Bug Summary

File:lib/Target/Hexagon/RDFGraph.cpp
Warning:line 566, column 7
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name RDFGraph.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-9/lib/clang/9.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-9~svn362543/build-llvm/lib/Target/Hexagon -I /build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon -I /build/llvm-toolchain-snapshot-9~svn362543/build-llvm/include -I /build/llvm-toolchain-snapshot-9~svn362543/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/9.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-9/lib/clang/9.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-9~svn362543/build-llvm/lib/Target/Hexagon -fdebug-prefix-map=/build/llvm-toolchain-snapshot-9~svn362543=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2019-06-05-060531-1271-1 -x c++ /build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp -faddrsig
1//===- RDFGraph.cpp -------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Target-independent, SSA-based data flow graph for register data flow (RDF).
10//
11#include "RDFGraph.h"
12#include "RDFRegisters.h"
13#include "llvm/ADT/BitVector.h"
14#include "llvm/ADT/STLExtras.h"
15#include "llvm/ADT/SetVector.h"
16#include "llvm/CodeGen/MachineBasicBlock.h"
17#include "llvm/CodeGen/MachineDominanceFrontier.h"
18#include "llvm/CodeGen/MachineDominators.h"
19#include "llvm/CodeGen/MachineFunction.h"
20#include "llvm/CodeGen/MachineInstr.h"
21#include "llvm/CodeGen/MachineOperand.h"
22#include "llvm/CodeGen/MachineRegisterInfo.h"
23#include "llvm/CodeGen/TargetInstrInfo.h"
24#include "llvm/CodeGen/TargetLowering.h"
25#include "llvm/CodeGen/TargetRegisterInfo.h"
26#include "llvm/CodeGen/TargetSubtargetInfo.h"
27#include "llvm/IR/Function.h"
28#include "llvm/MC/LaneBitmask.h"
29#include "llvm/MC/MCInstrDesc.h"
30#include "llvm/MC/MCRegisterInfo.h"
31#include "llvm/Support/Debug.h"
32#include "llvm/Support/ErrorHandling.h"
33#include "llvm/Support/raw_ostream.h"
34#include <algorithm>
35#include <cassert>
36#include <cstdint>
37#include <cstring>
38#include <iterator>
39#include <set>
40#include <utility>
41#include <vector>
42
43using namespace llvm;
44using namespace rdf;
45
46// Printing functions. Have them here first, so that the rest of the code
47// can use them.
48namespace llvm {
49namespace rdf {
50
51raw_ostream &operator<< (raw_ostream &OS, const PrintLaneMaskOpt &P) {
52 if (!P.Mask.all())
53 OS << ':' << PrintLaneMask(P.Mask);
54 return OS;
55}
56
57raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterRef> &P) {
58 auto &TRI = P.G.getTRI();
59 if (P.Obj.Reg > 0 && P.Obj.Reg < TRI.getNumRegs())
60 OS << TRI.getName(P.Obj.Reg);
61 else
62 OS << '#' << P.Obj.Reg;
63 OS << PrintLaneMaskOpt(P.Obj.Mask);
64 return OS;
65}
66
67raw_ostream &operator<< (raw_ostream &OS, const Print<NodeId> &P) {
68 auto NA = P.G.addr<NodeBase*>(P.Obj);
69 uint16_t Attrs = NA.Addr->getAttrs();
70 uint16_t Kind = NodeAttrs::kind(Attrs);
71 uint16_t Flags = NodeAttrs::flags(Attrs);
72 switch (NodeAttrs::type(Attrs)) {
73 case NodeAttrs::Code:
74 switch (Kind) {
75 case NodeAttrs::Func: OS << 'f'; break;
76 case NodeAttrs::Block: OS << 'b'; break;
77 case NodeAttrs::Stmt: OS << 's'; break;
78 case NodeAttrs::Phi: OS << 'p'; break;
79 default: OS << "c?"; break;
80 }
81 break;
82 case NodeAttrs::Ref:
83 if (Flags & NodeAttrs::Undef)
84 OS << '/';
85 if (Flags & NodeAttrs::Dead)
86 OS << '\\';
87 if (Flags & NodeAttrs::Preserving)
88 OS << '+';
89 if (Flags & NodeAttrs::Clobbering)
90 OS << '~';
91 switch (Kind) {
92 case NodeAttrs::Use: OS << 'u'; break;
93 case NodeAttrs::Def: OS << 'd'; break;
94 case NodeAttrs::Block: OS << 'b'; break;
95 default: OS << "r?"; break;
96 }
97 break;
98 default:
99 OS << '?';
100 break;
101 }
102 OS << P.Obj;
103 if (Flags & NodeAttrs::Shadow)
104 OS << '"';
105 return OS;
106}
107
108static void printRefHeader(raw_ostream &OS, const NodeAddr<RefNode*> RA,
109 const DataFlowGraph &G) {
110 OS << Print<NodeId>(RA.Id, G) << '<'
111 << Print<RegisterRef>(RA.Addr->getRegRef(G), G) << '>';
112 if (RA.Addr->getFlags() & NodeAttrs::Fixed)
113 OS << '!';
114}
115
116raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<DefNode*>> &P) {
117 printRefHeader(OS, P.Obj, P.G);
118 OS << '(';
119 if (NodeId N = P.Obj.Addr->getReachingDef())
120 OS << Print<NodeId>(N, P.G);
121 OS << ',';
122 if (NodeId N = P.Obj.Addr->getReachedDef())
123 OS << Print<NodeId>(N, P.G);
124 OS << ',';
125 if (NodeId N = P.Obj.Addr->getReachedUse())
126 OS << Print<NodeId>(N, P.G);
127 OS << "):";
128 if (NodeId N = P.Obj.Addr->getSibling())
129 OS << Print<NodeId>(N, P.G);
130 return OS;
131}
132
133raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<UseNode*>> &P) {
134 printRefHeader(OS, P.Obj, P.G);
135 OS << '(';
136 if (NodeId N = P.Obj.Addr->getReachingDef())
137 OS << Print<NodeId>(N, P.G);
138 OS << "):";
139 if (NodeId N = P.Obj.Addr->getSibling())
140 OS << Print<NodeId>(N, P.G);
141 return OS;
142}
143
144raw_ostream &operator<< (raw_ostream &OS,
145 const Print<NodeAddr<PhiUseNode*>> &P) {
146 printRefHeader(OS, P.Obj, P.G);
147 OS << '(';
148 if (NodeId N = P.Obj.Addr->getReachingDef())
149 OS << Print<NodeId>(N, P.G);
150 OS << ',';
151 if (NodeId N = P.Obj.Addr->getPredecessor())
152 OS << Print<NodeId>(N, P.G);
153 OS << "):";
154 if (NodeId N = P.Obj.Addr->getSibling())
155 OS << Print<NodeId>(N, P.G);
156 return OS;
157}
158
159raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<RefNode*>> &P) {
160 switch (P.Obj.Addr->getKind()) {
161 case NodeAttrs::Def:
162 OS << PrintNode<DefNode*>(P.Obj, P.G);
163 break;
164 case NodeAttrs::Use:
165 if (P.Obj.Addr->getFlags() & NodeAttrs::PhiRef)
166 OS << PrintNode<PhiUseNode*>(P.Obj, P.G);
167 else
168 OS << PrintNode<UseNode*>(P.Obj, P.G);
169 break;
170 }
171 return OS;
172}
173
174raw_ostream &operator<< (raw_ostream &OS, const Print<NodeList> &P) {
175 unsigned N = P.Obj.size();
176 for (auto I : P.Obj) {
177 OS << Print<NodeId>(I.Id, P.G);
178 if (--N)
179 OS << ' ';
180 }
181 return OS;
182}
183
184raw_ostream &operator<< (raw_ostream &OS, const Print<NodeSet> &P) {
185 unsigned N = P.Obj.size();
186 for (auto I : P.Obj) {
187 OS << Print<NodeId>(I, P.G);
188 if (--N)
189 OS << ' ';
190 }
191 return OS;
192}
193
194namespace {
195
196 template <typename T>
197 struct PrintListV {
198 PrintListV(const NodeList &L, const DataFlowGraph &G) : List(L), G(G) {}
199
200 using Type = T;
201 const NodeList &List;
202 const DataFlowGraph &G;
203 };
204
205 template <typename T>
206 raw_ostream &operator<< (raw_ostream &OS, const PrintListV<T> &P) {
207 unsigned N = P.List.size();
208 for (NodeAddr<T> A : P.List) {
209 OS << PrintNode<T>(A, P.G);
210 if (--N)
211 OS << ", ";
212 }
213 return OS;
214 }
215
216} // end anonymous namespace
217
218raw_ostream &operator<< (raw_ostream &OS, const Print<NodeAddr<PhiNode*>> &P) {
219 OS << Print<NodeId>(P.Obj.Id, P.G) << ": phi ["
220 << PrintListV<RefNode*>(P.Obj.Addr->members(P.G), P.G) << ']';
221 return OS;
222}
223
224raw_ostream &operator<<(raw_ostream &OS, const Print<NodeAddr<StmtNode *>> &P) {
225 const MachineInstr &MI = *P.Obj.Addr->getCode();
226 unsigned Opc = MI.getOpcode();
227 OS << Print<NodeId>(P.Obj.Id, P.G) << ": " << P.G.getTII().getName(Opc);
228 // Print the target for calls and branches (for readability).
229 if (MI.isCall() || MI.isBranch()) {
230 MachineInstr::const_mop_iterator T =
231 llvm::find_if(MI.operands(),
232 [] (const MachineOperand &Op) -> bool {
233 return Op.isMBB() || Op.isGlobal() || Op.isSymbol();
234 });
235 if (T != MI.operands_end()) {
236 OS << ' ';
237 if (T->isMBB())
238 OS << printMBBReference(*T->getMBB());
239 else if (T->isGlobal())
240 OS << T->getGlobal()->getName();
241 else if (T->isSymbol())
242 OS << T->getSymbolName();
243 }
244 }
245 OS << " [" << PrintListV<RefNode*>(P.Obj.Addr->members(P.G), P.G) << ']';
246 return OS;
247}
248
249raw_ostream &operator<< (raw_ostream &OS,
250 const Print<NodeAddr<InstrNode*>> &P) {
251 switch (P.Obj.Addr->getKind()) {
252 case NodeAttrs::Phi:
253 OS << PrintNode<PhiNode*>(P.Obj, P.G);
254 break;
255 case NodeAttrs::Stmt:
256 OS << PrintNode<StmtNode*>(P.Obj, P.G);
257 break;
258 default:
259 OS << "instr? " << Print<NodeId>(P.Obj.Id, P.G);
260 break;
261 }
262 return OS;
263}
264
265raw_ostream &operator<< (raw_ostream &OS,
266 const Print<NodeAddr<BlockNode*>> &P) {
267 MachineBasicBlock *BB = P.Obj.Addr->getCode();
268 unsigned NP = BB->pred_size();
269 std::vector<int> Ns;
270 auto PrintBBs = [&OS] (std::vector<int> Ns) -> void {
271 unsigned N = Ns.size();
272 for (int I : Ns) {
273 OS << "%bb." << I;
274 if (--N)
275 OS << ", ";
276 }
277 };
278
279 OS << Print<NodeId>(P.Obj.Id, P.G) << ": --- " << printMBBReference(*BB)
280 << " --- preds(" << NP << "): ";
281 for (MachineBasicBlock *B : BB->predecessors())
282 Ns.push_back(B->getNumber());
283 PrintBBs(Ns);
284
285 unsigned NS = BB->succ_size();
286 OS << " succs(" << NS << "): ";
287 Ns.clear();
288 for (MachineBasicBlock *B : BB->successors())
289 Ns.push_back(B->getNumber());
290 PrintBBs(Ns);
291 OS << '\n';
292
293 for (auto I : P.Obj.Addr->members(P.G))
294 OS << PrintNode<InstrNode*>(I, P.G) << '\n';
295 return OS;
296}
297
298raw_ostream &operator<<(raw_ostream &OS, const Print<NodeAddr<FuncNode *>> &P) {
299 OS << "DFG dump:[\n" << Print<NodeId>(P.Obj.Id, P.G) << ": Function: "
300 << P.Obj.Addr->getCode()->getName() << '\n';
301 for (auto I : P.Obj.Addr->members(P.G))
302 OS << PrintNode<BlockNode*>(I, P.G) << '\n';
303 OS << "]\n";
304 return OS;
305}
306
307raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterSet> &P) {
308 OS << '{';
309 for (auto I : P.Obj)
310 OS << ' ' << Print<RegisterRef>(I, P.G);
311 OS << " }";
312 return OS;
313}
314
315raw_ostream &operator<< (raw_ostream &OS, const Print<RegisterAggr> &P) {
316 P.Obj.print(OS);
317 return OS;
318}
319
320raw_ostream &operator<< (raw_ostream &OS,
321 const Print<DataFlowGraph::DefStack> &P) {
322 for (auto I = P.Obj.top(), E = P.Obj.bottom(); I != E; ) {
323 OS << Print<NodeId>(I->Id, P.G)
324 << '<' << Print<RegisterRef>(I->Addr->getRegRef(P.G), P.G) << '>';
325 I.down();
326 if (I != E)
327 OS << ' ';
328 }
329 return OS;
330}
331
332} // end namespace rdf
333} // end namespace llvm
334
335// Node allocation functions.
336//
337// Node allocator is like a slab memory allocator: it allocates blocks of
338// memory in sizes that are multiples of the size of a node. Each block has
339// the same size. Nodes are allocated from the currently active block, and
340// when it becomes full, a new one is created.
341// There is a mapping scheme between node id and its location in a block,
342// and within that block is described in the header file.
343//
344void NodeAllocator::startNewBlock() {
345 void *T = MemPool.Allocate(NodesPerBlock*NodeMemSize, NodeMemSize);
346 char *P = static_cast<char*>(T);
347 Blocks.push_back(P);
348 // Check if the block index is still within the allowed range, i.e. less
349 // than 2^N, where N is the number of bits in NodeId for the block index.
350 // BitsPerIndex is the number of bits per node index.
351 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 352, __PRETTY_FUNCTION__))
352 "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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 352, __PRETTY_FUNCTION__))
;
353 ActiveEnd = P;
354}
355
356bool NodeAllocator::needNewBlock() {
357 if (Blocks.empty())
358 return true;
359
360 char *ActiveBegin = Blocks.back();
361 uint32_t Index = (ActiveEnd-ActiveBegin)/NodeMemSize;
362 return Index >= NodesPerBlock;
363}
364
365NodeAddr<NodeBase*> NodeAllocator::New() {
366 if (needNewBlock())
367 startNewBlock();
368
369 uint32_t ActiveB = Blocks.size()-1;
370 uint32_t Index = (ActiveEnd - Blocks[ActiveB])/NodeMemSize;
371 NodeAddr<NodeBase*> NA = { reinterpret_cast<NodeBase*>(ActiveEnd),
372 makeId(ActiveB, Index) };
373 ActiveEnd += NodeMemSize;
374 return NA;
375}
376
377NodeId NodeAllocator::id(const NodeBase *P) const {
378 uintptr_t A = reinterpret_cast<uintptr_t>(P);
379 for (unsigned i = 0, n = Blocks.size(); i != n; ++i) {
380 uintptr_t B = reinterpret_cast<uintptr_t>(Blocks[i]);
381 if (A < B || A >= B + NodesPerBlock*NodeMemSize)
382 continue;
383 uint32_t Idx = (A-B)/NodeMemSize;
384 return makeId(i, Idx);
385 }
386 llvm_unreachable("Invalid node address")::llvm::llvm_unreachable_internal("Invalid node address", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 386)
;
387}
388
389void NodeAllocator::clear() {
390 MemPool.Reset();
391 Blocks.clear();
392 ActiveEnd = nullptr;
393}
394
395// Insert node NA after "this" in the circular chain.
396void NodeBase::append(NodeAddr<NodeBase*> NA) {
397 NodeId Nx = Next;
398 // If NA is already "next", do nothing.
399 if (Next != NA.Id) {
400 Next = NA.Id;
401 NA.Addr->Next = Nx;
402 }
403}
404
405// Fundamental node manipulator functions.
406
407// Obtain the register reference from a reference node.
408RegisterRef RefNode::getRegRef(const DataFlowGraph &G) const {
409 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 409, __PRETTY_FUNCTION__))
;
410 if (NodeAttrs::flags(Attrs) & NodeAttrs::PhiRef)
411 return G.unpack(Ref.PR);
412 assert(Ref.Op != nullptr)((Ref.Op != nullptr) ? static_cast<void> (0) : __assert_fail
("Ref.Op != nullptr", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 412, __PRETTY_FUNCTION__))
;
413 return G.makeRegRef(*Ref.Op);
414}
415
416// Set the register reference in the reference node directly (for references
417// in phi nodes).
418void RefNode::setRegRef(RegisterRef RR, DataFlowGraph &G) {
419 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 419, __PRETTY_FUNCTION__))
;
420 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 420, __PRETTY_FUNCTION__))
;
421 Ref.PR = G.pack(RR);
422}
423
424// Set the register reference in the reference node based on a machine
425// operand (for references in statement nodes).
426void RefNode::setRegRef(MachineOperand *Op, DataFlowGraph &G) {
427 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 427, __PRETTY_FUNCTION__))
;
428 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 428, __PRETTY_FUNCTION__))
;
429 (void)G;
430 Ref.Op = Op;
431}
432
433// Get the owner of a given reference node.
434NodeAddr<NodeBase*> RefNode::getOwner(const DataFlowGraph &G) {
435 NodeAddr<NodeBase*> NA = G.addr<NodeBase*>(getNext());
436
437 while (NA.Addr != this) {
438 if (NA.Addr->getType() == NodeAttrs::Code)
439 return NA;
440 NA = G.addr<NodeBase*>(NA.Addr->getNext());
441 }
442 llvm_unreachable("No owner in circular list")::llvm::llvm_unreachable_internal("No owner in circular list"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 442)
;
443}
444
445// Connect the def node to the reaching def node.
446void DefNode::linkToDef(NodeId Self, NodeAddr<DefNode*> DA) {
447 Ref.RD = DA.Id;
448 Ref.Sib = DA.Addr->getReachedDef();
449 DA.Addr->setReachedDef(Self);
450}
451
452// Connect the use node to the reaching def node.
453void UseNode::linkToDef(NodeId Self, NodeAddr<DefNode*> DA) {
454 Ref.RD = DA.Id;
455 Ref.Sib = DA.Addr->getReachedUse();
456 DA.Addr->setReachedUse(Self);
457}
458
459// Get the first member of the code node.
460NodeAddr<NodeBase*> CodeNode::getFirstMember(const DataFlowGraph &G) const {
461 if (Code.FirstM == 0)
462 return NodeAddr<NodeBase*>();
463 return G.addr<NodeBase*>(Code.FirstM);
464}
465
466// Get the last member of the code node.
467NodeAddr<NodeBase*> CodeNode::getLastMember(const DataFlowGraph &G) const {
468 if (Code.LastM == 0)
469 return NodeAddr<NodeBase*>();
470 return G.addr<NodeBase*>(Code.LastM);
471}
472
473// Add node NA at the end of the member list of the given code node.
474void CodeNode::addMember(NodeAddr<NodeBase*> NA, const DataFlowGraph &G) {
475 NodeAddr<NodeBase*> ML = getLastMember(G);
476 if (ML.Id != 0) {
477 ML.Addr->append(NA);
478 } else {
479 Code.FirstM = NA.Id;
480 NodeId Self = G.id(this);
481 NA.Addr->setNext(Self);
482 }
483 Code.LastM = NA.Id;
484}
485
486// Add node NA after member node MA in the given code node.
487void CodeNode::addMemberAfter(NodeAddr<NodeBase*> MA, NodeAddr<NodeBase*> NA,
488 const DataFlowGraph &G) {
489 MA.Addr->append(NA);
490 if (Code.LastM == MA.Id)
491 Code.LastM = NA.Id;
492}
493
494// Remove member node NA from the given code node.
495void CodeNode::removeMember(NodeAddr<NodeBase*> NA, const DataFlowGraph &G) {
496 NodeAddr<NodeBase*> MA = getFirstMember(G);
497 assert(MA.Id != 0)((MA.Id != 0) ? static_cast<void> (0) : __assert_fail (
"MA.Id != 0", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 497, __PRETTY_FUNCTION__))
;
498
499 // Special handling if the member to remove is the first member.
500 if (MA.Id == NA.Id) {
501 if (Code.LastM == MA.Id) {
502 // If it is the only member, set both first and last to 0.
503 Code.FirstM = Code.LastM = 0;
504 } else {
505 // Otherwise, advance the first member.
506 Code.FirstM = MA.Addr->getNext();
507 }
508 return;
509 }
510
511 while (MA.Addr != this) {
512 NodeId MX = MA.Addr->getNext();
513 if (MX == NA.Id) {
514 MA.Addr->setNext(NA.Addr->getNext());
515 // If the member to remove happens to be the last one, update the
516 // LastM indicator.
517 if (Code.LastM == NA.Id)
518 Code.LastM = MA.Id;
519 return;
520 }
521 MA = G.addr<NodeBase*>(MX);
522 }
523 llvm_unreachable("No such member")::llvm::llvm_unreachable_internal("No such member", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 523)
;
524}
525
526// Return the list of all members of the code node.
527NodeList CodeNode::members(const DataFlowGraph &G) const {
528 static auto True = [] (NodeAddr<NodeBase*>) -> bool { return true; };
529 return members_if(True, G);
530}
531
532// Return the owner of the given instr node.
533NodeAddr<NodeBase*> InstrNode::getOwner(const DataFlowGraph &G) {
534 NodeAddr<NodeBase*> NA = G.addr<NodeBase*>(getNext());
535
536 while (NA.Addr != this) {
537 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 537, __PRETTY_FUNCTION__))
;
538 if (NA.Addr->getKind() == NodeAttrs::Block)
539 return NA;
540 NA = G.addr<NodeBase*>(NA.Addr->getNext());
541 }
542 llvm_unreachable("No owner in circular list")::llvm::llvm_unreachable_internal("No owner in circular list"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 542)
;
543}
544
545// Add the phi node PA to the given block node.
546void BlockNode::addPhi(NodeAddr<PhiNode*> PA, const DataFlowGraph &G) {
547 NodeAddr<NodeBase*> M = getFirstMember(G);
548 if (M.Id == 0) {
11
Taking false branch
549 addMember(PA, G);
550 return;
551 }
552
553 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 553, __PRETTY_FUNCTION__))
;
12
Assuming the condition is true
13
'?' condition is true
554 if (M.Addr->getKind() == NodeAttrs::Stmt) {
14
Assuming the condition is false
15
Taking false branch
555 // If the first member of the block is a statement, insert the phi as
556 // the first member.
557 Code.FirstM = PA.Id;
558 PA.Addr->setNext(M.Id);
559 } else {
560 // If the first member is a phi, find the last phi, and append PA to it.
561 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 561, __PRETTY_FUNCTION__))
;
16
Assuming the condition is true
17
'?' condition is true
562 NodeAddr<NodeBase*> MN = M;
563 do {
564 M = MN;
565 MN = G.addr<NodeBase*>(M.Addr->getNext());
18
Null pointer value stored to 'MN.Addr'
566 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 566, __PRETTY_FUNCTION__))
;
19
Called C++ object pointer is null
567 } while (MN.Addr->getKind() == NodeAttrs::Phi);
568
569 // M is the last phi.
570 addMemberAfter(M, PA, G);
571 }
572}
573
574// Find the block node corresponding to the machine basic block BB in the
575// given func node.
576NodeAddr<BlockNode*> FuncNode::findBlock(const MachineBasicBlock *BB,
577 const DataFlowGraph &G) const {
578 auto EqBB = [BB] (NodeAddr<NodeBase*> NA) -> bool {
579 return NodeAddr<BlockNode*>(NA).Addr->getCode() == BB;
580 };
581 NodeList Ms = members_if(EqBB, G);
582 if (!Ms.empty())
583 return Ms[0];
584 return NodeAddr<BlockNode*>();
585}
586
587// Get the block node for the entry block in the given function.
588NodeAddr<BlockNode*> FuncNode::getEntryBlock(const DataFlowGraph &G) {
589 MachineBasicBlock *EntryB = &getCode()->front();
590 return findBlock(EntryB, G);
591}
592
593// Target operand information.
594//
595
596// For a given instruction, check if there are any bits of RR that can remain
597// unchanged across this def.
598bool TargetOperandInfo::isPreserving(const MachineInstr &In, unsigned OpNum)
599 const {
600 return TII.isPredicated(In);
601}
602
603// Check if the definition of RR produces an unspecified value.
604bool TargetOperandInfo::isClobbering(const MachineInstr &In, unsigned OpNum)
605 const {
606 const MachineOperand &Op = In.getOperand(OpNum);
607 if (Op.isRegMask())
608 return true;
609 assert(Op.isReg())((Op.isReg()) ? static_cast<void> (0) : __assert_fail (
"Op.isReg()", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 609, __PRETTY_FUNCTION__))
;
610 if (In.isCall())
611 if (Op.isDef() && Op.isDead())
612 return true;
613 return false;
614}
615
616// Check if the given instruction specifically requires
617bool TargetOperandInfo::isFixedReg(const MachineInstr &In, unsigned OpNum)
618 const {
619 if (In.isCall() || In.isReturn() || In.isInlineAsm())
620 return true;
621 // Check for a tail call.
622 if (In.isBranch())
623 for (const MachineOperand &O : In.operands())
624 if (O.isGlobal() || O.isSymbol())
625 return true;
626
627 const MCInstrDesc &D = In.getDesc();
628 if (!D.getImplicitDefs() && !D.getImplicitUses())
629 return false;
630 const MachineOperand &Op = In.getOperand(OpNum);
631 // If there is a sub-register, treat the operand as non-fixed. Currently,
632 // fixed registers are those that are listed in the descriptor as implicit
633 // uses or defs, and those lists do not allow sub-registers.
634 if (Op.getSubReg() != 0)
635 return false;
636 RegisterId Reg = Op.getReg();
637 const MCPhysReg *ImpR = Op.isDef() ? D.getImplicitDefs()
638 : D.getImplicitUses();
639 if (!ImpR)
640 return false;
641 while (*ImpR)
642 if (*ImpR++ == Reg)
643 return true;
644 return false;
645}
646
647//
648// The data flow graph construction.
649//
650
651DataFlowGraph::DataFlowGraph(MachineFunction &mf, const TargetInstrInfo &tii,
652 const TargetRegisterInfo &tri, const MachineDominatorTree &mdt,
653 const MachineDominanceFrontier &mdf, const TargetOperandInfo &toi)
654 : MF(mf), TII(tii), TRI(tri), PRI(tri, mf), MDT(mdt), MDF(mdf), TOI(toi),
655 LiveIns(PRI) {
656}
657
658// The implementation of the definition stack.
659// Each register reference has its own definition stack. In particular,
660// for a register references "Reg" and "Reg:subreg" will each have their
661// own definition stacks.
662
663// Construct a stack iterator.
664DataFlowGraph::DefStack::Iterator::Iterator(const DataFlowGraph::DefStack &S,
665 bool Top) : DS(S) {
666 if (!Top) {
667 // Initialize to bottom.
668 Pos = 0;
669 return;
670 }
671 // Initialize to the top, i.e. top-most non-delimiter (or 0, if empty).
672 Pos = DS.Stack.size();
673 while (Pos > 0 && DS.isDelimiter(DS.Stack[Pos-1]))
674 Pos--;
675}
676
677// Return the size of the stack, including block delimiters.
678unsigned DataFlowGraph::DefStack::size() const {
679 unsigned S = 0;
680 for (auto I = top(), E = bottom(); I != E; I.down())
681 S++;
682 return S;
683}
684
685// Remove the top entry from the stack. Remove all intervening delimiters
686// so that after this, the stack is either empty, or the top of the stack
687// is a non-delimiter.
688void DataFlowGraph::DefStack::pop() {
689 assert(!empty())((!empty()) ? static_cast<void> (0) : __assert_fail ("!empty()"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 689, __PRETTY_FUNCTION__))
;
690 unsigned P = nextDown(Stack.size());
691 Stack.resize(P);
692}
693
694// Push a delimiter for block node N on the stack.
695void DataFlowGraph::DefStack::start_block(NodeId N) {
696 assert(N != 0)((N != 0) ? static_cast<void> (0) : __assert_fail ("N != 0"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 696, __PRETTY_FUNCTION__))
;
697 Stack.push_back(NodeAddr<DefNode*>(nullptr, N));
698}
699
700// Remove all nodes from the top of the stack, until the delimited for
701// block node N is encountered. Remove the delimiter as well. In effect,
702// this will remove from the stack all definitions from block N.
703void DataFlowGraph::DefStack::clear_block(NodeId N) {
704 assert(N != 0)((N != 0) ? static_cast<void> (0) : __assert_fail ("N != 0"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 704, __PRETTY_FUNCTION__))
;
705 unsigned P = Stack.size();
706 while (P > 0) {
707 bool Found = isDelimiter(Stack[P-1], N);
708 P--;
709 if (Found)
710 break;
711 }
712 // This will also remove the delimiter, if found.
713 Stack.resize(P);
714}
715
716// Move the stack iterator up by one.
717unsigned DataFlowGraph::DefStack::nextUp(unsigned P) const {
718 // Get the next valid position after P (skipping all delimiters).
719 // The input position P does not have to point to a non-delimiter.
720 unsigned SS = Stack.size();
721 bool IsDelim;
722 assert(P < SS)((P < SS) ? static_cast<void> (0) : __assert_fail ("P < SS"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 722, __PRETTY_FUNCTION__))
;
723 do {
724 P++;
725 IsDelim = isDelimiter(Stack[P-1]);
726 } while (P < SS && IsDelim);
727 assert(!IsDelim)((!IsDelim) ? static_cast<void> (0) : __assert_fail ("!IsDelim"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 727, __PRETTY_FUNCTION__))
;
728 return P;
729}
730
731// Move the stack iterator down by one.
732unsigned DataFlowGraph::DefStack::nextDown(unsigned P) const {
733 // Get the preceding valid position before P (skipping all delimiters).
734 // The input position P does not have to point to a non-delimiter.
735 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 735, __PRETTY_FUNCTION__))
;
736 bool IsDelim = isDelimiter(Stack[P-1]);
737 do {
738 if (--P == 0)
739 break;
740 IsDelim = isDelimiter(Stack[P-1]);
741 } while (P > 0 && IsDelim);
742 assert(!IsDelim)((!IsDelim) ? static_cast<void> (0) : __assert_fail ("!IsDelim"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 742, __PRETTY_FUNCTION__))
;
743 return P;
744}
745
746// Register information.
747
748RegisterSet DataFlowGraph::getLandingPadLiveIns() const {
749 RegisterSet LR;
750 const Function &F = MF.getFunction();
751 const Constant *PF = F.hasPersonalityFn() ? F.getPersonalityFn()
752 : nullptr;
753 const TargetLowering &TLI = *MF.getSubtarget().getTargetLowering();
754 if (RegisterId R = TLI.getExceptionPointerRegister(PF))
755 LR.insert(RegisterRef(R));
756 if (RegisterId R = TLI.getExceptionSelectorRegister(PF))
757 LR.insert(RegisterRef(R));
758 return LR;
759}
760
761// Node management functions.
762
763// Get the pointer to the node with the id N.
764NodeBase *DataFlowGraph::ptr(NodeId N) const {
765 if (N == 0)
766 return nullptr;
767 return Memory.ptr(N);
768}
769
770// Get the id of the node at the address P.
771NodeId DataFlowGraph::id(const NodeBase *P) const {
772 if (P == nullptr)
773 return 0;
774 return Memory.id(P);
775}
776
777// Allocate a new node and set the attributes to Attrs.
778NodeAddr<NodeBase*> DataFlowGraph::newNode(uint16_t Attrs) {
779 NodeAddr<NodeBase*> P = Memory.New();
780 P.Addr->init();
781 P.Addr->setAttrs(Attrs);
782 return P;
783}
784
785// Make a copy of the given node B, except for the data-flow links, which
786// are set to 0.
787NodeAddr<NodeBase*> DataFlowGraph::cloneNode(const NodeAddr<NodeBase*> B) {
788 NodeAddr<NodeBase*> NA = newNode(0);
789 memcpy(NA.Addr, B.Addr, sizeof(NodeBase));
790 // Ref nodes need to have the data-flow links reset.
791 if (NA.Addr->getType() == NodeAttrs::Ref) {
792 NodeAddr<RefNode*> RA = NA;
793 RA.Addr->setReachingDef(0);
794 RA.Addr->setSibling(0);
795 if (NA.Addr->getKind() == NodeAttrs::Def) {
796 NodeAddr<DefNode*> DA = NA;
797 DA.Addr->setReachedDef(0);
798 DA.Addr->setReachedUse(0);
799 }
800 }
801 return NA;
802}
803
804// Allocation routines for specific node types/kinds.
805
806NodeAddr<UseNode*> DataFlowGraph::newUse(NodeAddr<InstrNode*> Owner,
807 MachineOperand &Op, uint16_t Flags) {
808 NodeAddr<UseNode*> UA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
809 UA.Addr->setRegRef(&Op, *this);
810 return UA;
811}
812
813NodeAddr<PhiUseNode*> DataFlowGraph::newPhiUse(NodeAddr<PhiNode*> Owner,
814 RegisterRef RR, NodeAddr<BlockNode*> PredB, uint16_t Flags) {
815 NodeAddr<PhiUseNode*> PUA = newNode(NodeAttrs::Ref | NodeAttrs::Use | Flags);
816 assert(Flags & NodeAttrs::PhiRef)((Flags & NodeAttrs::PhiRef) ? static_cast<void> (0
) : __assert_fail ("Flags & NodeAttrs::PhiRef", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 816, __PRETTY_FUNCTION__))
;
817 PUA.Addr->setRegRef(RR, *this);
818 PUA.Addr->setPredecessor(PredB.Id);
819 return PUA;
820}
821
822NodeAddr<DefNode*> DataFlowGraph::newDef(NodeAddr<InstrNode*> Owner,
823 MachineOperand &Op, uint16_t Flags) {
824 NodeAddr<DefNode*> DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
825 DA.Addr->setRegRef(&Op, *this);
826 return DA;
827}
828
829NodeAddr<DefNode*> DataFlowGraph::newDef(NodeAddr<InstrNode*> Owner,
830 RegisterRef RR, uint16_t Flags) {
831 NodeAddr<DefNode*> DA = newNode(NodeAttrs::Ref | NodeAttrs::Def | Flags);
832 assert(Flags & NodeAttrs::PhiRef)((Flags & NodeAttrs::PhiRef) ? static_cast<void> (0
) : __assert_fail ("Flags & NodeAttrs::PhiRef", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 832, __PRETTY_FUNCTION__))
;
833 DA.Addr->setRegRef(RR, *this);
834 return DA;
835}
836
837NodeAddr<PhiNode*> DataFlowGraph::newPhi(NodeAddr<BlockNode*> Owner) {
838 NodeAddr<PhiNode*> PA = newNode(NodeAttrs::Code | NodeAttrs::Phi);
839 Owner.Addr->addPhi(PA, *this);
10
Calling 'BlockNode::addPhi'
840 return PA;
841}
842
843NodeAddr<StmtNode*> DataFlowGraph::newStmt(NodeAddr<BlockNode*> Owner,
844 MachineInstr *MI) {
845 NodeAddr<StmtNode*> SA = newNode(NodeAttrs::Code | NodeAttrs::Stmt);
846 SA.Addr->setCode(MI);
847 Owner.Addr->addMember(SA, *this);
848 return SA;
849}
850
851NodeAddr<BlockNode*> DataFlowGraph::newBlock(NodeAddr<FuncNode*> Owner,
852 MachineBasicBlock *BB) {
853 NodeAddr<BlockNode*> BA = newNode(NodeAttrs::Code | NodeAttrs::Block);
854 BA.Addr->setCode(BB);
855 Owner.Addr->addMember(BA, *this);
856 return BA;
857}
858
859NodeAddr<FuncNode*> DataFlowGraph::newFunc(MachineFunction *MF) {
860 NodeAddr<FuncNode*> FA = newNode(NodeAttrs::Code | NodeAttrs::Func);
861 FA.Addr->setCode(MF);
862 return FA;
863}
864
865// Build the data flow graph.
866void DataFlowGraph::build(unsigned Options) {
867 reset();
868 Func = newFunc(&MF);
869
870 if (MF.empty())
1
Assuming the condition is false
2
Taking false branch
871 return;
872
873 for (MachineBasicBlock &B : MF) {
874 NodeAddr<BlockNode*> BA = newBlock(Func, &B);
875 BlockNodes.insert(std::make_pair(&B, BA));
876 for (MachineInstr &I : B) {
877 if (I.isDebugInstr())
878 continue;
879 buildStmt(BA, I);
880 }
881 }
882
883 NodeAddr<BlockNode*> EA = Func.Addr->getEntryBlock(*this);
884 NodeList Blocks = Func.Addr->members(*this);
885
886 // Collect information about block references.
887 RegisterSet AllRefs;
888 for (NodeAddr<BlockNode*> BA : Blocks)
3
Assuming '__begin1' is equal to '__end1'
889 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this))
890 for (NodeAddr<RefNode*> RA : IA.Addr->members(*this))
891 AllRefs.insert(RA.Addr->getRegRef(*this));
892
893 // Collect function live-ins and entry block live-ins.
894 MachineRegisterInfo &MRI = MF.getRegInfo();
895 MachineBasicBlock &EntryB = *EA.Addr->getCode();
896 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 896, __PRETTY_FUNCTION__))
;
4
Assuming the condition is true
5
'?' condition is true
897 for (std::pair<unsigned,unsigned> P : MRI.liveins())
6
Assuming '__begin1' is equal to '__end1'
898 LiveIns.insert(RegisterRef(P.first));
899 if (MRI.tracksLiveness()) {
7
Taking false branch
900 for (auto I : EntryB.liveins())
901 LiveIns.insert(RegisterRef(I.PhysReg, I.LaneMask));
902 }
903
904 // Add function-entry phi nodes for the live-in registers.
905 //for (std::pair<RegisterId,LaneBitmask> P : LiveIns) {
906 for (auto I = LiveIns.rr_begin(), E = LiveIns.rr_end(); I != E; ++I) {
8
Loop condition is true. Entering loop body
907 RegisterRef RR = *I;
908 NodeAddr<PhiNode*> PA = newPhi(EA);
9
Calling 'DataFlowGraph::newPhi'
909 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
910 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
911 PA.Addr->addMember(DA, *this);
912 }
913
914 // Add phis for landing pads.
915 // Landing pads, unlike usual backs blocks, are not entered through
916 // branches in the program, or fall-throughs from other blocks. They
917 // are entered from the exception handling runtime and target's ABI
918 // may define certain registers as defined on entry to such a block.
919 RegisterSet EHRegs = getLandingPadLiveIns();
920 if (!EHRegs.empty()) {
921 for (NodeAddr<BlockNode*> BA : Blocks) {
922 const MachineBasicBlock &B = *BA.Addr->getCode();
923 if (!B.isEHPad())
924 continue;
925
926 // Prepare a list of NodeIds of the block's predecessors.
927 NodeList Preds;
928 for (MachineBasicBlock *PB : B.predecessors())
929 Preds.push_back(findBlock(PB));
930
931 // Build phi nodes for each live-in.
932 for (RegisterRef RR : EHRegs) {
933 NodeAddr<PhiNode*> PA = newPhi(BA);
934 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
935 // Add def:
936 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
937 PA.Addr->addMember(DA, *this);
938 // Add uses (no reaching defs for phi uses):
939 for (NodeAddr<BlockNode*> PBA : Preds) {
940 NodeAddr<PhiUseNode*> PUA = newPhiUse(PA, RR, PBA);
941 PA.Addr->addMember(PUA, *this);
942 }
943 }
944 }
945 }
946
947 // Build a map "PhiM" which will contain, for each block, the set
948 // of references that will require phi definitions in that block.
949 BlockRefsMap PhiM;
950 for (NodeAddr<BlockNode*> BA : Blocks)
951 recordDefsForDF(PhiM, BA);
952 for (NodeAddr<BlockNode*> BA : Blocks)
953 buildPhis(PhiM, AllRefs, BA);
954
955 // Link all the refs. This will recursively traverse the dominator tree.
956 DefStackMap DM;
957 linkBlockRefs(DM, EA);
958
959 // Finally, remove all unused phi nodes.
960 if (!(Options & BuildOptions::KeepDeadPhis))
961 removeUnusedPhis();
962}
963
964RegisterRef DataFlowGraph::makeRegRef(unsigned Reg, unsigned Sub) const {
965 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 966, __PRETTY_FUNCTION__))
966 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 966, __PRETTY_FUNCTION__))
;
967 assert(Reg != 0)((Reg != 0) ? static_cast<void> (0) : __assert_fail ("Reg != 0"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 967, __PRETTY_FUNCTION__))
;
968 if (Sub != 0)
969 Reg = TRI.getSubReg(Reg, Sub);
970 return RegisterRef(Reg);
971}
972
973RegisterRef DataFlowGraph::makeRegRef(const MachineOperand &Op) const {
974 assert(Op.isReg() || Op.isRegMask())((Op.isReg() || Op.isRegMask()) ? static_cast<void> (0)
: __assert_fail ("Op.isReg() || Op.isRegMask()", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 974, __PRETTY_FUNCTION__))
;
975 if (Op.isReg())
976 return makeRegRef(Op.getReg(), Op.getSubReg());
977 return RegisterRef(PRI.getRegMaskId(Op.getRegMask()), LaneBitmask::getAll());
978}
979
980RegisterRef DataFlowGraph::restrictRef(RegisterRef AR, RegisterRef BR) const {
981 if (AR.Reg == BR.Reg) {
982 LaneBitmask M = AR.Mask & BR.Mask;
983 return M.any() ? RegisterRef(AR.Reg, M) : RegisterRef();
984 }
985#ifndef NDEBUG
986// RegisterRef NAR = PRI.normalize(AR);
987// RegisterRef NBR = PRI.normalize(BR);
988// assert(NAR.Reg != NBR.Reg);
989#endif
990 // This isn't strictly correct, because the overlap may happen in the
991 // part masked out.
992 if (PRI.alias(AR, BR))
993 return AR;
994 return RegisterRef();
995}
996
997// For each stack in the map DefM, push the delimiter for block B on it.
998void DataFlowGraph::markBlock(NodeId B, DefStackMap &DefM) {
999 // Push block delimiters.
1000 for (auto I = DefM.begin(), E = DefM.end(); I != E; ++I)
1001 I->second.start_block(B);
1002}
1003
1004// Remove all definitions coming from block B from each stack in DefM.
1005void DataFlowGraph::releaseBlock(NodeId B, DefStackMap &DefM) {
1006 // Pop all defs from this block from the definition stack. Defs that were
1007 // added to the map during the traversal of instructions will not have a
1008 // delimiter, but for those, the whole stack will be emptied.
1009 for (auto I = DefM.begin(), E = DefM.end(); I != E; ++I)
1010 I->second.clear_block(B);
1011
1012 // Finally, remove empty stacks from the map.
1013 for (auto I = DefM.begin(), E = DefM.end(), NextI = I; I != E; I = NextI) {
1014 NextI = std::next(I);
1015 // This preserves the validity of iterators other than I.
1016 if (I->second.empty())
1017 DefM.erase(I);
1018 }
1019}
1020
1021// Push all definitions from the instruction node IA to an appropriate
1022// stack in DefM.
1023void DataFlowGraph::pushAllDefs(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1024 pushClobbers(IA, DefM);
1025 pushDefs(IA, DefM);
1026}
1027
1028// Push all definitions from the instruction node IA to an appropriate
1029// stack in DefM.
1030void DataFlowGraph::pushClobbers(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1031 NodeSet Visited;
1032 std::set<RegisterId> Defined;
1033
1034 // The important objectives of this function are:
1035 // - to be able to handle instructions both while the graph is being
1036 // constructed, and after the graph has been constructed, and
1037 // - maintain proper ordering of definitions on the stack for each
1038 // register reference:
1039 // - if there are two or more related defs in IA (i.e. coming from
1040 // the same machine operand), then only push one def on the stack,
1041 // - if there are multiple unrelated defs of non-overlapping
1042 // subregisters of S, then the stack for S will have both (in an
1043 // unspecified order), but the order does not matter from the data-
1044 // -flow perspective.
1045
1046 for (NodeAddr<DefNode*> DA : IA.Addr->members_if(IsDef, *this)) {
1047 if (Visited.count(DA.Id))
1048 continue;
1049 if (!(DA.Addr->getFlags() & NodeAttrs::Clobbering))
1050 continue;
1051
1052 NodeList Rel = getRelatedRefs(IA, DA);
1053 NodeAddr<DefNode*> PDA = Rel.front();
1054 RegisterRef RR = PDA.Addr->getRegRef(*this);
1055
1056 // Push the definition on the stack for the register and all aliases.
1057 // The def stack traversal in linkNodeUp will check the exact aliasing.
1058 DefM[RR.Reg].push(DA);
1059 Defined.insert(RR.Reg);
1060 for (RegisterId A : PRI.getAliasSet(RR.Reg)) {
1061 // Check that we don't push the same def twice.
1062 assert(A != RR.Reg)((A != RR.Reg) ? static_cast<void> (0) : __assert_fail (
"A != RR.Reg", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1062, __PRETTY_FUNCTION__))
;
1063 if (!Defined.count(A))
1064 DefM[A].push(DA);
1065 }
1066 // Mark all the related defs as visited.
1067 for (NodeAddr<NodeBase*> T : Rel)
1068 Visited.insert(T.Id);
1069 }
1070}
1071
1072// Push all definitions from the instruction node IA to an appropriate
1073// stack in DefM.
1074void DataFlowGraph::pushDefs(NodeAddr<InstrNode*> IA, DefStackMap &DefM) {
1075 NodeSet Visited;
1076#ifndef NDEBUG
1077 std::set<RegisterId> Defined;
1078#endif
1079
1080 // The important objectives of this function are:
1081 // - to be able to handle instructions both while the graph is being
1082 // constructed, and after the graph has been constructed, and
1083 // - maintain proper ordering of definitions on the stack for each
1084 // register reference:
1085 // - if there are two or more related defs in IA (i.e. coming from
1086 // the same machine operand), then only push one def on the stack,
1087 // - if there are multiple unrelated defs of non-overlapping
1088 // subregisters of S, then the stack for S will have both (in an
1089 // unspecified order), but the order does not matter from the data-
1090 // -flow perspective.
1091
1092 for (NodeAddr<DefNode*> DA : IA.Addr->members_if(IsDef, *this)) {
1093 if (Visited.count(DA.Id))
1094 continue;
1095 if (DA.Addr->getFlags() & NodeAttrs::Clobbering)
1096 continue;
1097
1098 NodeList Rel = getRelatedRefs(IA, DA);
1099 NodeAddr<DefNode*> PDA = Rel.front();
1100 RegisterRef RR = PDA.Addr->getRegRef(*this);
1101#ifndef NDEBUG
1102 // Assert if the register is defined in two or more unrelated defs.
1103 // This could happen if there are two or more def operands defining it.
1104 if (!Defined.insert(RR.Reg).second) {
1105 MachineInstr *MI = NodeAddr<StmtNode*>(IA).Addr->getCode();
1106 dbgs() << "Multiple definitions of register: "
1107 << Print<RegisterRef>(RR, *this) << " in\n " << *MI << "in "
1108 << printMBBReference(*MI->getParent()) << '\n';
1109 llvm_unreachable(nullptr)::llvm::llvm_unreachable_internal(nullptr, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1109)
;
1110 }
1111#endif
1112 // Push the definition on the stack for the register and all aliases.
1113 // The def stack traversal in linkNodeUp will check the exact aliasing.
1114 DefM[RR.Reg].push(DA);
1115 for (RegisterId A : PRI.getAliasSet(RR.Reg)) {
1116 // Check that we don't push the same def twice.
1117 assert(A != RR.Reg)((A != RR.Reg) ? static_cast<void> (0) : __assert_fail (
"A != RR.Reg", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1117, __PRETTY_FUNCTION__))
;
1118 DefM[A].push(DA);
1119 }
1120 // Mark all the related defs as visited.
1121 for (NodeAddr<NodeBase*> T : Rel)
1122 Visited.insert(T.Id);
1123 }
1124}
1125
1126// Return the list of all reference nodes related to RA, including RA itself.
1127// See "getNextRelated" for the meaning of a "related reference".
1128NodeList DataFlowGraph::getRelatedRefs(NodeAddr<InstrNode*> IA,
1129 NodeAddr<RefNode*> RA) const {
1130 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1130, __PRETTY_FUNCTION__))
;
1131
1132 NodeList Refs;
1133 NodeId Start = RA.Id;
1134 do {
1135 Refs.push_back(RA);
1136 RA = getNextRelated(IA, RA);
1137 } while (RA.Id != 0 && RA.Id != Start);
1138 return Refs;
1139}
1140
1141// Clear all information in the graph.
1142void DataFlowGraph::reset() {
1143 Memory.clear();
1144 BlockNodes.clear();
1145 Func = NodeAddr<FuncNode*>();
1146}
1147
1148// Return the next reference node in the instruction node IA that is related
1149// to RA. Conceptually, two reference nodes are related if they refer to the
1150// same instance of a register access, but differ in flags or other minor
1151// characteristics. Specific examples of related nodes are shadow reference
1152// nodes.
1153// Return the equivalent of nullptr if there are no more related references.
1154NodeAddr<RefNode*> DataFlowGraph::getNextRelated(NodeAddr<InstrNode*> IA,
1155 NodeAddr<RefNode*> RA) const {
1156 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1156, __PRETTY_FUNCTION__))
;
1157
1158 auto Related = [this,RA](NodeAddr<RefNode*> TA) -> bool {
1159 if (TA.Addr->getKind() != RA.Addr->getKind())
1160 return false;
1161 if (TA.Addr->getRegRef(*this) != RA.Addr->getRegRef(*this))
1162 return false;
1163 return true;
1164 };
1165 auto RelatedStmt = [&Related,RA](NodeAddr<RefNode*> TA) -> bool {
1166 return Related(TA) &&
1167 &RA.Addr->getOp() == &TA.Addr->getOp();
1168 };
1169 auto RelatedPhi = [&Related,RA](NodeAddr<RefNode*> TA) -> bool {
1170 if (!Related(TA))
1171 return false;
1172 if (TA.Addr->getKind() != NodeAttrs::Use)
1173 return true;
1174 // For phi uses, compare predecessor blocks.
1175 const NodeAddr<const PhiUseNode*> TUA = TA;
1176 const NodeAddr<const PhiUseNode*> RUA = RA;
1177 return TUA.Addr->getPredecessor() == RUA.Addr->getPredecessor();
1178 };
1179
1180 RegisterRef RR = RA.Addr->getRegRef(*this);
1181 if (IA.Addr->getKind() == NodeAttrs::Stmt)
1182 return RA.Addr->getNextRef(RR, RelatedStmt, true, *this);
1183 return RA.Addr->getNextRef(RR, RelatedPhi, true, *this);
1184}
1185
1186// Find the next node related to RA in IA that satisfies condition P.
1187// If such a node was found, return a pair where the second element is the
1188// located node. If such a node does not exist, return a pair where the
1189// first element is the element after which such a node should be inserted,
1190// and the second element is a null-address.
1191template <typename Predicate>
1192std::pair<NodeAddr<RefNode*>,NodeAddr<RefNode*>>
1193DataFlowGraph::locateNextRef(NodeAddr<InstrNode*> IA, NodeAddr<RefNode*> RA,
1194 Predicate P) const {
1195 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1195, __PRETTY_FUNCTION__))
;
1196
1197 NodeAddr<RefNode*> NA;
1198 NodeId Start = RA.Id;
1199 while (true) {
1200 NA = getNextRelated(IA, RA);
1201 if (NA.Id == 0 || NA.Id == Start)
1202 break;
1203 if (P(NA))
1204 break;
1205 RA = NA;
1206 }
1207
1208 if (NA.Id != 0 && NA.Id != Start)
1209 return std::make_pair(RA, NA);
1210 return std::make_pair(RA, NodeAddr<RefNode*>());
1211}
1212
1213// Get the next shadow node in IA corresponding to RA, and optionally create
1214// such a node if it does not exist.
1215NodeAddr<RefNode*> DataFlowGraph::getNextShadow(NodeAddr<InstrNode*> IA,
1216 NodeAddr<RefNode*> RA, bool Create) {
1217 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1217, __PRETTY_FUNCTION__))
;
1218
1219 uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
1220 auto IsShadow = [Flags] (NodeAddr<RefNode*> TA) -> bool {
1221 return TA.Addr->getFlags() == Flags;
1222 };
1223 auto Loc = locateNextRef(IA, RA, IsShadow);
1224 if (Loc.second.Id != 0 || !Create)
1225 return Loc.second;
1226
1227 // Create a copy of RA and mark is as shadow.
1228 NodeAddr<RefNode*> NA = cloneNode(RA);
1229 NA.Addr->setFlags(Flags | NodeAttrs::Shadow);
1230 IA.Addr->addMemberAfter(Loc.first, NA, *this);
1231 return NA;
1232}
1233
1234// Get the next shadow node in IA corresponding to RA. Return null-address
1235// if such a node does not exist.
1236NodeAddr<RefNode*> DataFlowGraph::getNextShadow(NodeAddr<InstrNode*> IA,
1237 NodeAddr<RefNode*> RA) const {
1238 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1238, __PRETTY_FUNCTION__))
;
1239 uint16_t Flags = RA.Addr->getFlags() | NodeAttrs::Shadow;
1240 auto IsShadow = [Flags] (NodeAddr<RefNode*> TA) -> bool {
1241 return TA.Addr->getFlags() == Flags;
1242 };
1243 return locateNextRef(IA, RA, IsShadow).second;
1244}
1245
1246// Create a new statement node in the block node BA that corresponds to
1247// the machine instruction MI.
1248void DataFlowGraph::buildStmt(NodeAddr<BlockNode*> BA, MachineInstr &In) {
1249 NodeAddr<StmtNode*> SA = newStmt(BA, &In);
1250
1251 auto isCall = [] (const MachineInstr &In) -> bool {
1252 if (In.isCall())
1253 return true;
1254 // Is tail call?
1255 if (In.isBranch()) {
1256 for (const MachineOperand &Op : In.operands())
1257 if (Op.isGlobal() || Op.isSymbol())
1258 return true;
1259 // Assume indirect branches are calls. This is for the purpose of
1260 // keeping implicit operands, and so it won't hurt on intra-function
1261 // indirect branches.
1262 if (In.isIndirectBranch())
1263 return true;
1264 }
1265 return false;
1266 };
1267
1268 auto isDefUndef = [this] (const MachineInstr &In, RegisterRef DR) -> bool {
1269 // This instruction defines DR. Check if there is a use operand that
1270 // would make DR live on entry to the instruction.
1271 for (const MachineOperand &Op : In.operands()) {
1272 if (!Op.isReg() || Op.getReg() == 0 || !Op.isUse() || Op.isUndef())
1273 continue;
1274 RegisterRef UR = makeRegRef(Op);
1275 if (PRI.alias(DR, UR))
1276 return false;
1277 }
1278 return true;
1279 };
1280
1281 bool IsCall = isCall(In);
1282 unsigned NumOps = In.getNumOperands();
1283
1284 // Avoid duplicate implicit defs. This will not detect cases of implicit
1285 // defs that define registers that overlap, but it is not clear how to
1286 // interpret that in the absence of explicit defs. Overlapping explicit
1287 // defs are likely illegal already.
1288 BitVector DoneDefs(TRI.getNumRegs());
1289 // Process explicit defs first.
1290 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1291 MachineOperand &Op = In.getOperand(OpN);
1292 if (!Op.isReg() || !Op.isDef() || Op.isImplicit())
1293 continue;
1294 unsigned R = Op.getReg();
1295 if (!R || !TargetRegisterInfo::isPhysicalRegister(R))
1296 continue;
1297 uint16_t Flags = NodeAttrs::None;
1298 if (TOI.isPreserving(In, OpN)) {
1299 Flags |= NodeAttrs::Preserving;
1300 // If the def is preserving, check if it is also undefined.
1301 if (isDefUndef(In, makeRegRef(Op)))
1302 Flags |= NodeAttrs::Undef;
1303 }
1304 if (TOI.isClobbering(In, OpN))
1305 Flags |= NodeAttrs::Clobbering;
1306 if (TOI.isFixedReg(In, OpN))
1307 Flags |= NodeAttrs::Fixed;
1308 if (IsCall && Op.isDead())
1309 Flags |= NodeAttrs::Dead;
1310 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1311 SA.Addr->addMember(DA, *this);
1312 assert(!DoneDefs.test(R))((!DoneDefs.test(R)) ? static_cast<void> (0) : __assert_fail
("!DoneDefs.test(R)", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1312, __PRETTY_FUNCTION__))
;
1313 DoneDefs.set(R);
1314 }
1315
1316 // Process reg-masks (as clobbers).
1317 BitVector DoneClobbers(TRI.getNumRegs());
1318 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1319 MachineOperand &Op = In.getOperand(OpN);
1320 if (!Op.isRegMask())
1321 continue;
1322 uint16_t Flags = NodeAttrs::Clobbering | NodeAttrs::Fixed |
1323 NodeAttrs::Dead;
1324 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1325 SA.Addr->addMember(DA, *this);
1326 // Record all clobbered registers in DoneDefs.
1327 const uint32_t *RM = Op.getRegMask();
1328 for (unsigned i = 1, e = TRI.getNumRegs(); i != e; ++i)
1329 if (!(RM[i/32] & (1u << (i%32))))
1330 DoneClobbers.set(i);
1331 }
1332
1333 // Process implicit defs, skipping those that have already been added
1334 // as explicit.
1335 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1336 MachineOperand &Op = In.getOperand(OpN);
1337 if (!Op.isReg() || !Op.isDef() || !Op.isImplicit())
1338 continue;
1339 unsigned R = Op.getReg();
1340 if (!R || !TargetRegisterInfo::isPhysicalRegister(R) || DoneDefs.test(R))
1341 continue;
1342 RegisterRef RR = makeRegRef(Op);
1343 uint16_t Flags = NodeAttrs::None;
1344 if (TOI.isPreserving(In, OpN)) {
1345 Flags |= NodeAttrs::Preserving;
1346 // If the def is preserving, check if it is also undefined.
1347 if (isDefUndef(In, RR))
1348 Flags |= NodeAttrs::Undef;
1349 }
1350 if (TOI.isClobbering(In, OpN))
1351 Flags |= NodeAttrs::Clobbering;
1352 if (TOI.isFixedReg(In, OpN))
1353 Flags |= NodeAttrs::Fixed;
1354 if (IsCall && Op.isDead()) {
1355 if (DoneClobbers.test(R))
1356 continue;
1357 Flags |= NodeAttrs::Dead;
1358 }
1359 NodeAddr<DefNode*> DA = newDef(SA, Op, Flags);
1360 SA.Addr->addMember(DA, *this);
1361 DoneDefs.set(R);
1362 }
1363
1364 for (unsigned OpN = 0; OpN < NumOps; ++OpN) {
1365 MachineOperand &Op = In.getOperand(OpN);
1366 if (!Op.isReg() || !Op.isUse())
1367 continue;
1368 unsigned R = Op.getReg();
1369 if (!R || !TargetRegisterInfo::isPhysicalRegister(R))
1370 continue;
1371 uint16_t Flags = NodeAttrs::None;
1372 if (Op.isUndef())
1373 Flags |= NodeAttrs::Undef;
1374 if (TOI.isFixedReg(In, OpN))
1375 Flags |= NodeAttrs::Fixed;
1376 NodeAddr<UseNode*> UA = newUse(SA, Op, Flags);
1377 SA.Addr->addMember(UA, *this);
1378 }
1379}
1380
1381// Scan all defs in the block node BA and record in PhiM the locations of
1382// phi nodes corresponding to these defs.
1383void DataFlowGraph::recordDefsForDF(BlockRefsMap &PhiM,
1384 NodeAddr<BlockNode*> BA) {
1385 // Check all defs from block BA and record them in each block in BA's
1386 // iterated dominance frontier. This information will later be used to
1387 // create phi nodes.
1388 MachineBasicBlock *BB = BA.Addr->getCode();
1389 assert(BB)((BB) ? static_cast<void> (0) : __assert_fail ("BB", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1389, __PRETTY_FUNCTION__))
;
1390 auto DFLoc = MDF.find(BB);
1391 if (DFLoc == MDF.end() || DFLoc->second.empty())
1392 return;
1393
1394 // Traverse all instructions in the block and collect the set of all
1395 // defined references. For each reference there will be a phi created
1396 // in the block's iterated dominance frontier.
1397 // This is done to make sure that each defined reference gets only one
1398 // phi node, even if it is defined multiple times.
1399 RegisterSet Defs;
1400 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this))
1401 for (NodeAddr<RefNode*> RA : IA.Addr->members_if(IsDef, *this))
1402 Defs.insert(RA.Addr->getRegRef(*this));
1403
1404 // Calculate the iterated dominance frontier of BB.
1405 const MachineDominanceFrontier::DomSetType &DF = DFLoc->second;
1406 SetVector<MachineBasicBlock*> IDF(DF.begin(), DF.end());
1407 for (unsigned i = 0; i < IDF.size(); ++i) {
1408 auto F = MDF.find(IDF[i]);
1409 if (F != MDF.end())
1410 IDF.insert(F->second.begin(), F->second.end());
1411 }
1412
1413 // Finally, add the set of defs to each block in the iterated dominance
1414 // frontier.
1415 for (auto DB : IDF) {
1416 NodeAddr<BlockNode*> DBA = findBlock(DB);
1417 PhiM[DBA.Id].insert(Defs.begin(), Defs.end());
1418 }
1419}
1420
1421// Given the locations of phi nodes in the map PhiM, create the phi nodes
1422// that are located in the block node BA.
1423void DataFlowGraph::buildPhis(BlockRefsMap &PhiM, RegisterSet &AllRefs,
1424 NodeAddr<BlockNode*> BA) {
1425 // Check if this blocks has any DF defs, i.e. if there are any defs
1426 // that this block is in the iterated dominance frontier of.
1427 auto HasDF = PhiM.find(BA.Id);
1428 if (HasDF == PhiM.end() || HasDF->second.empty())
1429 return;
1430
1431 // First, remove all R in Refs in such that there exists T in Refs
1432 // such that T covers R. In other words, only leave those refs that
1433 // are not covered by another ref (i.e. maximal with respect to covering).
1434
1435 auto MaxCoverIn = [this] (RegisterRef RR, RegisterSet &RRs) -> RegisterRef {
1436 for (RegisterRef I : RRs)
1437 if (I != RR && RegisterAggr::isCoverOf(I, RR, PRI))
1438 RR = I;
1439 return RR;
1440 };
1441
1442 RegisterSet MaxDF;
1443 for (RegisterRef I : HasDF->second)
1444 MaxDF.insert(MaxCoverIn(I, HasDF->second));
1445
1446 std::vector<RegisterRef> MaxRefs;
1447 for (RegisterRef I : MaxDF)
1448 MaxRefs.push_back(MaxCoverIn(I, AllRefs));
1449
1450 // Now, for each R in MaxRefs, get the alias closure of R. If the closure
1451 // only has R in it, create a phi a def for R. Otherwise, create a phi,
1452 // and add a def for each S in the closure.
1453
1454 // Sort the refs so that the phis will be created in a deterministic order.
1455 llvm::sort(MaxRefs);
1456 // Remove duplicates.
1457 auto NewEnd = std::unique(MaxRefs.begin(), MaxRefs.end());
1458 MaxRefs.erase(NewEnd, MaxRefs.end());
1459
1460 auto Aliased = [this,&MaxRefs](RegisterRef RR,
1461 std::vector<unsigned> &Closure) -> bool {
1462 for (unsigned I : Closure)
1463 if (PRI.alias(RR, MaxRefs[I]))
1464 return true;
1465 return false;
1466 };
1467
1468 // Prepare a list of NodeIds of the block's predecessors.
1469 NodeList Preds;
1470 const MachineBasicBlock *MBB = BA.Addr->getCode();
1471 for (MachineBasicBlock *PB : MBB->predecessors())
1472 Preds.push_back(findBlock(PB));
1473
1474 while (!MaxRefs.empty()) {
1475 // Put the first element in the closure, and then add all subsequent
1476 // elements from MaxRefs to it, if they alias at least one element
1477 // already in the closure.
1478 // ClosureIdx: vector of indices in MaxRefs of members of the closure.
1479 std::vector<unsigned> ClosureIdx = { 0 };
1480 for (unsigned i = 1; i != MaxRefs.size(); ++i)
1481 if (Aliased(MaxRefs[i], ClosureIdx))
1482 ClosureIdx.push_back(i);
1483
1484 // Build a phi for the closure.
1485 unsigned CS = ClosureIdx.size();
1486 NodeAddr<PhiNode*> PA = newPhi(BA);
1487
1488 // Add defs.
1489 for (unsigned X = 0; X != CS; ++X) {
1490 RegisterRef RR = MaxRefs[ClosureIdx[X]];
1491 uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
1492 NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
1493 PA.Addr->addMember(DA, *this);
1494 }
1495 // Add phi uses.
1496 for (NodeAddr<BlockNode*> PBA : Preds) {
1497 for (unsigned X = 0; X != CS; ++X) {
1498 RegisterRef RR = MaxRefs[ClosureIdx[X]];
1499 NodeAddr<PhiUseNode*> PUA = newPhiUse(PA, RR, PBA);
1500 PA.Addr->addMember(PUA, *this);
1501 }
1502 }
1503
1504 // Erase from MaxRefs all elements in the closure.
1505 auto Begin = MaxRefs.begin();
1506 for (unsigned i = ClosureIdx.size(); i != 0; --i)
1507 MaxRefs.erase(Begin + ClosureIdx[i-1]);
1508 }
1509}
1510
1511// Remove any unneeded phi nodes that were created during the build process.
1512void DataFlowGraph::removeUnusedPhis() {
1513 // This will remove unused phis, i.e. phis where each def does not reach
1514 // any uses or other defs. This will not detect or remove circular phi
1515 // chains that are otherwise dead. Unused/dead phis are created during
1516 // the build process and this function is intended to remove these cases
1517 // that are easily determinable to be unnecessary.
1518
1519 SetVector<NodeId> PhiQ;
1520 for (NodeAddr<BlockNode*> BA : Func.Addr->members(*this)) {
1521 for (auto P : BA.Addr->members_if(IsPhi, *this))
1522 PhiQ.insert(P.Id);
1523 }
1524
1525 static auto HasUsedDef = [](NodeList &Ms) -> bool {
1526 for (NodeAddr<NodeBase*> M : Ms) {
1527 if (M.Addr->getKind() != NodeAttrs::Def)
1528 continue;
1529 NodeAddr<DefNode*> DA = M;
1530 if (DA.Addr->getReachedDef() != 0 || DA.Addr->getReachedUse() != 0)
1531 return true;
1532 }
1533 return false;
1534 };
1535
1536 // Any phi, if it is removed, may affect other phis (make them dead).
1537 // For each removed phi, collect the potentially affected phis and add
1538 // them back to the queue.
1539 while (!PhiQ.empty()) {
1540 auto PA = addr<PhiNode*>(PhiQ[0]);
1541 PhiQ.remove(PA.Id);
1542 NodeList Refs = PA.Addr->members(*this);
1543 if (HasUsedDef(Refs))
1544 continue;
1545 for (NodeAddr<RefNode*> RA : Refs) {
1546 if (NodeId RD = RA.Addr->getReachingDef()) {
1547 auto RDA = addr<DefNode*>(RD);
1548 NodeAddr<InstrNode*> OA = RDA.Addr->getOwner(*this);
1549 if (IsPhi(OA))
1550 PhiQ.insert(OA.Id);
1551 }
1552 if (RA.Addr->isDef())
1553 unlinkDef(RA, true);
1554 else
1555 unlinkUse(RA, true);
1556 }
1557 NodeAddr<BlockNode*> BA = PA.Addr->getOwner(*this);
1558 BA.Addr->removeMember(PA, *this);
1559 }
1560}
1561
1562// For a given reference node TA in an instruction node IA, connect the
1563// reaching def of TA to the appropriate def node. Create any shadow nodes
1564// as appropriate.
1565template <typename T>
1566void DataFlowGraph::linkRefUp(NodeAddr<InstrNode*> IA, NodeAddr<T> TA,
1567 DefStack &DS) {
1568 if (DS.empty())
1569 return;
1570 RegisterRef RR = TA.Addr->getRegRef(*this);
1571 NodeAddr<T> TAP;
1572
1573 // References from the def stack that have been examined so far.
1574 RegisterAggr Defs(PRI);
1575
1576 for (auto I = DS.top(), E = DS.bottom(); I != E; I.down()) {
1577 RegisterRef QR = I->Addr->getRegRef(*this);
1578
1579 // Skip all defs that are aliased to any of the defs that we have already
1580 // seen. If this completes a cover of RR, stop the stack traversal.
1581 bool Alias = Defs.hasAliasOf(QR);
1582 bool Cover = Defs.insert(QR).hasCoverOf(RR);
1583 if (Alias) {
1584 if (Cover)
1585 break;
1586 continue;
1587 }
1588
1589 // The reaching def.
1590 NodeAddr<DefNode*> RDA = *I;
1591
1592 // Pick the reached node.
1593 if (TAP.Id == 0) {
1594 TAP = TA;
1595 } else {
1596 // Mark the existing ref as "shadow" and create a new shadow.
1597 TAP.Addr->setFlags(TAP.Addr->getFlags() | NodeAttrs::Shadow);
1598 TAP = getNextShadow(IA, TAP, true);
1599 }
1600
1601 // Create the link.
1602 TAP.Addr->linkToDef(TAP.Id, RDA);
1603
1604 if (Cover)
1605 break;
1606 }
1607}
1608
1609// Create data-flow links for all reference nodes in the statement node SA.
1610template <typename Predicate>
1611void DataFlowGraph::linkStmtRefs(DefStackMap &DefM, NodeAddr<StmtNode*> SA,
1612 Predicate P) {
1613#ifndef NDEBUG
1614 RegisterSet Defs;
1615#endif
1616
1617 // Link all nodes (upwards in the data-flow) with their reaching defs.
1618 for (NodeAddr<RefNode*> RA : SA.Addr->members_if(P, *this)) {
1619 uint16_t Kind = RA.Addr->getKind();
1620 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1620, __PRETTY_FUNCTION__))
;
1621 RegisterRef RR = RA.Addr->getRegRef(*this);
1622#ifndef NDEBUG
1623 // Do not expect multiple defs of the same reference.
1624 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1624, __PRETTY_FUNCTION__))
;
1625 Defs.insert(RR);
1626#endif
1627
1628 auto F = DefM.find(RR.Reg);
1629 if (F == DefM.end())
1630 continue;
1631 DefStack &DS = F->second;
1632 if (Kind == NodeAttrs::Use)
1633 linkRefUp<UseNode*>(SA, RA, DS);
1634 else if (Kind == NodeAttrs::Def)
1635 linkRefUp<DefNode*>(SA, RA, DS);
1636 else
1637 llvm_unreachable("Unexpected node in instruction")::llvm::llvm_unreachable_internal("Unexpected node in instruction"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1637)
;
1638 }
1639}
1640
1641// Create data-flow links for all instructions in the block node BA. This
1642// will include updating any phi nodes in BA.
1643void DataFlowGraph::linkBlockRefs(DefStackMap &DefM, NodeAddr<BlockNode*> BA) {
1644 // Push block delimiters.
1645 markBlock(BA.Id, DefM);
1646
1647 auto IsClobber = [] (NodeAddr<RefNode*> RA) -> bool {
1648 return IsDef(RA) && (RA.Addr->getFlags() & NodeAttrs::Clobbering);
1649 };
1650 auto IsNoClobber = [] (NodeAddr<RefNode*> RA) -> bool {
1651 return IsDef(RA) && !(RA.Addr->getFlags() & NodeAttrs::Clobbering);
1652 };
1653
1654 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1654, __PRETTY_FUNCTION__))
;
1655 // For each non-phi instruction in the block, link all the defs and uses
1656 // to their reaching defs. For any member of the block (including phis),
1657 // push the defs on the corresponding stacks.
1658 for (NodeAddr<InstrNode*> IA : BA.Addr->members(*this)) {
1659 // Ignore phi nodes here. They will be linked part by part from the
1660 // predecessors.
1661 if (IA.Addr->getKind() == NodeAttrs::Stmt) {
1662 linkStmtRefs(DefM, IA, IsUse);
1663 linkStmtRefs(DefM, IA, IsClobber);
1664 }
1665
1666 // Push the definitions on the stack.
1667 pushClobbers(IA, DefM);
1668
1669 if (IA.Addr->getKind() == NodeAttrs::Stmt)
1670 linkStmtRefs(DefM, IA, IsNoClobber);
1671
1672 pushDefs(IA, DefM);
1673 }
1674
1675 // Recursively process all children in the dominator tree.
1676 MachineDomTreeNode *N = MDT.getNode(BA.Addr->getCode());
1677 for (auto I : *N) {
1678 MachineBasicBlock *SB = I->getBlock();
1679 NodeAddr<BlockNode*> SBA = findBlock(SB);
1680 linkBlockRefs(DefM, SBA);
1681 }
1682
1683 // Link the phi uses from the successor blocks.
1684 auto IsUseForBA = [BA](NodeAddr<NodeBase*> NA) -> bool {
1685 if (NA.Addr->getKind() != NodeAttrs::Use)
1686 return false;
1687 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-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1687, __PRETTY_FUNCTION__))
;
1688 NodeAddr<PhiUseNode*> PUA = NA;
1689 return PUA.Addr->getPredecessor() == BA.Id;
1690 };
1691
1692 RegisterSet EHLiveIns = getLandingPadLiveIns();
1693 MachineBasicBlock *MBB = BA.Addr->getCode();
1694
1695 for (MachineBasicBlock *SB : MBB->successors()) {
1696 bool IsEHPad = SB->isEHPad();
1697 NodeAddr<BlockNode*> SBA = findBlock(SB);
1698 for (NodeAddr<InstrNode*> IA : SBA.Addr->members_if(IsPhi, *this)) {
1699 // Do not link phi uses for landing pad live-ins.
1700 if (IsEHPad) {
1701 // Find what register this phi is for.
1702 NodeAddr<RefNode*> RA = IA.Addr->getFirstMember(*this);
1703 assert(RA.Id != 0)((RA.Id != 0) ? static_cast<void> (0) : __assert_fail (
"RA.Id != 0", "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1703, __PRETTY_FUNCTION__))
;
1704 if (EHLiveIns.count(RA.Addr->getRegRef(*this)))
1705 continue;
1706 }
1707 // Go over each phi use associated with MBB, and link it.
1708 for (auto U : IA.Addr->members_if(IsUseForBA, *this)) {
1709 NodeAddr<PhiUseNode*> PUA = U;
1710 RegisterRef RR = PUA.Addr->getRegRef(*this);
1711 linkRefUp<UseNode*>(IA, PUA, DefM[RR.Reg]);
1712 }
1713 }
1714 }
1715
1716 // Pop all defs from this block from the definition stacks.
1717 releaseBlock(BA.Id, DefM);
1718}
1719
1720// Remove the use node UA from any data-flow and structural links.
1721void DataFlowGraph::unlinkUseDF(NodeAddr<UseNode*> UA) {
1722 NodeId RD = UA.Addr->getReachingDef();
1723 NodeId Sib = UA.Addr->getSibling();
1724
1725 if (RD == 0) {
1726 assert(Sib == 0)((Sib == 0) ? static_cast<void> (0) : __assert_fail ("Sib == 0"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1726, __PRETTY_FUNCTION__))
;
1727 return;
1728 }
1729
1730 auto RDA = addr<DefNode*>(RD);
1731 auto TA = addr<UseNode*>(RDA.Addr->getReachedUse());
1732 if (TA.Id == UA.Id) {
1733 RDA.Addr->setReachedUse(Sib);
1734 return;
1735 }
1736
1737 while (TA.Id != 0) {
1738 NodeId S = TA.Addr->getSibling();
1739 if (S == UA.Id) {
1740 TA.Addr->setSibling(UA.Addr->getSibling());
1741 return;
1742 }
1743 TA = addr<UseNode*>(S);
1744 }
1745}
1746
1747// Remove the def node DA from any data-flow and structural links.
1748void DataFlowGraph::unlinkDefDF(NodeAddr<DefNode*> DA) {
1749 //
1750 // RD
1751 // | reached
1752 // | def
1753 // :
1754 // .
1755 // +----+
1756 // ... -- | DA | -- ... -- 0 : sibling chain of DA
1757 // +----+
1758 // | | reached
1759 // | : def
1760 // | .
1761 // | ... : Siblings (defs)
1762 // |
1763 // : reached
1764 // . use
1765 // ... : sibling chain of reached uses
1766
1767 NodeId RD = DA.Addr->getReachingDef();
1768
1769 // Visit all siblings of the reached def and reset their reaching defs.
1770 // Also, defs reached by DA are now "promoted" to being reached by RD,
1771 // so all of them will need to be spliced into the sibling chain where
1772 // DA belongs.
1773 auto getAllNodes = [this] (NodeId N) -> NodeList {
1774 NodeList Res;
1775 while (N) {
1776 auto RA = addr<RefNode*>(N);
1777 // Keep the nodes in the exact sibling order.
1778 Res.push_back(RA);
1779 N = RA.Addr->getSibling();
1780 }
1781 return Res;
1782 };
1783 NodeList ReachedDefs = getAllNodes(DA.Addr->getReachedDef());
1784 NodeList ReachedUses = getAllNodes(DA.Addr->getReachedUse());
1785
1786 if (RD == 0) {
1787 for (NodeAddr<RefNode*> I : ReachedDefs)
1788 I.Addr->setSibling(0);
1789 for (NodeAddr<RefNode*> I : ReachedUses)
1790 I.Addr->setSibling(0);
1791 }
1792 for (NodeAddr<DefNode*> I : ReachedDefs)
1793 I.Addr->setReachingDef(RD);
1794 for (NodeAddr<UseNode*> I : ReachedUses)
1795 I.Addr->setReachingDef(RD);
1796
1797 NodeId Sib = DA.Addr->getSibling();
1798 if (RD == 0) {
1799 assert(Sib == 0)((Sib == 0) ? static_cast<void> (0) : __assert_fail ("Sib == 0"
, "/build/llvm-toolchain-snapshot-9~svn362543/lib/Target/Hexagon/RDFGraph.cpp"
, 1799, __PRETTY_FUNCTION__))
;
1800 return;
1801 }
1802
1803 // Update the reaching def node and remove DA from the sibling list.
1804 auto RDA = addr<DefNode*>(RD);
1805 auto TA = addr<DefNode*>(RDA.Addr->getReachedDef());
1806 if (TA.Id == DA.Id) {
1807 // If DA is the first reached def, just update the RD's reached def
1808 // to the DA's sibling.
1809 RDA.Addr->setReachedDef(Sib);
1810 } else {
1811 // Otherwise, traverse the sibling list of the reached defs and remove
1812 // DA from it.
1813 while (TA.Id != 0) {
1814 NodeId S = TA.Addr->getSibling();
1815 if (S == DA.Id) {
1816 TA.Addr->setSibling(Sib);
1817 break;
1818 }
1819 TA = addr<DefNode*>(S);
1820 }
1821 }
1822
1823 // Splice the DA's reached defs into the RDA's reached def chain.
1824 if (!ReachedDefs.empty()) {
1825 auto Last = NodeAddr<DefNode*>(ReachedDefs.back());
1826 Last.Addr->setSibling(RDA.Addr->getReachedDef());
1827 RDA.Addr->setReachedDef(ReachedDefs.front().Id);
1828 }
1829 // Splice the DA's reached uses into the RDA's reached use chain.
1830 if (!ReachedUses.empty()) {
1831 auto Last = NodeAddr<UseNode*>(ReachedUses.back());
1832 Last.Addr->setSibling(RDA.Addr->getReachedUse());
1833 RDA.Addr->setReachedUse(ReachedUses.front().Id);
1834 }
1835}