueBitMap;
191   std::queue<const Value *, std::list<const Value *> > ValueQueue;
192   ValueQueue.push(V);
193   while (!ValueQueue.empty()) {
194     V = ValueQueue.front();
195     if (ValueBitMap.find(V) == ValueBitMap.end()) {
196       ValueBitMap[V] = true;
197       if (dyn_cast<Argument>(V) && dyn_cast<PointerType>(V->getType())) {
198         ret = V;
199         break;
200       } else if (dyn_cast<GlobalVariable>(V)) {
201         ret = V;
202         break;
203       } else if (dyn_cast<Constant>(V)) {
204         const ConstantExpr *CE = dyn_cast<ConstantExpr>(V);
205         if (CE) {
206           ValueQueue.push(CE->getOperand(0));
207         }
208       } else if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
209         ret = AI;
210         break;
211       } else if (const Instruction *I = dyn_cast<Instruction>(V)) {
212         uint32_t numOps = I->getNumOperands();
213         for (uint32_t x = 0; x < numOps; ++x) {
214           ValueQueue.push(I->getOperand(x));
215         }
216       } else {
217         // assert(0 && "Found a Value that we didn't know how to handle!");
218       }
219     }
220     ValueQueue.pop();
221   }
222   return ret;
223 }
224 
isGlobalStore(const StoreSDNode * N)225 bool AMDGPUDAGToDAGISel::isGlobalStore(const StoreSDNode *N) {
226   return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS);
227 }
228 
isPrivateStore(const StoreSDNode * N)229 bool AMDGPUDAGToDAGISel::isPrivateStore(const StoreSDNode *N) {
230   return (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS)
231           && !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS)
232           && !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS));
233 }
234 
isLocalStore(const StoreSDNode * N)235 bool AMDGPUDAGToDAGISel::isLocalStore(const StoreSDNode *N) {
236   return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS);
237 }
238 
isRegionStore(const StoreSDNode * N)239 bool AMDGPUDAGToDAGISel::isRegionStore(const StoreSDNode *N) {
240   return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS);
241 }
242 
isConstantLoad(const LoadSDNode * N,int cbID)243 bool AMDGPUDAGToDAGISel::isConstantLoad(const LoadSDNode *N, int cbID) {
244   if (checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS)) {
245     return true;
246   }
247   MachineMemOperand *MMO = N->getMemOperand();
248   const Value *V = MMO->getValue();
249   const Value *BV = getBasePointerValue(V);
250   if (MMO
251       && MMO->getValue()
252       && ((V && dyn_cast<GlobalValue>(V))
253           || (BV && dyn_cast<GlobalValue>(
254                         getBasePointerValue(MMO->getValue()))))) {
255     return checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS);
256   } else {
257     return false;
258   }
259 }
260 
isGlobalLoad(const LoadSDNode * N)261 bool AMDGPUDAGToDAGISel::isGlobalLoad(const LoadSDNode *N) {
262   return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS);
263 }
264 
isLocalLoad(const LoadSDNode * N)265 bool AMDGPUDAGToDAGISel::isLocalLoad(const  LoadSDNode *N) {
266   return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS);
267 }
268 
isRegionLoad(const LoadSDNode * N)269 bool AMDGPUDAGToDAGISel::isRegionLoad(const  LoadSDNode *N) {
270   return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS);
271 }
272 
isCPLoad(const LoadSDNode * N)273 bool AMDGPUDAGToDAGISel::isCPLoad(const LoadSDNode *N) {
274   MachineMemOperand *MMO = N->getMemOperand();
275   if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) {
276     if (MMO) {
277       const Value *V = MMO->getValue();
278       const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V);
279       if (PSV && PSV == PseudoSourceValue::getConstantPool()) {
280         return true;
281       }
282     }
283   }
284   return false;
285 }
286 
isPrivateLoad(const LoadSDNode * N)287 bool AMDGPUDAGToDAGISel::isPrivateLoad(const LoadSDNode *N) {
288   if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) {
289     // Check to make sure we are not a constant pool load or a constant load
290     // that is marked as a private load
291     if (isCPLoad(N) || isConstantLoad(N, -1)) {
292       return false;
293     }
294   }
295   if (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS)
296       && !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS)
297       && !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS)
298       && !checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS)
299       && !checkType(N->getSrcValue(), AMDGPUAS::PARAM_D_ADDRESS)
300       && !checkType(N->getSrcValue(), AMDGPUAS::PARAM_I_ADDRESS))
301   {
302     return true;
303   }
304   return false;
305 }
306 
getPassName() const307 const char *AMDGPUDAGToDAGISel::getPassName() const {
308   return "AMDGPU DAG->DAG Pattern Instruction Selection";
309 }
310 
311 #ifdef DEBUGTMP
312 #undef INT64_C
313 #endif
314 #undef DEBUGTMP
315 
316 ///==== AMDGPU Functions ====///
317 
SelectADDR8BitOffset(SDValue Addr,SDValue & Base,SDValue & Offset)318 bool AMDGPUDAGToDAGISel::SelectADDR8BitOffset(SDValue Addr, SDValue& Base,
319                                              SDValue& Offset) {
320   if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
321       Addr.getOpcode() == ISD::TargetGlobalAddress) {
322     return false;
323   }
324 
325 
326   if (Addr.getOpcode() == ISD::ADD) {
327     bool Match = false;
328 
329     // Find the base ptr and the offset
330     for (unsigned i = 0; i < Addr.getNumOperands(); i++) {
331       SDValue Arg = Addr.getOperand(i);
332       ConstantSDNode * OffsetNode = dyn_cast<ConstantSDNode>(Arg);
333       // This arg isn't a constant so it must be the base PTR.
334       if (!OffsetNode) {
335         Base = Addr.getOperand(i);
336         continue;
337       }
338       // Check if the constant argument fits in 8-bits.  The offset is in bytes
339       // so we need to convert it to dwords.
340       if (isInt<8>(OffsetNode->getZExtValue() >> 2)) {
341         Match = true;
342         Offset = CurDAG->getTargetConstant(OffsetNode->getZExtValue() >> 2,
343                                            MVT::i32);
344       }
345     }
346     return Match;
347   }
348 
349   // Default case, no offset
350   Base = Addr;
351   Offset = CurDAG->getTargetConstant(0, MVT::i32);
352   return true;
353 }
354 
SelectADDRVTX_READ(SDValue Addr,SDValue & Base,SDValue & Offset)355 bool AMDGPUDAGToDAGISel::SelectADDRVTX_READ(SDValue Addr, SDValue &Base,
356                                            SDValue &Offset)
357 {
358   ConstantSDNode * IMMOffset;
359 
360   if (Addr.getOpcode() == ISD::ADD
361       && (IMMOffset = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
362       && isInt<16>(IMMOffset->getZExtValue())) {
363 
364       Base = Addr.getOperand(0);
365       Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32);
366       return true;
367   // If the pointer address is constant, we can move it to the offset field.
368   } else if ((IMMOffset = dyn_cast<ConstantSDNode>(Addr))
369              && isInt<16>(IMMOffset->getZExtValue())) {
370     Base = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
371                                   CurDAG->getEntryNode().getDebugLoc(),
372                                   AMDGPU::ZERO, MVT::i32);
373     Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32);
374     return true;
375   }
376 
377   // Default case, no offset
378   Base = Addr;
379   Offset = CurDAG->getTargetConstant(0, MVT::i32);
380   return true;
381 }
382 
SelectADDRReg(SDValue Addr,SDValue & Base,SDValue & Offset)383 bool AMDGPUDAGToDAGISel::SelectADDRReg(SDValue Addr, SDValue& Base,
384                                       SDValue& Offset) {
385   if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
386       Addr.getOpcode() == ISD::TargetGlobalAddress  ||
387       Addr.getOpcode() != ISD::ADD) {
388     return false;
389   }
390 
391   Base = Addr.getOperand(0);
392   Offset = Addr.getOperand(1);
393 
394   return true;
395 }
396