Bug Summary

File:lib/Target/Hexagon/RDFGraph.cpp
Warning:line 72, column 20
Called C++ object pointer is null

Annotated Source Code

1//===- RDFGraph.cpp -------------------------------------------------------===//
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// Target-independent, SSA-based data flow graph for register data flow (RDF).
11//
12#include "RDFGraph.h"
13#include "RDFRegisters.h"
14#include "llvm/ADT/BitVector.h"
15#include "llvm/ADT/STLExtras.h"
16#include "llvm/ADT/SetVector.h"
17#include "llvm/CodeGen/MachineBasicBlock.h"
18#include "llvm/CodeGen/MachineDominanceFrontier.h"
19#include "llvm/CodeGen/MachineDominators.h"
20#include "llvm/CodeGen/MachineFunction.h"
21#include "llvm/CodeGen/MachineInstr.h"
22#include "llvm/CodeGen/MachineOperand.h"
23#include "llvm/CodeGen/MachineRegisterInfo.h"
24#include "llvm/IR/Function.h"
25#include "llvm/MC/LaneBitmask.h"
26#include "llvm/MC/MCInstrDesc.h"
27#include "llvm/MC/MCRegisterInfo.h"
28#include "llvm/Support/Debug.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/raw_ostream.h"
31#include "llvm/Target/TargetInstrInfo.h"
32#include "llvm/Target/TargetLowering.h"
33#include "llvm/Target/TargetRegisterInfo.h"
34#include "llvm/Target/TargetSubtargetInfo.h"
35#include <algorithm>
36#include <cassert>
37#include <cstdint>
38#include <cstring>
39#include <iterator>
40#include <set>
41#include <utility>
42#include <vector>
43
44using namespace llvm;
45using namespace rdf;
46
47// Printing functions. Have them here first, so that the rest of the code
48// can use them.
49namespace llvm {
50namespace rdf {
51
52raw_ostream &operator<< (raw_ostream &OS, const PrintLaneMaskOpt &P) {
53 if (!P.Mask.all())
54 OS << ':' << PrintLaneMask(P.Mask);
55 return OS;
56}
57
58template<>
59raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterRef> &P) {
60 auto &TRI = P.G.getTRI();
61 if (P.Obj.Reg > 0 && P.Obj.Reg < TRI.getNumRegs())
62 OS << TRI.getName(P.Obj.Reg);
63 else
64 OS << '#' << P.Obj.Reg;
65 OS << PrintLaneMaskOpt(P.Obj.Mask);
66 return OS;
67}
68
69template<>
70raw_ostream &operator<< (raw_ostream &OS, const Print<NodeId> &P) {
71 auto NA = P.G.addr<NodeBase*>(P.Obj);
2
Null pointer value stored to 'NA.Addr'
72 uint16_t Attrs = NA.Addr->getAttrs();
3
Called C++ object pointer is null
73 uint16_t Kind = NodeAttrs::kind(Attrs);
74 uint16_t Flags = NodeAttrs::flags(Attrs);
75 switch (NodeAttrs::type(Attrs)) {
76 case NodeAttrs::Code:
77 switch (Kind) {
78 case NodeAttrs::Func: OS << 'f'; break;
79 case NodeAttrs::Block: OS << 'b'; break;
80 case NodeAttrs::Stmt: OS << 's'; break;
81 case NodeAttrs::Phi: OS << 'p'; break;
82 default: OS << "c?"; break;
83 }
84 break;
85 case NodeAttrs::Ref:
86 if (Flags & NodeAttrs::Undef)
87 OS << '/';
88 if (Flags & NodeAttrs::Dead)
89 OS << '\\';
90 if (Flags & NodeAttrs::Preserving)
91 OS << '+';
92 if (Flags & NodeAttrs::Clobbering)
93 OS << '~';
94 switch (Kind) {
95 case NodeAttrs::Use: OS << 'u'; break;
96 case NodeAttrs::Def: OS << 'd'; break;
97 case NodeAttrs::Block: OS << 'b'; break;
98 default: OS << "r?"; break;
99 }
100 break;
101 default:
102 OS << '?';
103 break;
104 }
105 OS << P.Obj;
106 if (Flags & NodeAttrs::Shadow)
107 OS << '"';
108 return OS;
109}
110
111static void printRefHeader(raw_ostream &OS, const NodeAddr<RefNode*> RA,
112 const DataFlowGraph &G) {
113 OS << Print<NodeId>(RA.Id, G) << '<'
114 << Print<RegisterRef>(RA.Addr->getRegRef(G), G) << '>';
115 if (RA.Addr->getFlags() & NodeAttrs::Fixed)
116 OS << '!';
117}
118
119template<>
120raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<DefNode*>> &P) {
121 printRefHeader(OS, P.Obj, P.G);
122 OS << '(';
123 if (NodeId N = P.Obj.Addr->getReachingDef())
124 OS << Print<NodeId>(N, P.G);
125 OS << ',';
126 if (NodeId N = P.Obj.Addr->getReachedDef())
127 OS << Print<NodeId>(N, P.G);
128 OS << ',';
129 if (NodeId N = P.Obj.Addr->getReachedUse())
130 OS << Print<NodeId>(N, P.G);
131 OS << "):";
132 if (NodeId N = P.Obj.Addr->getSibling())
133 OS << Print<NodeId>(N, P.G);
134 return OS;
135}
136
137template<>
138raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<UseNode*>> &P) {
139 printRefHeader(OS, P.Obj, P.G);
140 OS << '(';
141 if (NodeId N = P.Obj.Addr->getReachingDef())
142 OS << Print<NodeId>(N, P.G);
143 OS << "):";
144 if (NodeId N = P.Obj.Addr->getSibling())
145 OS << Print<NodeId>(N, P.G);
146 return OS;
147}
148
149template<>
150raw_ostream &operator<< (raw_ostream &OS,
151 const Print<NodeAddr<PhiUseNode*>> &P) {
152 printRefHeader(OS, P.Obj, P.G);
153 OS << '(';
154 if (NodeId N = P.Obj.Addr->getReachingDef())
155 OS << Print<NodeId>(N, P.G);
156 OS << ',';
157 if (NodeId N = P.Obj.Addr->getPredecessor())
158 OS << Print<NodeId>(N, P.G);
159 OS << "):";
160 if (NodeId N = P.Obj.Addr->getSibling())
161 OS << Print<NodeId>(N, P.G);
162 return OS;
163}
164
165template<>
166raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<RefNode*>> &P) {
167 switch (P.Obj.Addr->getKind()) {
168 case NodeAttrs::Def:
169 OS << PrintNode<DefNode*>(P.Obj, P.G);
170 break;
171 case NodeAttrs::Use:
172 if (P.Obj.Addr->getFlags() & NodeAttrs::PhiRef)
173 OS << PrintNode<PhiUseNode*>(P.Obj, P.G);
174 else
175 OS << PrintNode<UseNode*>(P.Obj, P.G);
176 break;
177 }
178 return OS;
179}
180
181template<>
182raw_ostream &operator<< (raw_ostream &OS, const Print<NodeList> &P) {
183 unsigned N = P.Obj.size();
184 for (auto I : P.Obj) {
185 OS << Print<NodeId>(I.Id, P.G);
186 if (--N)
187 OS << ' ';
188 }
189 return OS;
190}
191
192template<>
193raw_ostream &operator<< (raw_ostream &OS, const Print<NodeSet> &P) {
194 unsigned N = P.Obj.size();
195 for (auto I : P.Obj) {
196 OS << Print<NodeId>(I, P.G);
1
Calling 'operator<<'
197 if (--N)
198 OS << ' ';
199 }
200 return OS;
201}
202
203namespace {
204
205 template <typename T>
206 struct PrintListV {
207 PrintListV(const NodeList &L, const DataFlowGraph &G) : List(L), G(G) {}
208
209 using Type = T;
210 const NodeList &List;
211 const DataFlowGraph &G;
212 };
213
214 template <typename T>
215 raw_ostream &operator<< (raw_ostream &OS, const PrintListV<T> &P) {
216 unsigned N = P.List.size();
217 for (NodeAddr<T> A : P.List) {
218 OS << PrintNode<T>(A, P.G);
219 if (--N)
220 OS << ", ";
221 }
222 return OS;
223 }
224
225} // end anonymous namespace
226
227template<>
228raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<PhiNode*>> &P) {
229 OS << Print<NodeId>(P.Obj.Id, P.G) << ": phi ["
230 << PrintListV<RefNode*>(P.Obj.Addr->members(P.G), P.G) << ']';
231 return OS;
232}
233
234template<>
235raw_ostream &operator<< (raw_ostream &OS,
236 const Print<NodeAddr<StmtNode*>> &P) {
237 const MachineInstr &MI = *P.Obj.Addr->getCode();
238 unsigned Opc = MI.getOpcode();
239 OS << Print<NodeId>(P.Obj.Id, P.G) << ": " << P.G.getTII().getName(Opc);
240 // Print the target for calls and branches (for readability).
241 if (MI.isCall() || MI.isBranch()) {
242 MachineInstr::const_mop_iterator T =
243 llvm::find_if(MI.operands(),
244 [] (const MachineOperand &Op) -> bool {
245 return Op.isMBB() || Op.isGlobal() || Op.isSymbol();
246 });
247 if (T != MI.operands_end()) {
248 OS << ' ';
249 if (T->isMBB())
250 OS << "BB#" << T->getMBB()->getNumber();
251 else if (T->isGlobal())
252 OS << T->getGlobal()->getName();
253 else if (T->isSymbol())
254 OS << T->getSymbolName();
255 }
256 }
257 OS << " [" << PrintListV<RefNode*>(P.Obj.Addr->members(P.G), P.G) << ']';
258 return OS;
259}
260
261template<>
262raw_ostream &operator<< (raw_ostream &OS,
263 const Print<NodeAddr<InstrNode*>> &P) {
264 switch (P.Obj.Addr->getKind()) {
265 case NodeAttrs::Phi:
266 OS << PrintNode<PhiNode*>(P.Obj, P.G);
267 break;
268 case NodeAttrs::Stmt:
269 OS << PrintNode<StmtNode*>(P.Obj, P.G);
270 break;
271 default:
272 OS << "instr? " << Print<NodeId>(P.Obj.Id, P.G);
273 break;
274 }
275 return OS;
276}
277
278template<>
279raw_ostream &operator<< (raw_ostream &OS,
280 const Print<NodeAddr<BlockNode*>> &P) {
281 MachineBasicBlock *BB = P.Obj.Addr->getCode();
282 unsigned NP = BB->pred_size();
283 std::vector<int> Ns;
284 auto PrintBBs = [&OS] (std::vector<int> Ns) -> void {
285 unsigned N = Ns.size();
286 for (int I : Ns) {
287 OS << "BB#" << I;
288 if (--N)
289 OS << ", ";
290 }
291 };
292
293 OS << Print<NodeId>(P.Obj.Id, P.G) << ": --- BB#" << BB->getNumber()
294 << " --- preds(" << NP << "): ";
295 for (MachineBasicBlock *B : BB->predecessors())
296 Ns.push_back(B->getNumber());
297 PrintBBs(Ns);
298
299 unsigned NS = BB->succ_size();
300 OS << " succs(" << NS << "): ";
301 Ns.clear();
302 for (MachineBasicBlock *B : BB->successors())
303 Ns.push_back(B->getNumber());
304 PrintBBs(Ns);
305 OS << '\n';
306
307 for (auto I : P.Obj.Addr->members(P.G))
308 OS << PrintNode<InstrNode*>(I, P.G) << '\n';
309 return OS;
310}
311
312template<>
313raw_ostream &operator<< (raw_ostream &OS,
314 const Print<NodeAddr<FuncNode*>> &P) {
315 OS << "DFG dump:[\n" << Print<NodeId>(P.Obj.Id, P.G) << ": Function: "
316 << P.Obj.Addr->getCode()->getName() << '\n';
317 for (auto I : P.Obj.Addr->members(P.G))
318 OS << PrintNode<BlockNode*>(I, P.G) << '\n';
319 OS << "]\n";
320 return OS;
321}
322
323template<>
324raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterSet> &P) {
325 OS << '{';
326 for (auto I : P.Obj)
327 OS << ' ' << Print<RegisterRef>(I, P.G);
328 OS << " }";
329 return OS;
330}
331
332template<>
333raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterAggr> &P) {
334 P.Obj.print(OS);
335 return OS;
336}
337
338template<>
339raw_ostream &operator<< (raw_ostream &OS,
340 const Print<DataFlowGraph::DefStack> &P) {
341 for (auto I = P.Obj.top(), E = P.Obj.bottom(); I != E; ) {
342 OS << Print<NodeId>(I->Id, P.G)
343 << '<' << Print<RegisterRef>(I->Addr->getRegRef(P.G), P.G) << '>';
344 I.down();
345 if (I != E)
346 OS << ' ';
347 }
348 return OS;
349}
350
351} // end namespace rdf
352} // end namespace llvm
353
354// Node allocation functions.
355//
356// Node allocator is like a slab memory allocator: it allocates blocks of
357// memory in sizes that are multiples of the size of a node. Each block has
358// the same size. Nodes are allocated from the currently active block, and
359// when it becomes full, a new one is created.
360// There is a mapping scheme between node id and its location in a block,
361// and within that block is described in the header file.
362//
363void NodeAllocator::startNewBlock() {
364 void *T = MemPool.Allocate(NodesPerBlock*NodeMemSize, NodeMemSize);
365 char *P = static_cast<char*>(T);
366 Blocks.push_back(P);
367 // Check if the block index is still within the allowed range, i.e. less
368 // than 2^N, where N is the number of bits in NodeId for the block index.
369 // BitsPerIndex is the number of bits per node index.
370 assert((Blocks.size() < ((size_t)1 << (8*sizeof(NodeId)-BitsPerIndex))) &&(((Blocks.size() < ((size_t)1 << (8*sizeof(NodeId)-BitsPerIndex
))) && "Out of bits for block index") ? static_cast<
void> (0) : __assert_fail ("(Blocks.size() < ((size_t)1 << (8*sizeof(NodeId)-BitsPerIndex))) && \"Out of bits for block index\""
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 371, __PRETTY_FUNCTION__))
371 "Out of bits for block index")(((Blocks.size() < ((size_t)1 << (8*sizeof(NodeId)-BitsPerIndex
))) && "Out of bits for block index") ? static_cast<
void> (0) : __assert_fail ("(Blocks.size() < ((size_t)1 << (8*sizeof(NodeId)-BitsPerIndex))) && \"Out of bits for block index\""
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 371, __PRETTY_FUNCTION__))
;
372 ActiveEnd = P;
373}
374
375bool NodeAllocator::needNewBlock() {
376 if (Blocks.empty())
377 return true;
378
379 char *ActiveBegin = Blocks.back();
380 uint32_t Index = (ActiveEnd-ActiveBegin)/NodeMemSize;
381 return Index >= NodesPerBlock;
382}
383
384NodeAddr<NodeBase*> NodeAllocator::New() {
385 if (needNewBlock())
386 startNewBlock();
387
388 uint32_t ActiveB = Blocks.size()-1;
389 uint32_t Index = (ActiveEnd - Blocks[ActiveB])/NodeMemSize;
390 NodeAddr<NodeBase*> NA = { reinterpret_cast<NodeBase*>(ActiveEnd),
391 makeId(ActiveB, Index) };
392 ActiveEnd += NodeMemSize;
393 return NA;
394}
395
396NodeId NodeAllocator::id(const NodeBase *P) const {
397 uintptr_t A = reinterpret_cast<uintptr_t>(P);
398 for (unsigned i = 0, n = Blocks.size(); i != n; ++i) {
399 uintptr_t B = reinterpret_cast<uintptr_t>(Blocks[i]);
400 if (A < B || A >= B + NodesPerBlock*NodeMemSize)
401 continue;
402 uint32_t Idx = (A-B)/NodeMemSize;
403 return makeId(i, Idx);
404 }
405 llvm_unreachable("Invalid node address")::llvm::llvm_unreachable_internal("Invalid node address", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 405)
;
406}
407
408void NodeAllocator::clear() {
409 MemPool.Reset();
410 Blocks.clear();
411 ActiveEnd = nullptr;
412}
413
414// Insert node NA after "this" in the circular chain.
415void NodeBase::append(NodeAddr<NodeBase*> NA) {
416 NodeId Nx = Next;
417 // If NA is already "next", do nothing.
418 if (Next != NA.Id) {
419 Next = NA.Id;
420 NA.Addr->Next = Nx;
421 }
422}
423
424// Fundamental node manipulator functions.
425
426// Obtain the register reference from a reference node.
427RegisterRef RefNode::getRegRef(const DataFlowGraph &G) const {
428 assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref)((NodeAttrs::type(Attrs) == NodeAttrs::Ref) ? static_cast<
void> (0) : __assert_fail ("NodeAttrs::type(Attrs) == NodeAttrs::Ref"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 428, __PRETTY_FUNCTION__))
;
429 if (NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)
430 return G.unpack(Ref.PR);
431 assert(Ref.Op != nullptr)((Ref.Op != nullptr) ? static_cast<void> (0) : __assert_fail
("Ref.Op != nullptr", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 431, __PRETTY_FUNCTION__))
;
432 return G.makeRegRef(*Ref.Op);
433}
434
435// Set the register reference in the reference node directly (for references
436// in phi nodes).
437void RefNode::setRegRef(RegisterRef RR, DataFlowGraph &G) {
438 assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref)((NodeAttrs::type(Attrs) == NodeAttrs::Ref) ? static_cast<
void> (0) : __assert_fail ("NodeAttrs::type(Attrs) == NodeAttrs::Ref"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 438, __PRETTY_FUNCTION__))
;
439 assert(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)((NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef) ? static_cast
<void> (0) : __assert_fail ("NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 439, __PRETTY_FUNCTION__))
;
440 Ref.PR = G.pack(RR);
441}
442
443// Set the register reference in the reference node based on a machine
444// operand (for references in statement nodes).
445void RefNode::setRegRef(MachineOperand *Op, DataFlowGraph &G) {
446 assert(NodeAttrs::type(Attrs) == NodeAttrs::Ref)((NodeAttrs::type(Attrs) == NodeAttrs::Ref) ? static_cast<
void> (0) : __assert_fail ("NodeAttrs::type(Attrs) == NodeAttrs::Ref"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 446, __PRETTY_FUNCTION__))
;
447 assert(!(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef))((!(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)) ? static_cast
<void> (0) : __assert_fail ("!(NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 447, __PRETTY_FUNCTION__))
;
448 (void)G;
449 Ref.Op = Op;
450}
451
452// Get the owner of a given reference node.
453NodeAddr<NodeBase*> RefNode::getOwner(const DataFlowGraph &G) {
454 NodeAddr<NodeBase*> NA = G.addr<NodeBase*>(getNext());
455
456 while (NA.Addr != this) {
457 if (NA.Addr->getType() == NodeAttrs::Code)
458 return NA;
459 NA = G.addr<NodeBase*>(NA.Addr->getNext());
460 }
461 llvm_unreachable("No owner in circular list")::llvm::llvm_unreachable_internal("No owner in circular list"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 461)
;
462}
463
464// Connect the def node to the reaching def node.
465void DefNode::linkToDef(NodeId Self, NodeAddr<DefNode*> DA) {
466 Ref.RD = DA.Id;
467 Ref.Sib = DA.Addr->getReachedDef();
468 DA.Addr->setReachedDef(Self);
469}
470
471// Connect the use node to the reaching def node.
472void UseNode::linkToDef(NodeId Self, NodeAddr<DefNode*> DA) {
473 Ref.RD = DA.Id;
474 Ref.Sib = DA.Addr->getReachedUse();
475 DA.Addr->setReachedUse(Self);
476}
477
478// Get the first member of the code node.
479NodeAddr<NodeBase*> CodeNode::getFirstMember(const DataFlowGraph &G) const {
480 if (Code.FirstM == 0)
481 return NodeAddr<NodeBase*>();
482 return G.addr<NodeBase*>(Code.FirstM);
483}
484
485// Get the last member of the code node.
486NodeAddr<NodeBase*> CodeNode::getLastMember(const DataFlowGraph &G) const {
487 if (Code.LastM == 0)
488 return NodeAddr<NodeBase*>();
489 return G.addr<NodeBase*>(Code.LastM);
490}
491
492// Add node NA at the end of the member list of the given code node.
493void CodeNode::addMember(NodeAddr<NodeBase*> NA, const DataFlowGraph &G) {
494 NodeAddr<NodeBase*> ML = getLastMember(G);
495 if (ML.Id != 0) {
496 ML.Addr->append(NA);
497 } else {
498 Code.FirstM = NA.Id;
499 NodeId Self = G.id(this);
500 NA.Addr->setNext(Self);
501 }
502 Code.LastM = NA.Id;
503}
504
505// Add node NA after member node MA in the given code node.
506void CodeNode::addMemberAfter(NodeAddr<NodeBase*> MA, NodeAddr<NodeBase*> NA,
507 const DataFlowGraph &G) {
508 MA.Addr->append(NA);
509 if (Code.LastM == MA.Id)
510 Code.LastM = NA.Id;
511}
512
513// Remove member node NA from the given code node.
514void CodeNode::removeMember(NodeAddr<NodeBase*> NA, const DataFlowGraph &G) {
515 NodeAddr<NodeBase*> MA = getFirstMember(G);
516 assert(MA.Id != 0)((MA.Id != 0) ? static_cast<void> (0) : __assert_fail (
"MA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 516, __PRETTY_FUNCTION__))
;
517
518 // Special handling if the member to remove is the first member.
519 if (MA.Id == NA.Id) {
520 if (Code.LastM == MA.Id) {
521 // If it is the only member, set both first and last to 0.
522 Code.FirstM = Code.LastM = 0;
523 } else {
524 // Otherwise, advance the first member.
525 Code.FirstM = MA.Addr->getNext();
526 }
527 return;
528 }
529
530 while (MA.Addr != this) {
531 NodeId MX = MA.Addr->getNext();
532 if (MX == NA.Id) {
533 MA.Addr->setNext(NA.Addr->getNext());
534 // If the member to remove happens to be the last one, update the
535 // LastM indicator.
536 if (Code.LastM == NA.Id)
537 Code.LastM = MA.Id;
538 return;
539 }
540 MA = G.addr<NodeBase*>(MX);
541 }
542 llvm_unreachable("No such member")::llvm::llvm_unreachable_internal("No such member", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 542)
;
543}
544
545// Return the list of all members of the code node.
546NodeList CodeNode::members(const DataFlowGraph &G) const {
547 static auto True = [] (NodeAddr<NodeBase*>) -> bool { return true; };
548 return members_if(True, G);
549}
550
551// Return the owner of the given instr node.
552NodeAddr<NodeBase*> InstrNode::getOwner(const DataFlowGraph &G) {
553 NodeAddr<NodeBase*> NA = G.addr<NodeBase*>(getNext());
554
555 while (NA.Addr != this) {
556 assert(NA.Addr->getType() == NodeAttrs::Code)((NA.Addr->getType() == NodeAttrs::Code) ? static_cast<
void> (0) : __assert_fail ("NA.Addr->getType() == NodeAttrs::Code"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 556, __PRETTY_FUNCTION__))
;
557 if (NA.Addr->getKind() == NodeAttrs::Block)
558 return NA;
559 NA = G.addr<NodeBase*>(NA.Addr->getNext());
560 }
561 llvm_unreachable("No owner in circular list")::llvm::llvm_unreachable_internal("No owner in circular list"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 561)
;
562}
563
564// Add the phi node PA to the given block node.
565void BlockNode::addPhi(NodeAddr<PhiNode*> PA, const DataFlowGraph &G) {
566 NodeAddr<NodeBase*> M = getFirstMember(G);
567 if (M.Id == 0) {
568 addMember(PA, G);
569 return;
570 }
571
572 assert(M.Addr->getType() == NodeAttrs::Code)((M.Addr->getType() == NodeAttrs::Code) ? static_cast<void
> (0) : __assert_fail ("M.Addr->getType() == NodeAttrs::Code"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 572, __PRETTY_FUNCTION__))
;
573 if (M.Addr->getKind() == NodeAttrs::Stmt) {
574 // If the first member of the block is a statement, insert the phi as
575 // the first member.
576 Code.FirstM = PA.Id;
577 PA.Addr->setNext(M.Id);
578 } else {
579 // If the first member is a phi, find the last phi, and append PA to it.
580 assert(M.Addr->getKind() == NodeAttrs::Phi)((M.Addr->getKind() == NodeAttrs::Phi) ? static_cast<void
> (0) : __assert_fail ("M.Addr->getKind() == NodeAttrs::Phi"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 580, __PRETTY_FUNCTION__))
;
581 NodeAddr<NodeBase*> MN = M;
582 do {
583 M = MN;
584 MN = G.addr<NodeBase*>(M.Addr->getNext());
585 assert(MN.Addr->getType() == NodeAttrs::Code)((MN.Addr->getType() == NodeAttrs::Code) ? static_cast<
void> (0) : __assert_fail ("MN.Addr->getType() == NodeAttrs::Code"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 585, __PRETTY_FUNCTION__))
;
586 } while (MN.Addr->getKind() == NodeAttrs::Phi);
587
588 // M is the last phi.
589 addMemberAfter(M, PA, G);
590 }
591}
592
593// Find the block node corresponding to the machine basic block BB in the
594// given func node.
595NodeAddr<BlockNode*> FuncNode::findBlock(const MachineBasicBlock *BB,
596 const DataFlowGraph &G) const {
597 auto EqBB = [BB] (NodeAddr<NodeBase*> NA) -> bool {
598 return NodeAddr<BlockNode*>(NA).Addr->getCode() == BB;
599 };
600 NodeList Ms = members_if(EqBB, G);
601 if (!Ms.empty())
602 return Ms[0];
603 return NodeAddr<BlockNode*>();
604}
605
606// Get the block node for the entry block in the given function.
607NodeAddr<BlockNode*> FuncNode::getEntryBlock(const DataFlowGraph &G) {
608 MachineBasicBlock *EntryB = &getCode()->front();
609 return findBlock(EntryB, G);
610}
611
612// Target operand information.
613//
614
615// For a given instruction, check if there are any bits of RR that can remain
616// unchanged across this def.
617bool TargetOperandInfo::isPreserving(const MachineInstr &In, unsigned OpNum)
618 const {
619 return TII.isPredicated(In);
620}
621
622// Check if the definition of RR produces an unspecified value.
623bool TargetOperandInfo::isClobbering(const MachineInstr &In, unsigned OpNum)
624 const {
625 const MachineOperand &Op = In.getOperand(OpNum);
626 if (Op.isRegMask())
627 return true;
628 assert(Op.isReg())((Op.isReg()) ? static_cast<void> (0) : __assert_fail (
"Op.isReg()", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 628, __PRETTY_FUNCTION__))
;
629 if (In.isCall())
630 if (Op.isDef() && Op.isDead())
631 return true;
632 return false;
633}
634
635// Check if the given instruction specifically requires
636bool TargetOperandInfo::isFixedReg(const MachineInstr &In, unsigned OpNum)
637 const {
638 if (In.isCall() || In.isReturn() || In.isInlineAsm())
639 return true;
640 // Check for a tail call.
641 if (In.isBranch())
642 for (const MachineOperand &O : In.operands())
643 if (O.isGlobal() || O.isSymbol())
644 return true;
645
646 const MCInstrDesc &D = In.getDesc();
647 if (!D.getImplicitDefs() && !D.getImplicitUses())
648 return false;
649 const MachineOperand &Op = In.getOperand(OpNum);
650 // If there is a sub-register, treat the operand as non-fixed. Currently,
651 // fixed registers are those that are listed in the descriptor as implicit
652 // uses or defs, and those lists do not allow sub-registers.
653 if (Op.getSubReg() != 0)
654 return false;
655 RegisterId Reg = Op.getReg();
656 const MCPhysReg *ImpR = Op.isDef() ? D.getImplicitDefs()
657 : D.getImplicitUses();
658 if (!ImpR)
659 return false;
660 while (*ImpR)
661 if (*ImpR++ == Reg)
662 return true;
663 return false;
664}
665
666//
667// The data flow graph construction.
668//
669
670DataFlowGraph::DataFlowGraph(MachineFunction &mf, const TargetInstrInfo &tii,
671 const TargetRegisterInfo &tri, const MachineDominatorTree &mdt,
672 const MachineDominanceFrontier &mdf, const TargetOperandInfo &toi)
673 : MF(mf), TII(tii), TRI(tri), PRI(tri, mf), MDT(mdt), MDF(mdf), TOI(toi),
674 LiveIns(PRI) {
675}
676
677// The implementation of the definition stack.
678// Each register reference has its own definition stack. In particular,
679// for a register references "Reg" and "Reg:subreg" will each have their
680// own definition stacks.
681
682// Construct a stack iterator.
683DataFlowGraph::DefStack::Iterator::Iterator(const DataFlowGraph::DefStack &S,
684 bool Top) : DS(S) {
685 if (!Top) {
686 // Initialize to bottom.
687 Pos = 0;
688 return;
689 }
690 // Initialize to the top, i.e. top-most non-delimiter (or 0, if empty).
691 Pos = DS.Stack.size();
692 while (Pos > 0 && DS.isDelimiter(DS.Stack[Pos-1]))
693 Pos--;
694}
695
696// Return the size of the stack, including block delimiters.
697unsigned DataFlowGraph::DefStack::size() const {
698 unsigned S = 0;
699 for (auto I = top(), E = bottom(); I != E; I.down())
700 S++;
701 return S;
702}
703
704// Remove the top entry from the stack. Remove all intervening delimiters
705// so that after this, the stack is either empty, or the top of the stack
706// is a non-delimiter.
707void DataFlowGraph::DefStack::pop() {
708 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 708, __PRETTY_FUNCTION__))
;
709 unsigned P = nextDown(Stack.size());
710 Stack.resize(P);
711}
712
713// Push a delimiter for block node N on the stack.
714void DataFlowGraph::DefStack::start_block(NodeId N) {
715 assert(N != 0)((N != 0) ? static_cast<void> (0) : __assert_fail ("N != 0"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 715, __PRETTY_FUNCTION__))
;
716 Stack.push_back(NodeAddr<DefNode*>(nullptr, N));
717}
718
719// Remove all nodes from the top of the stack, until the delimited for
720// block node N is encountered. Remove the delimiter as well. In effect,
721// this will remove from the stack all definitions from block N.
722void DataFlowGraph::DefStack::clear_block(NodeId N) {
723 assert(N != 0)((N != 0) ? static_cast<void> (0) : __assert_fail ("N != 0"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 723, __PRETTY_FUNCTION__))
;
724 unsigned P = Stack.size();
725 while (P > 0) {
726 bool Found = isDelimiter(Stack[P-1], N);
727 P--;
728 if (Found)
729 break;
730 }
731 // This will also remove the delimiter, if found.
732 Stack.resize(P);
733}
734
735// Move the stack iterator up by one.
736unsigned DataFlowGraph::DefStack::nextUp(unsigned P) const {
737 // Get the next valid position after P (skipping all delimiters).
738 // The input position P does not have to point to a non-delimiter.
739 unsigned SS = Stack.size();
740 bool IsDelim;
741 assert(P < SS)((P < SS) ? static_cast<void> (0) : __assert_fail ("P < SS"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 741, __PRETTY_FUNCTION__))
;
742 do {
743 P++;
744 IsDelim = isDelimiter(Stack[P-1]);
745 } while (P < SS && IsDelim);
746 assert(!IsDelim)((!IsDelim) ? static_cast<void> (0) : __assert_fail ("!IsDelim"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 746, __PRETTY_FUNCTION__))
;
747 return P;
748}
749
750// Move the stack iterator down by one.
751unsigned DataFlowGraph::DefStack::nextDown(unsigned P) const {
752 // Get the preceding valid position before P (skipping all delimiters).
753 // The input position P does not have to point to a non-delimiter.
754 assert(P > 0 && P <= Stack.size())((P > 0 && P <= Stack.size()) ? static_cast<
void> (0) : __assert_fail ("P > 0 && P <= Stack.size()"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 754, __PRETTY_FUNCTION__))
;
755 bool IsDelim = isDelimiter(Stack[P-1]);
756 do {
757 if (--P == 0)
758 break;
759 IsDelim = isDelimiter(Stack[P-1]);
760 } while (P > 0 && IsDelim);
761 assert(!IsDelim)((!IsDelim) ? static_cast<void> (0) : __assert_fail ("!IsDelim"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 761, __PRETTY_FUNCTION__))
;
762 return P;
763}
764
765// Register information.
766
767RegisterSet DataFlowGraph::getLandingPadLiveIns() const {
768 RegisterSet LR;
769 const Function &F = *MF.getFunction();
770 const Constant *PF = F.hasPersonalityFn() ? F.getPersonalityFn()
771 : nullptr;
772 const TargetLowering &TLI = *MF.getSubtarget().getTargetLowering();
773 if (RegisterId R = TLI.getExceptionPointerRegister(PF))
774 LR.insert(RegisterRef(R));
775 if (RegisterId R = TLI.getExceptionSelectorRegister(PF))
776 LR.insert(RegisterRef(R));
777 return LR;
778}
779
780// Node management functions.
781
782// Get the pointer to the node with the id N.
783NodeBase *DataFlowGraph::ptr(NodeId N) const {
784 if (N == 0)
785 return nullptr;
786 return Memory.ptr(N);
787}
788
789// Get the id of the node at the address P.
790NodeId DataFlowGraph::id(const NodeBase *P) const {
791 if (P == nullptr)
792 return 0;
793 return Memory.id(P);
794}
795
796// Allocate a new node and set the attributes to Attrs.
797NodeAddr<NodeBase*> DataFlowGraph::newNode(uint16_t Attrs) {
798 NodeAddr<NodeBase*> P = Memory.New();
799 P.Addr->init();
800 P.Addr->setAttrs(Attrs);
801 return P;
802}
803
804// Make a copy of the given node B, except for the data-flow links, which
805// are set to 0.
806NodeAddr<NodeBase*> DataFlowGraph::cloneNode(const NodeAddr<NodeBase*> B) {
807 NodeAddr<NodeBase*> NA = newNode(0);
808 memcpy(NA.Addr, B.Addr, sizeof(NodeBase));
809 // Ref nodes need to have the data-flow links reset.
810 if (NA.Addr->getType() == NodeAttrs::Ref) {
811 NodeAddr<RefNode*> RA = NA;
812 RA.Addr->setReachingDef(0);
813 RA.Addr->setSibling(0);
814 if (NA.Addr->getKind() == NodeAttrs::Def) {
815 NodeAddr<DefNode*> DA = NA;
816 DA.Addr->setReachedDef(0);
817 DA.Addr->setReachedUse(0);
818 }
819 }
820 return NA;
821}
822
823// Allocation routines for specific node types/kinds.
824
825NodeAddr<UseNode*> DataFlowGraph::newUse(NodeAddr<InstrNode*> Owner,
826 MachineOperand &Op, uint16_t Flags) {
827 NodeAddr<UseNode*> UA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
828 UA.Addr->setRegRef(&Op, *this);
829 return UA;
830}
831
832NodeAddr<PhiUseNode*> DataFlowGraph::newPhiUse(NodeAddr<PhiNode*> Owner,
833 RegisterRef RR, NodeAddr<BlockNode*> PredB, uint16_t Flags) {
834 NodeAddr<PhiUseNode*> PUA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
835 assert(Flags & NodeAttrs::PhiRef)((Flags & NodeAttrs::PhiRef) ? static_cast<void> (0
) : __assert_fail ("Flags & NodeAttrs::PhiRef", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 835, __PRETTY_FUNCTION__))
;
836 PUA.Addr->setRegRef(RR, *this);
837 PUA.Addr->setPredecessor(PredB.Id);
838 return PUA;
839}
840
841NodeAddr<DefNode*> DataFlowGraph::newDef(NodeAddr<InstrNode*> Owner,
842 MachineOperand &Op, uint16_t Flags) {
843 NodeAddr<DefNode*> DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
844 DA.Addr->setRegRef(&Op, *this);
845 return DA;
846}
847
848NodeAddr<DefNode*> DataFlowGraph::newDef(NodeAddr<InstrNode*> Owner,
849 RegisterRef RR, uint16_t Flags) {
850 NodeAddr<DefNode*> DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
851 assert(Flags & NodeAttrs::PhiRef)((Flags & NodeAttrs::PhiRef) ? static_cast<void> (0
) : __assert_fail ("Flags & NodeAttrs::PhiRef", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 851, __PRETTY_FUNCTION__))
;
852 DA.Addr->setRegRef(RR, *this);
853 return DA;
854}
855
856NodeAddr<PhiNode*> DataFlowGraph::newPhi(NodeAddr<BlockNode*> Owner) {
857 NodeAddr<PhiNode*> PA = newNode(NodeAttrs::Code | NodeAttrs::Phi);
858 Owner.Addr->addPhi(PA, *this);
859 return PA;
860}
861
862NodeAddr<StmtNode*> DataFlowGraph::newStmt(NodeAddr<BlockNode*> Owner,
863 MachineInstr *MI) {
864 NodeAddr<StmtNode*> SA = newNode(NodeAttrs::Code | NodeAttrs::Stmt);
865 SA.Addr->setCode(MI);
866 Owner.Addr->addMember(SA, *this);
867 return SA;
868}
869
870NodeAddr<BlockNode*> DataFlowGraph::newBlock(NodeAddr<FuncNode*> Owner,
871 MachineBasicBlock *BB) {
872 NodeAddr<BlockNode*> BA = newNode(NodeAttrs::Code | NodeAttrs::Block);
873 BA.Addr->setCode(BB);
874 Owner.Addr->addMember(BA, *this);
875 return BA;
876}
877
878NodeAddr<FuncNode*> DataFlowGraph::newFunc(MachineFunction *MF) {
879 NodeAddr<FuncNode*> FA = newNode(NodeAttrs::Code | NodeAttrs::Func);
880 FA.Addr->setCode(MF);
881 return FA;
882}
883
884// Build the data flow graph.
885void DataFlowGraph::build(unsigned Options) {
886 reset();
887 Func = newFunc(&MF);
888
889 if (MF.empty())
890 return;
891
892 for (MachineBasicBlock &B : MF) {
893 NodeAddr<BlockNode*> BA = newBlock(Func, &B);
894 BlockNodes.insert(std::make_pair(&B, BA));
895 for (MachineInstr &I : B) {
896 if (I.isDebugValue())
897 continue;
898 buildStmt(BA, I);
899 }
900 }
901
902 NodeAddr<BlockNode*> EA = Func.Addr->getEntryBlock(*this);
903 NodeList Blocks = Func.Addr->members(*this);
904
905 // Collect information about block references.
906 RegisterSet AllRefs;
907 for (NodeAddr<BlockNode*> BA : Blocks)
908 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this))
909 for (NodeAddr<RefNode*> RA : IA.Addr->members(*this))
910 AllRefs.insert(RA.Addr->getRegRef(*this));
911
912 // Collect function live-ins and entry block live-ins.
913 MachineRegisterInfo &MRI = MF.getRegInfo();
914 MachineBasicBlock &EntryB = *EA.Addr->getCode();
915 assert(EntryB.pred_empty() && "Function entry block has predecessors")((EntryB.pred_empty() && "Function entry block has predecessors"
) ? static_cast<void> (0) : __assert_fail ("EntryB.pred_empty() && \"Function entry block has predecessors\""
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 915, __PRETTY_FUNCTION__))
;
916 for (std::pair<unsigned,unsigned> P : MRI.liveins())
917 LiveIns.insert(RegisterRef(P.first));
918 if (MRI.tracksLiveness()) {
919 for (auto I : EntryB.liveins())
920 LiveIns.insert(RegisterRef(I.PhysReg, I.LaneMask));
921 }
922
923 // Add function-entry phi nodes for the live-in registers.
924 //for (std::pair<RegisterId,LaneBitmask> P : LiveIns) {
925 for (auto I = LiveIns.rr_begin(), E = LiveIns.rr_end(); I != E; ++I) {
926 RegisterRef RR = *I;
927 NodeAddr<PhiNode*> PA = newPhi(EA);
928 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
929 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
930 PA.Addr->addMember(DA, *this);
931 }
932
933 // Add phis for landing pads.
934 // Landing pads, unlike usual backs blocks, are not entered through
935 // branches in the program, or fall-throughs from other blocks. They
936 // are entered from the exception handling runtime and target's ABI
937 // may define certain registers as defined on entry to such a block.
938 RegisterSet EHRegs = getLandingPadLiveIns();
939 if (!EHRegs.empty()) {
940 for (NodeAddr<BlockNode*> BA : Blocks) {
941 const MachineBasicBlock &B = *BA.Addr->getCode();
942 if (!B.isEHPad())
943 continue;
944
945 // Prepare a list of NodeIds of the block's predecessors.
946 NodeList Preds;
947 for (MachineBasicBlock *PB : B.predecessors())
948 Preds.push_back(findBlock(PB));
949
950 // Build phi nodes for each live-in.
951 for (RegisterRef RR : EHRegs) {
952 NodeAddr<PhiNode*> PA = newPhi(BA);
953 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
954 // Add def:
955 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
956 PA.Addr->addMember(DA, *this);
957 // Add uses (no reaching defs for phi uses):
958 for (NodeAddr<BlockNode*> PBA : Preds) {
959 NodeAddr<PhiUseNode*> PUA = newPhiUse(PA, RR, PBA);
960 PA.Addr->addMember(PUA, *this);
961 }
962 }
963 }
964 }
965
966 // Build a map "PhiM" which will contain, for each block, the set
967 // of references that will require phi definitions in that block.
968 BlockRefsMap PhiM;
969 for (NodeAddr<BlockNode*> BA : Blocks)
970 recordDefsForDF(PhiM, BA);
971 for (NodeAddr<BlockNode*> BA : Blocks)
972 buildPhis(PhiM, AllRefs, BA);
973
974 // Link all the refs. This will recursively traverse the dominator tree.
975 DefStackMap DM;
976 linkBlockRefs(DM, EA);
977
978 // Finally, remove all unused phi nodes.
979 if (!(Options & BuildOptions::KeepDeadPhis))
980 removeUnusedPhis();
981}
982
983RegisterRef DataFlowGraph::makeRegRef(unsigned Reg, unsigned Sub) const {
984 assert(PhysicalRegisterInfo::isRegMaskId(Reg) ||((PhysicalRegisterInfo::isRegMaskId(Reg) || TargetRegisterInfo
::isPhysicalRegister(Reg)) ? static_cast<void> (0) : __assert_fail
("PhysicalRegisterInfo::isRegMaskId(Reg) || TargetRegisterInfo::isPhysicalRegister(Reg)"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 985, __PRETTY_FUNCTION__))
985 TargetRegisterInfo::isPhysicalRegister(Reg))((PhysicalRegisterInfo::isRegMaskId(Reg) || TargetRegisterInfo
::isPhysicalRegister(Reg)) ? static_cast<void> (0) : __assert_fail
("PhysicalRegisterInfo::isRegMaskId(Reg) || TargetRegisterInfo::isPhysicalRegister(Reg)"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 985, __PRETTY_FUNCTION__))
;
986 assert(Reg != 0)((Reg != 0) ? static_cast<void> (0) : __assert_fail ("Reg != 0"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 986, __PRETTY_FUNCTION__))
;
987 if (Sub != 0)
988 Reg = TRI.getSubReg(Reg, Sub);
989 return RegisterRef(Reg);
990}
991
992RegisterRef DataFlowGraph::makeRegRef(const MachineOperand &Op) const {
993 assert(Op.isReg() || Op.isRegMask())((Op.isReg() || Op.isRegMask()) ? static_cast<void> (0)
: __assert_fail ("Op.isReg() || Op.isRegMask()", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 993, __PRETTY_FUNCTION__))
;
994 if (Op.isReg())
995 return makeRegRef(Op.getReg(), Op.getSubReg());
996 return RegisterRef(PRI.getRegMaskId(Op.getRegMask()), LaneBitmask::getAll());
997}
998
999RegisterRef DataFlowGraph::restrictRef(RegisterRef AR, RegisterRef BR) const {
1000 if (AR.Reg == BR.Reg) {
1001 LaneBitmask M = AR.Mask & BR.Mask;
1002 return M.any() ? RegisterRef(AR.Reg, M) : RegisterRef();
1003 }
1004#ifndef NDEBUG
1005// RegisterRef NAR = PRI.normalize(AR);
1006// RegisterRef NBR = PRI.normalize(BR);
1007// assert(NAR.Reg != NBR.Reg);
1008#endif
1009 // This isn't strictly correct, because the overlap may happen in the
1010 // part masked out.
1011 if (PRI.alias(AR, BR))
1012 return AR;
1013 return RegisterRef();
1014}
1015
1016// For each stack in the map DefM, push the delimiter for block B on it.
1017void DataFlowGraph::markBlock(NodeId B, DefStackMap &DefM) {
1018 // Push block delimiters.
1019 for (auto I = DefM.begin(), E = DefM.end(); I != E; ++I)
1020 I->second.start_block(B);
1021}
1022
1023// Remove all definitions coming from block B from each stack in DefM.
1024void DataFlowGraph::releaseBlock(NodeId B, DefStackMap &DefM) {
1025 // Pop all defs from this block from the definition stack. Defs that were
1026 // added to the map during the traversal of instructions will not have a
1027 // delimiter, but for those, the whole stack will be emptied.
1028 for (auto I = DefM.begin(), E = DefM.end(); I != E; ++I)
1029 I->second.clear_block(B);
1030
1031 // Finally, remove empty stacks from the map.
1032 for (auto I = DefM.begin(), E = DefM.end(), NextI = I; I != E; I = NextI) {
1033 NextI = std::next(I);
1034 // This preserves the validity of iterators other than I.
1035 if (I->second.empty())
1036 DefM.erase(I);
1037 }
1038}
1039
1040// Push all definitions from the instruction node IA to an appropriate
1041// stack in DefM.
1042void DataFlowGraph::pushAllDefs(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1043 pushClobbers(IA, DefM);
1044 pushDefs(IA, DefM);
1045}
1046
1047// Push all definitions from the instruction node IA to an appropriate
1048// stack in DefM.
1049void DataFlowGraph::pushClobbers(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1050 NodeSet Visited;
1051 std::set<RegisterId> Defined;
1052
1053 // The important objectives of this function are:
1054 // - to be able to handle instructions both while the graph is being
1055 // constructed, and after the graph has been constructed, and
1056 // - maintain proper ordering of definitions on the stack for each
1057 // register reference:
1058 // - if there are two or more related defs in IA (i.e. coming from
1059 // the same machine operand), then only push one def on the stack,
1060 // - if there are multiple unrelated defs of non-overlapping
1061 // subregisters of S, then the stack for S will have both (in an
1062 // unspecified order), but the order does not matter from the data-
1063 // -flow perspective.
1064
1065 for (NodeAddr<DefNode*> DA : IA.Addr->members_if(IsDef, *this)) {
1066 if (Visited.count(DA.Id))
1067 continue;
1068 if (!(DA.Addr->getFlags() & NodeAttrs::Clobbering))
1069 continue;
1070
1071 NodeList Rel = getRelatedRefs(IA, DA);
1072 NodeAddr<DefNode*> PDA = Rel.front();
1073 RegisterRef RR = PDA.Addr->getRegRef(*this);
1074
1075 // Push the definition on the stack for the register and all aliases.
1076 // The def stack traversal in linkNodeUp will check the exact aliasing.
1077 DefM[RR.Reg].push(DA);
1078 Defined.insert(RR.Reg);
1079 for (RegisterId A : PRI.getAliasSet(RR.Reg)) {
1080 // Check that we don't push the same def twice.
1081 assert(A != RR.Reg)((A != RR.Reg) ? static_cast<void> (0) : __assert_fail (
"A != RR.Reg", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1081, __PRETTY_FUNCTION__))
;
1082 if (!Defined.count(A))
1083 DefM[A].push(DA);
1084 }
1085 // Mark all the related defs as visited.
1086 for (NodeAddr<NodeBase*> T : Rel)
1087 Visited.insert(T.Id);
1088 }
1089}
1090
1091// Push all definitions from the instruction node IA to an appropriate
1092// stack in DefM.
1093void DataFlowGraph::pushDefs(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1094 NodeSet Visited;
1095#ifndef NDEBUG
1096 std::set<RegisterId> Defined;
1097#endif
1098
1099 // The important objectives of this function are:
1100 // - to be able to handle instructions both while the graph is being
1101 // constructed, and after the graph has been constructed, and
1102 // - maintain proper ordering of definitions on the stack for each
1103 // register reference:
1104 // - if there are two or more related defs in IA (i.e. coming from
1105 // the same machine operand), then only push one def on the stack,
1106 // - if there are multiple unrelated defs of non-overlapping
1107 // subregisters of S, then the stack for S will have both (in an
1108 // unspecified order), but the order does not matter from the data-
1109 // -flow perspective.
1110
1111 for (NodeAddr<DefNode*> DA : IA.Addr->members_if(IsDef, *this)) {
1112 if (Visited.count(DA.Id))
1113 continue;
1114 if (DA.Addr->getFlags() & NodeAttrs::Clobbering)
1115 continue;
1116
1117 NodeList Rel = getRelatedRefs(IA, DA);
1118 NodeAddr<DefNode*> PDA = Rel.front();
1119 RegisterRef RR = PDA.Addr->getRegRef(*this);
1120#ifndef NDEBUG
1121 // Assert if the register is defined in two or more unrelated defs.
1122 // This could happen if there are two or more def operands defining it.
1123 if (!Defined.insert(RR.Reg).second) {
1124 MachineInstr *MI = NodeAddr<StmtNode*>(IA).Addr->getCode();
1125 dbgs() << "Multiple definitions of register: "
1126 << Print<RegisterRef>(RR, *this) << " in\n " << *MI
1127 << "in BB#" << MI->getParent()->getNumber() << '\n';
1128 llvm_unreachable(nullptr)::llvm::llvm_unreachable_internal(nullptr, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1128)
;
1129 }
1130#endif
1131 // Push the definition on the stack for the register and all aliases.
1132 // The def stack traversal in linkNodeUp will check the exact aliasing.
1133 DefM[RR.Reg].push(DA);
1134 for (RegisterId A : PRI.getAliasSet(RR.Reg)) {
1135 // Check that we don't push the same def twice.
1136 assert(A != RR.Reg)((A != RR.Reg) ? static_cast<void> (0) : __assert_fail (
"A != RR.Reg", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1136, __PRETTY_FUNCTION__))
;
1137 DefM[A].push(DA);
1138 }
1139 // Mark all the related defs as visited.
1140 for (NodeAddr<NodeBase*> T : Rel)
1141 Visited.insert(T.Id);
1142 }
1143}
1144
1145// Return the list of all reference nodes related to RA, including RA itself.
1146// See "getNextRelated" for the meaning of a "related reference".
1147NodeList DataFlowGraph::getRelatedRefs(NodeAddr<InstrNode*> IA,
1148 NodeAddr<RefNode*> RA) const {
1149 assert(IA.Id != 0 && RA.Id != 0)((IA.Id != 0 && RA.Id != 0) ? static_cast<void>
(0) : __assert_fail ("IA.Id != 0 && RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1149, __PRETTY_FUNCTION__))
;
1150
1151 NodeList Refs;
1152 NodeId Start = RA.Id;
1153 do {
1154 Refs.push_back(RA);
1155 RA = getNextRelated(IA, RA);
1156 } while (RA.Id != 0 && RA.Id != Start);
1157 return Refs;
1158}
1159
1160// Clear all information in the graph.
1161void DataFlowGraph::reset() {
1162 Memory.clear();
1163 BlockNodes.clear();
1164 Func = NodeAddr<FuncNode*>();
1165}
1166
1167// Return the next reference node in the instruction node IA that is related
1168// to RA. Conceptually, two reference nodes are related if they refer to the
1169// same instance of a register access, but differ in flags or other minor
1170// characteristics. Specific examples of related nodes are shadow reference
1171// nodes.
1172// Return the equivalent of nullptr if there are no more related references.
1173NodeAddr<RefNode*> DataFlowGraph::getNextRelated(NodeAddr<InstrNode*> IA,
1174 NodeAddr<RefNode*> RA) const {
1175 assert(IA.Id != 0 && RA.Id != 0)((IA.Id != 0 && RA.Id != 0) ? static_cast<void>
(0) : __assert_fail ("IA.Id != 0 && RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1175, __PRETTY_FUNCTION__))
;
1176
1177 auto Related = [this,RA](NodeAddr<RefNode*> TA) -> bool {
1178 if (TA.Addr->getKind() != RA.Addr->getKind())
1179 return false;
1180 if (TA.Addr->getRegRef(*this) != RA.Addr->getRegRef(*this))
1181 return false;
1182 return true;
1183 };
1184 auto RelatedStmt = [&Related,RA](NodeAddr<RefNode*> TA) -> bool {
1185 return Related(TA) &&
1186 &RA.Addr->getOp() == &TA.Addr->getOp();
1187 };
1188 auto RelatedPhi = [&Related,RA](NodeAddr<RefNode*> TA) -> bool {
1189 if (!Related(TA))
1190 return false;
1191 if (TA.Addr->getKind() != NodeAttrs::Use)
1192 return true;
1193 // For phi uses, compare predecessor blocks.
1194 const NodeAddr<const PhiUseNode*> TUA = TA;
1195 const NodeAddr<const PhiUseNode*> RUA = RA;
1196 return TUA.Addr->getPredecessor() == RUA.Addr->getPredecessor();
1197 };
1198
1199 RegisterRef RR = RA.Addr->getRegRef(*this);
1200 if (IA.Addr->getKind() == NodeAttrs::Stmt)
1201 return RA.Addr->getNextRef(RR, RelatedStmt, true, *this);
1202 return RA.Addr->getNextRef(RR, RelatedPhi, true, *this);
1203}
1204
1205// Find the next node related to RA in IA that satisfies condition P.
1206// If such a node was found, return a pair where the second element is the
1207// located node. If such a node does not exist, return a pair where the
1208// first element is the element after which such a node should be inserted,
1209// and the second element is a null-address.
1210template <typename Predicate>
1211std::pair<NodeAddr<RefNode*>,NodeAddr<RefNode*>>
1212DataFlowGraph::locateNextRef(NodeAddr<InstrNode*> IA, NodeAddr<RefNode*> RA,
1213 Predicate P) const {
1214 assert(IA.Id != 0 && RA.Id != 0)((IA.Id != 0 && RA.Id != 0) ? static_cast<void>
(0) : __assert_fail ("IA.Id != 0 && RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1214, __PRETTY_FUNCTION__))
;
1215
1216 NodeAddr<RefNode*> NA;
1217 NodeId Start = RA.Id;
1218 while (true) {
1219 NA = getNextRelated(IA, RA);
1220 if (NA.Id == 0 || NA.Id == Start)
1221 break;
1222 if (P(NA))
1223 break;
1224 RA = NA;
1225 }
1226
1227 if (NA.Id != 0 && NA.Id != Start)
1228 return std::make_pair(RA, NA);
1229 return std::make_pair(RA, NodeAddr<RefNode*>());
1230}
1231
1232// Get the next shadow node in IA corresponding to RA, and optionally create
1233// such a node if it does not exist.
1234NodeAddr<RefNode*> DataFlowGraph::getNextShadow(NodeAddr<InstrNode*> IA,
1235 NodeAddr<RefNode*> RA, bool Create) {
1236 assert(IA.Id != 0 && RA.Id != 0)((IA.Id != 0 && RA.Id != 0) ? static_cast<void>
(0) : __assert_fail ("IA.Id != 0 && RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1236, __PRETTY_FUNCTION__))
;
1237
1238 uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
1239 auto IsShadow = [Flags] (NodeAddr<RefNode*> TA) -> bool {
1240 return TA.Addr->getFlags() == Flags;
1241 };
1242 auto Loc = locateNextRef(IA, RA, IsShadow);
1243 if (Loc.second.Id != 0 || !Create)
1244 return Loc.second;
1245
1246 // Create a copy of RA and mark is as shadow.
1247 NodeAddr<RefNode*> NA = cloneNode(RA);
1248 NA.Addr->setFlags(Flags | NodeAttrs::Shadow);
1249 IA.Addr->addMemberAfter(Loc.first, NA, *this);
1250 return NA;
1251}
1252
1253// Get the next shadow node in IA corresponding to RA. Return null-address
1254// if such a node does not exist.
1255NodeAddr<RefNode*> DataFlowGraph::getNextShadow(NodeAddr<InstrNode*> IA,
1256 NodeAddr<RefNode*> RA) const {
1257 assert(IA.Id != 0 && RA.Id != 0)((IA.Id != 0 && RA.Id != 0) ? static_cast<void>
(0) : __assert_fail ("IA.Id != 0 && RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1257, __PRETTY_FUNCTION__))
;
1258 uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
1259 auto IsShadow = [Flags] (NodeAddr<RefNode*> TA) -> bool {
1260 return TA.Addr->getFlags() == Flags;
1261 };
1262 return locateNextRef(IA, RA, IsShadow).second;
1263}
1264
1265// Create a new statement node in the block node BA that corresponds to
1266// the machine instruction MI.
1267void DataFlowGraph::buildStmt(NodeAddr<BlockNode*> BA, MachineInstr &In) {
1268 NodeAddr<StmtNode*> SA = newStmt(BA, &In);
1269
1270 auto isCall = [] (const MachineInstr &In) -> bool {
1271 if (In.isCall())
1272 return true;
1273 // Is tail call?
1274 if (In.isBranch()) {
1275 for (const MachineOperand &Op : In.operands())
1276 if (Op.isGlobal() || Op.isSymbol())
1277 return true;
1278 // Assume indirect branches are calls. This is for the purpose of
1279 // keeping implicit operands, and so it won't hurt on intra-function
1280 // indirect branches.
1281 if (In.isIndirectBranch())
1282 return true;
1283 }
1284 return false;
1285 };
1286
1287 auto isDefUndef = [this] (const MachineInstr &In, RegisterRef DR) -> bool {
1288 // This instruction defines DR. Check if there is a use operand that
1289 // would make DR live on entry to the instruction.
1290 for (const MachineOperand &Op : In.operands()) {
1291 if (!Op.isReg() || Op.getReg() == 0 || !Op.isUse() || Op.isUndef())
1292 continue;
1293 RegisterRef UR = makeRegRef(Op);
1294 if (PRI.alias(DR, UR))
1295 return false;
1296 }
1297 return true;
1298 };
1299
1300 bool IsCall = isCall(In);
1301 unsigned NumOps = In.getNumOperands();
1302
1303 // Avoid duplicate implicit defs. This will not detect cases of implicit
1304 // defs that define registers that overlap, but it is not clear how to
1305 // interpret that in the absence of explicit defs. Overlapping explicit
1306 // defs are likely illegal already.
1307 BitVector DoneDefs(TRI.getNumRegs());
1308 // Process explicit defs first.
1309 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1310 MachineOperand &Op = In.getOperand(OpN);
1311 if (!Op.isReg() || !Op.isDef() || Op.isImplicit())
1312 continue;
1313 unsigned R = Op.getReg();
1314 if (!R || !TargetRegisterInfo::isPhysicalRegister(R))
1315 continue;
1316 uint16_t Flags = NodeAttrs::None;
1317 if (TOI.isPreserving(In, OpN)) {
1318 Flags |= NodeAttrs::Preserving;
1319 // If the def is preserving, check if it is also undefined.
1320 if (isDefUndef(In, makeRegRef(Op)))
1321 Flags |= NodeAttrs::Undef;
1322 }
1323 if (TOI.isClobbering(In, OpN))
1324 Flags |= NodeAttrs::Clobbering;
1325 if (TOI.isFixedReg(In, OpN))
1326 Flags |= NodeAttrs::Fixed;
1327 if (IsCall && Op.isDead())
1328 Flags |= NodeAttrs::Dead;
1329 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1330 SA.Addr->addMember(DA, *this);
1331 assert(!DoneDefs.test(R))((!DoneDefs.test(R)) ? static_cast<void> (0) : __assert_fail
("!DoneDefs.test(R)", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1331, __PRETTY_FUNCTION__))
;
1332 DoneDefs.set(R);
1333 }
1334
1335 // Process reg-masks (as clobbers).
1336 BitVector DoneClobbers(TRI.getNumRegs());
1337 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1338 MachineOperand &Op = In.getOperand(OpN);
1339 if (!Op.isRegMask())
1340 continue;
1341 uint16_t Flags = NodeAttrs::Clobbering | NodeAttrs::Fixed |
1342 NodeAttrs::Dead;
1343 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1344 SA.Addr->addMember(DA, *this);
1345 // Record all clobbered registers in DoneDefs.
1346 const uint32_t *RM = Op.getRegMask();
1347 for (unsigned i = 1, e = TRI.getNumRegs(); i != e; ++i)
1348 if (!(RM[i/32] & (1u << (i%32))))
1349 DoneClobbers.set(i);
1350 }
1351
1352 // Process implicit defs, skipping those that have already been added
1353 // as explicit.
1354 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1355 MachineOperand &Op = In.getOperand(OpN);
1356 if (!Op.isReg() || !Op.isDef() || !Op.isImplicit())
1357 continue;
1358 unsigned R = Op.getReg();
1359 if (!R || !TargetRegisterInfo::isPhysicalRegister(R) || DoneDefs.test(R))
1360 continue;
1361 RegisterRef RR = makeRegRef(Op);
1362 uint16_t Flags = NodeAttrs::None;
1363 if (TOI.isPreserving(In, OpN)) {
1364 Flags |= NodeAttrs::Preserving;
1365 // If the def is preserving, check if it is also undefined.
1366 if (isDefUndef(In, RR))
1367 Flags |= NodeAttrs::Undef;
1368 }
1369 if (TOI.isClobbering(In, OpN))
1370 Flags |= NodeAttrs::Clobbering;
1371 if (TOI.isFixedReg(In, OpN))
1372 Flags |= NodeAttrs::Fixed;
1373 if (IsCall && Op.isDead()) {
1374 if (DoneClobbers.test(R))
1375 continue;
1376 Flags |= NodeAttrs::Dead;
1377 }
1378 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1379 SA.Addr->addMember(DA, *this);
1380 DoneDefs.set(R);
1381 }
1382
1383 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1384 MachineOperand &Op = In.getOperand(OpN);
1385 if (!Op.isReg() || !Op.isUse())
1386 continue;
1387 unsigned R = Op.getReg();
1388 if (!R || !TargetRegisterInfo::isPhysicalRegister(R))
1389 continue;
1390 uint16_t Flags = NodeAttrs::None;
1391 if (Op.isUndef())
1392 Flags |= NodeAttrs::Undef;
1393 if (TOI.isFixedReg(In, OpN))
1394 Flags |= NodeAttrs::Fixed;
1395 NodeAddr<UseNode*> UA = newUse(SA, Op, Flags);
1396 SA.Addr->addMember(UA, *this);
1397 }
1398}
1399
1400// Scan all defs in the block node BA and record in PhiM the locations of
1401// phi nodes corresponding to these defs.
1402void DataFlowGraph::recordDefsForDF(BlockRefsMap &PhiM,
1403 NodeAddr<BlockNode*> BA) {
1404 // Check all defs from block BA and record them in each block in BA's
1405 // iterated dominance frontier. This information will later be used to
1406 // create phi nodes.
1407 MachineBasicBlock *BB = BA.Addr->getCode();
1408 assert(BB)((BB) ? static_cast<void> (0) : __assert_fail ("BB", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1408, __PRETTY_FUNCTION__))
;
1409 auto DFLoc = MDF.find(BB);
1410 if (DFLoc == MDF.end() || DFLoc->second.empty())
1411 return;
1412
1413 // Traverse all instructions in the block and collect the set of all
1414 // defined references. For each reference there will be a phi created
1415 // in the block's iterated dominance frontier.
1416 // This is done to make sure that each defined reference gets only one
1417 // phi node, even if it is defined multiple times.
1418 RegisterSet Defs;
1419 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this))
1420 for (NodeAddr<RefNode*> RA : IA.Addr->members_if(IsDef, *this))
1421 Defs.insert(RA.Addr->getRegRef(*this));
1422
1423 // Calculate the iterated dominance frontier of BB.
1424 const MachineDominanceFrontier::DomSetType &DF = DFLoc->second;
1425 SetVector<MachineBasicBlock*> IDF(DF.begin(), DF.end());
1426 for (unsigned i = 0; i < IDF.size(); ++i) {
1427 auto F = MDF.find(IDF[i]);
1428 if (F != MDF.end())
1429 IDF.insert(F->second.begin(), F->second.end());
1430 }
1431
1432 // Finally, add the set of defs to each block in the iterated dominance
1433 // frontier.
1434 for (auto DB : IDF) {
1435 NodeAddr<BlockNode*> DBA = findBlock(DB);
1436 PhiM[DBA.Id].insert(Defs.begin(), Defs.end());
1437 }
1438}
1439
1440// Given the locations of phi nodes in the map PhiM, create the phi nodes
1441// that are located in the block node BA.
1442void DataFlowGraph::buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs,
1443 NodeAddr<BlockNode*> BA) {
1444 // Check if this blocks has any DF defs, i.e. if there are any defs
1445 // that this block is in the iterated dominance frontier of.
1446 auto HasDF = PhiM.find(BA.Id);
1447 if (HasDF == PhiM.end() || HasDF->second.empty())
1448 return;
1449
1450 // First, remove all R in Refs in such that there exists T in Refs
1451 // such that T covers R. In other words, only leave those refs that
1452 // are not covered by another ref (i.e. maximal with respect to covering).
1453
1454 auto MaxCoverIn = [this] (RegisterRef RR, RegisterSet &RRs) -> RegisterRef {
1455 for (RegisterRef I : RRs)
1456 if (I != RR && RegisterAggr::isCoverOf(I, RR, PRI))
1457 RR = I;
1458 return RR;
1459 };
1460
1461 RegisterSet MaxDF;
1462 for (RegisterRef I : HasDF->second)
1463 MaxDF.insert(MaxCoverIn(I, HasDF->second));
1464
1465 std::vector<RegisterRef> MaxRefs;
1466 for (RegisterRef I : MaxDF)
1467 MaxRefs.push_back(MaxCoverIn(I, AllRefs));
1468
1469 // Now, for each R in MaxRefs, get the alias closure of R. If the closure
1470 // only has R in it, create a phi a def for R. Otherwise, create a phi,
1471 // and add a def for each S in the closure.
1472
1473 // Sort the refs so that the phis will be created in a deterministic order.
1474 std::sort(MaxRefs.begin(), MaxRefs.end());
1475 // Remove duplicates.
1476 auto NewEnd = std::unique(MaxRefs.begin(), MaxRefs.end());
1477 MaxRefs.erase(NewEnd, MaxRefs.end());
1478
1479 auto Aliased = [this,&MaxRefs](RegisterRef RR,
1480 std::vector<unsigned> &Closure) -> bool {
1481 for (unsigned I : Closure)
1482 if (PRI.alias(RR, MaxRefs[I]))
1483 return true;
1484 return false;
1485 };
1486
1487 // Prepare a list of NodeIds of the block's predecessors.
1488 NodeList Preds;
1489 const MachineBasicBlock *MBB = BA.Addr->getCode();
1490 for (MachineBasicBlock *PB : MBB->predecessors())
1491 Preds.push_back(findBlock(PB));
1492
1493 while (!MaxRefs.empty()) {
1494 // Put the first element in the closure, and then add all subsequent
1495 // elements from MaxRefs to it, if they alias at least one element
1496 // already in the closure.
1497 // ClosureIdx: vector of indices in MaxRefs of members of the closure.
1498 std::vector<unsigned> ClosureIdx = { 0 };
1499 for (unsigned i = 1; i != MaxRefs.size(); ++i)
1500 if (Aliased(MaxRefs[i], ClosureIdx))
1501 ClosureIdx.push_back(i);
1502
1503 // Build a phi for the closure.
1504 unsigned CS = ClosureIdx.size();
1505 NodeAddr<PhiNode*> PA = newPhi(BA);
1506
1507 // Add defs.
1508 for (unsigned X = 0; X != CS; ++X) {
1509 RegisterRef RR = MaxRefs[ClosureIdx[X]];
1510 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
1511 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
1512 PA.Addr->addMember(DA, *this);
1513 }
1514 // Add phi uses.
1515 for (NodeAddr<BlockNode*> PBA : Preds) {
1516 for (unsigned X = 0; X != CS; ++X) {
1517 RegisterRef RR = MaxRefs[ClosureIdx[X]];
1518 NodeAddr<PhiUseNode*> PUA = newPhiUse(PA, RR, PBA);
1519 PA.Addr->addMember(PUA, *this);
1520 }
1521 }
1522
1523 // Erase from MaxRefs all elements in the closure.
1524 auto Begin = MaxRefs.begin();
1525 for (unsigned i = ClosureIdx.size(); i != 0; --i)
1526 MaxRefs.erase(Begin + ClosureIdx[i-1]);
1527 }
1528}
1529
1530// Remove any unneeded phi nodes that were created during the build process.
1531void DataFlowGraph::removeUnusedPhis() {
1532 // This will remove unused phis, i.e. phis where each def does not reach
1533 // any uses or other defs. This will not detect or remove circular phi
1534 // chains that are otherwise dead. Unused/dead phis are created during
1535 // the build process and this function is intended to remove these cases
1536 // that are easily determinable to be unnecessary.
1537
1538 SetVector<NodeId> PhiQ;
1539 for (NodeAddr<BlockNode*> BA : Func.Addr->members(*this)) {
1540 for (auto P : BA.Addr->members_if(IsPhi, *this))
1541 PhiQ.insert(P.Id);
1542 }
1543
1544 static auto HasUsedDef = [](NodeList &Ms) -> bool {
1545 for (NodeAddr<NodeBase*> M : Ms) {
1546 if (M.Addr->getKind() != NodeAttrs::Def)
1547 continue;
1548 NodeAddr<DefNode*> DA = M;
1549 if (DA.Addr->getReachedDef() != 0 || DA.Addr->getReachedUse() != 0)
1550 return true;
1551 }
1552 return false;
1553 };
1554
1555 // Any phi, if it is removed, may affect other phis (make them dead).
1556 // For each removed phi, collect the potentially affected phis and add
1557 // them back to the queue.
1558 while (!PhiQ.empty()) {
1559 auto PA = addr<PhiNode*>(PhiQ[0]);
1560 PhiQ.remove(PA.Id);
1561 NodeList Refs = PA.Addr->members(*this);
1562 if (HasUsedDef(Refs))
1563 continue;
1564 for (NodeAddr<RefNode*> RA : Refs) {
1565 if (NodeId RD = RA.Addr->getReachingDef()) {
1566 auto RDA = addr<DefNode*>(RD);
1567 NodeAddr<InstrNode*> OA = RDA.Addr->getOwner(*this);
1568 if (IsPhi(OA))
1569 PhiQ.insert(OA.Id);
1570 }
1571 if (RA.Addr->isDef())
1572 unlinkDef(RA, true);
1573 else
1574 unlinkUse(RA, true);
1575 }
1576 NodeAddr<BlockNode*> BA = PA.Addr->getOwner(*this);
1577 BA.Addr->removeMember(PA, *this);
1578 }
1579}
1580
1581// For a given reference node TA in an instruction node IA, connect the
1582// reaching def of TA to the appropriate def node. Create any shadow nodes
1583// as appropriate.
1584template <typename T>
1585void DataFlowGraph::linkRefUp(NodeAddr<InstrNode*> IA, NodeAddr<T> TA,
1586 DefStack &DS) {
1587 if (DS.empty())
1588 return;
1589 RegisterRef RR = TA.Addr->getRegRef(*this);
1590 NodeAddr<T> TAP;
1591
1592 // References from the def stack that have been examined so far.
1593 RegisterAggr Defs(PRI);
1594
1595 for (auto I = DS.top(), E = DS.bottom(); I != E; I.down()) {
1596 RegisterRef QR = I->Addr->getRegRef(*this);
1597
1598 // Skip all defs that are aliased to any of the defs that we have already
1599 // seen. If this completes a cover of RR, stop the stack traversal.
1600 bool Alias = Defs.hasAliasOf(QR);
1601 bool Cover = Defs.insert(QR).hasCoverOf(RR);
1602 if (Alias) {
1603 if (Cover)
1604 break;
1605 continue;
1606 }
1607
1608 // The reaching def.
1609 NodeAddr<DefNode*> RDA = *I;
1610
1611 // Pick the reached node.
1612 if (TAP.Id == 0) {
1613 TAP = TA;
1614 } else {
1615 // Mark the existing ref as "shadow" and create a new shadow.
1616 TAP.Addr->setFlags(TAP.Addr->getFlags() | NodeAttrs::Shadow);
1617 TAP = getNextShadow(IA, TAP, true);
1618 }
1619
1620 // Create the link.
1621 TAP.Addr->linkToDef(TAP.Id, RDA);
1622
1623 if (Cover)
1624 break;
1625 }
1626}
1627
1628// Create data-flow links for all reference nodes in the statement node SA.
1629template <typename Predicate>
1630void DataFlowGraph::linkStmtRefs(DefStackMap &DefM, NodeAddr<StmtNode*> SA,
1631 Predicate P) {
1632#ifndef NDEBUG
1633 RegisterSet Defs;
1634#endif
1635
1636 // Link all nodes (upwards in the data-flow) with their reaching defs.
1637 for (NodeAddr<RefNode*> RA : SA.Addr->members_if(P, *this)) {
1638 uint16_t Kind = RA.Addr->getKind();
1639 assert(Kind == NodeAttrs::Def || Kind == NodeAttrs::Use)((Kind == NodeAttrs::Def || Kind == NodeAttrs::Use) ? static_cast
<void> (0) : __assert_fail ("Kind == NodeAttrs::Def || Kind == NodeAttrs::Use"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1639, __PRETTY_FUNCTION__))
;
1640 RegisterRef RR = RA.Addr->getRegRef(*this);
1641#ifndef NDEBUG
1642 // Do not expect multiple defs of the same reference.
1643 assert(Kind != NodeAttrs::Def || !Defs.count(RR))((Kind != NodeAttrs::Def || !Defs.count(RR)) ? static_cast<
void> (0) : __assert_fail ("Kind != NodeAttrs::Def || !Defs.count(RR)"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1643, __PRETTY_FUNCTION__))
;
1644 Defs.insert(RR);
1645#endif
1646
1647 auto F = DefM.find(RR.Reg);
1648 if (F == DefM.end())
1649 continue;
1650 DefStack &DS = F->second;
1651 if (Kind == NodeAttrs::Use)
1652 linkRefUp<UseNode*>(SA, RA, DS);
1653 else if (Kind == NodeAttrs::Def)
1654 linkRefUp<DefNode*>(SA, RA, DS);
1655 else
1656 llvm_unreachable("Unexpected node in instruction")::llvm::llvm_unreachable_internal("Unexpected node in instruction"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1656)
;
1657 }
1658}
1659
1660// Create data-flow links for all instructions in the block node BA. This
1661// will include updating any phi nodes in BA.
1662void DataFlowGraph::linkBlockRefs(DefStackMap &DefM, NodeAddr<BlockNode*> BA) {
1663 // Push block delimiters.
1664 markBlock(BA.Id, DefM);
1665
1666 auto IsClobber = [] (NodeAddr<RefNode*> RA) -> bool {
1667 return IsDef(RA) && (RA.Addr->getFlags() & NodeAttrs::Clobbering);
1668 };
1669 auto IsNoClobber = [] (NodeAddr<RefNode*> RA) -> bool {
1670 return IsDef(RA) && !(RA.Addr->getFlags() & NodeAttrs::Clobbering);
1671 };
1672
1673 assert(BA.Addr && "block node address is needed to create a data-flow link")((BA.Addr && "block node address is needed to create a data-flow link"
) ? static_cast<void> (0) : __assert_fail ("BA.Addr && \"block node address is needed to create a data-flow link\""
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1673, __PRETTY_FUNCTION__))
;
1674 // For each non-phi instruction in the block, link all the defs and uses
1675 // to their reaching defs. For any member of the block (including phis),
1676 // push the defs on the corresponding stacks.
1677 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this)) {
1678 // Ignore phi nodes here. They will be linked part by part from the
1679 // predecessors.
1680 if (IA.Addr->getKind() == NodeAttrs::Stmt) {
1681 linkStmtRefs(DefM, IA, IsUse);
1682 linkStmtRefs(DefM, IA, IsClobber);
1683 }
1684
1685 // Push the definitions on the stack.
1686 pushClobbers(IA, DefM);
1687
1688 if (IA.Addr->getKind() == NodeAttrs::Stmt)
1689 linkStmtRefs(DefM, IA, IsNoClobber);
1690
1691 pushDefs(IA, DefM);
1692 }
1693
1694 // Recursively process all children in the dominator tree.
1695 MachineDomTreeNode *N = MDT.getNode(BA.Addr->getCode());
1696 for (auto I : *N) {
1697 MachineBasicBlock *SB = I->getBlock();
1698 NodeAddr<BlockNode*> SBA = findBlock(SB);
1699 linkBlockRefs(DefM, SBA);
1700 }
1701
1702 // Link the phi uses from the successor blocks.
1703 auto IsUseForBA = [BA](NodeAddr<NodeBase*> NA) -> bool {
1704 if (NA.Addr->getKind() != NodeAttrs::Use)
1705 return false;
1706 assert(NA.Addr->getFlags() & NodeAttrs::PhiRef)((NA.Addr->getFlags() & NodeAttrs::PhiRef) ? static_cast
<void> (0) : __assert_fail ("NA.Addr->getFlags() & NodeAttrs::PhiRef"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1706, __PRETTY_FUNCTION__))
;
1707 NodeAddr<PhiUseNode*> PUA = NA;
1708 return PUA.Addr->getPredecessor() == BA.Id;
1709 };
1710
1711 RegisterSet EHLiveIns = getLandingPadLiveIns();
1712 MachineBasicBlock *MBB = BA.Addr->getCode();
1713
1714 for (MachineBasicBlock *SB : MBB->successors()) {
1715 bool IsEHPad = SB->isEHPad();
1716 NodeAddr<BlockNode*> SBA = findBlock(SB);
1717 for (NodeAddr<InstrNode*> IA : SBA.Addr->members_if(IsPhi, *this)) {
1718 // Do not link phi uses for landing pad live-ins.
1719 if (IsEHPad) {
1720 // Find what register this phi is for.
1721 NodeAddr<RefNode*> RA = IA.Addr->getFirstMember(*this);
1722 assert(RA.Id != 0)((RA.Id != 0) ? static_cast<void> (0) : __assert_fail (
"RA.Id != 0", "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1722, __PRETTY_FUNCTION__))
;
1723 if (EHLiveIns.count(RA.Addr->getRegRef(*this)))
1724 continue;
1725 }
1726 // Go over each phi use associated with MBB, and link it.
1727 for (auto U : IA.Addr->members_if(IsUseForBA, *this)) {
1728 NodeAddr<PhiUseNode*> PUA = U;
1729 RegisterRef RR = PUA.Addr->getRegRef(*this);
1730 linkRefUp<UseNode*>(IA, PUA, DefM[RR.Reg]);
1731 }
1732 }
1733 }
1734
1735 // Pop all defs from this block from the definition stacks.
1736 releaseBlock(BA.Id, DefM);
1737}
1738
1739// Remove the use node UA from any data-flow and structural links.
1740void DataFlowGraph::unlinkUseDF(NodeAddr<UseNode*> UA) {
1741 NodeId RD = UA.Addr->getReachingDef();
1742 NodeId Sib = UA.Addr->getSibling();
1743
1744 if (RD == 0) {
1745 assert(Sib == 0)((Sib == 0) ? static_cast<void> (0) : __assert_fail ("Sib == 0"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1745, __PRETTY_FUNCTION__))
;
1746 return;
1747 }
1748
1749 auto RDA = addr<DefNode*>(RD);
1750 auto TA = addr<UseNode*>(RDA.Addr->getReachedUse());
1751 if (TA.Id == UA.Id) {
1752 RDA.Addr->setReachedUse(Sib);
1753 return;
1754 }
1755
1756 while (TA.Id != 0) {
1757 NodeId S = TA.Addr->getSibling();
1758 if (S == UA.Id) {
1759 TA.Addr->setSibling(UA.Addr->getSibling());
1760 return;
1761 }
1762 TA = addr<UseNode*>(S);
1763 }
1764}
1765
1766// Remove the def node DA from any data-flow and structural links.
1767void DataFlowGraph::unlinkDefDF(NodeAddr<DefNode*> DA) {
1768 //
1769 // RD
1770 // | reached
1771 // | def
1772 // :
1773 // .
1774 // +----+
1775 // ... -- | DA | -- ... -- 0 : sibling chain of DA
1776 // +----+
1777 // | | reached
1778 // | : def
1779 // | .
1780 // | ... : Siblings (defs)
1781 // |
1782 // : reached
1783 // . use
1784 // ... : sibling chain of reached uses
1785
1786 NodeId RD = DA.Addr->getReachingDef();
1787
1788 // Visit all siblings of the reached def and reset their reaching defs.
1789 // Also, defs reached by DA are now "promoted" to being reached by RD,
1790 // so all of them will need to be spliced into the sibling chain where
1791 // DA belongs.
1792 auto getAllNodes = [this] (NodeId N) -> NodeList {
1793 NodeList Res;
1794 while (N) {
1795 auto RA = addr<RefNode*>(N);
1796 // Keep the nodes in the exact sibling order.
1797 Res.push_back(RA);
1798 N = RA.Addr->getSibling();
1799 }
1800 return Res;
1801 };
1802 NodeList ReachedDefs = getAllNodes(DA.Addr->getReachedDef());
1803 NodeList ReachedUses = getAllNodes(DA.Addr->getReachedUse());
1804
1805 if (RD == 0) {
1806 for (NodeAddr<RefNode*> I : ReachedDefs)
1807 I.Addr->setSibling(0);
1808 for (NodeAddr<RefNode*> I : ReachedUses)
1809 I.Addr->setSibling(0);
1810 }
1811 for (NodeAddr<DefNode*> I : ReachedDefs)
1812 I.Addr->setReachingDef(RD);
1813 for (NodeAddr<UseNode*> I : ReachedUses)
1814 I.Addr->setReachingDef(RD);
1815
1816 NodeId Sib = DA.Addr->getSibling();
1817 if (RD == 0) {
1818 assert(Sib == 0)((Sib == 0) ? static_cast<void> (0) : __assert_fail ("Sib == 0"
, "/build/llvm-toolchain-snapshot-6.0~svn315928/lib/Target/Hexagon/RDFGraph.cpp"
, 1818, __PRETTY_FUNCTION__))
;
1819 return;
1820 }
1821
1822 // Update the reaching def node and remove DA from the sibling list.
1823 auto RDA = addr<DefNode*>(RD);
1824 auto TA = addr<DefNode*>(RDA.Addr->getReachedDef());
1825 if (TA.Id == DA.Id) {
1826 // If DA is the first reached def, just update the RD's reached def
1827 // to the DA's sibling.
1828 RDA.Addr->setReachedDef(Sib);
1829 } else {
1830 // Otherwise, traverse the sibling list of the reached defs and remove
1831 // DA from it.
1832 while (TA.Id != 0) {
1833 NodeId S = TA.Addr->getSibling();
1834 if (S == DA.Id) {
1835 TA.Addr->setSibling(Sib);
1836 break;
1837 }
1838 TA = addr<DefNode*>(S);
1839 }
1840 }
1841
1842 // Splice the DA's reached defs into the RDA's reached def chain.
1843 if (!ReachedDefs.empty()) {
1844 auto Last = NodeAddr<DefNode*>(ReachedDefs.back());
1845 Last.Addr->setSibling(RDA.Addr->getReachedDef());
1846 RDA.Addr->setReachedDef(ReachedDefs.front().Id);
1847 }
1848 // Splice the DA's reached uses into the RDA's reached use chain.
1849 if (!ReachedUses.empty()) {
1850 auto Last = NodeAddr<UseNode*>(ReachedUses.back());
1851 Last.Addr->setSibling(RDA.Addr->getReachedUse());
1852 RDA.Addr->setReachedUse(ReachedUses.front().Id);
1853 }
1854}