Bug Summary

File:build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp
Warning:line 2228, column 9
Value stored to 'MBBJoined' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name VarLocBasedImpl.cpp -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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/build-llvm -resource-dir /usr/lib/llvm-16/lib/clang/16.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I lib/CodeGen -I /build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/llvm/lib/CodeGen -I include -I /build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-16/lib/clang/16.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-09-04-125545-48738-1 -x c++ /build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp
1//===- VarLocBasedImpl.cpp - Tracking Debug Value MIs with VarLoc class----===//
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/// \file VarLocBasedImpl.cpp
10///
11/// LiveDebugValues is an optimistic "available expressions" dataflow
12/// algorithm. The set of expressions is the set of machine locations
13/// (registers, spill slots, constants) that a variable fragment might be
14/// located, qualified by a DIExpression and indirect-ness flag, while each
15/// variable is identified by a DebugVariable object. The availability of an
16/// expression begins when a DBG_VALUE instruction specifies the location of a
17/// DebugVariable, and continues until that location is clobbered or
18/// re-specified by a different DBG_VALUE for the same DebugVariable.
19///
20/// The output of LiveDebugValues is additional DBG_VALUE instructions,
21/// placed to extend variable locations as far they're available. This file
22/// and the VarLocBasedLDV class is an implementation that explicitly tracks
23/// locations, using the VarLoc class.
24///
25/// The canonical "available expressions" problem doesn't have expression
26/// clobbering, instead when a variable is re-assigned, any expressions using
27/// that variable get invalidated. LiveDebugValues can map onto "available
28/// expressions" by having every register represented by a variable, which is
29/// used in an expression that becomes available at a DBG_VALUE instruction.
30/// When the register is clobbered, its variable is effectively reassigned, and
31/// expressions computed from it become unavailable. A similar construct is
32/// needed when a DebugVariable has its location re-specified, to invalidate
33/// all other locations for that DebugVariable.
34///
35/// Using the dataflow analysis to compute the available expressions, we create
36/// a DBG_VALUE at the beginning of each block where the expression is
37/// live-in. This propagates variable locations into every basic block where
38/// the location can be determined, rather than only having DBG_VALUEs in blocks
39/// where locations are specified due to an assignment or some optimization.
40/// Movements of values between registers and spill slots are annotated with
41/// DBG_VALUEs too to track variable values bewteen locations. All this allows
42/// DbgEntityHistoryCalculator to focus on only the locations within individual
43/// blocks, facilitating testing and improving modularity.
44///
45/// We follow an optimisic dataflow approach, with this lattice:
46///
47/// \verbatim
48/// ┬ "Unknown"
49/// |
50/// v
51/// True
52/// |
53/// v
54/// ⊥ False
55/// \endverbatim With "True" signifying that the expression is available (and
56/// thus a DebugVariable's location is the corresponding register), while
57/// "False" signifies that the expression is unavailable. "Unknown"s never
58/// survive to the end of the analysis (see below).
59///
60/// Formally, all DebugVariable locations that are live-out of a block are
61/// initialized to \top. A blocks live-in values take the meet of the lattice
62/// value for every predecessors live-outs, except for the entry block, where
63/// all live-ins are \bot. The usual dataflow propagation occurs: the transfer
64/// function for a block assigns an expression for a DebugVariable to be "True"
65/// if a DBG_VALUE in the block specifies it; "False" if the location is
66/// clobbered; or the live-in value if it is unaffected by the block. We
67/// visit each block in reverse post order until a fixedpoint is reached. The
68/// solution produced is maximal.
69///
70/// Intuitively, we start by assuming that every expression / variable location
71/// is at least "True", and then propagate "False" from the entry block and any
72/// clobbers until there are no more changes to make. This gives us an accurate
73/// solution because all incorrect locations will have a "False" propagated into
74/// them. It also gives us a solution that copes well with loops by assuming
75/// that variable locations are live-through every loop, and then removing those
76/// that are not through dataflow.
77///
78/// Within LiveDebugValues: each variable location is represented by a
79/// VarLoc object that identifies the source variable, the set of
80/// machine-locations that currently describe it (a single location for
81/// DBG_VALUE or multiple for DBG_VALUE_LIST), and the DBG_VALUE inst that
82/// specifies the location. Each VarLoc is indexed in the (function-scope) \p
83/// VarLocMap, giving each VarLoc a set of unique indexes, each of which
84/// corresponds to one of the VarLoc's machine-locations and can be used to
85/// lookup the VarLoc in the VarLocMap. Rather than operate directly on machine
86/// locations, the dataflow analysis in this pass identifies locations by their
87/// indices in the VarLocMap, meaning all the variable locations in a block can
88/// be described by a sparse vector of VarLocMap indicies.
89///
90/// All the storage for the dataflow analysis is local to the ExtendRanges
91/// method and passed down to helper methods. "OutLocs" and "InLocs" record the
92/// in and out lattice values for each block. "OpenRanges" maintains a list of
93/// variable locations and, with the "process" method, evaluates the transfer
94/// function of each block. "flushPendingLocs" installs debug value instructions
95/// for each live-in location at the start of blocks, while "Transfers" records
96/// transfers of values between machine-locations.
97///
98/// We avoid explicitly representing the "Unknown" (\top) lattice value in the
99/// implementation. Instead, unvisited blocks implicitly have all lattice
100/// values set as "Unknown". After being visited, there will be path back to
101/// the entry block where the lattice value is "False", and as the transfer
102/// function cannot make new "Unknown" locations, there are no scenarios where
103/// a block can have an "Unknown" location after being visited. Similarly, we
104/// don't enumerate all possible variable locations before exploring the
105/// function: when a new location is discovered, all blocks previously explored
106/// were implicitly "False" but unrecorded, and become explicitly "False" when
107/// a new VarLoc is created with its bit not set in predecessor InLocs or
108/// OutLocs.
109///
110//===----------------------------------------------------------------------===//
111
112#include "LiveDebugValues.h"
113
114#include "llvm/ADT/CoalescingBitVector.h"
115#include "llvm/ADT/DenseMap.h"
116#include "llvm/ADT/PostOrderIterator.h"
117#include "llvm/ADT/SmallPtrSet.h"
118#include "llvm/ADT/SmallSet.h"
119#include "llvm/ADT/SmallVector.h"
120#include "llvm/ADT/Statistic.h"
121#include "llvm/BinaryFormat/Dwarf.h"
122#include "llvm/CodeGen/LexicalScopes.h"
123#include "llvm/CodeGen/MachineBasicBlock.h"
124#include "llvm/CodeGen/MachineFunction.h"
125#include "llvm/CodeGen/MachineInstr.h"
126#include "llvm/CodeGen/MachineInstrBuilder.h"
127#include "llvm/CodeGen/MachineMemOperand.h"
128#include "llvm/CodeGen/MachineOperand.h"
129#include "llvm/CodeGen/PseudoSourceValue.h"
130#include "llvm/CodeGen/TargetFrameLowering.h"
131#include "llvm/CodeGen/TargetInstrInfo.h"
132#include "llvm/CodeGen/TargetLowering.h"
133#include "llvm/CodeGen/TargetPassConfig.h"
134#include "llvm/CodeGen/TargetRegisterInfo.h"
135#include "llvm/CodeGen/TargetSubtargetInfo.h"
136#include "llvm/Config/llvm-config.h"
137#include "llvm/IR/DebugInfoMetadata.h"
138#include "llvm/IR/DebugLoc.h"
139#include "llvm/IR/Function.h"
140#include "llvm/MC/MCRegisterInfo.h"
141#include "llvm/Support/Casting.h"
142#include "llvm/Support/Debug.h"
143#include "llvm/Support/TypeSize.h"
144#include "llvm/Support/raw_ostream.h"
145#include "llvm/Target/TargetMachine.h"
146#include <algorithm>
147#include <cassert>
148#include <cstdint>
149#include <functional>
150#include <map>
151#include <queue>
152#include <tuple>
153#include <utility>
154#include <vector>
155
156using namespace llvm;
157
158#define DEBUG_TYPE"livedebugvalues" "livedebugvalues"
159
160STATISTIC(NumInserted, "Number of DBG_VALUE instructions inserted")static llvm::Statistic NumInserted = {"livedebugvalues", "NumInserted"
, "Number of DBG_VALUE instructions inserted"}
;
161
162/// If \p Op is a stack or frame register return true, otherwise return false.
163/// This is used to avoid basing the debug entry values on the registers, since
164/// we do not support it at the moment.
165static bool isRegOtherThanSPAndFP(const MachineOperand &Op,
166 const MachineInstr &MI,
167 const TargetRegisterInfo *TRI) {
168 if (!Op.isReg())
169 return false;
170
171 const MachineFunction *MF = MI.getParent()->getParent();
172 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
173 Register SP = TLI->getStackPointerRegisterToSaveRestore();
174 Register FP = TRI->getFrameRegister(*MF);
175 Register Reg = Op.getReg();
176
177 return Reg && Reg != SP && Reg != FP;
178}
179
180namespace {
181
182// Max out the number of statically allocated elements in DefinedRegsSet, as
183// this prevents fallback to std::set::count() operations.
184using DefinedRegsSet = SmallSet<Register, 32>;
185
186// The IDs in this set correspond to MachineLocs in VarLocs, as well as VarLocs
187// that represent Entry Values; every VarLoc in the set will also appear
188// exactly once at Location=0.
189// As a result, each VarLoc may appear more than once in this "set", but each
190// range corresponding to a Reg, SpillLoc, or EntryValue type will still be a
191// "true" set (i.e. each VarLoc may appear only once), and the range Location=0
192// is the set of all VarLocs.
193using VarLocSet = CoalescingBitVector<uint64_t>;
194
195/// A type-checked pair of {Register Location (or 0), Index}, used to index
196/// into a \ref VarLocMap. This can be efficiently converted to a 64-bit int
197/// for insertion into a \ref VarLocSet, and efficiently converted back. The
198/// type-checker helps ensure that the conversions aren't lossy.
199///
200/// Why encode a location /into/ the VarLocMap index? This makes it possible
201/// to find the open VarLocs killed by a register def very quickly. This is a
202/// performance-critical operation for LiveDebugValues.
203struct LocIndex {
204 using u32_location_t = uint32_t;
205 using u32_index_t = uint32_t;
206
207 u32_location_t Location; // Physical registers live in the range [1;2^30) (see
208 // \ref MCRegister), so we have plenty of range left
209 // here to encode non-register locations.
210 u32_index_t Index;
211
212 /// The location that has an entry for every VarLoc in the map.
213 static constexpr u32_location_t kUniversalLocation = 0;
214
215 /// The first location that is reserved for VarLocs with locations of kind
216 /// RegisterKind.
217 static constexpr u32_location_t kFirstRegLocation = 1;
218
219 /// The first location greater than 0 that is not reserved for VarLocs with
220 /// locations of kind RegisterKind.
221 static constexpr u32_location_t kFirstInvalidRegLocation = 1 << 30;
222
223 /// A special location reserved for VarLocs with locations of kind
224 /// SpillLocKind.
225 static constexpr u32_location_t kSpillLocation = kFirstInvalidRegLocation;
226
227 /// A special location reserved for VarLocs of kind EntryValueBackupKind and
228 /// EntryValueCopyBackupKind.
229 static constexpr u32_location_t kEntryValueBackupLocation =
230 kFirstInvalidRegLocation + 1;
231
232 LocIndex(u32_location_t Location, u32_index_t Index)
233 : Location(Location), Index(Index) {}
234
235 uint64_t getAsRawInteger() const {
236 return (static_cast<uint64_t>(Location) << 32) | Index;
237 }
238
239 template<typename IntT> static LocIndex fromRawInteger(IntT ID) {
240 static_assert(std::is_unsigned<IntT>::value &&
241 sizeof(ID) == sizeof(uint64_t),
242 "Cannot convert raw integer to LocIndex");
243 return {static_cast<u32_location_t>(ID >> 32),
244 static_cast<u32_index_t>(ID)};
245 }
246
247 /// Get the start of the interval reserved for VarLocs of kind RegisterKind
248 /// which reside in \p Reg. The end is at rawIndexForReg(Reg+1)-1.
249 static uint64_t rawIndexForReg(Register Reg) {
250 return LocIndex(Reg, 0).getAsRawInteger();
251 }
252
253 /// Return a range covering all set indices in the interval reserved for
254 /// \p Location in \p Set.
255 static auto indexRangeForLocation(const VarLocSet &Set,
256 u32_location_t Location) {
257 uint64_t Start = LocIndex(Location, 0).getAsRawInteger();
258 uint64_t End = LocIndex(Location + 1, 0).getAsRawInteger();
259 return Set.half_open_range(Start, End);
260 }
261};
262
263// Simple Set for storing all the VarLoc Indices at a Location bucket.
264using VarLocsInRange = SmallSet<LocIndex::u32_index_t, 32>;
265// Vector of all `LocIndex`s for a given VarLoc; the same Location should not
266// appear in any two of these, as each VarLoc appears at most once in any
267// Location bucket.
268using LocIndices = SmallVector<LocIndex, 2>;
269
270class VarLocBasedLDV : public LDVImpl {
271private:
272 const TargetRegisterInfo *TRI;
273 const TargetInstrInfo *TII;
274 const TargetFrameLowering *TFI;
275 TargetPassConfig *TPC;
276 BitVector CalleeSavedRegs;
277 LexicalScopes LS;
278 VarLocSet::Allocator Alloc;
279
280 const MachineInstr *LastNonDbgMI;
281
282 enum struct TransferKind { TransferCopy, TransferSpill, TransferRestore };
283
284 using FragmentInfo = DIExpression::FragmentInfo;
285 using OptFragmentInfo = Optional<DIExpression::FragmentInfo>;
286
287 /// A pair of debug variable and value location.
288 struct VarLoc {
289 // The location at which a spilled variable resides. It consists of a
290 // register and an offset.
291 struct SpillLoc {
292 unsigned SpillBase;
293 StackOffset SpillOffset;
294 bool operator==(const SpillLoc &Other) const {
295 return SpillBase == Other.SpillBase && SpillOffset == Other.SpillOffset;
296 }
297 bool operator!=(const SpillLoc &Other) const {
298 return !(*this == Other);
299 }
300 };
301
302 /// Identity of the variable at this location.
303 const DebugVariable Var;
304
305 /// The expression applied to this location.
306 const DIExpression *Expr;
307
308 /// DBG_VALUE to clone var/expr information from if this location
309 /// is moved.
310 const MachineInstr &MI;
311
312 enum class MachineLocKind {
313 InvalidKind = 0,
314 RegisterKind,
315 SpillLocKind,
316 ImmediateKind
317 };
318
319 enum class EntryValueLocKind {
320 NonEntryValueKind = 0,
321 EntryValueKind,
322 EntryValueBackupKind,
323 EntryValueCopyBackupKind
324 } EVKind = EntryValueLocKind::NonEntryValueKind;
325
326 /// The value location. Stored separately to avoid repeatedly
327 /// extracting it from MI.
328 union MachineLocValue {
329 uint64_t RegNo;
330 SpillLoc SpillLocation;
331 uint64_t Hash;
332 int64_t Immediate;
333 const ConstantFP *FPImm;
334 const ConstantInt *CImm;
335 MachineLocValue() : Hash(0) {}
336 };
337
338 /// A single machine location; its Kind is either a register, spill
339 /// location, or immediate value.
340 /// If the VarLoc is not a NonEntryValueKind, then it will use only a
341 /// single MachineLoc of RegisterKind.
342 struct MachineLoc {
343 MachineLocKind Kind;
344 MachineLocValue Value;
345 bool operator==(const MachineLoc &Other) const {
346 if (Kind != Other.Kind)
347 return false;
348 switch (Kind) {
349 case MachineLocKind::SpillLocKind:
350 return Value.SpillLocation == Other.Value.SpillLocation;
351 case MachineLocKind::RegisterKind:
352 case MachineLocKind::ImmediateKind:
353 return Value.Hash == Other.Value.Hash;
354 default:
355 llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 355)
;
356 }
357 }
358 bool operator<(const MachineLoc &Other) const {
359 switch (Kind) {
360 case MachineLocKind::SpillLocKind:
361 return std::make_tuple(
362 Kind, Value.SpillLocation.SpillBase,
363 Value.SpillLocation.SpillOffset.getFixed(),
364 Value.SpillLocation.SpillOffset.getScalable()) <
365 std::make_tuple(
366 Other.Kind, Other.Value.SpillLocation.SpillBase,
367 Other.Value.SpillLocation.SpillOffset.getFixed(),
368 Other.Value.SpillLocation.SpillOffset.getScalable());
369 case MachineLocKind::RegisterKind:
370 case MachineLocKind::ImmediateKind:
371 return std::tie(Kind, Value.Hash) <
372 std::tie(Other.Kind, Other.Value.Hash);
373 default:
374 llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 374)
;
375 }
376 }
377 };
378
379 /// The set of machine locations used to determine the variable's value, in
380 /// conjunction with Expr. Initially populated with MI's debug operands,
381 /// but may be transformed independently afterwards.
382 SmallVector<MachineLoc, 8> Locs;
383 /// Used to map the index of each location in Locs back to the index of its
384 /// original debug operand in MI. Used when multiple location operands are
385 /// coalesced and the original MI's operands need to be accessed while
386 /// emitting a debug value.
387 SmallVector<unsigned, 8> OrigLocMap;
388
389 VarLoc(const MachineInstr &MI, LexicalScopes &LS)
390 : Var(MI.getDebugVariable(), MI.getDebugExpression(),
391 MI.getDebugLoc()->getInlinedAt()),
392 Expr(MI.getDebugExpression()), MI(MI) {
393 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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 393
, __extension__ __PRETTY_FUNCTION__))
;
394 assert((MI.isDebugValueList() || MI.getNumOperands() == 4) &&(static_cast <bool> ((MI.isDebugValueList() || MI.getNumOperands
() == 4) && "malformed DBG_VALUE") ? void (0) : __assert_fail
("(MI.isDebugValueList() || MI.getNumOperands() == 4) && \"malformed DBG_VALUE\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 395
, __extension__ __PRETTY_FUNCTION__))
395 "malformed DBG_VALUE")(static_cast <bool> ((MI.isDebugValueList() || MI.getNumOperands
() == 4) && "malformed DBG_VALUE") ? void (0) : __assert_fail
("(MI.isDebugValueList() || MI.getNumOperands() == 4) && \"malformed DBG_VALUE\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 395
, __extension__ __PRETTY_FUNCTION__))
;
396 for (const MachineOperand &Op : MI.debug_operands()) {
397 MachineLoc ML = GetLocForOp(Op);
398 auto It = find(Locs, ML);
399 if (It == Locs.end()) {
400 Locs.push_back(ML);
401 OrigLocMap.push_back(MI.getDebugOperandIndex(&Op));
402 } else {
403 // ML duplicates an element in Locs; replace references to Op
404 // with references to the duplicating element.
405 unsigned OpIdx = Locs.size();
406 unsigned DuplicatingIdx = std::distance(Locs.begin(), It);
407 Expr = DIExpression::replaceArg(Expr, OpIdx, DuplicatingIdx);
408 }
409 }
410
411 // We create the debug entry values from the factory functions rather
412 // than from this ctor.
413 assert(EVKind != EntryValueLocKind::EntryValueKind &&(static_cast <bool> (EVKind != EntryValueLocKind::EntryValueKind
&& !isEntryBackupLoc()) ? void (0) : __assert_fail (
"EVKind != EntryValueLocKind::EntryValueKind && !isEntryBackupLoc()"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 414
, __extension__ __PRETTY_FUNCTION__))
414 !isEntryBackupLoc())(static_cast <bool> (EVKind != EntryValueLocKind::EntryValueKind
&& !isEntryBackupLoc()) ? void (0) : __assert_fail (
"EVKind != EntryValueLocKind::EntryValueKind && !isEntryBackupLoc()"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 414
, __extension__ __PRETTY_FUNCTION__))
;
415 }
416
417 static MachineLoc GetLocForOp(const MachineOperand &Op) {
418 MachineLocKind Kind;
419 MachineLocValue Loc;
420 if (Op.isReg()) {
421 Kind = MachineLocKind::RegisterKind;
422 Loc.RegNo = Op.getReg();
423 } else if (Op.isImm()) {
424 Kind = MachineLocKind::ImmediateKind;
425 Loc.Immediate = Op.getImm();
426 } else if (Op.isFPImm()) {
427 Kind = MachineLocKind::ImmediateKind;
428 Loc.FPImm = Op.getFPImm();
429 } else if (Op.isCImm()) {
430 Kind = MachineLocKind::ImmediateKind;
431 Loc.CImm = Op.getCImm();
432 } else
433 llvm_unreachable("Invalid Op kind for MachineLoc.")::llvm::llvm_unreachable_internal("Invalid Op kind for MachineLoc."
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 433
)
;
434 return {Kind, Loc};
435 }
436
437 /// Take the variable and machine-location in DBG_VALUE MI, and build an
438 /// entry location using the given expression.
439 static VarLoc CreateEntryLoc(const MachineInstr &MI, LexicalScopes &LS,
440 const DIExpression *EntryExpr, Register Reg) {
441 VarLoc VL(MI, LS);
442 assert(VL.Locs.size() == 1 &&(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 443
, __extension__ __PRETTY_FUNCTION__))
443 VL.Locs[0].Kind == MachineLocKind::RegisterKind)(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 443
, __extension__ __PRETTY_FUNCTION__))
;
444 VL.EVKind = EntryValueLocKind::EntryValueKind;
445 VL.Expr = EntryExpr;
446 VL.Locs[0].Value.RegNo = Reg;
447 return VL;
448 }
449
450 /// Take the variable and machine-location from the DBG_VALUE (from the
451 /// function entry), and build an entry value backup location. The backup
452 /// location will turn into the normal location if the backup is valid at
453 /// the time of the primary location clobbering.
454 static VarLoc CreateEntryBackupLoc(const MachineInstr &MI,
455 LexicalScopes &LS,
456 const DIExpression *EntryExpr) {
457 VarLoc VL(MI, LS);
458 assert(VL.Locs.size() == 1 &&(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 459
, __extension__ __PRETTY_FUNCTION__))
459 VL.Locs[0].Kind == MachineLocKind::RegisterKind)(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 459
, __extension__ __PRETTY_FUNCTION__))
;
460 VL.EVKind = EntryValueLocKind::EntryValueBackupKind;
461 VL.Expr = EntryExpr;
462 return VL;
463 }
464
465 /// Take the variable and machine-location from the DBG_VALUE (from the
466 /// function entry), and build a copy of an entry value backup location by
467 /// setting the register location to NewReg.
468 static VarLoc CreateEntryCopyBackupLoc(const MachineInstr &MI,
469 LexicalScopes &LS,
470 const DIExpression *EntryExpr,
471 Register NewReg) {
472 VarLoc VL(MI, LS);
473 assert(VL.Locs.size() == 1 &&(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 474
, __extension__ __PRETTY_FUNCTION__))
474 VL.Locs[0].Kind == MachineLocKind::RegisterKind)(static_cast <bool> (VL.Locs.size() == 1 && VL.
Locs[0].Kind == MachineLocKind::RegisterKind) ? void (0) : __assert_fail
("VL.Locs.size() == 1 && VL.Locs[0].Kind == MachineLocKind::RegisterKind"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 474
, __extension__ __PRETTY_FUNCTION__))
;
475 VL.EVKind = EntryValueLocKind::EntryValueCopyBackupKind;
476 VL.Expr = EntryExpr;
477 VL.Locs[0].Value.RegNo = NewReg;
478 return VL;
479 }
480
481 /// Copy the register location in DBG_VALUE MI, updating the register to
482 /// be NewReg.
483 static VarLoc CreateCopyLoc(const VarLoc &OldVL, const MachineLoc &OldML,
484 Register NewReg) {
485 VarLoc VL = OldVL;
486 for (MachineLoc &ML : VL.Locs)
487 if (ML == OldML) {
488 ML.Kind = MachineLocKind::RegisterKind;
489 ML.Value.RegNo = NewReg;
490 return VL;
491 }
492 llvm_unreachable("Should have found OldML in new VarLoc.")::llvm::llvm_unreachable_internal("Should have found OldML in new VarLoc."
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 492
)
;
493 }
494
495 /// Take the variable described by DBG_VALUE* MI, and create a VarLoc
496 /// locating it in the specified spill location.
497 static VarLoc CreateSpillLoc(const VarLoc &OldVL, const MachineLoc &OldML,
498 unsigned SpillBase, StackOffset SpillOffset) {
499 VarLoc VL = OldVL;
500 for (MachineLoc &ML : VL.Locs)
501 if (ML == OldML) {
502 ML.Kind = MachineLocKind::SpillLocKind;
503 ML.Value.SpillLocation = {SpillBase, SpillOffset};
504 return VL;
505 }
506 llvm_unreachable("Should have found OldML in new VarLoc.")::llvm::llvm_unreachable_internal("Should have found OldML in new VarLoc."
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 506
)
;
507 }
508
509 /// Create a DBG_VALUE representing this VarLoc in the given function.
510 /// Copies variable-specific information such as DILocalVariable and
511 /// inlining information from the original DBG_VALUE instruction, which may
512 /// have been several transfers ago.
513 MachineInstr *BuildDbgValue(MachineFunction &MF) const {
514 assert(!isEntryBackupLoc() &&(static_cast <bool> (!isEntryBackupLoc() && "Tried to produce DBG_VALUE for backup VarLoc"
) ? void (0) : __assert_fail ("!isEntryBackupLoc() && \"Tried to produce DBG_VALUE for backup VarLoc\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 515
, __extension__ __PRETTY_FUNCTION__))
515 "Tried to produce DBG_VALUE for backup VarLoc")(static_cast <bool> (!isEntryBackupLoc() && "Tried to produce DBG_VALUE for backup VarLoc"
) ? void (0) : __assert_fail ("!isEntryBackupLoc() && \"Tried to produce DBG_VALUE for backup VarLoc\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 515
, __extension__ __PRETTY_FUNCTION__))
;
516 const DebugLoc &DbgLoc = MI.getDebugLoc();
517 bool Indirect = MI.isIndirectDebugValue();
518 const auto &IID = MI.getDesc();
519 const DILocalVariable *Var = MI.getDebugVariable();
520 NumInserted++;
521
522 const DIExpression *DIExpr = Expr;
523 SmallVector<MachineOperand, 8> MOs;
524 for (unsigned I = 0, E = Locs.size(); I < E; ++I) {
525 MachineLocKind LocKind = Locs[I].Kind;
526 MachineLocValue Loc = Locs[I].Value;
527 const MachineOperand &Orig = MI.getDebugOperand(OrigLocMap[I]);
528 switch (LocKind) {
529 case MachineLocKind::RegisterKind:
530 // An entry value is a register location -- but with an updated
531 // expression. The register location of such DBG_VALUE is always the
532 // one from the entry DBG_VALUE, it does not matter if the entry value
533 // was copied in to another register due to some optimizations.
534 // Non-entry value register locations are like the source
535 // DBG_VALUE, but with the register number from this VarLoc.
536 MOs.push_back(MachineOperand::CreateReg(
537 EVKind == EntryValueLocKind::EntryValueKind ? Orig.getReg()
538 : Register(Loc.RegNo),
539 false));
540 break;
541 case MachineLocKind::SpillLocKind: {
542 // Spills are indirect DBG_VALUEs, with a base register and offset.
543 // Use the original DBG_VALUEs expression to build the spilt location
544 // on top of. FIXME: spill locations created before this pass runs
545 // are not recognized, and not handled here.
546 unsigned Base = Loc.SpillLocation.SpillBase;
547 auto *TRI = MF.getSubtarget().getRegisterInfo();
548 if (MI.isNonListDebugValue()) {
549 auto Deref = Indirect ? DIExpression::DerefAfter : 0;
550 DIExpr = TRI->prependOffsetExpression(
551 DIExpr, DIExpression::ApplyOffset | Deref,
552 Loc.SpillLocation.SpillOffset);
553 Indirect = true;
554 } else {
555 SmallVector<uint64_t, 4> Ops;
556 TRI->getOffsetOpcodes(Loc.SpillLocation.SpillOffset, Ops);
557 Ops.push_back(dwarf::DW_OP_deref);
558 DIExpr = DIExpression::appendOpsToArg(DIExpr, Ops, I);
559 }
560 MOs.push_back(MachineOperand::CreateReg(Base, false));
561 break;
562 }
563 case MachineLocKind::ImmediateKind: {
564 MOs.push_back(Orig);
565 break;
566 }
567 case MachineLocKind::InvalidKind:
568 llvm_unreachable("Tried to produce DBG_VALUE for invalid VarLoc")::llvm::llvm_unreachable_internal("Tried to produce DBG_VALUE for invalid VarLoc"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 568
)
;
569 }
570 }
571 return BuildMI(MF, DbgLoc, IID, Indirect, MOs, Var, DIExpr);
572 }
573
574 /// Is the Loc field a constant or constant object?
575 bool isConstant(MachineLocKind Kind) const {
576 return Kind == MachineLocKind::ImmediateKind;
577 }
578
579 /// Check if the Loc field is an entry backup location.
580 bool isEntryBackupLoc() const {
581 return EVKind == EntryValueLocKind::EntryValueBackupKind ||
582 EVKind == EntryValueLocKind::EntryValueCopyBackupKind;
583 }
584
585 /// If this variable is described by register \p Reg holding the entry
586 /// value, return true.
587 bool isEntryValueBackupReg(Register Reg) const {
588 return EVKind == EntryValueLocKind::EntryValueBackupKind && usesReg(Reg);
589 }
590
591 /// If this variable is described by register \p Reg holding a copy of the
592 /// entry value, return true.
593 bool isEntryValueCopyBackupReg(Register Reg) const {
594 return EVKind == EntryValueLocKind::EntryValueCopyBackupKind &&
595 usesReg(Reg);
596 }
597
598 /// If this variable is described in whole or part by \p Reg, return true.
599 bool usesReg(Register Reg) const {
600 MachineLoc RegML;
601 RegML.Kind = MachineLocKind::RegisterKind;
602 RegML.Value.RegNo = Reg;
603 return is_contained(Locs, RegML);
604 }
605
606 /// If this variable is described in whole or part by \p Reg, return true.
607 unsigned getRegIdx(Register Reg) const {
608 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
609 if (Locs[Idx].Kind == MachineLocKind::RegisterKind &&
610 Register{static_cast<unsigned>(Locs[Idx].Value.RegNo)} == Reg)
611 return Idx;
612 llvm_unreachable("Could not find given Reg in Locs")::llvm::llvm_unreachable_internal("Could not find given Reg in Locs"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 612
)
;
613 }
614
615 /// If this variable is described in whole or part by 1 or more registers,
616 /// add each of them to \p Regs and return true.
617 bool getDescribingRegs(SmallVectorImpl<uint32_t> &Regs) const {
618 bool AnyRegs = false;
619 for (const auto &Loc : Locs)
620 if (Loc.Kind == MachineLocKind::RegisterKind) {
621 Regs.push_back(Loc.Value.RegNo);
622 AnyRegs = true;
623 }
624 return AnyRegs;
625 }
626
627 bool containsSpillLocs() const {
628 return any_of(Locs, [](VarLoc::MachineLoc ML) {
629 return ML.Kind == VarLoc::MachineLocKind::SpillLocKind;
630 });
631 }
632
633 /// If this variable is described in whole or part by \p SpillLocation,
634 /// return true.
635 bool usesSpillLoc(SpillLoc SpillLocation) const {
636 MachineLoc SpillML;
637 SpillML.Kind = MachineLocKind::SpillLocKind;
638 SpillML.Value.SpillLocation = SpillLocation;
639 return is_contained(Locs, SpillML);
640 }
641
642 /// If this variable is described in whole or part by \p SpillLocation,
643 /// return the index .
644 unsigned getSpillLocIdx(SpillLoc SpillLocation) const {
645 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
646 if (Locs[Idx].Kind == MachineLocKind::SpillLocKind &&
647 Locs[Idx].Value.SpillLocation == SpillLocation)
648 return Idx;
649 llvm_unreachable("Could not find given SpillLoc in Locs")::llvm::llvm_unreachable_internal("Could not find given SpillLoc in Locs"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 649
)
;
650 }
651
652 /// Determine whether the lexical scope of this value's debug location
653 /// dominates MBB.
654 bool dominates(LexicalScopes &LS, MachineBasicBlock &MBB) const {
655 return LS.dominates(MI.getDebugLoc().get(), &MBB);
656 }
657
658#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
659 // TRI can be null.
660 void dump(const TargetRegisterInfo *TRI, raw_ostream &Out = dbgs()) const {
661 Out << "VarLoc(";
662 for (const MachineLoc &MLoc : Locs) {
663 if (Locs.begin() != &MLoc)
664 Out << ", ";
665 switch (MLoc.Kind) {
666 case MachineLocKind::RegisterKind:
667 Out << printReg(MLoc.Value.RegNo, TRI);
668 break;
669 case MachineLocKind::SpillLocKind:
670 Out << printReg(MLoc.Value.SpillLocation.SpillBase, TRI);
671 Out << "[" << MLoc.Value.SpillLocation.SpillOffset.getFixed() << " + "
672 << MLoc.Value.SpillLocation.SpillOffset.getScalable()
673 << "x vscale"
674 << "]";
675 break;
676 case MachineLocKind::ImmediateKind:
677 Out << MLoc.Value.Immediate;
678 break;
679 case MachineLocKind::InvalidKind:
680 llvm_unreachable("Invalid VarLoc in dump method")::llvm::llvm_unreachable_internal("Invalid VarLoc in dump method"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 680
)
;
681 }
682 }
683
684 Out << ", \"" << Var.getVariable()->getName() << "\", " << *Expr << ", ";
685 if (Var.getInlinedAt())
686 Out << "!" << Var.getInlinedAt()->getMetadataID() << ")\n";
687 else
688 Out << "(null))";
689
690 if (isEntryBackupLoc())
691 Out << " (backup loc)\n";
692 else
693 Out << "\n";
694 }
695#endif
696
697 bool operator==(const VarLoc &Other) const {
698 return std::tie(EVKind, Var, Expr, Locs) ==
699 std::tie(Other.EVKind, Other.Var, Other.Expr, Other.Locs);
700 }
701
702 /// This operator guarantees that VarLocs are sorted by Variable first.
703 bool operator<(const VarLoc &Other) const {
704 return std::tie(Var, EVKind, Locs, Expr) <
705 std::tie(Other.Var, Other.EVKind, Other.Locs, Other.Expr);
706 }
707 };
708
709#ifndef NDEBUG
710 using VarVec = SmallVector<VarLoc, 32>;
711#endif
712
713 /// VarLocMap is used for two things:
714 /// 1) Assigning LocIndices to a VarLoc. The LocIndices can be used to
715 /// virtually insert a VarLoc into a VarLocSet.
716 /// 2) Given a LocIndex, look up the unique associated VarLoc.
717 class VarLocMap {
718 /// Map a VarLoc to an index within the vector reserved for its location
719 /// within Loc2Vars.
720 std::map<VarLoc, LocIndices> Var2Indices;
721
722 /// Map a location to a vector which holds VarLocs which live in that
723 /// location.
724 SmallDenseMap<LocIndex::u32_location_t, std::vector<VarLoc>> Loc2Vars;
725
726 public:
727 /// Retrieve LocIndices for \p VL.
728 LocIndices insert(const VarLoc &VL) {
729 LocIndices &Indices = Var2Indices[VL];
730 // If Indices is not empty, VL is already in the map.
731 if (!Indices.empty())
732 return Indices;
733 SmallVector<LocIndex::u32_location_t, 4> Locations;
734 // LocIndices are determined by EVKind and MLs; each Register has a
735 // unique location, while all SpillLocs use a single bucket, and any EV
736 // VarLocs use only the Backup bucket or none at all (except the
737 // compulsory entry at the universal location index). LocIndices will
738 // always have an index at the universal location index as the last index.
739 if (VL.EVKind == VarLoc::EntryValueLocKind::NonEntryValueKind) {
740 VL.getDescribingRegs(Locations);
741 assert(all_of(Locations,(static_cast <bool> (all_of(Locations, [](auto RegNo) {
return RegNo < LocIndex::kFirstInvalidRegLocation; }) &&
"Physreg out of range?") ? void (0) : __assert_fail ("all_of(Locations, [](auto RegNo) { return RegNo < LocIndex::kFirstInvalidRegLocation; }) && \"Physreg out of range?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 745
, __extension__ __PRETTY_FUNCTION__))
742 [](auto RegNo) {(static_cast <bool> (all_of(Locations, [](auto RegNo) {
return RegNo < LocIndex::kFirstInvalidRegLocation; }) &&
"Physreg out of range?") ? void (0) : __assert_fail ("all_of(Locations, [](auto RegNo) { return RegNo < LocIndex::kFirstInvalidRegLocation; }) && \"Physreg out of range?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 745
, __extension__ __PRETTY_FUNCTION__))
743 return RegNo < LocIndex::kFirstInvalidRegLocation;(static_cast <bool> (all_of(Locations, [](auto RegNo) {
return RegNo < LocIndex::kFirstInvalidRegLocation; }) &&
"Physreg out of range?") ? void (0) : __assert_fail ("all_of(Locations, [](auto RegNo) { return RegNo < LocIndex::kFirstInvalidRegLocation; }) && \"Physreg out of range?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 745
, __extension__ __PRETTY_FUNCTION__))
744 }) &&(static_cast <bool> (all_of(Locations, [](auto RegNo) {
return RegNo < LocIndex::kFirstInvalidRegLocation; }) &&
"Physreg out of range?") ? void (0) : __assert_fail ("all_of(Locations, [](auto RegNo) { return RegNo < LocIndex::kFirstInvalidRegLocation; }) && \"Physreg out of range?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 745
, __extension__ __PRETTY_FUNCTION__))
745 "Physreg out of range?")(static_cast <bool> (all_of(Locations, [](auto RegNo) {
return RegNo < LocIndex::kFirstInvalidRegLocation; }) &&
"Physreg out of range?") ? void (0) : __assert_fail ("all_of(Locations, [](auto RegNo) { return RegNo < LocIndex::kFirstInvalidRegLocation; }) && \"Physreg out of range?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 745
, __extension__ __PRETTY_FUNCTION__))
;
746 if (VL.containsSpillLocs()) {
747 LocIndex::u32_location_t Loc = LocIndex::kSpillLocation;
748 Locations.push_back(Loc);
749 }
750 } else if (VL.EVKind != VarLoc::EntryValueLocKind::EntryValueKind) {
751 LocIndex::u32_location_t Loc = LocIndex::kEntryValueBackupLocation;
752 Locations.push_back(Loc);
753 }
754 Locations.push_back(LocIndex::kUniversalLocation);
755 for (LocIndex::u32_location_t Location : Locations) {
756 auto &Vars = Loc2Vars[Location];
757 Indices.push_back(
758 {Location, static_cast<LocIndex::u32_index_t>(Vars.size())});
759 Vars.push_back(VL);
760 }
761 return Indices;
762 }
763
764 LocIndices getAllIndices(const VarLoc &VL) const {
765 auto IndIt = Var2Indices.find(VL);
766 assert(IndIt != Var2Indices.end() && "VarLoc not tracked")(static_cast <bool> (IndIt != Var2Indices.end() &&
"VarLoc not tracked") ? void (0) : __assert_fail ("IndIt != Var2Indices.end() && \"VarLoc not tracked\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 766
, __extension__ __PRETTY_FUNCTION__))
;
767 return IndIt->second;
768 }
769
770 /// Retrieve the unique VarLoc associated with \p ID.
771 const VarLoc &operator[](LocIndex ID) const {
772 auto LocIt = Loc2Vars.find(ID.Location);
773 assert(LocIt != Loc2Vars.end() && "Location not tracked")(static_cast <bool> (LocIt != Loc2Vars.end() &&
"Location not tracked") ? void (0) : __assert_fail ("LocIt != Loc2Vars.end() && \"Location not tracked\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 773
, __extension__ __PRETTY_FUNCTION__))
;
774 return LocIt->second[ID.Index];
775 }
776 };
777
778 using VarLocInMBB =
779 SmallDenseMap<const MachineBasicBlock *, std::unique_ptr<VarLocSet>>;
780 struct TransferDebugPair {
781 MachineInstr *TransferInst; ///< Instruction where this transfer occurs.
782 LocIndex LocationID; ///< Location number for the transfer dest.
783 };
784 using TransferMap = SmallVector<TransferDebugPair, 4>;
785 // Types for recording Entry Var Locations emitted by a single MachineInstr,
786 // as well as recording MachineInstr which last defined a register.
787 using InstToEntryLocMap = std::multimap<const MachineInstr *, LocIndex>;
788 using RegDefToInstMap = DenseMap<Register, MachineInstr *>;
789
790 // Types for recording sets of variable fragments that overlap. For a given
791 // local variable, we record all other fragments of that variable that could
792 // overlap it, to reduce search time.
793 using FragmentOfVar =
794 std::pair<const DILocalVariable *, DIExpression::FragmentInfo>;
795 using OverlapMap =
796 DenseMap<FragmentOfVar, SmallVector<DIExpression::FragmentInfo, 1>>;
797
798 // Helper while building OverlapMap, a map of all fragments seen for a given
799 // DILocalVariable.
800 using VarToFragments =
801 DenseMap<const DILocalVariable *, SmallSet<FragmentInfo, 4>>;
802
803 /// Collects all VarLocs from \p CollectFrom. Each unique VarLoc is added
804 /// to \p Collected once, in order of insertion into \p VarLocIDs.
805 static void collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
806 const VarLocSet &CollectFrom,
807 const VarLocMap &VarLocIDs);
808
809 /// Get the registers which are used by VarLocs of kind RegisterKind tracked
810 /// by \p CollectFrom.
811 void getUsedRegs(const VarLocSet &CollectFrom,
812 SmallVectorImpl<Register> &UsedRegs) const;
813
814 /// This holds the working set of currently open ranges. For fast
815 /// access, this is done both as a set of VarLocIDs, and a map of
816 /// DebugVariable to recent VarLocID. Note that a DBG_VALUE ends all
817 /// previous open ranges for the same variable. In addition, we keep
818 /// two different maps (Vars/EntryValuesBackupVars), so erase/insert
819 /// methods act differently depending on whether a VarLoc is primary
820 /// location or backup one. In the case the VarLoc is backup location
821 /// we will erase/insert from the EntryValuesBackupVars map, otherwise
822 /// we perform the operation on the Vars.
823 class OpenRangesSet {
824 VarLocSet::Allocator &Alloc;
825 VarLocSet VarLocs;
826 // Map the DebugVariable to recent primary location ID.
827 SmallDenseMap<DebugVariable, LocIndices, 8> Vars;
828 // Map the DebugVariable to recent backup location ID.
829 SmallDenseMap<DebugVariable, LocIndices, 8> EntryValuesBackupVars;
830 OverlapMap &OverlappingFragments;
831
832 public:
833 OpenRangesSet(VarLocSet::Allocator &Alloc, OverlapMap &_OLapMap)
834 : Alloc(Alloc), VarLocs(Alloc), OverlappingFragments(_OLapMap) {}
835
836 const VarLocSet &getVarLocs() const { return VarLocs; }
837
838 // Fetches all VarLocs in \p VarLocIDs and inserts them into \p Collected.
839 // This method is needed to get every VarLoc once, as each VarLoc may have
840 // multiple indices in a VarLocMap (corresponding to each applicable
841 // location), but all VarLocs appear exactly once at the universal location
842 // index.
843 void getUniqueVarLocs(SmallVectorImpl<VarLoc> &Collected,
844 const VarLocMap &VarLocIDs) const {
845 collectAllVarLocs(Collected, VarLocs, VarLocIDs);
846 }
847
848 /// Terminate all open ranges for VL.Var by removing it from the set.
849 void erase(const VarLoc &VL);
850
851 /// Terminate all open ranges listed as indices in \c KillSet with
852 /// \c Location by removing them from the set.
853 void erase(const VarLocsInRange &KillSet, const VarLocMap &VarLocIDs,
854 LocIndex::u32_location_t Location);
855
856 /// Insert a new range into the set.
857 void insert(LocIndices VarLocIDs, const VarLoc &VL);
858
859 /// Insert a set of ranges.
860 void insertFromLocSet(const VarLocSet &ToLoad, const VarLocMap &Map);
861
862 llvm::Optional<LocIndices> getEntryValueBackup(DebugVariable Var);
863
864 /// Empty the set.
865 void clear() {
866 VarLocs.clear();
867 Vars.clear();
868 EntryValuesBackupVars.clear();
869 }
870
871 /// Return whether the set is empty or not.
872 bool empty() const {
873 assert(Vars.empty() == EntryValuesBackupVars.empty() &&(static_cast <bool> (Vars.empty() == EntryValuesBackupVars
.empty() && Vars.empty() == VarLocs.empty() &&
"open ranges are inconsistent") ? void (0) : __assert_fail (
"Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 875
, __extension__ __PRETTY_FUNCTION__))
874 Vars.empty() == VarLocs.empty() &&(static_cast <bool> (Vars.empty() == EntryValuesBackupVars
.empty() && Vars.empty() == VarLocs.empty() &&
"open ranges are inconsistent") ? void (0) : __assert_fail (
"Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 875
, __extension__ __PRETTY_FUNCTION__))
875 "open ranges are inconsistent")(static_cast <bool> (Vars.empty() == EntryValuesBackupVars
.empty() && Vars.empty() == VarLocs.empty() &&
"open ranges are inconsistent") ? void (0) : __assert_fail (
"Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 875
, __extension__ __PRETTY_FUNCTION__))
;
876 return VarLocs.empty();
877 }
878
879 /// Get an empty range of VarLoc IDs.
880 auto getEmptyVarLocRange() const {
881 return iterator_range<VarLocSet::const_iterator>(getVarLocs().end(),
882 getVarLocs().end());
883 }
884
885 /// Get all set IDs for VarLocs with MLs of kind RegisterKind in \p Reg.
886 auto getRegisterVarLocs(Register Reg) const {
887 return LocIndex::indexRangeForLocation(getVarLocs(), Reg);
888 }
889
890 /// Get all set IDs for VarLocs with MLs of kind SpillLocKind.
891 auto getSpillVarLocs() const {
892 return LocIndex::indexRangeForLocation(getVarLocs(),
893 LocIndex::kSpillLocation);
894 }
895
896 /// Get all set IDs for VarLocs of EVKind EntryValueBackupKind or
897 /// EntryValueCopyBackupKind.
898 auto getEntryValueBackupVarLocs() const {
899 return LocIndex::indexRangeForLocation(
900 getVarLocs(), LocIndex::kEntryValueBackupLocation);
901 }
902 };
903
904 /// Collect all VarLoc IDs from \p CollectFrom for VarLocs with MLs of kind
905 /// RegisterKind which are located in any reg in \p Regs. The IDs for each
906 /// VarLoc correspond to entries in the universal location bucket, which every
907 /// VarLoc has exactly 1 entry for. Insert collected IDs into \p Collected.
908 static void collectIDsForRegs(VarLocsInRange &Collected,
909 const DefinedRegsSet &Regs,
910 const VarLocSet &CollectFrom,
911 const VarLocMap &VarLocIDs);
912
913 VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB, VarLocInMBB &Locs) {
914 std::unique_ptr<VarLocSet> &VLS = Locs[MBB];
915 if (!VLS)
916 VLS = std::make_unique<VarLocSet>(Alloc);
917 return *VLS;
918 }
919
920 const VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB,
921 const VarLocInMBB &Locs) const {
922 auto It = Locs.find(MBB);
923 assert(It != Locs.end() && "MBB not in map")(static_cast <bool> (It != Locs.end() && "MBB not in map"
) ? void (0) : __assert_fail ("It != Locs.end() && \"MBB not in map\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 923
, __extension__ __PRETTY_FUNCTION__))
;
924 return *It->second;
925 }
926
927 /// Tests whether this instruction is a spill to a stack location.
928 bool isSpillInstruction(const MachineInstr &MI, MachineFunction *MF);
929
930 /// Decide if @MI is a spill instruction and return true if it is. We use 2
931 /// criteria to make this decision:
932 /// - Is this instruction a store to a spill slot?
933 /// - Is there a register operand that is both used and killed?
934 /// TODO: Store optimization can fold spills into other stores (including
935 /// other spills). We do not handle this yet (more than one memory operand).
936 bool isLocationSpill(const MachineInstr &MI, MachineFunction *MF,
937 Register &Reg);
938
939 /// Returns true if the given machine instruction is a debug value which we
940 /// can emit entry values for.
941 ///
942 /// Currently, we generate debug entry values only for parameters that are
943 /// unmodified throughout the function and located in a register.
944 bool isEntryValueCandidate(const MachineInstr &MI,
945 const DefinedRegsSet &Regs) const;
946
947 /// If a given instruction is identified as a spill, return the spill location
948 /// and set \p Reg to the spilled register.
949 Optional<VarLoc::SpillLoc> isRestoreInstruction(const MachineInstr &MI,
950 MachineFunction *MF,
951 Register &Reg);
952 /// Given a spill instruction, extract the register and offset used to
953 /// address the spill location in a target independent way.
954 VarLoc::SpillLoc extractSpillBaseRegAndOffset(const MachineInstr &MI);
955 void insertTransferDebugPair(MachineInstr &MI, OpenRangesSet &OpenRanges,
956 TransferMap &Transfers, VarLocMap &VarLocIDs,
957 LocIndex OldVarID, TransferKind Kind,
958 const VarLoc::MachineLoc &OldLoc,
959 Register NewReg = Register());
960
961 void transferDebugValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
962 VarLocMap &VarLocIDs,
963 InstToEntryLocMap &EntryValTransfers,
964 RegDefToInstMap &RegSetInstrs);
965 void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
966 VarLocMap &VarLocIDs, TransferMap &Transfers);
967 void cleanupEntryValueTransfers(const MachineInstr *MI,
968 OpenRangesSet &OpenRanges,
969 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
970 InstToEntryLocMap &EntryValTransfers);
971 void removeEntryValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
972 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
973 InstToEntryLocMap &EntryValTransfers,
974 RegDefToInstMap &RegSetInstrs);
975 void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
976 VarLocMap &VarLocIDs,
977 InstToEntryLocMap &EntryValTransfers,
978 VarLocsInRange &KillSet);
979 void recordEntryValue(const MachineInstr &MI,
980 const DefinedRegsSet &DefinedRegs,
981 OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs);
982 void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
983 VarLocMap &VarLocIDs, TransferMap &Transfers);
984 void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
985 VarLocMap &VarLocIDs,
986 InstToEntryLocMap &EntryValTransfers,
987 RegDefToInstMap &RegSetInstrs);
988 bool transferTerminator(MachineBasicBlock *MBB, OpenRangesSet &OpenRanges,
989 VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
990
991 void process(MachineInstr &MI, OpenRangesSet &OpenRanges,
992 VarLocMap &VarLocIDs, TransferMap &Transfers,
993 InstToEntryLocMap &EntryValTransfers,
994 RegDefToInstMap &RegSetInstrs);
995
996 void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
997 OverlapMap &OLapMap);
998
999 bool join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1000 const VarLocMap &VarLocIDs,
1001 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1002 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks);
1003
1004 /// Create DBG_VALUE insts for inlocs that have been propagated but
1005 /// had their instruction creation deferred.
1006 void flushPendingLocs(VarLocInMBB &PendingInLocs, VarLocMap &VarLocIDs);
1007
1008 bool ExtendRanges(MachineFunction &MF, MachineDominatorTree *DomTree,
1009 TargetPassConfig *TPC, unsigned InputBBLimit,
1010 unsigned InputDbgValLimit) override;
1011
1012public:
1013 /// Default construct and initialize the pass.
1014 VarLocBasedLDV();
1015
1016 ~VarLocBasedLDV();
1017
1018 /// Print to ostream with a message.
1019 void printVarLocInMBB(const MachineFunction &MF, const VarLocInMBB &V,
1020 const VarLocMap &VarLocIDs, const char *msg,
1021 raw_ostream &Out) const;
1022};
1023
1024} // end anonymous namespace
1025
1026//===----------------------------------------------------------------------===//
1027// Implementation
1028//===----------------------------------------------------------------------===//
1029
1030VarLocBasedLDV::VarLocBasedLDV() = default;
1031
1032VarLocBasedLDV::~VarLocBasedLDV() = default;
1033
1034/// Erase a variable from the set of open ranges, and additionally erase any
1035/// fragments that may overlap it. If the VarLoc is a backup location, erase
1036/// the variable from the EntryValuesBackupVars set, indicating we should stop
1037/// tracking its backup entry location. Otherwise, if the VarLoc is primary
1038/// location, erase the variable from the Vars set.
1039void VarLocBasedLDV::OpenRangesSet::erase(const VarLoc &VL) {
1040 // Erasure helper.
1041 auto DoErase = [VL, this](DebugVariable VarToErase) {
1042 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1043 auto It = EraseFrom->find(VarToErase);
1044 if (It != EraseFrom->end()) {
1045 LocIndices IDs = It->second;
1046 for (LocIndex ID : IDs)
1047 VarLocs.reset(ID.getAsRawInteger());
1048 EraseFrom->erase(It);
1049 }
1050 };
1051
1052 DebugVariable Var = VL.Var;
1053
1054 // Erase the variable/fragment that ends here.
1055 DoErase(Var);
1056
1057 // Extract the fragment. Interpret an empty fragment as one that covers all
1058 // possible bits.
1059 FragmentInfo ThisFragment = Var.getFragmentOrDefault();
1060
1061 // There may be fragments that overlap the designated fragment. Look them up
1062 // in the pre-computed overlap map, and erase them too.
1063 auto MapIt = OverlappingFragments.find({Var.getVariable(), ThisFragment});
1064 if (MapIt != OverlappingFragments.end()) {
1065 for (auto Fragment : MapIt->second) {
1066 VarLocBasedLDV::OptFragmentInfo FragmentHolder;
1067 if (!DebugVariable::isDefaultFragment(Fragment))
1068 FragmentHolder = VarLocBasedLDV::OptFragmentInfo(Fragment);
1069 DoErase({Var.getVariable(), FragmentHolder, Var.getInlinedAt()});
1070 }
1071 }
1072}
1073
1074void VarLocBasedLDV::OpenRangesSet::erase(const VarLocsInRange &KillSet,
1075 const VarLocMap &VarLocIDs,
1076 LocIndex::u32_location_t Location) {
1077 VarLocSet RemoveSet(Alloc);
1078 for (LocIndex::u32_index_t ID : KillSet) {
1079 const VarLoc &VL = VarLocIDs[LocIndex(Location, ID)];
1080 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1081 EraseFrom->erase(VL.Var);
1082 LocIndices VLI = VarLocIDs.getAllIndices(VL);
1083 for (LocIndex ID : VLI)
1084 RemoveSet.set(ID.getAsRawInteger());
1085 }
1086 VarLocs.intersectWithComplement(RemoveSet);
1087}
1088
1089void VarLocBasedLDV::OpenRangesSet::insertFromLocSet(const VarLocSet &ToLoad,
1090 const VarLocMap &Map) {
1091 VarLocsInRange UniqueVarLocIDs;
1092 DefinedRegsSet Regs;
1093 Regs.insert(LocIndex::kUniversalLocation);
1094 collectIDsForRegs(UniqueVarLocIDs, Regs, ToLoad, Map);
1095 for (uint64_t ID : UniqueVarLocIDs) {
1096 LocIndex Idx = LocIndex::fromRawInteger(ID);
1097 const VarLoc &VarL = Map[Idx];
1098 const LocIndices Indices = Map.getAllIndices(VarL);
1099 insert(Indices, VarL);
1100 }
1101}
1102
1103void VarLocBasedLDV::OpenRangesSet::insert(LocIndices VarLocIDs,
1104 const VarLoc &VL) {
1105 auto *InsertInto = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1106 for (LocIndex ID : VarLocIDs)
1107 VarLocs.set(ID.getAsRawInteger());
1108 InsertInto->insert({VL.Var, VarLocIDs});
1109}
1110
1111/// Return the Loc ID of an entry value backup location, if it exists for the
1112/// variable.
1113llvm::Optional<LocIndices>
1114VarLocBasedLDV::OpenRangesSet::getEntryValueBackup(DebugVariable Var) {
1115 auto It = EntryValuesBackupVars.find(Var);
1116 if (It != EntryValuesBackupVars.end())
1117 return It->second;
1118
1119 return llvm::None;
1120}
1121
1122void VarLocBasedLDV::collectIDsForRegs(VarLocsInRange &Collected,
1123 const DefinedRegsSet &Regs,
1124 const VarLocSet &CollectFrom,
1125 const VarLocMap &VarLocIDs) {
1126 assert(!Regs.empty() && "Nothing to collect")(static_cast <bool> (!Regs.empty() && "Nothing to collect"
) ? void (0) : __assert_fail ("!Regs.empty() && \"Nothing to collect\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1126
, __extension__ __PRETTY_FUNCTION__))
;
1127 SmallVector<Register, 32> SortedRegs;
1128 append_range(SortedRegs, Regs);
1129 array_pod_sort(SortedRegs.begin(), SortedRegs.end());
1130 auto It = CollectFrom.find(LocIndex::rawIndexForReg(SortedRegs.front()));
1131 auto End = CollectFrom.end();
1132 for (Register Reg : SortedRegs) {
1133 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains
1134 // all possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which
1135 // live in Reg.
1136 uint64_t FirstIndexForReg = LocIndex::rawIndexForReg(Reg);
1137 uint64_t FirstInvalidIndex = LocIndex::rawIndexForReg(Reg + 1);
1138 It.advanceToLowerBound(FirstIndexForReg);
1139
1140 // Iterate through that half-open interval and collect all the set IDs.
1141 for (; It != End && *It < FirstInvalidIndex; ++It) {
1142 LocIndex ItIdx = LocIndex::fromRawInteger(*It);
1143 const VarLoc &VL = VarLocIDs[ItIdx];
1144 LocIndices LI = VarLocIDs.getAllIndices(VL);
1145 // For now, the back index is always the universal location index.
1146 assert(LI.back().Location == LocIndex::kUniversalLocation &&(static_cast <bool> (LI.back().Location == LocIndex::kUniversalLocation
&& "Unexpected order of LocIndices for VarLoc; was it inserted into "
"the VarLocMap correctly?") ? void (0) : __assert_fail ("LI.back().Location == LocIndex::kUniversalLocation && \"Unexpected order of LocIndices for VarLoc; was it inserted into \" \"the VarLocMap correctly?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1148
, __extension__ __PRETTY_FUNCTION__))
1147 "Unexpected order of LocIndices for VarLoc; was it inserted into "(static_cast <bool> (LI.back().Location == LocIndex::kUniversalLocation
&& "Unexpected order of LocIndices for VarLoc; was it inserted into "
"the VarLocMap correctly?") ? void (0) : __assert_fail ("LI.back().Location == LocIndex::kUniversalLocation && \"Unexpected order of LocIndices for VarLoc; was it inserted into \" \"the VarLocMap correctly?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1148
, __extension__ __PRETTY_FUNCTION__))
1148 "the VarLocMap correctly?")(static_cast <bool> (LI.back().Location == LocIndex::kUniversalLocation
&& "Unexpected order of LocIndices for VarLoc; was it inserted into "
"the VarLocMap correctly?") ? void (0) : __assert_fail ("LI.back().Location == LocIndex::kUniversalLocation && \"Unexpected order of LocIndices for VarLoc; was it inserted into \" \"the VarLocMap correctly?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1148
, __extension__ __PRETTY_FUNCTION__))
;
1149 Collected.insert(LI.back().Index);
1150 }
1151
1152 if (It == End)
1153 return;
1154 }
1155}
1156
1157void VarLocBasedLDV::getUsedRegs(const VarLocSet &CollectFrom,
1158 SmallVectorImpl<Register> &UsedRegs) const {
1159 // All register-based VarLocs are assigned indices greater than or equal to
1160 // FirstRegIndex.
1161 uint64_t FirstRegIndex =
1162 LocIndex::rawIndexForReg(LocIndex::kFirstRegLocation);
1163 uint64_t FirstInvalidIndex =
1164 LocIndex::rawIndexForReg(LocIndex::kFirstInvalidRegLocation);
1165 for (auto It = CollectFrom.find(FirstRegIndex),
1166 End = CollectFrom.find(FirstInvalidIndex);
1167 It != End;) {
1168 // We found a VarLoc ID for a VarLoc that lives in a register. Figure out
1169 // which register and add it to UsedRegs.
1170 uint32_t FoundReg = LocIndex::fromRawInteger(*It).Location;
1171 assert((UsedRegs.empty() || FoundReg != UsedRegs.back()) &&(static_cast <bool> ((UsedRegs.empty() || FoundReg != UsedRegs
.back()) && "Duplicate used reg") ? void (0) : __assert_fail
("(UsedRegs.empty() || FoundReg != UsedRegs.back()) && \"Duplicate used reg\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1172
, __extension__ __PRETTY_FUNCTION__))
1172 "Duplicate used reg")(static_cast <bool> ((UsedRegs.empty() || FoundReg != UsedRegs
.back()) && "Duplicate used reg") ? void (0) : __assert_fail
("(UsedRegs.empty() || FoundReg != UsedRegs.back()) && \"Duplicate used reg\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1172
, __extension__ __PRETTY_FUNCTION__))
;
1173 UsedRegs.push_back(FoundReg);
1174
1175 // Skip to the next /set/ register. Note that this finds a lower bound, so
1176 // even if there aren't any VarLocs living in `FoundReg+1`, we're still
1177 // guaranteed to move on to the next register (or to end()).
1178 uint64_t NextRegIndex = LocIndex::rawIndexForReg(FoundReg + 1);
1179 It.advanceToLowerBound(NextRegIndex);
1180 }
1181}
1182
1183//===----------------------------------------------------------------------===//
1184// Debug Range Extension Implementation
1185//===----------------------------------------------------------------------===//
1186
1187#ifndef NDEBUG
1188void VarLocBasedLDV::printVarLocInMBB(const MachineFunction &MF,
1189 const VarLocInMBB &V,
1190 const VarLocMap &VarLocIDs,
1191 const char *msg,
1192 raw_ostream &Out) const {
1193 Out << '\n' << msg << '\n';
1194 for (const MachineBasicBlock &BB : MF) {
1195 if (!V.count(&BB))
1196 continue;
1197 const VarLocSet &L = getVarLocsInMBB(&BB, V);
1198 if (L.empty())
1199 continue;
1200 SmallVector<VarLoc, 32> VarLocs;
1201 collectAllVarLocs(VarLocs, L, VarLocIDs);
1202 Out << "MBB: " << BB.getNumber() << ":\n";
1203 for (const VarLoc &VL : VarLocs) {
1204 Out << " Var: " << VL.Var.getVariable()->getName();
1205 Out << " MI: ";
1206 VL.dump(TRI, Out);
1207 }
1208 }
1209 Out << "\n";
1210}
1211#endif
1212
1213VarLocBasedLDV::VarLoc::SpillLoc
1214VarLocBasedLDV::extractSpillBaseRegAndOffset(const MachineInstr &MI) {
1215 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?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1216
, __extension__ __PRETTY_FUNCTION__))
1216 "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?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1216
, __extension__ __PRETTY_FUNCTION__))
;
1217 auto MMOI = MI.memoperands_begin();
1218 const PseudoSourceValue *PVal = (*MMOI)->getPseudoValue();
1219 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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1220
, __extension__ __PRETTY_FUNCTION__))
1220 "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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1220
, __extension__ __PRETTY_FUNCTION__))
;
1221 int FI = cast<FixedStackPseudoSourceValue>(PVal)->getFrameIndex();
1222 const MachineBasicBlock *MBB = MI.getParent();
1223 Register Reg;
1224 StackOffset Offset = TFI->getFrameIndexReference(*MBB->getParent(), FI, Reg);
1225 return {Reg, Offset};
1226}
1227
1228/// Do cleanup of \p EntryValTransfers created by \p TRInst, by removing the
1229/// Transfer, which uses the to-be-deleted \p EntryVL.
1230void VarLocBasedLDV::cleanupEntryValueTransfers(
1231 const MachineInstr *TRInst, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
1232 const VarLoc &EntryVL, InstToEntryLocMap &EntryValTransfers) {
1233 if (EntryValTransfers.empty() || TRInst == nullptr)
1234 return;
1235
1236 auto TransRange = EntryValTransfers.equal_range(TRInst);
1237 for (auto TDPair : llvm::make_range(TransRange.first, TransRange.second)) {
1238 const VarLoc &EmittedEV = VarLocIDs[TDPair.second];
1239 if (std::tie(EntryVL.Var, EntryVL.Locs[0].Value.RegNo, EntryVL.Expr) ==
1240 std::tie(EmittedEV.Var, EmittedEV.Locs[0].Value.RegNo,
1241 EmittedEV.Expr)) {
1242 OpenRanges.erase(EmittedEV);
1243 EntryValTransfers.erase(TRInst);
1244 break;
1245 }
1246 }
1247}
1248
1249/// Try to salvage the debug entry value if we encounter a new debug value
1250/// describing the same parameter, otherwise stop tracking the value. Return
1251/// true if we should stop tracking the entry value and do the cleanup of
1252/// emitted Entry Value Transfers, otherwise return false.
1253void VarLocBasedLDV::removeEntryValue(const MachineInstr &MI,
1254 OpenRangesSet &OpenRanges,
1255 VarLocMap &VarLocIDs,
1256 const VarLoc &EntryVL,
1257 InstToEntryLocMap &EntryValTransfers,
1258 RegDefToInstMap &RegSetInstrs) {
1259 // Skip the DBG_VALUE which is the debug entry value itself.
1260 if (&MI == &EntryVL.MI)
1261 return;
1262
1263 // If the parameter's location is not register location, we can not track
1264 // the entry value any more. It doesn't have the TransferInst which defines
1265 // register, so no Entry Value Transfers have been emitted already.
1266 if (!MI.getDebugOperand(0).isReg())
1267 return;
1268
1269 // Try to get non-debug instruction responsible for the DBG_VALUE.
1270 const MachineInstr *TransferInst = nullptr;
1271 Register Reg = MI.getDebugOperand(0).getReg();
1272 if (Reg.isValid() && RegSetInstrs.find(Reg) != RegSetInstrs.end())
1273 TransferInst = RegSetInstrs.find(Reg)->second;
1274
1275 // Case of the parameter's DBG_VALUE at the start of entry MBB.
1276 if (!TransferInst && !LastNonDbgMI && MI.getParent()->isEntryBlock())
1277 return;
1278
1279 // If the debug expression from the DBG_VALUE is not empty, we can assume the
1280 // parameter's value has changed indicating that we should stop tracking its
1281 // entry value as well.
1282 if (MI.getDebugExpression()->getNumElements() == 0 && TransferInst) {
1283 // If the DBG_VALUE comes from a copy instruction that copies the entry
1284 // value, it means the parameter's value has not changed and we should be
1285 // able to use its entry value.
1286 // TODO: Try to keep tracking of an entry value if we encounter a propagated
1287 // DBG_VALUE describing the copy of the entry value. (Propagated entry value
1288 // does not indicate the parameter modification.)
1289 auto DestSrc = TII->isCopyInstr(*TransferInst);
1290 if (DestSrc) {
1291 const MachineOperand *SrcRegOp, *DestRegOp;
1292 SrcRegOp = DestSrc->Source;
1293 DestRegOp = DestSrc->Destination;
1294 if (Reg == DestRegOp->getReg()) {
1295 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1296 const VarLoc &VL = VarLocIDs[LocIndex::fromRawInteger(ID)];
1297 if (VL.isEntryValueCopyBackupReg(Reg) &&
1298 // Entry Values should not be variadic.
1299 VL.MI.getDebugOperand(0).getReg() == SrcRegOp->getReg())
1300 return;
1301 }
1302 }
1303 }
1304 }
1305
1306 LLVM_DEBUG(dbgs() << "Deleting a DBG entry value because of: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Deleting a DBG entry value because of: "
; MI.print(dbgs(), false, false, false, true, TII); } } while
(false)
1307 MI.print(dbgs(), /*IsStandalone*/ false,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Deleting a DBG entry value because of: "
; MI.print(dbgs(), false, false, false, true, TII); } } while
(false)
1308 /*SkipOpers*/ false, /*SkipDebugLoc*/ false,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Deleting a DBG entry value because of: "
; MI.print(dbgs(), false, false, false, true, TII); } } while
(false)
1309 /*AddNewLine*/ true, TII))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Deleting a DBG entry value because of: "
; MI.print(dbgs(), false, false, false, true, TII); } } while
(false)
;
1310 cleanupEntryValueTransfers(TransferInst, OpenRanges, VarLocIDs, EntryVL,
1311 EntryValTransfers);
1312 OpenRanges.erase(EntryVL);
1313}
1314
1315/// End all previous ranges related to @MI and start a new range from @MI
1316/// if it is a DBG_VALUE instr.
1317void VarLocBasedLDV::transferDebugValue(const MachineInstr &MI,
1318 OpenRangesSet &OpenRanges,
1319 VarLocMap &VarLocIDs,
1320 InstToEntryLocMap &EntryValTransfers,
1321 RegDefToInstMap &RegSetInstrs) {
1322 if (!MI.isDebugValue())
1323 return;
1324 const DILocalVariable *Var = MI.getDebugVariable();
1325 const DIExpression *Expr = MI.getDebugExpression();
1326 const DILocation *DebugLoc = MI.getDebugLoc();
1327 const DILocation *InlinedAt = DebugLoc->getInlinedAt();
1328 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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1329
, __extension__ __PRETTY_FUNCTION__))
1329 "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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1329
, __extension__ __PRETTY_FUNCTION__))
;
1330
1331 DebugVariable V(Var, Expr, InlinedAt);
1332
1333 // Check if this DBG_VALUE indicates a parameter's value changing.
1334 // If that is the case, we should stop tracking its entry value.
1335 auto EntryValBackupID = OpenRanges.getEntryValueBackup(V);
1336 if (Var->isParameter() && EntryValBackupID) {
1337 const VarLoc &EntryVL = VarLocIDs[EntryValBackupID->back()];
1338 removeEntryValue(MI, OpenRanges, VarLocIDs, EntryVL, EntryValTransfers,
1339 RegSetInstrs);
1340 }
1341
1342 if (all_of(MI.debug_operands(), [](const MachineOperand &MO) {
1343 return (MO.isReg() && MO.getReg()) || MO.isImm() || MO.isFPImm() ||
1344 MO.isCImm();
1345 })) {
1346 // Use normal VarLoc constructor for registers and immediates.
1347 VarLoc VL(MI, LS);
1348 // End all previous ranges of VL.Var.
1349 OpenRanges.erase(VL);
1350
1351 LocIndices IDs = VarLocIDs.insert(VL);
1352 // Add the VarLoc to OpenRanges from this DBG_VALUE.
1353 OpenRanges.insert(IDs, VL);
1354 } else if (MI.memoperands().size() > 0) {
1355 llvm_unreachable("DBG_VALUE with mem operand encountered after regalloc?")::llvm::llvm_unreachable_internal("DBG_VALUE with mem operand encountered after regalloc?"
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1355
)
;
1356 } else {
1357 // This must be an undefined location. If it has an open range, erase it.
1358 assert(MI.isUndefDebugValue() &&(static_cast <bool> (MI.isUndefDebugValue() && "Unexpected non-undef DBG_VALUE encountered"
) ? void (0) : __assert_fail ("MI.isUndefDebugValue() && \"Unexpected non-undef DBG_VALUE encountered\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1359
, __extension__ __PRETTY_FUNCTION__))
1359 "Unexpected non-undef DBG_VALUE encountered")(static_cast <bool> (MI.isUndefDebugValue() && "Unexpected non-undef DBG_VALUE encountered"
) ? void (0) : __assert_fail ("MI.isUndefDebugValue() && \"Unexpected non-undef DBG_VALUE encountered\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1359
, __extension__ __PRETTY_FUNCTION__))
;
1360 VarLoc VL(MI, LS);
1361 OpenRanges.erase(VL);
1362 }
1363}
1364
1365// This should be removed later, doesn't fit the new design.
1366void VarLocBasedLDV::collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
1367 const VarLocSet &CollectFrom,
1368 const VarLocMap &VarLocIDs) {
1369 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains all
1370 // possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which live
1371 // in Reg.
1372 uint64_t FirstIndex = LocIndex::rawIndexForReg(LocIndex::kUniversalLocation);
1373 uint64_t FirstInvalidIndex =
1374 LocIndex::rawIndexForReg(LocIndex::kUniversalLocation + 1);
1375 // Iterate through that half-open interval and collect all the set IDs.
1376 for (auto It = CollectFrom.find(FirstIndex), End = CollectFrom.end();
1377 It != End && *It < FirstInvalidIndex; ++It) {
1378 LocIndex RegIdx = LocIndex::fromRawInteger(*It);
1379 Collected.push_back(VarLocIDs[RegIdx]);
1380 }
1381}
1382
1383/// Turn the entry value backup locations into primary locations.
1384void VarLocBasedLDV::emitEntryValues(MachineInstr &MI,
1385 OpenRangesSet &OpenRanges,
1386 VarLocMap &VarLocIDs,
1387 InstToEntryLocMap &EntryValTransfers,
1388 VarLocsInRange &KillSet) {
1389 // Do not insert entry value locations after a terminator.
1390 if (MI.isTerminator())
1391 return;
1392
1393 for (uint32_t ID : KillSet) {
1394 // The KillSet IDs are indices for the universal location bucket.
1395 LocIndex Idx = LocIndex(LocIndex::kUniversalLocation, ID);
1396 const VarLoc &VL = VarLocIDs[Idx];
1397 if (!VL.Var.getVariable()->isParameter())
1398 continue;
1399
1400 auto DebugVar = VL.Var;
1401 Optional<LocIndices> EntryValBackupIDs =
1402 OpenRanges.getEntryValueBackup(DebugVar);
1403
1404 // If the parameter has the entry value backup, it means we should
1405 // be able to use its entry value.
1406 if (!EntryValBackupIDs)
1407 continue;
1408
1409 const VarLoc &EntryVL = VarLocIDs[EntryValBackupIDs->back()];
1410 VarLoc EntryLoc = VarLoc::CreateEntryLoc(EntryVL.MI, LS, EntryVL.Expr,
1411 EntryVL.Locs[0].Value.RegNo);
1412 LocIndices EntryValueIDs = VarLocIDs.insert(EntryLoc);
1413 assert(EntryValueIDs.size() == 1 &&(static_cast <bool> (EntryValueIDs.size() == 1 &&
"EntryValue loc should not be variadic") ? void (0) : __assert_fail
("EntryValueIDs.size() == 1 && \"EntryValue loc should not be variadic\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1414
, __extension__ __PRETTY_FUNCTION__))
1414 "EntryValue loc should not be variadic")(static_cast <bool> (EntryValueIDs.size() == 1 &&
"EntryValue loc should not be variadic") ? void (0) : __assert_fail
("EntryValueIDs.size() == 1 && \"EntryValue loc should not be variadic\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1414
, __extension__ __PRETTY_FUNCTION__))
;
1415 EntryValTransfers.insert({&MI, EntryValueIDs.back()});
1416 OpenRanges.insert(EntryValueIDs, EntryLoc);
1417 }
1418}
1419
1420/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
1421/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
1422/// new VarLoc. If \p NewReg is different than default zero value then the
1423/// new location will be register location created by the copy like instruction,
1424/// otherwise it is variable's location on the stack.
1425void VarLocBasedLDV::insertTransferDebugPair(
1426 MachineInstr &MI, OpenRangesSet &OpenRanges, TransferMap &Transfers,
1427 VarLocMap &VarLocIDs, LocIndex OldVarID, TransferKind Kind,
1428 const VarLoc::MachineLoc &OldLoc, Register NewReg) {
1429 const VarLoc &OldVarLoc = VarLocIDs[OldVarID];
1430
1431 auto ProcessVarLoc = [&MI, &OpenRanges, &Transfers, &VarLocIDs](VarLoc &VL) {
1432 LocIndices LocIds = VarLocIDs.insert(VL);
1433
1434 // Close this variable's previous location range.
1435 OpenRanges.erase(VL);
1436
1437 // Record the new location as an open range, and a postponed transfer
1438 // inserting a DBG_VALUE for this location.
1439 OpenRanges.insert(LocIds, VL);
1440 assert(!MI.isTerminator() && "Cannot insert DBG_VALUE after terminator")(static_cast <bool> (!MI.isTerminator() && "Cannot insert DBG_VALUE after terminator"
) ? void (0) : __assert_fail ("!MI.isTerminator() && \"Cannot insert DBG_VALUE after terminator\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1440
, __extension__ __PRETTY_FUNCTION__))
;
1441 TransferDebugPair MIP = {&MI, LocIds.back()};
1442 Transfers.push_back(MIP);
1443 };
1444
1445 // End all previous ranges of VL.Var.
1446 OpenRanges.erase(VarLocIDs[OldVarID]);
1447 switch (Kind) {
1448 case TransferKind::TransferCopy: {
1449 assert(NewReg &&(static_cast <bool> (NewReg && "No register supplied when handling a copy of a debug value"
) ? void (0) : __assert_fail ("NewReg && \"No register supplied when handling a copy of a debug value\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1450
, __extension__ __PRETTY_FUNCTION__))
1450 "No register supplied when handling a copy of a debug value")(static_cast <bool> (NewReg && "No register supplied when handling a copy of a debug value"
) ? void (0) : __assert_fail ("NewReg && \"No register supplied when handling a copy of a debug value\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1450
, __extension__ __PRETTY_FUNCTION__))
;
1451 // Create a DBG_VALUE instruction to describe the Var in its new
1452 // register location.
1453 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1454 ProcessVarLoc(VL);
1455 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1456 dbgs() << "Creating VarLoc for register copy:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1457 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1458 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
;
1459 return;
1460 }
1461 case TransferKind::TransferSpill: {
1462 // Create a DBG_VALUE instruction to describe the Var in its spilled
1463 // location.
1464 VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI);
1465 VarLoc VL = VarLoc::CreateSpillLoc(
1466 OldVarLoc, OldLoc, SpillLocation.SpillBase, SpillLocation.SpillOffset);
1467 ProcessVarLoc(VL);
1468 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1469 dbgs() << "Creating VarLoc for spill:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1470 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1471 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
;
1472 return;
1473 }
1474 case TransferKind::TransferRestore: {
1475 assert(NewReg &&(static_cast <bool> (NewReg && "No register supplied when handling a restore of a debug value"
) ? void (0) : __assert_fail ("NewReg && \"No register supplied when handling a restore of a debug value\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1476
, __extension__ __PRETTY_FUNCTION__))
1476 "No register supplied when handling a restore of a debug value")(static_cast <bool> (NewReg && "No register supplied when handling a restore of a debug value"
) ? void (0) : __assert_fail ("NewReg && \"No register supplied when handling a restore of a debug value\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1476
, __extension__ __PRETTY_FUNCTION__))
;
1477 // DebugInstr refers to the pre-spill location, therefore we can reuse
1478 // its expression.
1479 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1480 ProcessVarLoc(VL);
1481 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1482 dbgs() << "Creating VarLoc for restore:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1483 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1484 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
;
1485 return;
1486 }
1487 }
1488 llvm_unreachable("Invalid transfer kind")::llvm::llvm_unreachable_internal("Invalid transfer kind", "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1488)
;
1489}
1490
1491/// A definition of a register may mark the end of a range.
1492void VarLocBasedLDV::transferRegisterDef(MachineInstr &MI,
1493 OpenRangesSet &OpenRanges,
1494 VarLocMap &VarLocIDs,
1495 InstToEntryLocMap &EntryValTransfers,
1496 RegDefToInstMap &RegSetInstrs) {
1497
1498 // Meta Instructions do not affect the debug liveness of any register they
1499 // define.
1500 if (MI.isMetaInstruction())
1501 return;
1502
1503 MachineFunction *MF = MI.getMF();
1504 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1505 Register SP = TLI->getStackPointerRegisterToSaveRestore();
1506
1507 // Find the regs killed by MI, and find regmasks of preserved regs.
1508 DefinedRegsSet DeadRegs;
1509 SmallVector<const uint32_t *, 4> RegMasks;
1510 for (const MachineOperand &MO : MI.operands()) {
1511 // Determine whether the operand is a register def.
1512 if (MO.isReg() && MO.isDef() && MO.getReg() &&
1513 Register::isPhysicalRegister(MO.getReg()) &&
1514 !(MI.isCall() && MO.getReg() == SP)) {
1515 // Remove ranges of all aliased registers.
1516 for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
1517 // FIXME: Can we break out of this loop early if no insertion occurs?
1518 DeadRegs.insert(*RAI);
1519 RegSetInstrs.erase(MO.getReg());
1520 RegSetInstrs.insert({MO.getReg(), &MI});
1521 } else if (MO.isRegMask()) {
1522 RegMasks.push_back(MO.getRegMask());
1523 }
1524 }
1525
1526 // Erase VarLocs which reside in one of the dead registers. For performance
1527 // reasons, it's critical to not iterate over the full set of open VarLocs.
1528 // Iterate over the set of dying/used regs instead.
1529 if (!RegMasks.empty()) {
1530 SmallVector<Register, 32> UsedRegs;
1531 getUsedRegs(OpenRanges.getVarLocs(), UsedRegs);
1532 for (Register Reg : UsedRegs) {
1533 // Remove ranges of all clobbered registers. Register masks don't usually
1534 // list SP as preserved. Assume that call instructions never clobber SP,
1535 // because some backends (e.g., AArch64) never list SP in the regmask.
1536 // While the debug info may be off for an instruction or two around
1537 // callee-cleanup calls, transferring the DEBUG_VALUE across the call is
1538 // still a better user experience.
1539 if (Reg == SP)
1540 continue;
1541 bool AnyRegMaskKillsReg =
1542 any_of(RegMasks, [Reg](const uint32_t *RegMask) {
1543 return MachineOperand::clobbersPhysReg(RegMask, Reg);
1544 });
1545 if (AnyRegMaskKillsReg)
1546 DeadRegs.insert(Reg);
1547 if (AnyRegMaskKillsReg) {
1548 RegSetInstrs.erase(Reg);
1549 RegSetInstrs.insert({Reg, &MI});
1550 }
1551 }
1552 }
1553
1554 if (DeadRegs.empty())
1555 return;
1556
1557 VarLocsInRange KillSet;
1558 collectIDsForRegs(KillSet, DeadRegs, OpenRanges.getVarLocs(), VarLocIDs);
1559 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kUniversalLocation);
1560
1561 if (TPC) {
1562 auto &TM = TPC->getTM<TargetMachine>();
1563 if (TM.Options.ShouldEmitDebugEntryValues())
1564 emitEntryValues(MI, OpenRanges, VarLocIDs, EntryValTransfers, KillSet);
1565 }
1566}
1567
1568bool VarLocBasedLDV::isSpillInstruction(const MachineInstr &MI,
1569 MachineFunction *MF) {
1570 // TODO: Handle multiple stores folded into one.
1571 if (!MI.hasOneMemOperand())
1572 return false;
1573
1574 if (!MI.getSpillSize(TII) && !MI.getFoldedSpillSize(TII))
1575 return false; // This is not a spill instruction, since no valid size was
1576 // returned from either function.
1577
1578 return true;
1579}
1580
1581bool VarLocBasedLDV::isLocationSpill(const MachineInstr &MI,
1582 MachineFunction *MF, Register &Reg) {
1583 if (!isSpillInstruction(MI, MF))
1584 return false;
1585
1586 auto isKilledReg = [&](const MachineOperand MO, Register &Reg) {
1587 if (!MO.isReg() || !MO.isUse()) {
1588 Reg = 0;
1589 return false;
1590 }
1591 Reg = MO.getReg();
1592 return MO.isKill();
1593 };
1594
1595 for (const MachineOperand &MO : MI.operands()) {
1596 // In a spill instruction generated by the InlineSpiller the spilled
1597 // register has its kill flag set.
1598 if (isKilledReg(MO, Reg))
1599 return true;
1600 if (Reg != 0) {
1601 // Check whether next instruction kills the spilled register.
1602 // FIXME: Current solution does not cover search for killed register in
1603 // bundles and instructions further down the chain.
1604 auto NextI = std::next(MI.getIterator());
1605 // Skip next instruction that points to basic block end iterator.
1606 if (MI.getParent()->end() == NextI)
1607 continue;
1608 Register RegNext;
1609 for (const MachineOperand &MONext : NextI->operands()) {
1610 // Return true if we came across the register from the
1611 // previous spill instruction that is killed in NextI.
1612 if (isKilledReg(MONext, RegNext) && RegNext == Reg)
1613 return true;
1614 }
1615 }
1616 }
1617 // Return false if we didn't find spilled register.
1618 return false;
1619}
1620
1621Optional<VarLocBasedLDV::VarLoc::SpillLoc>
1622VarLocBasedLDV::isRestoreInstruction(const MachineInstr &MI,
1623 MachineFunction *MF, Register &Reg) {
1624 if (!MI.hasOneMemOperand())
1625 return None;
1626
1627 // FIXME: Handle folded restore instructions with more than one memory
1628 // operand.
1629 if (MI.getRestoreSize(TII)) {
1630 Reg = MI.getOperand(0).getReg();
1631 return extractSpillBaseRegAndOffset(MI);
1632 }
1633 return None;
1634}
1635
1636/// A spilled register may indicate that we have to end the current range of
1637/// a variable and create a new one for the spill location.
1638/// A restored register may indicate the reverse situation.
1639/// We don't want to insert any instructions in process(), so we just create
1640/// the DBG_VALUE without inserting it and keep track of it in \p Transfers.
1641/// It will be inserted into the BB when we're done iterating over the
1642/// instructions.
1643void VarLocBasedLDV::transferSpillOrRestoreInst(MachineInstr &MI,
1644 OpenRangesSet &OpenRanges,
1645 VarLocMap &VarLocIDs,
1646 TransferMap &Transfers) {
1647 MachineFunction *MF = MI.getMF();
1648 TransferKind TKind;
1649 Register Reg;
1650 Optional<VarLoc::SpillLoc> Loc;
1651
1652 LLVM_DEBUG(dbgs() << "Examining instruction: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Examining instruction: "
; MI.dump();; } } while (false)
;
1653
1654 // First, if there are any DBG_VALUEs pointing at a spill slot that is
1655 // written to, then close the variable location. The value in memory
1656 // will have changed.
1657 VarLocsInRange KillSet;
1658 if (isSpillInstruction(MI, MF)) {
1659 Loc = extractSpillBaseRegAndOffset(MI);
1660 for (uint64_t ID : OpenRanges.getSpillVarLocs()) {
1661 LocIndex Idx = LocIndex::fromRawInteger(ID);
1662 const VarLoc &VL = VarLocIDs[Idx];
1663 assert(VL.containsSpillLocs() && "Broken VarLocSet?")(static_cast <bool> (VL.containsSpillLocs() && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("VL.containsSpillLocs() && \"Broken VarLocSet?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1663
, __extension__ __PRETTY_FUNCTION__))
;
1664 if (VL.usesSpillLoc(*Loc)) {
1665 // This location is overwritten by the current instruction -- terminate
1666 // the open range, and insert an explicit DBG_VALUE $noreg.
1667 //
1668 // Doing this at a later stage would require re-interpreting all
1669 // DBG_VALUes and DIExpressions to identify whether they point at
1670 // memory, and then analysing all memory writes to see if they
1671 // overwrite that memory, which is expensive.
1672 //
1673 // At this stage, we already know which DBG_VALUEs are for spills and
1674 // where they are located; it's best to fix handle overwrites now.
1675 KillSet.insert(ID);
1676 unsigned SpillLocIdx = VL.getSpillLocIdx(*Loc);
1677 VarLoc::MachineLoc OldLoc = VL.Locs[SpillLocIdx];
1678 VarLoc UndefVL = VarLoc::CreateCopyLoc(VL, OldLoc, 0);
1679 LocIndices UndefLocIDs = VarLocIDs.insert(UndefVL);
1680 Transfers.push_back({&MI, UndefLocIDs.back()});
1681 }
1682 }
1683 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kSpillLocation);
1684 }
1685
1686 // Try to recognise spill and restore instructions that may create a new
1687 // variable location.
1688 if (isLocationSpill(MI, MF, Reg)) {
1689 TKind = TransferKind::TransferSpill;
1690 LLVM_DEBUG(dbgs() << "Recognized as spill: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as spill: "
; MI.dump();; } } while (false)
;
1691 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1692 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1693 } else {
1694 if (!(Loc = isRestoreInstruction(MI, MF, Reg)))
1695 return;
1696 TKind = TransferKind::TransferRestore;
1697 LLVM_DEBUG(dbgs() << "Recognized as restore: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as restore: "
; MI.dump();; } } while (false)
;
1698 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1699 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1700 }
1701 // Check if the register or spill location is the location of a debug value.
1702 auto TransferCandidates = OpenRanges.getEmptyVarLocRange();
1703 if (TKind == TransferKind::TransferSpill)
1704 TransferCandidates = OpenRanges.getRegisterVarLocs(Reg);
1705 else if (TKind == TransferKind::TransferRestore)
1706 TransferCandidates = OpenRanges.getSpillVarLocs();
1707 for (uint64_t ID : TransferCandidates) {
1708 LocIndex Idx = LocIndex::fromRawInteger(ID);
1709 const VarLoc &VL = VarLocIDs[Idx];
1710 unsigned LocIdx;
1711 if (TKind == TransferKind::TransferSpill) {
1712 assert(VL.usesReg(Reg) && "Broken VarLocSet?")(static_cast <bool> (VL.usesReg(Reg) && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("VL.usesReg(Reg) && \"Broken VarLocSet?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1712
, __extension__ __PRETTY_FUNCTION__))
;
1713 LLVM_DEBUG(dbgs() << "Spilling Register " << printReg(Reg, TRI) << '('do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Spilling Register " <<
printReg(Reg, TRI) << '(' << VL.Var.getVariable(
)->getName() << ")\n"; } } while (false)
1714 << VL.Var.getVariable()->getName() << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Spilling Register " <<
printReg(Reg, TRI) << '(' << VL.Var.getVariable(
)->getName() << ")\n"; } } while (false)
;
1715 LocIdx = VL.getRegIdx(Reg);
1716 } else {
1717 assert(TKind == TransferKind::TransferRestore && VL.containsSpillLocs() &&(static_cast <bool> (TKind == TransferKind::TransferRestore
&& VL.containsSpillLocs() && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("TKind == TransferKind::TransferRestore && VL.containsSpillLocs() && \"Broken VarLocSet?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1718
, __extension__ __PRETTY_FUNCTION__))
1718 "Broken VarLocSet?")(static_cast <bool> (TKind == TransferKind::TransferRestore
&& VL.containsSpillLocs() && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("TKind == TransferKind::TransferRestore && VL.containsSpillLocs() && \"Broken VarLocSet?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1718
, __extension__ __PRETTY_FUNCTION__))
;
1719 if (!VL.usesSpillLoc(*Loc))
1720 // The spill location is not the location of a debug value.
1721 continue;
1722 LLVM_DEBUG(dbgs() << "Restoring Register " << printReg(Reg, TRI) << '('do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Restoring Register " <<
printReg(Reg, TRI) << '(' << VL.Var.getVariable(
)->getName() << ")\n"; } } while (false)
1723 << VL.Var.getVariable()->getName() << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Restoring Register " <<
printReg(Reg, TRI) << '(' << VL.Var.getVariable(
)->getName() << ")\n"; } } while (false)
;
1724 LocIdx = VL.getSpillLocIdx(*Loc);
1725 }
1726 VarLoc::MachineLoc MLoc = VL.Locs[LocIdx];
1727 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx, TKind,
1728 MLoc, Reg);
1729 // FIXME: A comment should explain why it's correct to return early here,
1730 // if that is in fact correct.
1731 return;
1732 }
1733}
1734
1735/// If \p MI is a register copy instruction, that copies a previously tracked
1736/// value from one register to another register that is callee saved, we
1737/// create new DBG_VALUE instruction described with copy destination register.
1738void VarLocBasedLDV::transferRegisterCopy(MachineInstr &MI,
1739 OpenRangesSet &OpenRanges,
1740 VarLocMap &VarLocIDs,
1741 TransferMap &Transfers) {
1742 auto DestSrc = TII->isCopyInstr(MI);
1743 if (!DestSrc)
1744 return;
1745
1746 const MachineOperand *DestRegOp = DestSrc->Destination;
1747 const MachineOperand *SrcRegOp = DestSrc->Source;
1748
1749 if (!DestRegOp->isDef())
1750 return;
1751
1752 auto isCalleeSavedReg = [&](Register Reg) {
1753 for (MCRegAliasIterator RAI(Reg, TRI, true); RAI.isValid(); ++RAI)
1754 if (CalleeSavedRegs.test(*RAI))
1755 return true;
1756 return false;
1757 };
1758
1759 Register SrcReg = SrcRegOp->getReg();
1760 Register DestReg = DestRegOp->getReg();
1761
1762 // We want to recognize instructions where destination register is callee
1763 // saved register. If register that could be clobbered by the call is
1764 // included, there would be a great chance that it is going to be clobbered
1765 // soon. It is more likely that previous register location, which is callee
1766 // saved, is going to stay unclobbered longer, even if it is killed.
1767 if (!isCalleeSavedReg(DestReg))
1768 return;
1769
1770 // Remember an entry value movement. If we encounter a new debug value of
1771 // a parameter describing only a moving of the value around, rather then
1772 // modifying it, we are still able to use the entry value if needed.
1773 if (isRegOtherThanSPAndFP(*DestRegOp, MI, TRI)) {
1774 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1775 LocIndex Idx = LocIndex::fromRawInteger(ID);
1776 const VarLoc &VL = VarLocIDs[Idx];
1777 if (VL.isEntryValueBackupReg(SrcReg)) {
1778 LLVM_DEBUG(dbgs() << "Copy of the entry value: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Copy of the entry value: "
; MI.dump();; } } while (false)
;
1779 VarLoc EntryValLocCopyBackup =
1780 VarLoc::CreateEntryCopyBackupLoc(VL.MI, LS, VL.Expr, DestReg);
1781 // Stop tracking the original entry value.
1782 OpenRanges.erase(VL);
1783
1784 // Start tracking the entry value copy.
1785 LocIndices EntryValCopyLocIDs = VarLocIDs.insert(EntryValLocCopyBackup);
1786 OpenRanges.insert(EntryValCopyLocIDs, EntryValLocCopyBackup);
1787 break;
1788 }
1789 }
1790 }
1791
1792 if (!SrcRegOp->isKill())
1793 return;
1794
1795 for (uint64_t ID : OpenRanges.getRegisterVarLocs(SrcReg)) {
1796 LocIndex Idx = LocIndex::fromRawInteger(ID);
1797 assert(VarLocIDs[Idx].usesReg(SrcReg) && "Broken VarLocSet?")(static_cast <bool> (VarLocIDs[Idx].usesReg(SrcReg) &&
"Broken VarLocSet?") ? void (0) : __assert_fail ("VarLocIDs[Idx].usesReg(SrcReg) && \"Broken VarLocSet?\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1797
, __extension__ __PRETTY_FUNCTION__))
;
1798 VarLoc::MachineLocValue Loc;
1799 Loc.RegNo = SrcReg;
1800 VarLoc::MachineLoc MLoc{VarLoc::MachineLocKind::RegisterKind, Loc};
1801 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx,
1802 TransferKind::TransferCopy, MLoc, DestReg);
1803 // FIXME: A comment should explain why it's correct to return early here,
1804 // if that is in fact correct.
1805 return;
1806 }
1807}
1808
1809/// Terminate all open ranges at the end of the current basic block.
1810bool VarLocBasedLDV::transferTerminator(MachineBasicBlock *CurMBB,
1811 OpenRangesSet &OpenRanges,
1812 VarLocInMBB &OutLocs,
1813 const VarLocMap &VarLocIDs) {
1814 bool Changed = false;
1815 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1816 VarVec VarLocs;do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1817 OpenRanges.getUniqueVarLocs(VarLocs, VarLocIDs);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1818 for (VarLoc &VL : VarLocs) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1819 // Copy OpenRanges to OutLocs, if not already present.do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1820 dbgs() << "Add to OutLocs in MBB #" << CurMBB->getNumber() << ": ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1821 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1822 }do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
1823 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { VarVec VarLocs; OpenRanges.getUniqueVarLocs
(VarLocs, VarLocIDs); for (VarLoc &VL : VarLocs) { dbgs()
<< "Add to OutLocs in MBB #" << CurMBB->getNumber
() << ": "; VL.dump(TRI); } }; } } while (false)
;
1824 VarLocSet &VLS = getVarLocsInMBB(CurMBB, OutLocs);
1825 Changed = VLS != OpenRanges.getVarLocs();
1826 // New OutLocs set may be different due to spill, restore or register
1827 // copy instruction processing.
1828 if (Changed)
1829 VLS = OpenRanges.getVarLocs();
1830 OpenRanges.clear();
1831 return Changed;
1832}
1833
1834/// Accumulate a mapping between each DILocalVariable fragment and other
1835/// fragments of that DILocalVariable which overlap. This reduces work during
1836/// the data-flow stage from "Find any overlapping fragments" to "Check if the
1837/// known-to-overlap fragments are present".
1838/// \param MI A previously unprocessed DEBUG_VALUE instruction to analyze for
1839/// fragment usage.
1840/// \param SeenFragments Map from DILocalVariable to all fragments of that
1841/// Variable which are known to exist.
1842/// \param OverlappingFragments The overlap map being constructed, from one
1843/// Var/Fragment pair to a vector of fragments known to overlap.
1844void VarLocBasedLDV::accumulateFragmentMap(MachineInstr &MI,
1845 VarToFragments &SeenFragments,
1846 OverlapMap &OverlappingFragments) {
1847 DebugVariable MIVar(MI.getDebugVariable(), MI.getDebugExpression(),
1848 MI.getDebugLoc()->getInlinedAt());
1849 FragmentInfo ThisFragment = MIVar.getFragmentOrDefault();
1850
1851 // If this is the first sighting of this variable, then we are guaranteed
1852 // there are currently no overlapping fragments either. Initialize the set
1853 // of seen fragments, record no overlaps for the current one, and return.
1854 auto SeenIt = SeenFragments.find(MIVar.getVariable());
1855 if (SeenIt == SeenFragments.end()) {
1856 SmallSet<FragmentInfo, 4> OneFragment;
1857 OneFragment.insert(ThisFragment);
1858 SeenFragments.insert({MIVar.getVariable(), OneFragment});
1859
1860 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1861 return;
1862 }
1863
1864 // If this particular Variable/Fragment pair already exists in the overlap
1865 // map, it has already been accounted for.
1866 auto IsInOLapMap =
1867 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1868 if (!IsInOLapMap.second)
1869 return;
1870
1871 auto &ThisFragmentsOverlaps = IsInOLapMap.first->second;
1872 auto &AllSeenFragments = SeenIt->second;
1873
1874 // Otherwise, examine all other seen fragments for this variable, with "this"
1875 // fragment being a previously unseen fragment. Record any pair of
1876 // overlapping fragments.
1877 for (const auto &ASeenFragment : AllSeenFragments) {
1878 // Does this previously seen fragment overlap?
1879 if (DIExpression::fragmentsOverlap(ThisFragment, ASeenFragment)) {
1880 // Yes: Mark the current fragment as being overlapped.
1881 ThisFragmentsOverlaps.push_back(ASeenFragment);
1882 // Mark the previously seen fragment as being overlapped by the current
1883 // one.
1884 auto ASeenFragmentsOverlaps =
1885 OverlappingFragments.find({MIVar.getVariable(), ASeenFragment});
1886 assert(ASeenFragmentsOverlaps != OverlappingFragments.end() &&(static_cast <bool> (ASeenFragmentsOverlaps != OverlappingFragments
.end() && "Previously seen var fragment has no vector of overlaps"
) ? void (0) : __assert_fail ("ASeenFragmentsOverlaps != OverlappingFragments.end() && \"Previously seen var fragment has no vector of overlaps\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1887
, __extension__ __PRETTY_FUNCTION__))
1887 "Previously seen var fragment has no vector of overlaps")(static_cast <bool> (ASeenFragmentsOverlaps != OverlappingFragments
.end() && "Previously seen var fragment has no vector of overlaps"
) ? void (0) : __assert_fail ("ASeenFragmentsOverlaps != OverlappingFragments.end() && \"Previously seen var fragment has no vector of overlaps\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1887
, __extension__ __PRETTY_FUNCTION__))
;
1888 ASeenFragmentsOverlaps->second.push_back(ThisFragment);
1889 }
1890 }
1891
1892 AllSeenFragments.insert(ThisFragment);
1893}
1894
1895/// This routine creates OpenRanges.
1896void VarLocBasedLDV::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
1897 VarLocMap &VarLocIDs, TransferMap &Transfers,
1898 InstToEntryLocMap &EntryValTransfers,
1899 RegDefToInstMap &RegSetInstrs) {
1900 if (!MI.isDebugInstr())
1901 LastNonDbgMI = &MI;
1902 transferDebugValue(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1903 RegSetInstrs);
1904 transferRegisterDef(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1905 RegSetInstrs);
1906 transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
1907 transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
1908}
1909
1910/// This routine joins the analysis results of all incoming edges in @MBB by
1911/// inserting a new DBG_VALUE instruction at the start of the @MBB - if the same
1912/// source variable in all the predecessors of @MBB reside in the same location.
1913bool VarLocBasedLDV::join(
1914 MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1915 const VarLocMap &VarLocIDs,
1916 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1917 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks) {
1918 LLVM_DEBUG(dbgs() << "join MBB: " << MBB.getNumber() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "join MBB: " << MBB
.getNumber() << "\n"; } } while (false)
;
1919
1920 VarLocSet InLocsT(Alloc); // Temporary incoming locations.
1921
1922 // For all predecessors of this MBB, find the set of VarLocs that
1923 // can be joined.
1924 int NumVisited = 0;
1925 for (auto *p : MBB.predecessors()) {
1926 // Ignore backedges if we have not visited the predecessor yet. As the
1927 // predecessor hasn't yet had locations propagated into it, most locations
1928 // will not yet be valid, so treat them as all being uninitialized and
1929 // potentially valid. If a location guessed to be correct here is
1930 // invalidated later, we will remove it when we revisit this block.
1931 if (!Visited.count(p)) {
1932 LLVM_DEBUG(dbgs() << " ignoring unvisited pred MBB: " << p->getNumber()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << " ignoring unvisited pred MBB: "
<< p->getNumber() << "\n"; } } while (false)
1933 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << " ignoring unvisited pred MBB: "
<< p->getNumber() << "\n"; } } while (false)
;
1934 continue;
1935 }
1936 auto OL = OutLocs.find(p);
1937 // Join is null in case of empty OutLocs from any of the pred.
1938 if (OL == OutLocs.end())
1939 return false;
1940
1941 // Just copy over the Out locs to incoming locs for the first visited
1942 // predecessor, and for all other predecessors join the Out locs.
1943 VarLocSet &OutLocVLS = *OL->second;
1944 if (!NumVisited)
1945 InLocsT = OutLocVLS;
1946 else
1947 InLocsT &= OutLocVLS;
1948
1949 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1950 if (!InLocsT.empty()) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1951 VarVec VarLocs;do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1952 collectAllVarLocs(VarLocs, InLocsT, VarLocIDs);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1953 for (const VarLoc &VL : VarLocs)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1954 dbgs() << " gathered candidate incoming var: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1955 << VL.Var.getVariable()->getName() << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1956 }do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
1957 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { if (!InLocsT.empty()) { VarVec VarLocs
; collectAllVarLocs(VarLocs, InLocsT, VarLocIDs); for (const VarLoc
&VL : VarLocs) dbgs() << " gathered candidate incoming var: "
<< VL.Var.getVariable()->getName() << "\n"; }
}; } } while (false)
;
1958
1959 NumVisited++;
1960 }
1961
1962 // Filter out DBG_VALUES that are out of scope.
1963 VarLocSet KillSet(Alloc);
1964 bool IsArtificial = ArtificialBlocks.count(&MBB);
1965 if (!IsArtificial) {
1966 for (uint64_t ID : InLocsT) {
1967 LocIndex Idx = LocIndex::fromRawInteger(ID);
1968 if (!VarLocIDs[Idx].dominates(LS, MBB)) {
1969 KillSet.set(ID);
1970 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { auto Name = VarLocIDs[Idx].Var.getVariable
()->getName(); dbgs() << " killing " << Name <<
", it doesn't dominate MBB\n"; }; } } while (false)
1971 auto Name = VarLocIDs[Idx].Var.getVariable()->getName();do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { auto Name = VarLocIDs[Idx].Var.getVariable
()->getName(); dbgs() << " killing " << Name <<
", it doesn't dominate MBB\n"; }; } } while (false)
1972 dbgs() << " killing " << Name << ", it doesn't dominate MBB\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { auto Name = VarLocIDs[Idx].Var.getVariable
()->getName(); dbgs() << " killing " << Name <<
", it doesn't dominate MBB\n"; }; } } while (false)
1973 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { auto Name = VarLocIDs[Idx].Var.getVariable
()->getName(); dbgs() << " killing " << Name <<
", it doesn't dominate MBB\n"; }; } } while (false)
;
1974 }
1975 }
1976 }
1977 InLocsT.intersectWithComplement(KillSet);
1978
1979 // As we are processing blocks in reverse post-order we
1980 // should have processed at least one predecessor, unless it
1981 // is the entry block which has no predecessor.
1982 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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1983
, __extension__ __PRETTY_FUNCTION__))
1983 "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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 1983
, __extension__ __PRETTY_FUNCTION__))
;
1984
1985 VarLocSet &ILS = getVarLocsInMBB(&MBB, InLocs);
1986 bool Changed = false;
1987 if (ILS != InLocsT) {
1988 ILS = InLocsT;
1989 Changed = true;
1990 }
1991
1992 return Changed;
1993}
1994
1995void VarLocBasedLDV::flushPendingLocs(VarLocInMBB &PendingInLocs,
1996 VarLocMap &VarLocIDs) {
1997 // PendingInLocs records all locations propagated into blocks, which have
1998 // not had DBG_VALUE insts created. Go through and create those insts now.
1999 for (auto &Iter : PendingInLocs) {
2000 // Map is keyed on a constant pointer, unwrap it so we can insert insts.
2001 auto &MBB = const_cast<MachineBasicBlock &>(*Iter.first);
2002 VarLocSet &Pending = *Iter.second;
2003
2004 SmallVector<VarLoc, 32> VarLocs;
2005 collectAllVarLocs(VarLocs, Pending, VarLocIDs);
2006
2007 for (VarLoc DiffIt : VarLocs) {
2008 // The ID location is live-in to MBB -- work out what kind of machine
2009 // location it is and create a DBG_VALUE.
2010 if (DiffIt.isEntryBackupLoc())
2011 continue;
2012 MachineInstr *MI = DiffIt.BuildDbgValue(*MBB.getParent());
2013 MBB.insert(MBB.instr_begin(), MI);
2014
2015 (void)MI;
2016 LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Inserted: "; MI->dump
();; } } while (false)
;
2017 }
2018 }
2019}
2020
2021bool VarLocBasedLDV::isEntryValueCandidate(
2022 const MachineInstr &MI, const DefinedRegsSet &DefinedRegs) const {
2023 assert(MI.isDebugValue() && "This must be DBG_VALUE.")(static_cast <bool> (MI.isDebugValue() && "This must be DBG_VALUE."
) ? void (0) : __assert_fail ("MI.isDebugValue() && \"This must be DBG_VALUE.\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2023
, __extension__ __PRETTY_FUNCTION__))
;
2024
2025 // TODO: Add support for local variables that are expressed in terms of
2026 // parameters entry values.
2027 // TODO: Add support for modified arguments that can be expressed
2028 // by using its entry value.
2029 auto *DIVar = MI.getDebugVariable();
2030 if (!DIVar->isParameter())
2031 return false;
2032
2033 // Do not consider parameters that belong to an inlined function.
2034 if (MI.getDebugLoc()->getInlinedAt())
2035 return false;
2036
2037 // Only consider parameters that are described using registers. Parameters
2038 // that are passed on the stack are not yet supported, so ignore debug
2039 // values that are described by the frame or stack pointer.
2040 if (!isRegOtherThanSPAndFP(MI.getDebugOperand(0), MI, TRI))
2041 return false;
2042
2043 // If a parameter's value has been propagated from the caller, then the
2044 // parameter's DBG_VALUE may be described using a register defined by some
2045 // instruction in the entry block, in which case we shouldn't create an
2046 // entry value.
2047 if (DefinedRegs.count(MI.getDebugOperand(0).getReg()))
2048 return false;
2049
2050 // TODO: Add support for parameters that have a pre-existing debug expressions
2051 // (e.g. fragments).
2052 if (MI.getDebugExpression()->getNumElements() > 0)
2053 return false;
2054
2055 return true;
2056}
2057
2058/// Collect all register defines (including aliases) for the given instruction.
2059static void collectRegDefs(const MachineInstr &MI, DefinedRegsSet &Regs,
2060 const TargetRegisterInfo *TRI) {
2061 for (const MachineOperand &MO : MI.operands())
2062 if (MO.isReg() && MO.isDef() && MO.getReg())
2063 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI)
2064 Regs.insert(*AI);
2065}
2066
2067/// This routine records the entry values of function parameters. The values
2068/// could be used as backup values. If we loose the track of some unmodified
2069/// parameters, the backup values will be used as a primary locations.
2070void VarLocBasedLDV::recordEntryValue(const MachineInstr &MI,
2071 const DefinedRegsSet &DefinedRegs,
2072 OpenRangesSet &OpenRanges,
2073 VarLocMap &VarLocIDs) {
2074 if (TPC) {
2075 auto &TM = TPC->getTM<TargetMachine>();
2076 if (!TM.Options.ShouldEmitDebugEntryValues())
2077 return;
2078 }
2079
2080 DebugVariable V(MI.getDebugVariable(), MI.getDebugExpression(),
2081 MI.getDebugLoc()->getInlinedAt());
2082
2083 if (!isEntryValueCandidate(MI, DefinedRegs) ||
2084 OpenRanges.getEntryValueBackup(V))
2085 return;
2086
2087 LLVM_DEBUG(dbgs() << "Creating the backup entry location: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Creating the backup entry location: "
; MI.dump();; } } while (false)
;
2088
2089 // Create the entry value and use it as a backup location until it is
2090 // valid. It is valid until a parameter is not changed.
2091 DIExpression *NewExpr =
2092 DIExpression::prepend(MI.getDebugExpression(), DIExpression::EntryValue);
2093 VarLoc EntryValLocAsBackup = VarLoc::CreateEntryBackupLoc(MI, LS, NewExpr);
2094 LocIndices EntryValLocIDs = VarLocIDs.insert(EntryValLocAsBackup);
2095 OpenRanges.insert(EntryValLocIDs, EntryValLocAsBackup);
2096}
2097
2098/// Calculate the liveness information for the given machine function and
2099/// extend ranges across basic blocks.
2100bool VarLocBasedLDV::ExtendRanges(MachineFunction &MF,
2101 MachineDominatorTree *DomTree,
2102 TargetPassConfig *TPC, unsigned InputBBLimit,
2103 unsigned InputDbgValLimit) {
2104 (void)DomTree;
2105 LLVM_DEBUG(dbgs() << "\nDebug Range Extension\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "\nDebug Range Extension\n"
; } } while (false)
;
2106
2107 if (!MF.getFunction().getSubprogram())
2108 // VarLocBaseLDV will already have removed all DBG_VALUEs.
2109 return false;
2110
2111 // Skip functions from NoDebug compilation units.
2112 if (MF.getFunction().getSubprogram()->getUnit()->getEmissionKind() ==
2113 DICompileUnit::NoDebug)
2114 return false;
2115
2116 TRI = MF.getSubtarget().getRegisterInfo();
2117 TII = MF.getSubtarget().getInstrInfo();
2118 TFI = MF.getSubtarget().getFrameLowering();
2119 TFI->getCalleeSaves(MF, CalleeSavedRegs);
2120 this->TPC = TPC;
2121 LS.initialize(MF);
2122
2123 bool Changed = false;
2124 bool OLChanged = false;
2125 bool MBBJoined = false;
2126
2127 VarLocMap VarLocIDs; // Map VarLoc<>unique ID for use in bitvectors.
2128 OverlapMap OverlapFragments; // Map of overlapping variable fragments.
2129 OpenRangesSet OpenRanges(Alloc, OverlapFragments);
2130 // Ranges that are open until end of bb.
2131 VarLocInMBB OutLocs; // Ranges that exist beyond bb.
2132 VarLocInMBB InLocs; // Ranges that are incoming after joining.
2133 TransferMap Transfers; // DBG_VALUEs associated with transfers (such as
2134 // spills, copies and restores).
2135 // Map responsible MI to attached Transfer emitted from Backup Entry Value.
2136 InstToEntryLocMap EntryValTransfers;
2137 // Map a Register to the last MI which clobbered it.
2138 RegDefToInstMap RegSetInstrs;
2139
2140 VarToFragments SeenFragments;
2141
2142 // Blocks which are artificial, i.e. blocks which exclusively contain
2143 // instructions without locations, or with line 0 locations.
2144 SmallPtrSet<const MachineBasicBlock *, 16> ArtificialBlocks;
2145
2146 DenseMap<unsigned int, MachineBasicBlock *> OrderToBB;
2147 DenseMap<MachineBasicBlock *, unsigned int> BBToOrder;
2148 std::priority_queue<unsigned int, std::vector<unsigned int>,
2149 std::greater<unsigned int>>
2150 Worklist;
2151 std::priority_queue<unsigned int, std::vector<unsigned int>,
2152 std::greater<unsigned int>>
2153 Pending;
2154
2155 // Set of register defines that are seen when traversing the entry block
2156 // looking for debug entry value candidates.
2157 DefinedRegsSet DefinedRegs;
2158
2159 // Only in the case of entry MBB collect DBG_VALUEs representing
2160 // function parameters in order to generate debug entry values for them.
2161 MachineBasicBlock &First_MBB = *(MF.begin());
2162 for (auto &MI : First_MBB) {
2163 collectRegDefs(MI, DefinedRegs, TRI);
2164 if (MI.isDebugValue())
2165 recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs);
2166 }
2167
2168 // Initialize per-block structures and scan for fragment overlaps.
2169 for (auto &MBB : MF)
2170 for (auto &MI : MBB)
2171 if (MI.isDebugValue())
2172 accumulateFragmentMap(MI, SeenFragments, OverlapFragments);
2173
2174 auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
2175 if (const DebugLoc &DL = MI.getDebugLoc())
2176 return DL.getLine() != 0;
2177 return false;
2178 };
2179 for (auto &MBB : MF)
2180 if (none_of(MBB.instrs(), hasNonArtificialLocation))
2181 ArtificialBlocks.insert(&MBB);
2182
2183 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
2184 "OutLocs after initialization", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
;
2185
2186 ReversePostOrderTraversal<MachineFunction *> RPOT(&MF);
2187 unsigned int RPONumber = 0;
2188 for (MachineBasicBlock *MBB : RPOT) {
2189 OrderToBB[RPONumber] = MBB;
2190 BBToOrder[MBB] = RPONumber;
2191 Worklist.push(RPONumber);
2192 ++RPONumber;
2193 }
2194
2195 if (RPONumber > InputBBLimit) {
2196 unsigned NumInputDbgValues = 0;
2197 for (auto &MBB : MF)
2198 for (auto &MI : MBB)
2199 if (MI.isDebugValue())
2200 ++NumInputDbgValues;
2201 if (NumInputDbgValues > InputDbgValLimit) {
2202 LLVM_DEBUG(dbgs() << "Disabling VarLocBasedLDV: " << MF.getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Disabling VarLocBasedLDV: "
<< MF.getName() << " has " << RPONumber <<
" basic blocks and " << NumInputDbgValues << " input DBG_VALUEs, exceeding limits.\n"
; } } while (false)
2203 << " has " << RPONumber << " basic blocks and "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Disabling VarLocBasedLDV: "
<< MF.getName() << " has " << RPONumber <<
" basic blocks and " << NumInputDbgValues << " input DBG_VALUEs, exceeding limits.\n"
; } } while (false)
2204 << NumInputDbgValuesdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Disabling VarLocBasedLDV: "
<< MF.getName() << " has " << RPONumber <<
" basic blocks and " << NumInputDbgValues << " input DBG_VALUEs, exceeding limits.\n"
; } } while (false)
2205 << " input DBG_VALUEs, exceeding limits.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Disabling VarLocBasedLDV: "
<< MF.getName() << " has " << RPONumber <<
" basic blocks and " << NumInputDbgValues << " input DBG_VALUEs, exceeding limits.\n"
; } } while (false)
;
2206 return false;
2207 }
2208 }
2209
2210 // This is a standard "union of predecessor outs" dataflow problem.
2211 // To solve it, we perform join() and process() using the two worklist method
2212 // until the ranges converge.
2213 // Ranges have converged when both worklists are empty.
2214 SmallPtrSet<const MachineBasicBlock *, 16> Visited;
2215 while (!Worklist.empty() || !Pending.empty()) {
2216 // We track what is on the pending worklist to avoid inserting the same
2217 // thing twice. We could avoid this with a custom priority queue, but this
2218 // is probably not worth it.
2219 SmallPtrSet<MachineBasicBlock *, 16> OnPending;
2220 LLVM_DEBUG(dbgs() << "Processing Worklist\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Processing Worklist\n"
; } } while (false)
;
2221 while (!Worklist.empty()) {
2222 MachineBasicBlock *MBB = OrderToBB[Worklist.top()];
2223 Worklist.pop();
2224 MBBJoined = join(*MBB, OutLocs, InLocs, VarLocIDs, Visited,
2225 ArtificialBlocks);
2226 MBBJoined |= Visited.insert(MBB).second;
2227 if (MBBJoined) {
2228 MBBJoined = false;
Value stored to 'MBBJoined' is never read
2229 Changed = true;
2230 // Now that we have started to extend ranges across BBs we need to
2231 // examine spill, copy and restore instructions to see whether they
2232 // operate with registers that correspond to user variables.
2233 // First load any pending inlocs.
2234 OpenRanges.insertFromLocSet(getVarLocsInMBB(MBB, InLocs), VarLocIDs);
2235 LastNonDbgMI = nullptr;
2236 RegSetInstrs.clear();
2237 for (auto &MI : *MBB)
2238 process(MI, OpenRanges, VarLocIDs, Transfers, EntryValTransfers,
2239 RegSetInstrs);
2240 OLChanged |= transferTerminator(MBB, OpenRanges, OutLocs, VarLocIDs);
2241
2242 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
2243 "OutLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
;
2244 LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
2245 "InLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
;
2246
2247 if (OLChanged) {
2248 OLChanged = false;
2249 for (auto *s : MBB->successors())
2250 if (OnPending.insert(s).second) {
2251 Pending.push(BBToOrder[s]);
2252 }
2253 }
2254 }
2255 }
2256 Worklist.swap(Pending);
2257 // At this point, pending must be empty, since it was just the empty
2258 // worklist
2259 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\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2259
, __extension__ __PRETTY_FUNCTION__))
;
2260 }
2261
2262 // Add any DBG_VALUE instructions created by location transfers.
2263 for (auto &TR : Transfers) {
2264 assert(!TR.TransferInst->isTerminator() &&(static_cast <bool> (!TR.TransferInst->isTerminator(
) && "Cannot insert DBG_VALUE after terminator") ? void
(0) : __assert_fail ("!TR.TransferInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2265
, __extension__ __PRETTY_FUNCTION__))
2265 "Cannot insert DBG_VALUE after terminator")(static_cast <bool> (!TR.TransferInst->isTerminator(
) && "Cannot insert DBG_VALUE after terminator") ? void
(0) : __assert_fail ("!TR.TransferInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2265
, __extension__ __PRETTY_FUNCTION__))
;
2266 MachineBasicBlock *MBB = TR.TransferInst->getParent();
2267 const VarLoc &VL = VarLocIDs[TR.LocationID];
2268 MachineInstr *MI = VL.BuildDbgValue(MF);
2269 MBB->insertAfterBundle(TR.TransferInst->getIterator(), MI);
2270 }
2271 Transfers.clear();
2272
2273 // Add DBG_VALUEs created using Backup Entry Value location.
2274 for (auto &TR : EntryValTransfers) {
2275 MachineInstr *TRInst = const_cast<MachineInstr *>(TR.first);
2276 assert(!TRInst->isTerminator() &&(static_cast <bool> (!TRInst->isTerminator() &&
"Cannot insert DBG_VALUE after terminator") ? void (0) : __assert_fail
("!TRInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2277
, __extension__ __PRETTY_FUNCTION__))
2277 "Cannot insert DBG_VALUE after terminator")(static_cast <bool> (!TRInst->isTerminator() &&
"Cannot insert DBG_VALUE after terminator") ? void (0) : __assert_fail
("!TRInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\""
, "llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp", 2277
, __extension__ __PRETTY_FUNCTION__))
;
2278 MachineBasicBlock *MBB = TRInst->getParent();
2279 const VarLoc &VL = VarLocIDs[TR.second];
2280 MachineInstr *MI = VL.BuildDbgValue(MF);
2281 MBB->insertAfterBundle(TRInst->getIterator(), MI);
2282 }
2283 EntryValTransfers.clear();
2284
2285 // Deferred inlocs will not have had any DBG_VALUE insts created; do
2286 // that now.
2287 flushPendingLocs(InLocs, VarLocIDs);
2288
2289 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)
;
2290 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)
;
2291 return Changed;
2292}
2293
2294LDVImpl *
2295llvm::makeVarLocBasedLiveDebugValues()
2296{
2297 return new VarLocBasedLDV();
2298}