Bug Summary

File:lib/CodeGen/LiveDebugValues.cpp
Warning:line 764, column 9
Value stored to 'MBBJoined' is never read

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 LiveDebugValues.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -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 -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-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/lib/CodeGen -I /build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn338205/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/lib/gcc/x86_64-linux-gnu/8/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-class-memaccess -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/lib/CodeGen -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-07-29-043837-17923-1 -x c++ /build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp -faddrsig
1//===- LiveDebugValues.cpp - Tracking Debug Value MIs ---------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// This pass implements a data flow analysis that propagates debug location
11/// information by inserting additional DBG_VALUE instructions into the machine
12/// instruction stream. The pass internally builds debug location liveness
13/// ranges to determine the points where additional DBG_VALUEs need to be
14/// inserted.
15///
16/// This is a separate pass from DbgValueHistoryCalculator to facilitate
17/// testing and improve modularity.
18///
19//===----------------------------------------------------------------------===//
20
21#include "llvm/ADT/DenseMap.h"
22#include "llvm/ADT/PostOrderIterator.h"
23#include "llvm/ADT/SmallPtrSet.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/ADT/SparseBitVector.h"
26#include "llvm/ADT/Statistic.h"
27#include "llvm/ADT/UniqueVector.h"
28#include "llvm/CodeGen/LexicalScopes.h"
29#include "llvm/CodeGen/MachineBasicBlock.h"
30#include "llvm/CodeGen/MachineFrameInfo.h"
31#include "llvm/CodeGen/MachineFunction.h"
32#include "llvm/CodeGen/MachineFunctionPass.h"
33#include "llvm/CodeGen/MachineInstr.h"
34#include "llvm/CodeGen/MachineInstrBuilder.h"
35#include "llvm/CodeGen/MachineMemOperand.h"
36#include "llvm/CodeGen/MachineOperand.h"
37#include "llvm/CodeGen/PseudoSourceValue.h"
38#include "llvm/CodeGen/TargetFrameLowering.h"
39#include "llvm/CodeGen/TargetInstrInfo.h"
40#include "llvm/CodeGen/TargetLowering.h"
41#include "llvm/CodeGen/TargetRegisterInfo.h"
42#include "llvm/CodeGen/TargetSubtargetInfo.h"
43#include "llvm/CodeGen/RegisterScavenging.h"
44#include "llvm/Config/llvm-config.h"
45#include "llvm/IR/DebugInfoMetadata.h"
46#include "llvm/IR/DebugLoc.h"
47#include "llvm/IR/Function.h"
48#include "llvm/IR/Module.h"
49#include "llvm/MC/MCRegisterInfo.h"
50#include "llvm/Pass.h"
51#include "llvm/Support/Casting.h"
52#include "llvm/Support/Compiler.h"
53#include "llvm/Support/Debug.h"
54#include "llvm/Support/raw_ostream.h"
55#include <algorithm>
56#include <cassert>
57#include <cstdint>
58#include <functional>
59#include <queue>
60#include <utility>
61#include <vector>
62
63using namespace llvm;
64
65#define DEBUG_TYPE"livedebugvalues" "livedebugvalues"
66
67STATISTIC(NumInserted, "Number of DBG_VALUE instructions inserted")static llvm::Statistic NumInserted = {"livedebugvalues", "NumInserted"
, "Number of DBG_VALUE instructions inserted", {0}, {false}};
68
69// If @MI is a DBG_VALUE with debug value described by a defined
70// register, returns the number of this register. In the other case, returns 0.
71static unsigned isDbgValueDescribedByReg(const MachineInstr &MI) {
72 assert(MI.isDebugValue() && "expected a DBG_VALUE")(static_cast <bool> (MI.isDebugValue() && "expected a DBG_VALUE"
) ? void (0) : __assert_fail ("MI.isDebugValue() && \"expected a DBG_VALUE\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 72, __extension__ __PRETTY_FUNCTION__));
73 assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE")(static_cast <bool> (MI.getNumOperands() == 4 &&
"malformed DBG_VALUE") ? void (0) : __assert_fail ("MI.getNumOperands() == 4 && \"malformed DBG_VALUE\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 73, __extension__ __PRETTY_FUNCTION__));
74 // If location of variable is described using a register (directly
75 // or indirectly), this register is always a first operand.
76 return MI.getOperand(0).isReg() ? MI.getOperand(0).getReg() : 0;
77}
78
79namespace {
80
81class LiveDebugValues : public MachineFunctionPass {
82private:
83 const TargetRegisterInfo *TRI;
84 const TargetInstrInfo *TII;
85 const TargetFrameLowering *TFI;
86 BitVector CalleeSavedRegs;
87 LexicalScopes LS;
88
89 /// Keeps track of lexical scopes associated with a user value's source
90 /// location.
91 class UserValueScopes {
92 DebugLoc DL;
93 LexicalScopes &LS;
94 SmallPtrSet<const MachineBasicBlock *, 4> LBlocks;
95
96 public:
97 UserValueScopes(DebugLoc D, LexicalScopes &L) : DL(std::move(D)), LS(L) {}
98
99 /// Return true if current scope dominates at least one machine
100 /// instruction in a given machine basic block.
101 bool dominates(MachineBasicBlock *MBB) {
102 if (LBlocks.empty())
103 LS.getMachineBasicBlocks(DL, LBlocks);
104 return LBlocks.count(MBB) != 0 || LS.dominates(DL, MBB);
105 }
106 };
107
108 /// Based on std::pair so it can be used as an index into a DenseMap.
109 using DebugVariableBase =
110 std::pair<const DILocalVariable *, const DILocation *>;
111 /// A potentially inlined instance of a variable.
112 struct DebugVariable : public DebugVariableBase {
113 DebugVariable(const DILocalVariable *Var, const DILocation *InlinedAt)
114 : DebugVariableBase(Var, InlinedAt) {}
115
116 const DILocalVariable *getVar() const { return this->first; }
117 const DILocation *getInlinedAt() const { return this->second; }
118
119 bool operator<(const DebugVariable &DV) const {
120 if (getVar() == DV.getVar())
121 return getInlinedAt() < DV.getInlinedAt();
122 return getVar() < DV.getVar();
123 }
124 };
125
126 /// A pair of debug variable and value location.
127 struct VarLoc {
128 const DebugVariable Var;
129 const MachineInstr &MI; ///< Only used for cloning a new DBG_VALUE.
130 mutable UserValueScopes UVS;
131 enum { InvalidKind = 0, RegisterKind } Kind = InvalidKind;
132
133 /// The value location. Stored separately to avoid repeatedly
134 /// extracting it from MI.
135 union {
136 uint64_t RegNo;
137 uint64_t Hash;
138 } Loc;
139
140 VarLoc(const MachineInstr &MI, LexicalScopes &LS)
141 : Var(MI.getDebugVariable(), MI.getDebugLoc()->getInlinedAt()), MI(MI),
142 UVS(MI.getDebugLoc(), LS) {
143 static_assert((sizeof(Loc) == sizeof(uint64_t)),
144 "hash does not cover all members of Loc");
145 assert(MI.isDebugValue() && "not a DBG_VALUE")(static_cast <bool> (MI.isDebugValue() && "not a DBG_VALUE"
) ? void (0) : __assert_fail ("MI.isDebugValue() && \"not a DBG_VALUE\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 145, __extension__ __PRETTY_FUNCTION__));
146 assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE")(static_cast <bool> (MI.getNumOperands() == 4 &&
"malformed DBG_VALUE") ? void (0) : __assert_fail ("MI.getNumOperands() == 4 && \"malformed DBG_VALUE\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 146, __extension__ __PRETTY_FUNCTION__));
147 if (int RegNo = isDbgValueDescribedByReg(MI)) {
148 Kind = RegisterKind;
149 Loc.RegNo = RegNo;
150 }
151 }
152
153 /// If this variable is described by a register, return it,
154 /// otherwise return 0.
155 unsigned isDescribedByReg() const {
156 if (Kind == RegisterKind)
157 return Loc.RegNo;
158 return 0;
159 }
160
161 /// Determine whether the lexical scope of this value's debug location
162 /// dominates MBB.
163 bool dominates(MachineBasicBlock &MBB) const { return UVS.dominates(&MBB); }
164
165#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
166 LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void dump() const { MI.dump(); }
167#endif
168
169 bool operator==(const VarLoc &Other) const {
170 return Var == Other.Var && Loc.Hash == Other.Loc.Hash;
171 }
172
173 /// This operator guarantees that VarLocs are sorted by Variable first.
174 bool operator<(const VarLoc &Other) const {
175 if (Var == Other.Var)
176 return Loc.Hash < Other.Loc.Hash;
177 return Var < Other.Var;
178 }
179 };
180
181 using VarLocMap = UniqueVector<VarLoc>;
182 using VarLocSet = SparseBitVector<>;
183 using VarLocInMBB = SmallDenseMap<const MachineBasicBlock *, VarLocSet>;
184 struct TransferDebugPair {
185 MachineInstr *TransferInst;
186 MachineInstr *DebugInst;
187 };
188 using TransferMap = SmallVector<TransferDebugPair, 4>;
189
190 /// This holds the working set of currently open ranges. For fast
191 /// access, this is done both as a set of VarLocIDs, and a map of
192 /// DebugVariable to recent VarLocID. Note that a DBG_VALUE ends all
193 /// previous open ranges for the same variable.
194 class OpenRangesSet {
195 VarLocSet VarLocs;
196 SmallDenseMap<DebugVariableBase, unsigned, 8> Vars;
197
198 public:
199 const VarLocSet &getVarLocs() const { return VarLocs; }
200
201 /// Terminate all open ranges for Var by removing it from the set.
202 void erase(DebugVariable Var) {
203 auto It = Vars.find(Var);
204 if (It != Vars.end()) {
205 unsigned ID = It->second;
206 VarLocs.reset(ID);
207 Vars.erase(It);
208 }
209 }
210
211 /// Terminate all open ranges listed in \c KillSet by removing
212 /// them from the set.
213 void erase(const VarLocSet &KillSet, const VarLocMap &VarLocIDs) {
214 VarLocs.intersectWithComplement(KillSet);
215 for (unsigned ID : KillSet)
216 Vars.erase(VarLocIDs[ID].Var);
217 }
218
219 /// Insert a new range into the set.
220 void insert(unsigned VarLocID, DebugVariableBase Var) {
221 VarLocs.set(VarLocID);
222 Vars.insert({Var, VarLocID});
223 }
224
225 /// Empty the set.
226 void clear() {
227 VarLocs.clear();
228 Vars.clear();
229 }
230
231 /// Return whether the set is empty or not.
232 bool empty() const {
233 assert(Vars.empty() == VarLocs.empty() && "open ranges are inconsistent")(static_cast <bool> (Vars.empty() == VarLocs.empty() &&
"open ranges are inconsistent") ? void (0) : __assert_fail (
"Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 233, __extension__ __PRETTY_FUNCTION__));
234 return VarLocs.empty();
235 }
236 };
237
238 bool isSpillInstruction(const MachineInstr &MI, MachineFunction *MF,
239 unsigned &Reg);
240 int extractSpillBaseRegAndOffset(const MachineInstr &MI, unsigned &Reg);
241 void insertTransferDebugPair(MachineInstr &MI, OpenRangesSet &OpenRanges,
242 TransferMap &Transfers, VarLocMap &VarLocIDs,
243 unsigned OldVarID, unsigned NewReg = 0);
244
245 void transferDebugValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
246 VarLocMap &VarLocIDs);
247 void transferSpillInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
248 VarLocMap &VarLocIDs, TransferMap &Transfers);
249 void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
250 VarLocMap &VarLocIDs, TransferMap &Transfers);
251 void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
252 const VarLocMap &VarLocIDs);
253 bool transferTerminatorInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
254 VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
255 bool process(MachineInstr &MI, OpenRangesSet &OpenRanges,
256 VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
257 TransferMap &Transfers, bool transferChanges);
258
259 bool join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
260 const VarLocMap &VarLocIDs,
261 SmallPtrSet<const MachineBasicBlock *, 16> &Visited);
262
263 bool ExtendRanges(MachineFunction &MF);
264
265public:
266 static char ID;
267
268 /// Default construct and initialize the pass.
269 LiveDebugValues();
270
271 /// Tell the pass manager which passes we depend on and what
272 /// information we preserve.
273 void getAnalysisUsage(AnalysisUsage &AU) const override;
274
275 MachineFunctionProperties getRequiredProperties() const override {
276 return MachineFunctionProperties().set(
277 MachineFunctionProperties::Property::NoVRegs);
278 }
279
280 /// Print to ostream with a message.
281 void printVarLocInMBB(const MachineFunction &MF, const VarLocInMBB &V,
282 const VarLocMap &VarLocIDs, const char *msg,
283 raw_ostream &Out) const;
284
285 /// Calculate the liveness information for the given machine function.
286 bool runOnMachineFunction(MachineFunction &MF) override;
287};
288
289} // end anonymous namespace
290
291//===----------------------------------------------------------------------===//
292// Implementation
293//===----------------------------------------------------------------------===//
294
295char LiveDebugValues::ID = 0;
296
297char &llvm::LiveDebugValuesID = LiveDebugValues::ID;
298
299INITIALIZE_PASS(LiveDebugValues, DEBUG_TYPE, "Live DEBUG_VALUE analysis",static void *initializeLiveDebugValuesPassOnce(PassRegistry &
Registry) { PassInfo *PI = new PassInfo( "Live DEBUG_VALUE analysis"
, "livedebugvalues", &LiveDebugValues::ID, PassInfo::NormalCtor_t
(callDefaultCtor<LiveDebugValues>), false, false); Registry
.registerPass(*PI, true); return PI; } static llvm::once_flag
InitializeLiveDebugValuesPassFlag; void llvm::initializeLiveDebugValuesPass
(PassRegistry &Registry) { llvm::call_once(InitializeLiveDebugValuesPassFlag
, initializeLiveDebugValuesPassOnce, std::ref(Registry)); }
300 false, false)static void *initializeLiveDebugValuesPassOnce(PassRegistry &
Registry) { PassInfo *PI = new PassInfo( "Live DEBUG_VALUE analysis"
, "livedebugvalues", &LiveDebugValues::ID, PassInfo::NormalCtor_t
(callDefaultCtor<LiveDebugValues>), false, false); Registry
.registerPass(*PI, true); return PI; } static llvm::once_flag
InitializeLiveDebugValuesPassFlag; void llvm::initializeLiveDebugValuesPass
(PassRegistry &Registry) { llvm::call_once(InitializeLiveDebugValuesPassFlag
, initializeLiveDebugValuesPassOnce, std::ref(Registry)); }
301
302/// Default construct and initialize the pass.
303LiveDebugValues::LiveDebugValues() : MachineFunctionPass(ID) {
304 initializeLiveDebugValuesPass(*PassRegistry::getPassRegistry());
305}
306
307/// Tell the pass manager which passes we depend on and what information we
308/// preserve.
309void LiveDebugValues::getAnalysisUsage(AnalysisUsage &AU) const {
310 AU.setPreservesCFG();
311 MachineFunctionPass::getAnalysisUsage(AU);
312}
313
314//===----------------------------------------------------------------------===//
315// Debug Range Extension Implementation
316//===----------------------------------------------------------------------===//
317
318#ifndef NDEBUG
319void LiveDebugValues::printVarLocInMBB(const MachineFunction &MF,
320 const VarLocInMBB &V,
321 const VarLocMap &VarLocIDs,
322 const char *msg,
323 raw_ostream &Out) const {
324 Out << '\n' << msg << '\n';
325 for (const MachineBasicBlock &BB : MF) {
326 const auto &L = V.lookup(&BB);
327 Out << "MBB: " << BB.getName() << ":\n";
328 for (unsigned VLL : L) {
329 const VarLoc &VL = VarLocIDs[VLL];
330 Out << " Var: " << VL.Var.getVar()->getName();
331 Out << " MI: ";
332 VL.dump();
333 }
334 }
335 Out << "\n";
336}
337#endif
338
339/// Given a spill instruction, extract the register and offset used to
340/// address the spill location in a target independent way.
341int LiveDebugValues::extractSpillBaseRegAndOffset(const MachineInstr &MI,
342 unsigned &Reg) {
343 assert(MI.hasOneMemOperand() &&(static_cast <bool> (MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?"
) ? void (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 344, __extension__ __PRETTY_FUNCTION__))
344 "Spill instruction does not have exactly one memory operand?")(static_cast <bool> (MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?"
) ? void (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 344, __extension__ __PRETTY_FUNCTION__));
345 auto MMOI = MI.memoperands_begin();
346 const PseudoSourceValue *PVal = (*MMOI)->getPseudoValue();
347 assert(PVal->kind() == PseudoSourceValue::FixedStack &&(static_cast <bool> (PVal->kind() == PseudoSourceValue
::FixedStack && "Inconsistent memory operand in spill instruction"
) ? void (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 348, __extension__ __PRETTY_FUNCTION__))
348 "Inconsistent memory operand in spill instruction")(static_cast <bool> (PVal->kind() == PseudoSourceValue
::FixedStack && "Inconsistent memory operand in spill instruction"
) ? void (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 348, __extension__ __PRETTY_FUNCTION__));
349 int FI = cast<FixedStackPseudoSourceValue>(PVal)->getFrameIndex();
350 const MachineBasicBlock *MBB = MI.getParent();
351 return TFI->getFrameIndexReference(*MBB->getParent(), FI, Reg);
352}
353
354/// End all previous ranges related to @MI and start a new range from @MI
355/// if it is a DBG_VALUE instr.
356void LiveDebugValues::transferDebugValue(const MachineInstr &MI,
357 OpenRangesSet &OpenRanges,
358 VarLocMap &VarLocIDs) {
359 if (!MI.isDebugValue())
360 return;
361 const DILocalVariable *Var = MI.getDebugVariable();
362 const DILocation *DebugLoc = MI.getDebugLoc();
363 const DILocation *InlinedAt = DebugLoc->getInlinedAt();
364 assert(Var->isValidLocationForIntrinsic(DebugLoc) &&(static_cast <bool> (Var->isValidLocationForIntrinsic
(DebugLoc) && "Expected inlined-at fields to agree") ?
void (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 365, __extension__ __PRETTY_FUNCTION__))
365 "Expected inlined-at fields to agree")(static_cast <bool> (Var->isValidLocationForIntrinsic
(DebugLoc) && "Expected inlined-at fields to agree") ?
void (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 365, __extension__ __PRETTY_FUNCTION__));
366
367 // End all previous ranges of Var.
368 DebugVariable V(Var, InlinedAt);
369 OpenRanges.erase(V);
370
371 // Add the VarLoc to OpenRanges from this DBG_VALUE.
372 // TODO: Currently handles DBG_VALUE which has only reg as location.
373 if (isDbgValueDescribedByReg(MI)) {
374 VarLoc VL(MI, LS);
375 unsigned ID = VarLocIDs.insert(VL);
376 OpenRanges.insert(ID, VL.Var);
377 }
378}
379
380/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
381/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
382/// new VarLoc. If \p NewReg is different than default zero value then the
383/// new location will be register location created by the copy like instruction,
384/// otherwise it is variable's location on the stack.
385void LiveDebugValues::insertTransferDebugPair(
386 MachineInstr &MI, OpenRangesSet &OpenRanges, TransferMap &Transfers,
387 VarLocMap &VarLocIDs, unsigned OldVarID, unsigned NewReg) {
388 const MachineInstr *DMI = &VarLocIDs[OldVarID].MI;
389 MachineFunction *MF = MI.getParent()->getParent();
390 MachineInstr *NewDMI;
391 if (NewReg) {
392 // Create a DBG_VALUE instruction to describe the Var in its new
393 // register location.
394 NewDMI = BuildMI(*MF, DMI->getDebugLoc(), DMI->getDesc(),
395 DMI->isIndirectDebugValue(), NewReg,
396 DMI->getDebugVariable(), DMI->getDebugExpression());
397 if (DMI->isIndirectDebugValue())
398 NewDMI->getOperand(1).setImm(DMI->getOperand(1).getImm());
399 LLVM_DEBUG(dbgs() << "Creating DBG_VALUE inst for register copy: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Creating DBG_VALUE inst for register copy: "
; NewDMI->print(dbgs(), false, false, false, TII); } } while
(false)
400 NewDMI->print(dbgs(), false, false, false, TII))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Creating DBG_VALUE inst for register copy: "
; NewDMI->print(dbgs(), false, false, false, TII); } } while
(false);
401 } else {
402 // Create a DBG_VALUE instruction to describe the Var in its spilled
403 // location.
404 unsigned SpillBase;
405 int SpillOffset = extractSpillBaseRegAndOffset(MI, SpillBase);
406 auto *SpillExpr = DIExpression::prepend(DMI->getDebugExpression(),
407 DIExpression::NoDeref, SpillOffset);
408 NewDMI = BuildMI(*MF, DMI->getDebugLoc(), DMI->getDesc(), true, SpillBase,
409 DMI->getDebugVariable(), SpillExpr);
410 LLVM_DEBUG(dbgs() << "Creating DBG_VALUE inst for spill: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Creating DBG_VALUE inst for spill: "
; NewDMI->print(dbgs(), false, false, false, TII); } } while
(false)
411 NewDMI->print(dbgs(), false, false, false, TII))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Creating DBG_VALUE inst for spill: "
; NewDMI->print(dbgs(), false, false, false, TII); } } while
(false);
412 }
413
414 // The newly created DBG_VALUE instruction NewDMI must be inserted after
415 // MI. Keep track of the pairing.
416 TransferDebugPair MIP = {&MI, NewDMI};
417 Transfers.push_back(MIP);
418
419 // End all previous ranges of Var.
420 OpenRanges.erase(VarLocIDs[OldVarID].Var);
421
422 // Add the VarLoc to OpenRanges.
423 VarLoc VL(*NewDMI, LS);
424 unsigned LocID = VarLocIDs.insert(VL);
425 OpenRanges.insert(LocID, VL.Var);
426}
427
428/// A definition of a register may mark the end of a range.
429void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
430 OpenRangesSet &OpenRanges,
431 const VarLocMap &VarLocIDs) {
432 MachineFunction *MF = MI.getMF();
433 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
434 unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
435 SparseBitVector<> KillSet;
436 for (const MachineOperand &MO : MI.operands()) {
437 // Determine whether the operand is a register def. Assume that call
438 // instructions never clobber SP, because some backends (e.g., AArch64)
439 // never list SP in the regmask.
440 if (MO.isReg() && MO.isDef() && MO.getReg() &&
441 TRI->isPhysicalRegister(MO.getReg()) &&
442 !(MI.isCall() && MO.getReg() == SP)) {
443 // Remove ranges of all aliased registers.
444 for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
445 for (unsigned ID : OpenRanges.getVarLocs())
446 if (VarLocIDs[ID].isDescribedByReg() == *RAI)
447 KillSet.set(ID);
448 } else if (MO.isRegMask()) {
449 // Remove ranges of all clobbered registers. Register masks don't usually
450 // list SP as preserved. While the debug info may be off for an
451 // instruction or two around callee-cleanup calls, transferring the
452 // DEBUG_VALUE across the call is still a better user experience.
453 for (unsigned ID : OpenRanges.getVarLocs()) {
454 unsigned Reg = VarLocIDs[ID].isDescribedByReg();
455 if (Reg && Reg != SP && MO.clobbersPhysReg(Reg))
456 KillSet.set(ID);
457 }
458 }
459 }
460 OpenRanges.erase(KillSet, VarLocIDs);
461}
462
463/// Decide if @MI is a spill instruction and return true if it is. We use 2
464/// criteria to make this decision:
465/// - Is this instruction a store to a spill slot?
466/// - Is there a register operand that is both used and killed?
467/// TODO: Store optimization can fold spills into other stores (including
468/// other spills). We do not handle this yet (more than one memory operand).
469bool LiveDebugValues::isSpillInstruction(const MachineInstr &MI,
470 MachineFunction *MF, unsigned &Reg) {
471 const MachineFrameInfo &FrameInfo = MF->getFrameInfo();
472 int FI;
473 const MachineMemOperand *MMO;
474
475 // TODO: Handle multiple stores folded into one.
476 if (!MI.hasOneMemOperand())
477 return false;
478
479 // To identify a spill instruction, use the same criteria as in AsmPrinter.
480 if (!((TII->isStoreToStackSlotPostFE(MI, FI) ||
481 TII->hasStoreToStackSlot(MI, MMO, FI)) &&
482 FrameInfo.isSpillSlotObjectIndex(FI)))
483 return false;
484
485 auto isKilledReg = [&](const MachineOperand MO, unsigned &Reg) {
486 if (!MO.isReg() || !MO.isUse()) {
487 Reg = 0;
488 return false;
489 }
490 Reg = MO.getReg();
491 return MO.isKill();
492 };
493
494 for (const MachineOperand &MO : MI.operands()) {
495 // In a spill instruction generated by the InlineSpiller the spilled
496 // register has its kill flag set.
497 if (isKilledReg(MO, Reg))
498 return true;
499 if (Reg != 0) {
500 // Check whether next instruction kills the spilled register.
501 // FIXME: Current solution does not cover search for killed register in
502 // bundles and instructions further down the chain.
503 auto NextI = std::next(MI.getIterator());
504 // Skip next instruction that points to basic block end iterator.
505 if (MI.getParent()->end() == NextI)
506 continue;
507 unsigned RegNext;
508 for (const MachineOperand &MONext : NextI->operands()) {
509 // Return true if we came across the register from the
510 // previous spill instruction that is killed in NextI.
511 if (isKilledReg(MONext, RegNext) && RegNext == Reg)
512 return true;
513 }
514 }
515 }
516 // Return false if we didn't find spilled register.
517 return false;
518}
519
520/// A spilled register may indicate that we have to end the current range of
521/// a variable and create a new one for the spill location.
522/// We don't want to insert any instructions in process(), so we just create
523/// the DBG_VALUE without inserting it and keep track of it in \p Transfers.
524/// It will be inserted into the BB when we're done iterating over the
525/// instructions.
526void LiveDebugValues::transferSpillInst(MachineInstr &MI,
527 OpenRangesSet &OpenRanges,
528 VarLocMap &VarLocIDs,
529 TransferMap &Transfers) {
530 unsigned Reg;
531 MachineFunction *MF = MI.getMF();
532 if (!isSpillInstruction(MI, MF, Reg))
533 return;
534
535 // Check if the register is the location of a debug value.
536 for (unsigned ID : OpenRanges.getVarLocs()) {
537 if (VarLocIDs[ID].isDescribedByReg() == Reg) {
538 LLVM_DEBUG(dbgs() << "Spilling Register " << printReg(Reg, TRI) << '('do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Spilling Register " <<
printReg(Reg, TRI) << '(' << VarLocIDs[ID].Var.getVar
()->getName() << ")\n"; } } while (false)
539 << VarLocIDs[ID].Var.getVar()->getName() << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Spilling Register " <<
printReg(Reg, TRI) << '(' << VarLocIDs[ID].Var.getVar
()->getName() << ")\n"; } } while (false);
540 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, ID);
541 return;
542 }
543 }
544}
545
546/// If \p MI is a register copy instruction, that copies a previously tracked
547/// value from one register to another register that is callee saved, we
548/// create new DBG_VALUE instruction described with copy destination register.
549void LiveDebugValues::transferRegisterCopy(MachineInstr &MI,
550 OpenRangesSet &OpenRanges,
551 VarLocMap &VarLocIDs,
552 TransferMap &Transfers) {
553 const MachineOperand *SrcRegOp, *DestRegOp;
554
555 if (!TII->isCopyInstr(MI, SrcRegOp, DestRegOp) || !SrcRegOp->isKill() ||
556 !DestRegOp->isDef())
557 return;
558
559 auto isCalleSavedReg = [&](unsigned Reg) {
560 for (MCRegAliasIterator RAI(Reg, TRI, true); RAI.isValid(); ++RAI)
561 if (CalleeSavedRegs.test(*RAI))
562 return true;
563 return false;
564 };
565
566 unsigned SrcReg = SrcRegOp->getReg();
567 unsigned DestReg = DestRegOp->getReg();
568
569 // We want to recognize instructions where destination register is callee
570 // saved register. If register that could be clobbered by the call is
571 // included, there would be a great chance that it is going to be clobbered
572 // soon. It is more likely that previous register location, which is callee
573 // saved, is going to stay unclobbered longer, even if it is killed.
574 if (!isCalleSavedReg(DestReg))
575 return;
576
577 for (unsigned ID : OpenRanges.getVarLocs()) {
578 if (VarLocIDs[ID].isDescribedByReg() == SrcReg) {
579 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, ID,
580 DestReg);
581 return;
582 }
583 }
584}
585
586/// Terminate all open ranges at the end of the current basic block.
587bool LiveDebugValues::transferTerminatorInst(MachineInstr &MI,
588 OpenRangesSet &OpenRanges,
589 VarLocInMBB &OutLocs,
590 const VarLocMap &VarLocIDs) {
591 bool Changed = false;
592 const MachineBasicBlock *CurMBB = MI.getParent();
593 if (!(MI.isTerminator() || (&MI == &CurMBB->back())))
594 return false;
595
596 if (OpenRanges.empty())
597 return false;
598
599 LLVM_DEBUG(for (unsigned IDdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false)
600 : OpenRanges.getVarLocs()) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false)
601 // Copy OpenRanges to OutLocs, if not already present.do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false)
602 dbgs() << "Add to OutLocs: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false)
603 VarLocIDs[ID].dump();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false)
604 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { for (unsigned ID : OpenRanges.getVarLocs
()) { dbgs() << "Add to OutLocs: "; VarLocIDs[ID].dump(
); }; } } while (false);
605 VarLocSet &VLS = OutLocs[CurMBB];
606 Changed = VLS |= OpenRanges.getVarLocs();
607 OpenRanges.clear();
608 return Changed;
609}
610
611/// This routine creates OpenRanges and OutLocs.
612bool LiveDebugValues::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
613 VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
614 TransferMap &Transfers, bool transferChanges) {
615 bool Changed = false;
616 transferDebugValue(MI, OpenRanges, VarLocIDs);
617 transferRegisterDef(MI, OpenRanges, VarLocIDs);
618 if (transferChanges) {
619 transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
620 transferSpillInst(MI, OpenRanges, VarLocIDs, Transfers);
621 }
622 Changed = transferTerminatorInst(MI, OpenRanges, OutLocs, VarLocIDs);
623 return Changed;
624}
625
626/// This routine joins the analysis results of all incoming edges in @MBB by
627/// inserting a new DBG_VALUE instruction at the start of the @MBB - if the same
628/// source variable in all the predecessors of @MBB reside in the same location.
629bool LiveDebugValues::join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs,
630 VarLocInMBB &InLocs, const VarLocMap &VarLocIDs,
631 SmallPtrSet<const MachineBasicBlock *, 16> &Visited) {
632 LLVM_DEBUG(dbgs() << "join MBB: " << MBB.getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "join MBB: " << MBB
.getName() << "\n"; } } while (false);
633 bool Changed = false;
634
635 VarLocSet InLocsT; // Temporary incoming locations.
636
637 // For all predecessors of this MBB, find the set of VarLocs that
638 // can be joined.
639 int NumVisited = 0;
640 for (auto p : MBB.predecessors()) {
641 // Ignore unvisited predecessor blocks. As we are processing
642 // the blocks in reverse post-order any unvisited block can
643 // be considered to not remove any incoming values.
644 if (!Visited.count(p))
645 continue;
646 auto OL = OutLocs.find(p);
647 // Join is null in case of empty OutLocs from any of the pred.
648 if (OL == OutLocs.end())
649 return false;
650
651 // Just copy over the Out locs to incoming locs for the first visited
652 // predecessor, and for all other predecessors join the Out locs.
653 if (!NumVisited)
654 InLocsT = OL->second;
655 else
656 InLocsT &= OL->second;
657 NumVisited++;
658 }
659
660 // Filter out DBG_VALUES that are out of scope.
661 VarLocSet KillSet;
662 for (auto ID : InLocsT)
663 if (!VarLocIDs[ID].dominates(MBB))
664 KillSet.set(ID);
665 InLocsT.intersectWithComplement(KillSet);
666
667 // As we are processing blocks in reverse post-order we
668 // should have processed at least one predecessor, unless it
669 // is the entry block which has no predecessor.
670 assert((NumVisited || MBB.pred_empty()) &&(static_cast <bool> ((NumVisited || MBB.pred_empty()) &&
"Should have processed at least one predecessor") ? void (0)
: __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 671, __extension__ __PRETTY_FUNCTION__))
671 "Should have processed at least one predecessor")(static_cast <bool> ((NumVisited || MBB.pred_empty()) &&
"Should have processed at least one predecessor") ? void (0)
: __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 671, __extension__ __PRETTY_FUNCTION__));
672 if (InLocsT.empty())
673 return false;
674
675 VarLocSet &ILS = InLocs[&MBB];
676
677 // Insert DBG_VALUE instructions, if not already inserted.
678 VarLocSet Diff = InLocsT;
679 Diff.intersectWithComplement(ILS);
680 for (auto ID : Diff) {
681 // This VarLoc is not found in InLocs i.e. it is not yet inserted. So, a
682 // new range is started for the var from the mbb's beginning by inserting
683 // a new DBG_VALUE. process() will end this range however appropriate.
684 const VarLoc &DiffIt = VarLocIDs[ID];
685 const MachineInstr *DMI = &DiffIt.MI;
686 MachineInstr *MI =
687 BuildMI(MBB, MBB.instr_begin(), DMI->getDebugLoc(), DMI->getDesc(),
688 DMI->isIndirectDebugValue(), DMI->getOperand(0).getReg(),
689 DMI->getDebugVariable(), DMI->getDebugExpression());
690 if (DMI->isIndirectDebugValue())
691 MI->getOperand(1).setImm(DMI->getOperand(1).getImm());
692 LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Inserted: "; MI->dump
();; } } while (false);
693 ILS.set(ID);
694 ++NumInserted;
695 Changed = true;
696 }
697 return Changed;
698}
699
700/// Calculate the liveness information for the given machine function and
701/// extend ranges across basic blocks.
702bool LiveDebugValues::ExtendRanges(MachineFunction &MF) {
703 LLVM_DEBUG(dbgs() << "\nDebug Range Extension\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "\nDebug Range Extension\n"
; } } while (false);
704
705 bool Changed = false;
706 bool OLChanged = false;
707 bool MBBJoined = false;
708
709 VarLocMap VarLocIDs; // Map VarLoc<>unique ID for use in bitvectors.
710 OpenRangesSet OpenRanges; // Ranges that are open until end of bb.
711 VarLocInMBB OutLocs; // Ranges that exist beyond bb.
712 VarLocInMBB InLocs; // Ranges that are incoming after joining.
713 TransferMap Transfers; // DBG_VALUEs associated with spills.
714
715 DenseMap<unsigned int, MachineBasicBlock *> OrderToBB;
716 DenseMap<MachineBasicBlock *, unsigned int> BBToOrder;
717 std::priority_queue<unsigned int, std::vector<unsigned int>,
718 std::greater<unsigned int>>
719 Worklist;
720 std::priority_queue<unsigned int, std::vector<unsigned int>,
721 std::greater<unsigned int>>
722 Pending;
723
724 enum : bool { dontTransferChanges = false, transferChanges = true };
725
726 // Initialize every mbb with OutLocs.
727 // We are not looking at any spill instructions during the initial pass
728 // over the BBs. The LiveDebugVariables pass has already created DBG_VALUE
729 // instructions for spills of registers that are known to be user variables
730 // within the BB in which the spill occurs.
731 for (auto &MBB : MF)
732 for (auto &MI : MBB)
733 process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
734 dontTransferChanges);
735
736 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
737 "OutLocs after initialization", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false);
738
739 ReversePostOrderTraversal<MachineFunction *> RPOT(&MF);
740 unsigned int RPONumber = 0;
741 for (auto RI = RPOT.begin(), RE = RPOT.end(); RI != RE; ++RI) {
742 OrderToBB[RPONumber] = *RI;
743 BBToOrder[*RI] = RPONumber;
744 Worklist.push(RPONumber);
745 ++RPONumber;
746 }
747 // This is a standard "union of predecessor outs" dataflow problem.
748 // To solve it, we perform join() and process() using the two worklist method
749 // until the ranges converge.
750 // Ranges have converged when both worklists are empty.
751 SmallPtrSet<const MachineBasicBlock *, 16> Visited;
752 while (!Worklist.empty() || !Pending.empty()) {
753 // We track what is on the pending worklist to avoid inserting the same
754 // thing twice. We could avoid this with a custom priority queue, but this
755 // is probably not worth it.
756 SmallPtrSet<MachineBasicBlock *, 16> OnPending;
757 LLVM_DEBUG(dbgs() << "Processing Worklist\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Processing Worklist\n"
; } } while (false);
758 while (!Worklist.empty()) {
759 MachineBasicBlock *MBB = OrderToBB[Worklist.top()];
760 Worklist.pop();
761 MBBJoined = join(*MBB, OutLocs, InLocs, VarLocIDs, Visited);
762 Visited.insert(MBB);
763 if (MBBJoined) {
764 MBBJoined = false;
Value stored to 'MBBJoined' is never read
765 Changed = true;
766 // Now that we have started to extend ranges across BBs we need to
767 // examine spill instructions to see whether they spill registers that
768 // correspond to user variables.
769 for (auto &MI : *MBB)
770 OLChanged |= process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
771 transferChanges);
772
773 // Add any DBG_VALUE instructions necessitated by spills.
774 for (auto &TR : Transfers)
775 MBB->insertAfter(MachineBasicBlock::iterator(*TR.TransferInst),
776 TR.DebugInst);
777 Transfers.clear();
778
779 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
780 "OutLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false);
781 LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
782 "InLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false);
783
784 if (OLChanged) {
785 OLChanged = false;
786 for (auto s : MBB->successors())
787 if (OnPending.insert(s).second) {
788 Pending.push(BBToOrder[s]);
789 }
790 }
791 }
792 }
793 Worklist.swap(Pending);
794 // At this point, pending must be empty, since it was just the empty
795 // worklist
796 assert(Pending.empty() && "Pending should be empty")(static_cast <bool> (Pending.empty() && "Pending should be empty"
) ? void (0) : __assert_fail ("Pending.empty() && \"Pending should be empty\""
, "/build/llvm-toolchain-snapshot-7~svn338205/lib/CodeGen/LiveDebugValues.cpp"
, 796, __extension__ __PRETTY_FUNCTION__));
797 }
798
799 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs, "Final OutLocs", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "Final OutLocs", dbgs()); } } while (false);
800 LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs, "Final InLocs", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "Final InLocs", dbgs()); } } while (false);
801 return Changed;
802}
803
804bool LiveDebugValues::runOnMachineFunction(MachineFunction &MF) {
805 if (!MF.getFunction().getSubprogram())
806 // LiveDebugValues will already have removed all DBG_VALUEs.
807 return false;
808
809 // Skip functions from NoDebug compilation units.
810 if (MF.getFunction().getSubprogram()->getUnit()->getEmissionKind() ==
811 DICompileUnit::NoDebug)
812 return false;
813
814 TRI = MF.getSubtarget().getRegisterInfo();
815 TII = MF.getSubtarget().getInstrInfo();
816 TFI = MF.getSubtarget().getFrameLowering();
817 TFI->determineCalleeSaves(MF, CalleeSavedRegs,
818 make_unique<RegScavenger>().get());
819 LS.initialize(MF);
820
821 bool Changed = ExtendRanges(MF);
822 return Changed;
823}