Bug Summary

File:llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp
Warning:line 2239, 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-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -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-14~++20211016100712+8e1d532707fd/build-llvm -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -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-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen -I include -I /build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/include -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-14/lib/clang/14.0.0/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 -O2 -Wno-unused-command-line-argument -Wno-unknown-warning-option -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 -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/build-llvm -ferror-limit 19 -fvisibility-inlines-hidden -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-2021-10-17-004846-21170-1 -x c++ /build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/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/ADT/UniqueVector.h"
122#include "llvm/CodeGen/LexicalScopes.h"
123#include "llvm/CodeGen/MachineBasicBlock.h"
124#include "llvm/CodeGen/MachineFrameInfo.h"
125#include "llvm/CodeGen/MachineFunction.h"
126#include "llvm/CodeGen/MachineFunctionPass.h"
127#include "llvm/CodeGen/MachineInstr.h"
128#include "llvm/CodeGen/MachineInstrBuilder.h"
129#include "llvm/CodeGen/MachineMemOperand.h"
130#include "llvm/CodeGen/MachineOperand.h"
131#include "llvm/CodeGen/PseudoSourceValue.h"
132#include "llvm/CodeGen/RegisterScavenging.h"
133#include "llvm/CodeGen/TargetFrameLowering.h"
134#include "llvm/CodeGen/TargetInstrInfo.h"
135#include "llvm/CodeGen/TargetLowering.h"
136#include "llvm/CodeGen/TargetPassConfig.h"
137#include "llvm/CodeGen/TargetRegisterInfo.h"
138#include "llvm/CodeGen/TargetSubtargetInfo.h"
139#include "llvm/Config/llvm-config.h"
140#include "llvm/IR/DIBuilder.h"
141#include "llvm/IR/DebugInfoMetadata.h"
142#include "llvm/IR/DebugLoc.h"
143#include "llvm/IR/Function.h"
144#include "llvm/IR/Module.h"
145#include "llvm/InitializePasses.h"
146#include "llvm/MC/MCRegisterInfo.h"
147#include "llvm/Pass.h"
148#include "llvm/Support/Casting.h"
149#include "llvm/Support/Compiler.h"
150#include "llvm/Support/Debug.h"
151#include "llvm/Support/TypeSize.h"
152#include "llvm/Support/raw_ostream.h"
153#include "llvm/Target/TargetMachine.h"
154#include <algorithm>
155#include <cassert>
156#include <cstdint>
157#include <functional>
158#include <map>
159#include <queue>
160#include <tuple>
161#include <utility>
162#include <vector>
163
164using namespace llvm;
165
166#define DEBUG_TYPE"livedebugvalues" "livedebugvalues"
167
168STATISTIC(NumInserted, "Number of DBG_VALUE instructions inserted")static llvm::Statistic NumInserted = {"livedebugvalues", "NumInserted"
, "Number of DBG_VALUE instructions inserted"}
;
169
170/// If \p Op is a stack or frame register return true, otherwise return false.
171/// This is used to avoid basing the debug entry values on the registers, since
172/// we do not support it at the moment.
173static bool isRegOtherThanSPAndFP(const MachineOperand &Op,
174 const MachineInstr &MI,
175 const TargetRegisterInfo *TRI) {
176 if (!Op.isReg())
177 return false;
178
179 const MachineFunction *MF = MI.getParent()->getParent();
180 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
181 Register SP = TLI->getStackPointerRegisterToSaveRestore();
182 Register FP = TRI->getFrameRegister(*MF);
183 Register Reg = Op.getReg();
184
185 return Reg && Reg != SP && Reg != FP;
186}
187
188namespace {
189
190// Max out the number of statically allocated elements in DefinedRegsSet, as
191// this prevents fallback to std::set::count() operations.
192using DefinedRegsSet = SmallSet<Register, 32>;
193
194// The IDs in this set correspond to MachineLocs in VarLocs, as well as VarLocs
195// that represent Entry Values; every VarLoc in the set will also appear
196// exactly once at Location=0.
197// As a result, each VarLoc may appear more than once in this "set", but each
198// range corresponding to a Reg, SpillLoc, or EntryValue type will still be a
199// "true" set (i.e. each VarLoc may appear only once), and the range Location=0
200// is the set of all VarLocs.
201using VarLocSet = CoalescingBitVector<uint64_t>;
202
203/// A type-checked pair of {Register Location (or 0), Index}, used to index
204/// into a \ref VarLocMap. This can be efficiently converted to a 64-bit int
205/// for insertion into a \ref VarLocSet, and efficiently converted back. The
206/// type-checker helps ensure that the conversions aren't lossy.
207///
208/// Why encode a location /into/ the VarLocMap index? This makes it possible
209/// to find the open VarLocs killed by a register def very quickly. This is a
210/// performance-critical operation for LiveDebugValues.
211struct LocIndex {
212 using u32_location_t = uint32_t;
213 using u32_index_t = uint32_t;
214
215 u32_location_t Location; // Physical registers live in the range [1;2^30) (see
216 // \ref MCRegister), so we have plenty of range left
217 // here to encode non-register locations.
218 u32_index_t Index;
219
220 /// The location that has an entry for every VarLoc in the map.
221 static constexpr u32_location_t kUniversalLocation = 0;
222
223 /// The first location that is reserved for VarLocs with locations of kind
224 /// RegisterKind.
225 static constexpr u32_location_t kFirstRegLocation = 1;
226
227 /// The first location greater than 0 that is not reserved for VarLocs with
228 /// locations of kind RegisterKind.
229 static constexpr u32_location_t kFirstInvalidRegLocation = 1 << 30;
230
231 /// A special location reserved for VarLocs with locations of kind
232 /// SpillLocKind.
233 static constexpr u32_location_t kSpillLocation = kFirstInvalidRegLocation;
234
235 /// A special location reserved for VarLocs of kind EntryValueBackupKind and
236 /// EntryValueCopyBackupKind.
237 static constexpr u32_location_t kEntryValueBackupLocation =
238 kFirstInvalidRegLocation + 1;
239
240 LocIndex(u32_location_t Location, u32_index_t Index)
241 : Location(Location), Index(Index) {}
242
243 uint64_t getAsRawInteger() const {
244 return (static_cast<uint64_t>(Location) << 32) | Index;
245 }
246
247 template<typename IntT> static LocIndex fromRawInteger(IntT ID) {
248 static_assert(std::is_unsigned<IntT>::value &&
249 sizeof(ID) == sizeof(uint64_t),
250 "Cannot convert raw integer to LocIndex");
251 return {static_cast<u32_location_t>(ID >> 32),
252 static_cast<u32_index_t>(ID)};
253 }
254
255 /// Get the start of the interval reserved for VarLocs of kind RegisterKind
256 /// which reside in \p Reg. The end is at rawIndexForReg(Reg+1)-1.
257 static uint64_t rawIndexForReg(Register Reg) {
258 return LocIndex(Reg, 0).getAsRawInteger();
259 }
260
261 /// Return a range covering all set indices in the interval reserved for
262 /// \p Location in \p Set.
263 static auto indexRangeForLocation(const VarLocSet &Set,
264 u32_location_t Location) {
265 uint64_t Start = LocIndex(Location, 0).getAsRawInteger();
266 uint64_t End = LocIndex(Location + 1, 0).getAsRawInteger();
267 return Set.half_open_range(Start, End);
268 }
269};
270
271// Simple Set for storing all the VarLoc Indices at a Location bucket.
272using VarLocsInRange = SmallSet<LocIndex::u32_index_t, 32>;
273// Vector of all `LocIndex`s for a given VarLoc; the same Location should not
274// appear in any two of these, as each VarLoc appears at most once in any
275// Location bucket.
276using LocIndices = SmallVector<LocIndex, 2>;
277
278class VarLocBasedLDV : public LDVImpl {
279private:
280 const TargetRegisterInfo *TRI;
281 const TargetInstrInfo *TII;
282 const TargetFrameLowering *TFI;
283 TargetPassConfig *TPC;
284 BitVector CalleeSavedRegs;
285 LexicalScopes LS;
286 VarLocSet::Allocator Alloc;
287
288 const MachineInstr *LastNonDbgMI;
289
290 enum struct TransferKind { TransferCopy, TransferSpill, TransferRestore };
291
292 using FragmentInfo = DIExpression::FragmentInfo;
293 using OptFragmentInfo = Optional<DIExpression::FragmentInfo>;
294
295 /// A pair of debug variable and value location.
296 struct VarLoc {
297 // The location at which a spilled variable resides. It consists of a
298 // register and an offset.
299 struct SpillLoc {
300 unsigned SpillBase;
301 StackOffset SpillOffset;
302 bool operator==(const SpillLoc &Other) const {
303 return SpillBase == Other.SpillBase && SpillOffset == Other.SpillOffset;
304 }
305 bool operator!=(const SpillLoc &Other) const {
306 return !(*this == Other);
307 }
308 };
309
310 /// Identity of the variable at this location.
311 const DebugVariable Var;
312
313 /// The expression applied to this location.
314 const DIExpression *Expr;
315
316 /// DBG_VALUE to clone var/expr information from if this location
317 /// is moved.
318 const MachineInstr &MI;
319
320 enum class MachineLocKind {
321 InvalidKind = 0,
322 RegisterKind,
323 SpillLocKind,
324 ImmediateKind
325 };
326
327 enum class EntryValueLocKind {
328 NonEntryValueKind = 0,
329 EntryValueKind,
330 EntryValueBackupKind,
331 EntryValueCopyBackupKind
332 } EVKind;
333
334 /// The value location. Stored separately to avoid repeatedly
335 /// extracting it from MI.
336 union MachineLocValue {
337 uint64_t RegNo;
338 SpillLoc SpillLocation;
339 uint64_t Hash;
340 int64_t Immediate;
341 const ConstantFP *FPImm;
342 const ConstantInt *CImm;
343 MachineLocValue() : Hash(0) {}
344 };
345
346 /// A single machine location; its Kind is either a register, spill
347 /// location, or immediate value.
348 /// If the VarLoc is not a NonEntryValueKind, then it will use only a
349 /// single MachineLoc of RegisterKind.
350 struct MachineLoc {
351 MachineLocKind Kind;
352 MachineLocValue Value;
353 bool operator==(const MachineLoc &Other) const {
354 if (Kind != Other.Kind)
355 return false;
356 switch (Kind) {
357 case MachineLocKind::SpillLocKind:
358 return Value.SpillLocation == Other.Value.SpillLocation;
359 case MachineLocKind::RegisterKind:
360 case MachineLocKind::ImmediateKind:
361 return Value.Hash == Other.Value.Hash;
362 default:
363 llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 363)
;
364 }
365 }
366 bool operator<(const MachineLoc &Other) const {
367 switch (Kind) {
368 case MachineLocKind::SpillLocKind:
369 return std::make_tuple(
370 Kind, Value.SpillLocation.SpillBase,
371 Value.SpillLocation.SpillOffset.getFixed(),
372 Value.SpillLocation.SpillOffset.getScalable()) <
373 std::make_tuple(
374 Other.Kind, Other.Value.SpillLocation.SpillBase,
375 Other.Value.SpillLocation.SpillOffset.getFixed(),
376 Other.Value.SpillLocation.SpillOffset.getScalable());
377 case MachineLocKind::RegisterKind:
378 case MachineLocKind::ImmediateKind:
379 return std::tie(Kind, Value.Hash) <
380 std::tie(Other.Kind, Other.Value.Hash);
381 default:
382 llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 382)
;
383 }
384 }
385 };
386
387 /// The set of machine locations used to determine the variable's value, in
388 /// conjunction with Expr. Initially populated with MI's debug operands,
389 /// but may be transformed independently afterwards.
390 SmallVector<MachineLoc, 8> Locs;
391 /// Used to map the index of each location in Locs back to the index of its
392 /// original debug operand in MI. Used when multiple location operands are
393 /// coalesced and the original MI's operands need to be accessed while
394 /// emitting a debug value.
395 SmallVector<unsigned, 8> OrigLocMap;
396
397 VarLoc(const MachineInstr &MI, LexicalScopes &LS)
398 : Var(MI.getDebugVariable(), MI.getDebugExpression(),
399 MI.getDebugLoc()->getInlinedAt()),
400 Expr(MI.getDebugExpression()), MI(MI),
401 EVKind(EntryValueLocKind::NonEntryValueKind) {
402 assert(MI.isDebugValue() && "not a DBG_VALUE")(static_cast <bool> (MI.isDebugValue() && "not a DBG_VALUE"
) ? void (0) : __assert_fail ("MI.isDebugValue() && \"not a DBG_VALUE\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 402, __extension__ __PRETTY_FUNCTION__))
;
403 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 404, __extension__ __PRETTY_FUNCTION__))
404 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 404, __extension__ __PRETTY_FUNCTION__))
;
405 for (const MachineOperand &Op : MI.debug_operands()) {
406 MachineLoc ML = GetLocForOp(Op);
407 auto It = find(Locs, ML);
408 if (It == Locs.end()) {
409 Locs.push_back(ML);
410 OrigLocMap.push_back(MI.getDebugOperandIndex(&Op));
411 } else {
412 // ML duplicates an element in Locs; replace references to Op
413 // with references to the duplicating element.
414 unsigned OpIdx = Locs.size();
415 unsigned DuplicatingIdx = std::distance(Locs.begin(), It);
416 Expr = DIExpression::replaceArg(Expr, OpIdx, DuplicatingIdx);
417 }
418 }
419
420 // We create the debug entry values from the factory functions rather
421 // than from this ctor.
422 assert(EVKind != EntryValueLocKind::EntryValueKind &&(static_cast <bool> (EVKind != EntryValueLocKind::EntryValueKind
&& !isEntryBackupLoc()) ? void (0) : __assert_fail (
"EVKind != EntryValueLocKind::EntryValueKind && !isEntryBackupLoc()"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 423, __extension__ __PRETTY_FUNCTION__))
423 !isEntryBackupLoc())(static_cast <bool> (EVKind != EntryValueLocKind::EntryValueKind
&& !isEntryBackupLoc()) ? void (0) : __assert_fail (
"EVKind != EntryValueLocKind::EntryValueKind && !isEntryBackupLoc()"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 423, __extension__ __PRETTY_FUNCTION__))
;
424 }
425
426 static MachineLoc GetLocForOp(const MachineOperand &Op) {
427 MachineLocKind Kind;
428 MachineLocValue Loc;
429 if (Op.isReg()) {
430 Kind = MachineLocKind::RegisterKind;
431 Loc.RegNo = Op.getReg();
432 } else if (Op.isImm()) {
433 Kind = MachineLocKind::ImmediateKind;
434 Loc.Immediate = Op.getImm();
435 } else if (Op.isFPImm()) {
436 Kind = MachineLocKind::ImmediateKind;
437 Loc.FPImm = Op.getFPImm();
438 } else if (Op.isCImm()) {
439 Kind = MachineLocKind::ImmediateKind;
440 Loc.CImm = Op.getCImm();
441 } else
442 llvm_unreachable("Invalid Op kind for MachineLoc.")::llvm::llvm_unreachable_internal("Invalid Op kind for MachineLoc."
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 442)
;
443 return {Kind, Loc};
444 }
445
446 /// Take the variable and machine-location in DBG_VALUE MI, and build an
447 /// entry location using the given expression.
448 static VarLoc CreateEntryLoc(const MachineInstr &MI, LexicalScopes &LS,
449 const DIExpression *EntryExpr, Register Reg) {
450 VarLoc VL(MI, LS);
451 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 452, __extension__ __PRETTY_FUNCTION__))
452 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 452, __extension__ __PRETTY_FUNCTION__))
;
453 VL.EVKind = EntryValueLocKind::EntryValueKind;
454 VL.Expr = EntryExpr;
455 VL.Locs[0].Value.RegNo = Reg;
456 return VL;
457 }
458
459 /// Take the variable and machine-location from the DBG_VALUE (from the
460 /// function entry), and build an entry value backup location. The backup
461 /// location will turn into the normal location if the backup is valid at
462 /// the time of the primary location clobbering.
463 static VarLoc CreateEntryBackupLoc(const MachineInstr &MI,
464 LexicalScopes &LS,
465 const DIExpression *EntryExpr) {
466 VarLoc VL(MI, LS);
467 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 468, __extension__ __PRETTY_FUNCTION__))
468 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 468, __extension__ __PRETTY_FUNCTION__))
;
469 VL.EVKind = EntryValueLocKind::EntryValueBackupKind;
470 VL.Expr = EntryExpr;
471 return VL;
472 }
473
474 /// Take the variable and machine-location from the DBG_VALUE (from the
475 /// function entry), and build a copy of an entry value backup location by
476 /// setting the register location to NewReg.
477 static VarLoc CreateEntryCopyBackupLoc(const MachineInstr &MI,
478 LexicalScopes &LS,
479 const DIExpression *EntryExpr,
480 Register NewReg) {
481 VarLoc VL(MI, LS);
482 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 483, __extension__ __PRETTY_FUNCTION__))
483 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"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 483, __extension__ __PRETTY_FUNCTION__))
;
484 VL.EVKind = EntryValueLocKind::EntryValueCopyBackupKind;
485 VL.Expr = EntryExpr;
486 VL.Locs[0].Value.RegNo = NewReg;
487 return VL;
488 }
489
490 /// Copy the register location in DBG_VALUE MI, updating the register to
491 /// be NewReg.
492 static VarLoc CreateCopyLoc(const VarLoc &OldVL, const MachineLoc &OldML,
493 Register NewReg) {
494 VarLoc VL = OldVL;
495 for (size_t I = 0, E = VL.Locs.size(); I < E; ++I)
496 if (VL.Locs[I] == OldML) {
497 VL.Locs[I].Kind = MachineLocKind::RegisterKind;
498 VL.Locs[I].Value.RegNo = NewReg;
499 return VL;
500 }
501 llvm_unreachable("Should have found OldML in new VarLoc.")::llvm::llvm_unreachable_internal("Should have found OldML in new VarLoc."
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 501)
;
502 }
503
504 /// Take the variable described by DBG_VALUE* MI, and create a VarLoc
505 /// locating it in the specified spill location.
506 static VarLoc CreateSpillLoc(const VarLoc &OldVL, const MachineLoc &OldML,
507 unsigned SpillBase, StackOffset SpillOffset) {
508 VarLoc VL = OldVL;
509 for (int I = 0, E = VL.Locs.size(); I < E; ++I)
510 if (VL.Locs[I] == OldML) {
511 VL.Locs[I].Kind = MachineLocKind::SpillLocKind;
512 VL.Locs[I].Value.SpillLocation = {SpillBase, SpillOffset};
513 return VL;
514 }
515 llvm_unreachable("Should have found OldML in new VarLoc.")::llvm::llvm_unreachable_internal("Should have found OldML in new VarLoc."
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 515)
;
516 }
517
518 /// Create a DBG_VALUE representing this VarLoc in the given function.
519 /// Copies variable-specific information such as DILocalVariable and
520 /// inlining information from the original DBG_VALUE instruction, which may
521 /// have been several transfers ago.
522 MachineInstr *BuildDbgValue(MachineFunction &MF) const {
523 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 524, __extension__ __PRETTY_FUNCTION__))
524 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 524, __extension__ __PRETTY_FUNCTION__))
;
525 const DebugLoc &DbgLoc = MI.getDebugLoc();
526 bool Indirect = MI.isIndirectDebugValue();
527 const auto &IID = MI.getDesc();
528 const DILocalVariable *Var = MI.getDebugVariable();
529 NumInserted++;
530
531 const DIExpression *DIExpr = Expr;
532 SmallVector<MachineOperand, 8> MOs;
533 for (unsigned I = 0, E = Locs.size(); I < E; ++I) {
534 MachineLocKind LocKind = Locs[I].Kind;
535 MachineLocValue Loc = Locs[I].Value;
536 const MachineOperand &Orig = MI.getDebugOperand(OrigLocMap[I]);
537 switch (LocKind) {
538 case MachineLocKind::RegisterKind:
539 // An entry value is a register location -- but with an updated
540 // expression. The register location of such DBG_VALUE is always the
541 // one from the entry DBG_VALUE, it does not matter if the entry value
542 // was copied in to another register due to some optimizations.
543 // Non-entry value register locations are like the source
544 // DBG_VALUE, but with the register number from this VarLoc.
545 MOs.push_back(MachineOperand::CreateReg(
546 EVKind == EntryValueLocKind::EntryValueKind ? Orig.getReg()
547 : Register(Loc.RegNo),
548 false));
549 break;
550 case MachineLocKind::SpillLocKind: {
551 // Spills are indirect DBG_VALUEs, with a base register and offset.
552 // Use the original DBG_VALUEs expression to build the spilt location
553 // on top of. FIXME: spill locations created before this pass runs
554 // are not recognized, and not handled here.
555 unsigned Base = Loc.SpillLocation.SpillBase;
556 auto *TRI = MF.getSubtarget().getRegisterInfo();
557 if (MI.isNonListDebugValue()) {
558 auto Deref = Indirect ? DIExpression::DerefAfter : 0;
559 DIExpr = TRI->prependOffsetExpression(
560 DIExpr, DIExpression::ApplyOffset | Deref,
561 Loc.SpillLocation.SpillOffset);
562 Indirect = true;
563 } else {
564 SmallVector<uint64_t, 4> Ops;
565 TRI->getOffsetOpcodes(Loc.SpillLocation.SpillOffset, Ops);
566 Ops.push_back(dwarf::DW_OP_deref);
567 DIExpr = DIExpression::appendOpsToArg(DIExpr, Ops, I);
568 }
569 MOs.push_back(MachineOperand::CreateReg(Base, false));
570 break;
571 }
572 case MachineLocKind::ImmediateKind: {
573 MOs.push_back(Orig);
574 break;
575 }
576 case MachineLocKind::InvalidKind:
577 llvm_unreachable("Tried to produce DBG_VALUE for invalid VarLoc")::llvm::llvm_unreachable_internal("Tried to produce DBG_VALUE for invalid VarLoc"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 577)
;
578 }
579 }
580 return BuildMI(MF, DbgLoc, IID, Indirect, MOs, Var, DIExpr);
581 }
582
583 /// Is the Loc field a constant or constant object?
584 bool isConstant(MachineLocKind Kind) const {
585 return Kind == MachineLocKind::ImmediateKind;
586 }
587
588 /// Check if the Loc field is an entry backup location.
589 bool isEntryBackupLoc() const {
590 return EVKind == EntryValueLocKind::EntryValueBackupKind ||
591 EVKind == EntryValueLocKind::EntryValueCopyBackupKind;
592 }
593
594 /// If this variable is described by register \p Reg holding the entry
595 /// value, return true.
596 bool isEntryValueBackupReg(Register Reg) const {
597 return EVKind == EntryValueLocKind::EntryValueBackupKind && usesReg(Reg);
598 }
599
600 /// If this variable is described by register \p Reg holding a copy of the
601 /// entry value, return true.
602 bool isEntryValueCopyBackupReg(Register Reg) const {
603 return EVKind == EntryValueLocKind::EntryValueCopyBackupKind &&
604 usesReg(Reg);
605 }
606
607 /// If this variable is described in whole or part by \p Reg, return true.
608 bool usesReg(Register Reg) const {
609 MachineLoc RegML;
610 RegML.Kind = MachineLocKind::RegisterKind;
611 RegML.Value.RegNo = Reg;
612 return is_contained(Locs, RegML);
613 }
614
615 /// If this variable is described in whole or part by \p Reg, return true.
616 unsigned getRegIdx(Register Reg) const {
617 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
618 if (Locs[Idx].Kind == MachineLocKind::RegisterKind &&
619 Register{static_cast<unsigned>(Locs[Idx].Value.RegNo)} == Reg)
620 return Idx;
621 llvm_unreachable("Could not find given Reg in Locs")::llvm::llvm_unreachable_internal("Could not find given Reg in Locs"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 621)
;
622 }
623
624 /// If this variable is described in whole or part by 1 or more registers,
625 /// add each of them to \p Regs and return true.
626 bool getDescribingRegs(SmallVectorImpl<uint32_t> &Regs) const {
627 bool AnyRegs = false;
628 for (const auto &Loc : Locs)
629 if (Loc.Kind == MachineLocKind::RegisterKind) {
630 Regs.push_back(Loc.Value.RegNo);
631 AnyRegs = true;
632 }
633 return AnyRegs;
634 }
635
636 bool containsSpillLocs() const {
637 return any_of(Locs, [](VarLoc::MachineLoc ML) {
638 return ML.Kind == VarLoc::MachineLocKind::SpillLocKind;
639 });
640 }
641
642 /// If this variable is described in whole or part by \p SpillLocation,
643 /// return true.
644 bool usesSpillLoc(SpillLoc SpillLocation) const {
645 MachineLoc SpillML;
646 SpillML.Kind = MachineLocKind::SpillLocKind;
647 SpillML.Value.SpillLocation = SpillLocation;
648 return is_contained(Locs, SpillML);
649 }
650
651 /// If this variable is described in whole or part by \p SpillLocation,
652 /// return the index .
653 unsigned getSpillLocIdx(SpillLoc SpillLocation) const {
654 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
655 if (Locs[Idx].Kind == MachineLocKind::SpillLocKind &&
656 Locs[Idx].Value.SpillLocation == SpillLocation)
657 return Idx;
658 llvm_unreachable("Could not find given SpillLoc in Locs")::llvm::llvm_unreachable_internal("Could not find given SpillLoc in Locs"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 658)
;
659 }
660
661 /// Determine whether the lexical scope of this value's debug location
662 /// dominates MBB.
663 bool dominates(LexicalScopes &LS, MachineBasicBlock &MBB) const {
664 return LS.dominates(MI.getDebugLoc().get(), &MBB);
665 }
666
667#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
668 // TRI can be null.
669 void dump(const TargetRegisterInfo *TRI, raw_ostream &Out = dbgs()) const {
670 Out << "VarLoc(";
671 for (const MachineLoc &MLoc : Locs) {
672 if (Locs.begin() != &MLoc)
673 Out << ", ";
674 switch (MLoc.Kind) {
675 case MachineLocKind::RegisterKind:
676 Out << printReg(MLoc.Value.RegNo, TRI);
677 break;
678 case MachineLocKind::SpillLocKind:
679 Out << printReg(MLoc.Value.SpillLocation.SpillBase, TRI);
680 Out << "[" << MLoc.Value.SpillLocation.SpillOffset.getFixed() << " + "
681 << MLoc.Value.SpillLocation.SpillOffset.getScalable()
682 << "x vscale"
683 << "]";
684 break;
685 case MachineLocKind::ImmediateKind:
686 Out << MLoc.Value.Immediate;
687 break;
688 case MachineLocKind::InvalidKind:
689 llvm_unreachable("Invalid VarLoc in dump method")::llvm::llvm_unreachable_internal("Invalid VarLoc in dump method"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 689)
;
690 }
691 }
692
693 Out << ", \"" << Var.getVariable()->getName() << "\", " << *Expr << ", ";
694 if (Var.getInlinedAt())
695 Out << "!" << Var.getInlinedAt()->getMetadataID() << ")\n";
696 else
697 Out << "(null))";
698
699 if (isEntryBackupLoc())
700 Out << " (backup loc)\n";
701 else
702 Out << "\n";
703 }
704#endif
705
706 bool operator==(const VarLoc &Other) const {
707 return std::tie(EVKind, Var, Expr, Locs) ==
708 std::tie(Other.EVKind, Other.Var, Other.Expr, Other.Locs);
709 }
710
711 /// This operator guarantees that VarLocs are sorted by Variable first.
712 bool operator<(const VarLoc &Other) const {
713 return std::tie(Var, EVKind, Locs, Expr) <
714 std::tie(Other.Var, Other.EVKind, Other.Locs, Other.Expr);
715 }
716 };
717
718#ifndef NDEBUG
719 using VarVec = SmallVector<VarLoc, 32>;
720#endif
721
722 /// VarLocMap is used for two things:
723 /// 1) Assigning LocIndices to a VarLoc. The LocIndices can be used to
724 /// virtually insert a VarLoc into a VarLocSet.
725 /// 2) Given a LocIndex, look up the unique associated VarLoc.
726 class VarLocMap {
727 /// Map a VarLoc to an index within the vector reserved for its location
728 /// within Loc2Vars.
729 std::map<VarLoc, LocIndices> Var2Indices;
730
731 /// Map a location to a vector which holds VarLocs which live in that
732 /// location.
733 SmallDenseMap<LocIndex::u32_location_t, std::vector<VarLoc>> Loc2Vars;
734
735 public:
736 /// Retrieve LocIndices for \p VL.
737 LocIndices insert(const VarLoc &VL) {
738 LocIndices &Indices = Var2Indices[VL];
739 // If Indices is not empty, VL is already in the map.
740 if (!Indices.empty())
741 return Indices;
742 SmallVector<LocIndex::u32_location_t, 4> Locations;
743 // LocIndices are determined by EVKind and MLs; each Register has a
744 // unique location, while all SpillLocs use a single bucket, and any EV
745 // VarLocs use only the Backup bucket or none at all (except the
746 // compulsory entry at the universal location index). LocIndices will
747 // always have an index at the universal location index as the last index.
748 if (VL.EVKind == VarLoc::EntryValueLocKind::NonEntryValueKind) {
749 VL.getDescribingRegs(Locations);
750 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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 754, __extension__ __PRETTY_FUNCTION__))
751 [](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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 754, __extension__ __PRETTY_FUNCTION__))
752 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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 754, __extension__ __PRETTY_FUNCTION__))
753 }) &&(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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 754, __extension__ __PRETTY_FUNCTION__))
754 "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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 754, __extension__ __PRETTY_FUNCTION__))
;
755 if (VL.containsSpillLocs()) {
756 LocIndex::u32_location_t Loc = LocIndex::kSpillLocation;
757 Locations.push_back(Loc);
758 }
759 } else if (VL.EVKind != VarLoc::EntryValueLocKind::EntryValueKind) {
760 LocIndex::u32_location_t Loc = LocIndex::kEntryValueBackupLocation;
761 Locations.push_back(Loc);
762 }
763 Locations.push_back(LocIndex::kUniversalLocation);
764 for (LocIndex::u32_location_t Location : Locations) {
765 auto &Vars = Loc2Vars[Location];
766 Indices.push_back(
767 {Location, static_cast<LocIndex::u32_index_t>(Vars.size())});
768 Vars.push_back(VL);
769 }
770 return Indices;
771 }
772
773 LocIndices getAllIndices(const VarLoc &VL) const {
774 auto IndIt = Var2Indices.find(VL);
775 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 775, __extension__ __PRETTY_FUNCTION__))
;
776 return IndIt->second;
777 }
778
779 /// Retrieve the unique VarLoc associated with \p ID.
780 const VarLoc &operator[](LocIndex ID) const {
781 auto LocIt = Loc2Vars.find(ID.Location);
782 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 782, __extension__ __PRETTY_FUNCTION__))
;
783 return LocIt->second[ID.Index];
784 }
785 };
786
787 using VarLocInMBB =
788 SmallDenseMap<const MachineBasicBlock *, std::unique_ptr<VarLocSet>>;
789 struct TransferDebugPair {
790 MachineInstr *TransferInst; ///< Instruction where this transfer occurs.
791 LocIndex LocationID; ///< Location number for the transfer dest.
792 };
793 using TransferMap = SmallVector<TransferDebugPair, 4>;
794 // Types for recording Entry Var Locations emitted by a single MachineInstr,
795 // as well as recording MachineInstr which last defined a register.
796 using InstToEntryLocMap = std::multimap<const MachineInstr *, LocIndex>;
797 using RegDefToInstMap = DenseMap<Register, MachineInstr *>;
798
799 // Types for recording sets of variable fragments that overlap. For a given
800 // local variable, we record all other fragments of that variable that could
801 // overlap it, to reduce search time.
802 using FragmentOfVar =
803 std::pair<const DILocalVariable *, DIExpression::FragmentInfo>;
804 using OverlapMap =
805 DenseMap<FragmentOfVar, SmallVector<DIExpression::FragmentInfo, 1>>;
806
807 // Helper while building OverlapMap, a map of all fragments seen for a given
808 // DILocalVariable.
809 using VarToFragments =
810 DenseMap<const DILocalVariable *, SmallSet<FragmentInfo, 4>>;
811
812 /// Collects all VarLocs from \p CollectFrom. Each unique VarLoc is added
813 /// to \p Collected once, in order of insertion into \p VarLocIDs.
814 static void collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
815 const VarLocSet &CollectFrom,
816 const VarLocMap &VarLocIDs);
817
818 /// Get the registers which are used by VarLocs of kind RegisterKind tracked
819 /// by \p CollectFrom.
820 void getUsedRegs(const VarLocSet &CollectFrom,
821 SmallVectorImpl<Register> &UsedRegs) const;
822
823 /// This holds the working set of currently open ranges. For fast
824 /// access, this is done both as a set of VarLocIDs, and a map of
825 /// DebugVariable to recent VarLocID. Note that a DBG_VALUE ends all
826 /// previous open ranges for the same variable. In addition, we keep
827 /// two different maps (Vars/EntryValuesBackupVars), so erase/insert
828 /// methods act differently depending on whether a VarLoc is primary
829 /// location or backup one. In the case the VarLoc is backup location
830 /// we will erase/insert from the EntryValuesBackupVars map, otherwise
831 /// we perform the operation on the Vars.
832 class OpenRangesSet {
833 VarLocSet::Allocator &Alloc;
834 VarLocSet VarLocs;
835 // Map the DebugVariable to recent primary location ID.
836 SmallDenseMap<DebugVariable, LocIndices, 8> Vars;
837 // Map the DebugVariable to recent backup location ID.
838 SmallDenseMap<DebugVariable, LocIndices, 8> EntryValuesBackupVars;
839 OverlapMap &OverlappingFragments;
840
841 public:
842 OpenRangesSet(VarLocSet::Allocator &Alloc, OverlapMap &_OLapMap)
843 : Alloc(Alloc), VarLocs(Alloc), OverlappingFragments(_OLapMap) {}
844
845 const VarLocSet &getVarLocs() const { return VarLocs; }
846
847 // Fetches all VarLocs in \p VarLocIDs and inserts them into \p Collected.
848 // This method is needed to get every VarLoc once, as each VarLoc may have
849 // multiple indices in a VarLocMap (corresponding to each applicable
850 // location), but all VarLocs appear exactly once at the universal location
851 // index.
852 void getUniqueVarLocs(SmallVectorImpl<VarLoc> &Collected,
853 const VarLocMap &VarLocIDs) const {
854 collectAllVarLocs(Collected, VarLocs, VarLocIDs);
855 }
856
857 /// Terminate all open ranges for VL.Var by removing it from the set.
858 void erase(const VarLoc &VL);
859
860 /// Terminate all open ranges listed as indices in \c KillSet with
861 /// \c Location by removing them from the set.
862 void erase(const VarLocsInRange &KillSet, const VarLocMap &VarLocIDs,
863 LocIndex::u32_location_t Location);
864
865 /// Insert a new range into the set.
866 void insert(LocIndices VarLocIDs, const VarLoc &VL);
867
868 /// Insert a set of ranges.
869 void insertFromLocSet(const VarLocSet &ToLoad, const VarLocMap &Map);
870
871 llvm::Optional<LocIndices> getEntryValueBackup(DebugVariable Var);
872
873 /// Empty the set.
874 void clear() {
875 VarLocs.clear();
876 Vars.clear();
877 EntryValuesBackupVars.clear();
878 }
879
880 /// Return whether the set is empty or not.
881 bool empty() const {
882 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 884, __extension__ __PRETTY_FUNCTION__))
883 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 884, __extension__ __PRETTY_FUNCTION__))
884 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 884, __extension__ __PRETTY_FUNCTION__))
;
885 return VarLocs.empty();
886 }
887
888 /// Get an empty range of VarLoc IDs.
889 auto getEmptyVarLocRange() const {
890 return iterator_range<VarLocSet::const_iterator>(getVarLocs().end(),
891 getVarLocs().end());
892 }
893
894 /// Get all set IDs for VarLocs with MLs of kind RegisterKind in \p Reg.
895 auto getRegisterVarLocs(Register Reg) const {
896 return LocIndex::indexRangeForLocation(getVarLocs(), Reg);
897 }
898
899 /// Get all set IDs for VarLocs with MLs of kind SpillLocKind.
900 auto getSpillVarLocs() const {
901 return LocIndex::indexRangeForLocation(getVarLocs(),
902 LocIndex::kSpillLocation);
903 }
904
905 /// Get all set IDs for VarLocs of EVKind EntryValueBackupKind or
906 /// EntryValueCopyBackupKind.
907 auto getEntryValueBackupVarLocs() const {
908 return LocIndex::indexRangeForLocation(
909 getVarLocs(), LocIndex::kEntryValueBackupLocation);
910 }
911 };
912
913 /// Collect all VarLoc IDs from \p CollectFrom for VarLocs with MLs of kind
914 /// RegisterKind which are located in any reg in \p Regs. The IDs for each
915 /// VarLoc correspond to entries in the universal location bucket, which every
916 /// VarLoc has exactly 1 entry for. Insert collected IDs into \p Collected.
917 static void collectIDsForRegs(VarLocsInRange &Collected,
918 const DefinedRegsSet &Regs,
919 const VarLocSet &CollectFrom,
920 const VarLocMap &VarLocIDs);
921
922 VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB, VarLocInMBB &Locs) {
923 std::unique_ptr<VarLocSet> &VLS = Locs[MBB];
924 if (!VLS)
925 VLS = std::make_unique<VarLocSet>(Alloc);
926 return *VLS.get();
927 }
928
929 const VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB,
930 const VarLocInMBB &Locs) const {
931 auto It = Locs.find(MBB);
932 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 932, __extension__ __PRETTY_FUNCTION__))
;
933 return *It->second.get();
934 }
935
936 /// Tests whether this instruction is a spill to a stack location.
937 bool isSpillInstruction(const MachineInstr &MI, MachineFunction *MF);
938
939 /// Decide if @MI is a spill instruction and return true if it is. We use 2
940 /// criteria to make this decision:
941 /// - Is this instruction a store to a spill slot?
942 /// - Is there a register operand that is both used and killed?
943 /// TODO: Store optimization can fold spills into other stores (including
944 /// other spills). We do not handle this yet (more than one memory operand).
945 bool isLocationSpill(const MachineInstr &MI, MachineFunction *MF,
946 Register &Reg);
947
948 /// Returns true if the given machine instruction is a debug value which we
949 /// can emit entry values for.
950 ///
951 /// Currently, we generate debug entry values only for parameters that are
952 /// unmodified throughout the function and located in a register.
953 bool isEntryValueCandidate(const MachineInstr &MI,
954 const DefinedRegsSet &Regs) const;
955
956 /// If a given instruction is identified as a spill, return the spill location
957 /// and set \p Reg to the spilled register.
958 Optional<VarLoc::SpillLoc> isRestoreInstruction(const MachineInstr &MI,
959 MachineFunction *MF,
960 Register &Reg);
961 /// Given a spill instruction, extract the register and offset used to
962 /// address the spill location in a target independent way.
963 VarLoc::SpillLoc extractSpillBaseRegAndOffset(const MachineInstr &MI);
964 void insertTransferDebugPair(MachineInstr &MI, OpenRangesSet &OpenRanges,
965 TransferMap &Transfers, VarLocMap &VarLocIDs,
966 LocIndex OldVarID, TransferKind Kind,
967 const VarLoc::MachineLoc &OldLoc,
968 Register NewReg = Register());
969
970 void transferDebugValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
971 VarLocMap &VarLocIDs,
972 InstToEntryLocMap &EntryValTransfers,
973 RegDefToInstMap &RegSetInstrs);
974 void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
975 VarLocMap &VarLocIDs, TransferMap &Transfers);
976 void cleanupEntryValueTransfers(const MachineInstr *MI,
977 OpenRangesSet &OpenRanges,
978 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
979 InstToEntryLocMap &EntryValTransfers);
980 void removeEntryValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
981 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
982 InstToEntryLocMap &EntryValTransfers,
983 RegDefToInstMap &RegSetInstrs);
984 void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
985 VarLocMap &VarLocIDs,
986 InstToEntryLocMap &EntryValTransfers,
987 VarLocsInRange &KillSet);
988 void recordEntryValue(const MachineInstr &MI,
989 const DefinedRegsSet &DefinedRegs,
990 OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs);
991 void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
992 VarLocMap &VarLocIDs, TransferMap &Transfers);
993 void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
994 VarLocMap &VarLocIDs,
995 InstToEntryLocMap &EntryValTransfers,
996 RegDefToInstMap &RegSetInstrs);
997 bool transferTerminator(MachineBasicBlock *MBB, OpenRangesSet &OpenRanges,
998 VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
999
1000 void process(MachineInstr &MI, OpenRangesSet &OpenRanges,
1001 VarLocMap &VarLocIDs, TransferMap &Transfers,
1002 InstToEntryLocMap &EntryValTransfers,
1003 RegDefToInstMap &RegSetInstrs);
1004
1005 void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
1006 OverlapMap &OLapMap);
1007
1008 bool join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1009 const VarLocMap &VarLocIDs,
1010 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1011 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks);
1012
1013 /// Create DBG_VALUE insts for inlocs that have been propagated but
1014 /// had their instruction creation deferred.
1015 void flushPendingLocs(VarLocInMBB &PendingInLocs, VarLocMap &VarLocIDs);
1016
1017 bool ExtendRanges(MachineFunction &MF, MachineDominatorTree *DomTree,
1018 TargetPassConfig *TPC, unsigned InputBBLimit,
1019 unsigned InputDbgValLimit) override;
1020
1021public:
1022 /// Default construct and initialize the pass.
1023 VarLocBasedLDV();
1024
1025 ~VarLocBasedLDV();
1026
1027 /// Print to ostream with a message.
1028 void printVarLocInMBB(const MachineFunction &MF, const VarLocInMBB &V,
1029 const VarLocMap &VarLocIDs, const char *msg,
1030 raw_ostream &Out) const;
1031};
1032
1033} // end anonymous namespace
1034
1035//===----------------------------------------------------------------------===//
1036// Implementation
1037//===----------------------------------------------------------------------===//
1038
1039VarLocBasedLDV::VarLocBasedLDV() { }
1040
1041VarLocBasedLDV::~VarLocBasedLDV() { }
1042
1043/// Erase a variable from the set of open ranges, and additionally erase any
1044/// fragments that may overlap it. If the VarLoc is a backup location, erase
1045/// the variable from the EntryValuesBackupVars set, indicating we should stop
1046/// tracking its backup entry location. Otherwise, if the VarLoc is primary
1047/// location, erase the variable from the Vars set.
1048void VarLocBasedLDV::OpenRangesSet::erase(const VarLoc &VL) {
1049 // Erasure helper.
1050 auto DoErase = [VL, this](DebugVariable VarToErase) {
1051 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1052 auto It = EraseFrom->find(VarToErase);
1053 if (It != EraseFrom->end()) {
1054 LocIndices IDs = It->second;
1055 for (LocIndex ID : IDs)
1056 VarLocs.reset(ID.getAsRawInteger());
1057 EraseFrom->erase(It);
1058 }
1059 };
1060
1061 DebugVariable Var = VL.Var;
1062
1063 // Erase the variable/fragment that ends here.
1064 DoErase(Var);
1065
1066 // Extract the fragment. Interpret an empty fragment as one that covers all
1067 // possible bits.
1068 FragmentInfo ThisFragment = Var.getFragmentOrDefault();
1069
1070 // There may be fragments that overlap the designated fragment. Look them up
1071 // in the pre-computed overlap map, and erase them too.
1072 auto MapIt = OverlappingFragments.find({Var.getVariable(), ThisFragment});
1073 if (MapIt != OverlappingFragments.end()) {
1074 for (auto Fragment : MapIt->second) {
1075 VarLocBasedLDV::OptFragmentInfo FragmentHolder;
1076 if (!DebugVariable::isDefaultFragment(Fragment))
1077 FragmentHolder = VarLocBasedLDV::OptFragmentInfo(Fragment);
1078 DoErase({Var.getVariable(), FragmentHolder, Var.getInlinedAt()});
1079 }
1080 }
1081}
1082
1083void VarLocBasedLDV::OpenRangesSet::erase(const VarLocsInRange &KillSet,
1084 const VarLocMap &VarLocIDs,
1085 LocIndex::u32_location_t Location) {
1086 VarLocSet RemoveSet(Alloc);
1087 for (LocIndex::u32_index_t ID : KillSet) {
1088 const VarLoc &VL = VarLocIDs[LocIndex(Location, ID)];
1089 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1090 EraseFrom->erase(VL.Var);
1091 LocIndices VLI = VarLocIDs.getAllIndices(VL);
1092 for (LocIndex ID : VLI)
1093 RemoveSet.set(ID.getAsRawInteger());
1094 }
1095 VarLocs.intersectWithComplement(RemoveSet);
1096}
1097
1098void VarLocBasedLDV::OpenRangesSet::insertFromLocSet(const VarLocSet &ToLoad,
1099 const VarLocMap &Map) {
1100 VarLocsInRange UniqueVarLocIDs;
1101 DefinedRegsSet Regs;
1102 Regs.insert(LocIndex::kUniversalLocation);
1103 collectIDsForRegs(UniqueVarLocIDs, Regs, ToLoad, Map);
1104 for (uint64_t ID : UniqueVarLocIDs) {
1105 LocIndex Idx = LocIndex::fromRawInteger(ID);
1106 const VarLoc &VarL = Map[Idx];
1107 const LocIndices Indices = Map.getAllIndices(VarL);
1108 insert(Indices, VarL);
1109 }
1110}
1111
1112void VarLocBasedLDV::OpenRangesSet::insert(LocIndices VarLocIDs,
1113 const VarLoc &VL) {
1114 auto *InsertInto = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1115 for (LocIndex ID : VarLocIDs)
1116 VarLocs.set(ID.getAsRawInteger());
1117 InsertInto->insert({VL.Var, VarLocIDs});
1118}
1119
1120/// Return the Loc ID of an entry value backup location, if it exists for the
1121/// variable.
1122llvm::Optional<LocIndices>
1123VarLocBasedLDV::OpenRangesSet::getEntryValueBackup(DebugVariable Var) {
1124 auto It = EntryValuesBackupVars.find(Var);
1125 if (It != EntryValuesBackupVars.end())
1126 return It->second;
1127
1128 return llvm::None;
1129}
1130
1131void VarLocBasedLDV::collectIDsForRegs(VarLocsInRange &Collected,
1132 const DefinedRegsSet &Regs,
1133 const VarLocSet &CollectFrom,
1134 const VarLocMap &VarLocIDs) {
1135 assert(!Regs.empty() && "Nothing to collect")(static_cast <bool> (!Regs.empty() && "Nothing to collect"
) ? void (0) : __assert_fail ("!Regs.empty() && \"Nothing to collect\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1135, __extension__ __PRETTY_FUNCTION__))
;
1136 SmallVector<Register, 32> SortedRegs;
1137 append_range(SortedRegs, Regs);
1138 array_pod_sort(SortedRegs.begin(), SortedRegs.end());
1139 auto It = CollectFrom.find(LocIndex::rawIndexForReg(SortedRegs.front()));
1140 auto End = CollectFrom.end();
1141 for (Register Reg : SortedRegs) {
1142 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains
1143 // all possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which
1144 // live in Reg.
1145 uint64_t FirstIndexForReg = LocIndex::rawIndexForReg(Reg);
1146 uint64_t FirstInvalidIndex = LocIndex::rawIndexForReg(Reg + 1);
1147 It.advanceToLowerBound(FirstIndexForReg);
1148
1149 // Iterate through that half-open interval and collect all the set IDs.
1150 for (; It != End && *It < FirstInvalidIndex; ++It) {
1151 LocIndex ItIdx = LocIndex::fromRawInteger(*It);
1152 const VarLoc &VL = VarLocIDs[ItIdx];
1153 LocIndices LI = VarLocIDs.getAllIndices(VL);
1154 // For now, the back index is always the universal location index.
1155 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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1157, __extension__ __PRETTY_FUNCTION__))
1156 "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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1157, __extension__ __PRETTY_FUNCTION__))
1157 "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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1157, __extension__ __PRETTY_FUNCTION__))
;
1158 Collected.insert(LI.back().Index);
1159 }
1160
1161 if (It == End)
1162 return;
1163 }
1164}
1165
1166void VarLocBasedLDV::getUsedRegs(const VarLocSet &CollectFrom,
1167 SmallVectorImpl<Register> &UsedRegs) const {
1168 // All register-based VarLocs are assigned indices greater than or equal to
1169 // FirstRegIndex.
1170 uint64_t FirstRegIndex =
1171 LocIndex::rawIndexForReg(LocIndex::kFirstRegLocation);
1172 uint64_t FirstInvalidIndex =
1173 LocIndex::rawIndexForReg(LocIndex::kFirstInvalidRegLocation);
1174 for (auto It = CollectFrom.find(FirstRegIndex),
1175 End = CollectFrom.find(FirstInvalidIndex);
1176 It != End;) {
1177 // We found a VarLoc ID for a VarLoc that lives in a register. Figure out
1178 // which register and add it to UsedRegs.
1179 uint32_t FoundReg = LocIndex::fromRawInteger(*It).Location;
1180 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1181, __extension__ __PRETTY_FUNCTION__))
1181 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1181, __extension__ __PRETTY_FUNCTION__))
;
1182 UsedRegs.push_back(FoundReg);
1183
1184 // Skip to the next /set/ register. Note that this finds a lower bound, so
1185 // even if there aren't any VarLocs living in `FoundReg+1`, we're still
1186 // guaranteed to move on to the next register (or to end()).
1187 uint64_t NextRegIndex = LocIndex::rawIndexForReg(FoundReg + 1);
1188 It.advanceToLowerBound(NextRegIndex);
1189 }
1190}
1191
1192//===----------------------------------------------------------------------===//
1193// Debug Range Extension Implementation
1194//===----------------------------------------------------------------------===//
1195
1196#ifndef NDEBUG
1197void VarLocBasedLDV::printVarLocInMBB(const MachineFunction &MF,
1198 const VarLocInMBB &V,
1199 const VarLocMap &VarLocIDs,
1200 const char *msg,
1201 raw_ostream &Out) const {
1202 Out << '\n' << msg << '\n';
1203 for (const MachineBasicBlock &BB : MF) {
1204 if (!V.count(&BB))
1205 continue;
1206 const VarLocSet &L = getVarLocsInMBB(&BB, V);
1207 if (L.empty())
1208 continue;
1209 SmallVector<VarLoc, 32> VarLocs;
1210 collectAllVarLocs(VarLocs, L, VarLocIDs);
1211 Out << "MBB: " << BB.getNumber() << ":\n";
1212 for (const VarLoc &VL : VarLocs) {
1213 Out << " Var: " << VL.Var.getVariable()->getName();
1214 Out << " MI: ";
1215 VL.dump(TRI, Out);
1216 }
1217 }
1218 Out << "\n";
1219}
1220#endif
1221
1222VarLocBasedLDV::VarLoc::SpillLoc
1223VarLocBasedLDV::extractSpillBaseRegAndOffset(const MachineInstr &MI) {
1224 assert(MI.hasOneMemOperand() &&(static_cast <bool> (MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?"
) ? void (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1225, __extension__ __PRETTY_FUNCTION__))
1225 "Spill instruction does not have exactly one memory operand?")(static_cast <bool> (MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?"
) ? void (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1225, __extension__ __PRETTY_FUNCTION__))
;
1226 auto MMOI = MI.memoperands_begin();
1227 const PseudoSourceValue *PVal = (*MMOI)->getPseudoValue();
1228 assert(PVal->kind() == PseudoSourceValue::FixedStack &&(static_cast <bool> (PVal->kind() == PseudoSourceValue
::FixedStack && "Inconsistent memory operand in spill instruction"
) ? void (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1229, __extension__ __PRETTY_FUNCTION__))
1229 "Inconsistent memory operand in spill instruction")(static_cast <bool> (PVal->kind() == PseudoSourceValue
::FixedStack && "Inconsistent memory operand in spill instruction"
) ? void (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1229, __extension__ __PRETTY_FUNCTION__))
;
1230 int FI = cast<FixedStackPseudoSourceValue>(PVal)->getFrameIndex();
1231 const MachineBasicBlock *MBB = MI.getParent();
1232 Register Reg;
1233 StackOffset Offset = TFI->getFrameIndexReference(*MBB->getParent(), FI, Reg);
1234 return {Reg, Offset};
1235}
1236
1237/// Do cleanup of \p EntryValTransfers created by \p TRInst, by removing the
1238/// Transfer, which uses the to-be-deleted \p EntryVL.
1239void VarLocBasedLDV::cleanupEntryValueTransfers(
1240 const MachineInstr *TRInst, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
1241 const VarLoc &EntryVL, InstToEntryLocMap &EntryValTransfers) {
1242 if (EntryValTransfers.empty() || TRInst == nullptr)
1243 return;
1244
1245 auto TransRange = EntryValTransfers.equal_range(TRInst);
1246 for (auto TDPair : llvm::make_range(TransRange.first, TransRange.second)) {
1247 const VarLoc &EmittedEV = VarLocIDs[TDPair.second];
1248 if (std::tie(EntryVL.Var, EntryVL.Locs[0].Value.RegNo, EntryVL.Expr) ==
1249 std::tie(EmittedEV.Var, EmittedEV.Locs[0].Value.RegNo,
1250 EmittedEV.Expr)) {
1251 OpenRanges.erase(EmittedEV);
1252 EntryValTransfers.erase(TRInst);
1253 break;
1254 }
1255 }
1256}
1257
1258/// Try to salvage the debug entry value if we encounter a new debug value
1259/// describing the same parameter, otherwise stop tracking the value. Return
1260/// true if we should stop tracking the entry value and do the cleanup of
1261/// emitted Entry Value Transfers, otherwise return false.
1262void VarLocBasedLDV::removeEntryValue(const MachineInstr &MI,
1263 OpenRangesSet &OpenRanges,
1264 VarLocMap &VarLocIDs,
1265 const VarLoc &EntryVL,
1266 InstToEntryLocMap &EntryValTransfers,
1267 RegDefToInstMap &RegSetInstrs) {
1268 // Skip the DBG_VALUE which is the debug entry value itself.
1269 if (&MI == &EntryVL.MI)
1270 return;
1271
1272 // If the parameter's location is not register location, we can not track
1273 // the entry value any more. It doesn't have the TransferInst which defines
1274 // register, so no Entry Value Transfers have been emitted already.
1275 if (!MI.getDebugOperand(0).isReg())
1276 return;
1277
1278 // Try to get non-debug instruction responsible for the DBG_VALUE.
1279 const MachineInstr *TransferInst = nullptr;
1280 Register Reg = MI.getDebugOperand(0).getReg();
1281 if (Reg.isValid() && RegSetInstrs.find(Reg) != RegSetInstrs.end())
1282 TransferInst = RegSetInstrs.find(Reg)->second;
1283
1284 // Case of the parameter's DBG_VALUE at the start of entry MBB.
1285 if (!TransferInst && !LastNonDbgMI && MI.getParent()->isEntryBlock())
1286 return;
1287
1288 // If the debug expression from the DBG_VALUE is not empty, we can assume the
1289 // parameter's value has changed indicating that we should stop tracking its
1290 // entry value as well.
1291 if (MI.getDebugExpression()->getNumElements() == 0 && TransferInst) {
1292 // If the DBG_VALUE comes from a copy instruction that copies the entry
1293 // value, it means the parameter's value has not changed and we should be
1294 // able to use its entry value.
1295 // TODO: Try to keep tracking of an entry value if we encounter a propagated
1296 // DBG_VALUE describing the copy of the entry value. (Propagated entry value
1297 // does not indicate the parameter modification.)
1298 auto DestSrc = TII->isCopyInstr(*TransferInst);
1299 if (DestSrc) {
1300 const MachineOperand *SrcRegOp, *DestRegOp;
1301 SrcRegOp = DestSrc->Source;
1302 DestRegOp = DestSrc->Destination;
1303 if (Reg == DestRegOp->getReg()) {
1304 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1305 const VarLoc &VL = VarLocIDs[LocIndex::fromRawInteger(ID)];
1306 if (VL.isEntryValueCopyBackupReg(Reg) &&
1307 // Entry Values should not be variadic.
1308 VL.MI.getDebugOperand(0).getReg() == SrcRegOp->getReg())
1309 return;
1310 }
1311 }
1312 }
1313 }
1314
1315 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)
1316 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)
1317 /*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)
1318 /*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)
;
1319 cleanupEntryValueTransfers(TransferInst, OpenRanges, VarLocIDs, EntryVL,
1320 EntryValTransfers);
1321 OpenRanges.erase(EntryVL);
1322}
1323
1324/// End all previous ranges related to @MI and start a new range from @MI
1325/// if it is a DBG_VALUE instr.
1326void VarLocBasedLDV::transferDebugValue(const MachineInstr &MI,
1327 OpenRangesSet &OpenRanges,
1328 VarLocMap &VarLocIDs,
1329 InstToEntryLocMap &EntryValTransfers,
1330 RegDefToInstMap &RegSetInstrs) {
1331 if (!MI.isDebugValue())
1332 return;
1333 const DILocalVariable *Var = MI.getDebugVariable();
1334 const DIExpression *Expr = MI.getDebugExpression();
1335 const DILocation *DebugLoc = MI.getDebugLoc();
1336 const DILocation *InlinedAt = DebugLoc->getInlinedAt();
1337 assert(Var->isValidLocationForIntrinsic(DebugLoc) &&(static_cast <bool> (Var->isValidLocationForIntrinsic
(DebugLoc) && "Expected inlined-at fields to agree") ?
void (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
1338 "Expected inlined-at fields to agree")(static_cast <bool> (Var->isValidLocationForIntrinsic
(DebugLoc) && "Expected inlined-at fields to agree") ?
void (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
;
1339
1340 DebugVariable V(Var, Expr, InlinedAt);
1341
1342 // Check if this DBG_VALUE indicates a parameter's value changing.
1343 // If that is the case, we should stop tracking its entry value.
1344 auto EntryValBackupID = OpenRanges.getEntryValueBackup(V);
1345 if (Var->isParameter() && EntryValBackupID) {
1346 const VarLoc &EntryVL = VarLocIDs[EntryValBackupID->back()];
1347 removeEntryValue(MI, OpenRanges, VarLocIDs, EntryVL, EntryValTransfers,
1348 RegSetInstrs);
1349 }
1350
1351 if (all_of(MI.debug_operands(), [](const MachineOperand &MO) {
1352 return (MO.isReg() && MO.getReg()) || MO.isImm() || MO.isFPImm() ||
1353 MO.isCImm();
1354 })) {
1355 // Use normal VarLoc constructor for registers and immediates.
1356 VarLoc VL(MI, LS);
1357 // End all previous ranges of VL.Var.
1358 OpenRanges.erase(VL);
1359
1360 LocIndices IDs = VarLocIDs.insert(VL);
1361 // Add the VarLoc to OpenRanges from this DBG_VALUE.
1362 OpenRanges.insert(IDs, VL);
1363 } else if (MI.memoperands().size() > 0) {
1364 llvm_unreachable("DBG_VALUE with mem operand encountered after regalloc?")::llvm::llvm_unreachable_internal("DBG_VALUE with mem operand encountered after regalloc?"
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1364)
;
1365 } else {
1366 // This must be an undefined location. If it has an open range, erase it.
1367 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1368, __extension__ __PRETTY_FUNCTION__))
1368 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1368, __extension__ __PRETTY_FUNCTION__))
;
1369 VarLoc VL(MI, LS);
1370 OpenRanges.erase(VL);
1371 }
1372}
1373
1374// This should be removed later, doesn't fit the new design.
1375void VarLocBasedLDV::collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
1376 const VarLocSet &CollectFrom,
1377 const VarLocMap &VarLocIDs) {
1378 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains all
1379 // possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which live
1380 // in Reg.
1381 uint64_t FirstIndex = LocIndex::rawIndexForReg(LocIndex::kUniversalLocation);
1382 uint64_t FirstInvalidIndex =
1383 LocIndex::rawIndexForReg(LocIndex::kUniversalLocation + 1);
1384 // Iterate through that half-open interval and collect all the set IDs.
1385 for (auto It = CollectFrom.find(FirstIndex), End = CollectFrom.end();
1386 It != End && *It < FirstInvalidIndex; ++It) {
1387 LocIndex RegIdx = LocIndex::fromRawInteger(*It);
1388 Collected.push_back(VarLocIDs[RegIdx]);
1389 }
1390}
1391
1392/// Turn the entry value backup locations into primary locations.
1393void VarLocBasedLDV::emitEntryValues(MachineInstr &MI,
1394 OpenRangesSet &OpenRanges,
1395 VarLocMap &VarLocIDs,
1396 InstToEntryLocMap &EntryValTransfers,
1397 VarLocsInRange &KillSet) {
1398 // Do not insert entry value locations after a terminator.
1399 if (MI.isTerminator())
1400 return;
1401
1402 for (uint32_t ID : KillSet) {
1403 // The KillSet IDs are indices for the universal location bucket.
1404 LocIndex Idx = LocIndex(LocIndex::kUniversalLocation, ID);
1405 const VarLoc &VL = VarLocIDs[Idx];
1406 if (!VL.Var.getVariable()->isParameter())
1407 continue;
1408
1409 auto DebugVar = VL.Var;
1410 Optional<LocIndices> EntryValBackupIDs =
1411 OpenRanges.getEntryValueBackup(DebugVar);
1412
1413 // If the parameter has the entry value backup, it means we should
1414 // be able to use its entry value.
1415 if (!EntryValBackupIDs)
1416 continue;
1417
1418 const VarLoc &EntryVL = VarLocIDs[EntryValBackupIDs->back()];
1419 VarLoc EntryLoc = VarLoc::CreateEntryLoc(EntryVL.MI, LS, EntryVL.Expr,
1420 EntryVL.Locs[0].Value.RegNo);
1421 LocIndices EntryValueIDs = VarLocIDs.insert(EntryLoc);
1422 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1423, __extension__ __PRETTY_FUNCTION__))
1423 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1423, __extension__ __PRETTY_FUNCTION__))
;
1424 EntryValTransfers.insert({&MI, EntryValueIDs.back()});
1425 OpenRanges.insert(EntryValueIDs, EntryLoc);
1426 }
1427}
1428
1429/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
1430/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
1431/// new VarLoc. If \p NewReg is different than default zero value then the
1432/// new location will be register location created by the copy like instruction,
1433/// otherwise it is variable's location on the stack.
1434void VarLocBasedLDV::insertTransferDebugPair(
1435 MachineInstr &MI, OpenRangesSet &OpenRanges, TransferMap &Transfers,
1436 VarLocMap &VarLocIDs, LocIndex OldVarID, TransferKind Kind,
1437 const VarLoc::MachineLoc &OldLoc, Register NewReg) {
1438 const VarLoc &OldVarLoc = VarLocIDs[OldVarID];
1439
1440 auto ProcessVarLoc = [&MI, &OpenRanges, &Transfers, &VarLocIDs](VarLoc &VL) {
1441 LocIndices LocIds = VarLocIDs.insert(VL);
1442
1443 // Close this variable's previous location range.
1444 OpenRanges.erase(VL);
1445
1446 // Record the new location as an open range, and a postponed transfer
1447 // inserting a DBG_VALUE for this location.
1448 OpenRanges.insert(LocIds, VL);
1449 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1449, __extension__ __PRETTY_FUNCTION__))
;
1450 TransferDebugPair MIP = {&MI, LocIds.back()};
1451 Transfers.push_back(MIP);
1452 };
1453
1454 // End all previous ranges of VL.Var.
1455 OpenRanges.erase(VarLocIDs[OldVarID]);
1456 switch (Kind) {
1457 case TransferKind::TransferCopy: {
1458 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1459, __extension__ __PRETTY_FUNCTION__))
1459 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1459, __extension__ __PRETTY_FUNCTION__))
;
1460 // Create a DBG_VALUE instruction to describe the Var in its new
1461 // register location.
1462 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1463 ProcessVarLoc(VL);
1464 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1465 dbgs() << "Creating VarLoc for register copy:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1466 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1467 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
;
1468 return;
1469 }
1470 case TransferKind::TransferSpill: {
1471 // Create a DBG_VALUE instruction to describe the Var in its spilled
1472 // location.
1473 VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI);
1474 VarLoc VL = VarLoc::CreateSpillLoc(
1475 OldVarLoc, OldLoc, SpillLocation.SpillBase, SpillLocation.SpillOffset);
1476 ProcessVarLoc(VL);
1477 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1478 dbgs() << "Creating VarLoc for spill:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1479 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1480 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
;
1481 return;
1482 }
1483 case TransferKind::TransferRestore: {
1484 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1485, __extension__ __PRETTY_FUNCTION__))
1485 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1485, __extension__ __PRETTY_FUNCTION__))
;
1486 // DebugInstr refers to the pre-spill location, therefore we can reuse
1487 // its expression.
1488 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1489 ProcessVarLoc(VL);
1490 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1491 dbgs() << "Creating VarLoc for restore:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1492 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1493 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
;
1494 return;
1495 }
1496 }
1497 llvm_unreachable("Invalid transfer kind")::llvm::llvm_unreachable_internal("Invalid transfer kind", "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1497)
;
1498}
1499
1500/// A definition of a register may mark the end of a range.
1501void VarLocBasedLDV::transferRegisterDef(MachineInstr &MI,
1502 OpenRangesSet &OpenRanges,
1503 VarLocMap &VarLocIDs,
1504 InstToEntryLocMap &EntryValTransfers,
1505 RegDefToInstMap &RegSetInstrs) {
1506
1507 // Meta Instructions do not affect the debug liveness of any register they
1508 // define.
1509 if (MI.isMetaInstruction())
1510 return;
1511
1512 MachineFunction *MF = MI.getMF();
1513 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1514 Register SP = TLI->getStackPointerRegisterToSaveRestore();
1515
1516 // Find the regs killed by MI, and find regmasks of preserved regs.
1517 DefinedRegsSet DeadRegs;
1518 SmallVector<const uint32_t *, 4> RegMasks;
1519 for (const MachineOperand &MO : MI.operands()) {
1520 // Determine whether the operand is a register def.
1521 if (MO.isReg() && MO.isDef() && MO.getReg() &&
1522 Register::isPhysicalRegister(MO.getReg()) &&
1523 !(MI.isCall() && MO.getReg() == SP)) {
1524 // Remove ranges of all aliased registers.
1525 for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
1526 // FIXME: Can we break out of this loop early if no insertion occurs?
1527 DeadRegs.insert(*RAI);
1528 if (RegSetInstrs.find(MO.getReg()) != RegSetInstrs.end())
1529 RegSetInstrs.erase(MO.getReg());
1530 RegSetInstrs.insert({MO.getReg(), &MI});
1531 } else if (MO.isRegMask()) {
1532 RegMasks.push_back(MO.getRegMask());
1533 }
1534 }
1535
1536 // Erase VarLocs which reside in one of the dead registers. For performance
1537 // reasons, it's critical to not iterate over the full set of open VarLocs.
1538 // Iterate over the set of dying/used regs instead.
1539 if (!RegMasks.empty()) {
1540 SmallVector<Register, 32> UsedRegs;
1541 getUsedRegs(OpenRanges.getVarLocs(), UsedRegs);
1542 for (Register Reg : UsedRegs) {
1543 // Remove ranges of all clobbered registers. Register masks don't usually
1544 // list SP as preserved. Assume that call instructions never clobber SP,
1545 // because some backends (e.g., AArch64) never list SP in the regmask.
1546 // While the debug info may be off for an instruction or two around
1547 // callee-cleanup calls, transferring the DEBUG_VALUE across the call is
1548 // still a better user experience.
1549 if (Reg == SP)
1550 continue;
1551 bool AnyRegMaskKillsReg =
1552 any_of(RegMasks, [Reg](const uint32_t *RegMask) {
1553 return MachineOperand::clobbersPhysReg(RegMask, Reg);
1554 });
1555 if (AnyRegMaskKillsReg)
1556 DeadRegs.insert(Reg);
1557 if (AnyRegMaskKillsReg) {
1558 if (RegSetInstrs.find(Reg) != RegSetInstrs.end())
1559 RegSetInstrs.erase(Reg);
1560 RegSetInstrs.insert({Reg, &MI});
1561 }
1562 }
1563 }
1564
1565 if (DeadRegs.empty())
1566 return;
1567
1568 VarLocsInRange KillSet;
1569 collectIDsForRegs(KillSet, DeadRegs, OpenRanges.getVarLocs(), VarLocIDs);
1570 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kUniversalLocation);
1571
1572 if (TPC) {
1573 auto &TM = TPC->getTM<TargetMachine>();
1574 if (TM.Options.ShouldEmitDebugEntryValues())
1575 emitEntryValues(MI, OpenRanges, VarLocIDs, EntryValTransfers, KillSet);
1576 }
1577}
1578
1579bool VarLocBasedLDV::isSpillInstruction(const MachineInstr &MI,
1580 MachineFunction *MF) {
1581 // TODO: Handle multiple stores folded into one.
1582 if (!MI.hasOneMemOperand())
1583 return false;
1584
1585 if (!MI.getSpillSize(TII) && !MI.getFoldedSpillSize(TII))
1586 return false; // This is not a spill instruction, since no valid size was
1587 // returned from either function.
1588
1589 return true;
1590}
1591
1592bool VarLocBasedLDV::isLocationSpill(const MachineInstr &MI,
1593 MachineFunction *MF, Register &Reg) {
1594 if (!isSpillInstruction(MI, MF))
1595 return false;
1596
1597 auto isKilledReg = [&](const MachineOperand MO, Register &Reg) {
1598 if (!MO.isReg() || !MO.isUse()) {
1599 Reg = 0;
1600 return false;
1601 }
1602 Reg = MO.getReg();
1603 return MO.isKill();
1604 };
1605
1606 for (const MachineOperand &MO : MI.operands()) {
1607 // In a spill instruction generated by the InlineSpiller the spilled
1608 // register has its kill flag set.
1609 if (isKilledReg(MO, Reg))
1610 return true;
1611 if (Reg != 0) {
1612 // Check whether next instruction kills the spilled register.
1613 // FIXME: Current solution does not cover search for killed register in
1614 // bundles and instructions further down the chain.
1615 auto NextI = std::next(MI.getIterator());
1616 // Skip next instruction that points to basic block end iterator.
1617 if (MI.getParent()->end() == NextI)
1618 continue;
1619 Register RegNext;
1620 for (const MachineOperand &MONext : NextI->operands()) {
1621 // Return true if we came across the register from the
1622 // previous spill instruction that is killed in NextI.
1623 if (isKilledReg(MONext, RegNext) && RegNext == Reg)
1624 return true;
1625 }
1626 }
1627 }
1628 // Return false if we didn't find spilled register.
1629 return false;
1630}
1631
1632Optional<VarLocBasedLDV::VarLoc::SpillLoc>
1633VarLocBasedLDV::isRestoreInstruction(const MachineInstr &MI,
1634 MachineFunction *MF, Register &Reg) {
1635 if (!MI.hasOneMemOperand())
1636 return None;
1637
1638 // FIXME: Handle folded restore instructions with more than one memory
1639 // operand.
1640 if (MI.getRestoreSize(TII)) {
1641 Reg = MI.getOperand(0).getReg();
1642 return extractSpillBaseRegAndOffset(MI);
1643 }
1644 return None;
1645}
1646
1647/// A spilled register may indicate that we have to end the current range of
1648/// a variable and create a new one for the spill location.
1649/// A restored register may indicate the reverse situation.
1650/// We don't want to insert any instructions in process(), so we just create
1651/// the DBG_VALUE without inserting it and keep track of it in \p Transfers.
1652/// It will be inserted into the BB when we're done iterating over the
1653/// instructions.
1654void VarLocBasedLDV::transferSpillOrRestoreInst(MachineInstr &MI,
1655 OpenRangesSet &OpenRanges,
1656 VarLocMap &VarLocIDs,
1657 TransferMap &Transfers) {
1658 MachineFunction *MF = MI.getMF();
1659 TransferKind TKind;
1660 Register Reg;
1661 Optional<VarLoc::SpillLoc> Loc;
1662
1663 LLVM_DEBUG(dbgs() << "Examining instruction: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Examining instruction: "
; MI.dump();; } } while (false)
;
1664
1665 // First, if there are any DBG_VALUEs pointing at a spill slot that is
1666 // written to, then close the variable location. The value in memory
1667 // will have changed.
1668 VarLocsInRange KillSet;
1669 if (isSpillInstruction(MI, MF)) {
1670 Loc = extractSpillBaseRegAndOffset(MI);
1671 for (uint64_t ID : OpenRanges.getSpillVarLocs()) {
1672 LocIndex Idx = LocIndex::fromRawInteger(ID);
1673 const VarLoc &VL = VarLocIDs[Idx];
1674 assert(VL.containsSpillLocs() && "Broken VarLocSet?")(static_cast <bool> (VL.containsSpillLocs() && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("VL.containsSpillLocs() && \"Broken VarLocSet?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1674, __extension__ __PRETTY_FUNCTION__))
;
1675 if (VL.usesSpillLoc(*Loc)) {
1676 // This location is overwritten by the current instruction -- terminate
1677 // the open range, and insert an explicit DBG_VALUE $noreg.
1678 //
1679 // Doing this at a later stage would require re-interpreting all
1680 // DBG_VALUes and DIExpressions to identify whether they point at
1681 // memory, and then analysing all memory writes to see if they
1682 // overwrite that memory, which is expensive.
1683 //
1684 // At this stage, we already know which DBG_VALUEs are for spills and
1685 // where they are located; it's best to fix handle overwrites now.
1686 KillSet.insert(ID);
1687 unsigned SpillLocIdx = VL.getSpillLocIdx(*Loc);
1688 VarLoc::MachineLoc OldLoc = VL.Locs[SpillLocIdx];
1689 VarLoc UndefVL = VarLoc::CreateCopyLoc(VL, OldLoc, 0);
1690 LocIndices UndefLocIDs = VarLocIDs.insert(UndefVL);
1691 Transfers.push_back({&MI, UndefLocIDs.back()});
1692 }
1693 }
1694 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kSpillLocation);
1695 }
1696
1697 // Try to recognise spill and restore instructions that may create a new
1698 // variable location.
1699 if (isLocationSpill(MI, MF, Reg)) {
1700 TKind = TransferKind::TransferSpill;
1701 LLVM_DEBUG(dbgs() << "Recognized as spill: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as spill: "
; MI.dump();; } } while (false)
;
1702 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1703 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1704 } else {
1705 if (!(Loc = isRestoreInstruction(MI, MF, Reg)))
1706 return;
1707 TKind = TransferKind::TransferRestore;
1708 LLVM_DEBUG(dbgs() << "Recognized as restore: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as restore: "
; MI.dump();; } } while (false)
;
1709 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1710 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1711 }
1712 // Check if the register or spill location is the location of a debug value.
1713 auto TransferCandidates = OpenRanges.getEmptyVarLocRange();
1714 if (TKind == TransferKind::TransferSpill)
1715 TransferCandidates = OpenRanges.getRegisterVarLocs(Reg);
1716 else if (TKind == TransferKind::TransferRestore)
1717 TransferCandidates = OpenRanges.getSpillVarLocs();
1718 for (uint64_t ID : TransferCandidates) {
1719 LocIndex Idx = LocIndex::fromRawInteger(ID);
1720 const VarLoc &VL = VarLocIDs[Idx];
1721 unsigned LocIdx;
1722 if (TKind == TransferKind::TransferSpill) {
1723 assert(VL.usesReg(Reg) && "Broken VarLocSet?")(static_cast <bool> (VL.usesReg(Reg) && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("VL.usesReg(Reg) && \"Broken VarLocSet?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1723, __extension__ __PRETTY_FUNCTION__))
;
1724 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)
1725 << 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)
;
1726 LocIdx = VL.getRegIdx(Reg);
1727 } else {
1728 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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1729, __extension__ __PRETTY_FUNCTION__))
1729 "Broken VarLocSet?")(static_cast <bool> (TKind == TransferKind::TransferRestore
&& VL.containsSpillLocs() && "Broken VarLocSet?"
) ? void (0) : __assert_fail ("TKind == TransferKind::TransferRestore && VL.containsSpillLocs() && \"Broken VarLocSet?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1729, __extension__ __PRETTY_FUNCTION__))
;
1730 if (!VL.usesSpillLoc(*Loc))
1731 // The spill location is not the location of a debug value.
1732 continue;
1733 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)
1734 << 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)
;
1735 LocIdx = VL.getSpillLocIdx(*Loc);
1736 }
1737 VarLoc::MachineLoc MLoc = VL.Locs[LocIdx];
1738 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx, TKind,
1739 MLoc, Reg);
1740 // FIXME: A comment should explain why it's correct to return early here,
1741 // if that is in fact correct.
1742 return;
1743 }
1744}
1745
1746/// If \p MI is a register copy instruction, that copies a previously tracked
1747/// value from one register to another register that is callee saved, we
1748/// create new DBG_VALUE instruction described with copy destination register.
1749void VarLocBasedLDV::transferRegisterCopy(MachineInstr &MI,
1750 OpenRangesSet &OpenRanges,
1751 VarLocMap &VarLocIDs,
1752 TransferMap &Transfers) {
1753 auto DestSrc = TII->isCopyInstr(MI);
1754 if (!DestSrc)
1755 return;
1756
1757 const MachineOperand *DestRegOp = DestSrc->Destination;
1758 const MachineOperand *SrcRegOp = DestSrc->Source;
1759
1760 if (!DestRegOp->isDef())
1761 return;
1762
1763 auto isCalleeSavedReg = [&](Register Reg) {
1764 for (MCRegAliasIterator RAI(Reg, TRI, true); RAI.isValid(); ++RAI)
1765 if (CalleeSavedRegs.test(*RAI))
1766 return true;
1767 return false;
1768 };
1769
1770 Register SrcReg = SrcRegOp->getReg();
1771 Register DestReg = DestRegOp->getReg();
1772
1773 // We want to recognize instructions where destination register is callee
1774 // saved register. If register that could be clobbered by the call is
1775 // included, there would be a great chance that it is going to be clobbered
1776 // soon. It is more likely that previous register location, which is callee
1777 // saved, is going to stay unclobbered longer, even if it is killed.
1778 if (!isCalleeSavedReg(DestReg))
1779 return;
1780
1781 // Remember an entry value movement. If we encounter a new debug value of
1782 // a parameter describing only a moving of the value around, rather then
1783 // modifying it, we are still able to use the entry value if needed.
1784 if (isRegOtherThanSPAndFP(*DestRegOp, MI, TRI)) {
1785 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1786 LocIndex Idx = LocIndex::fromRawInteger(ID);
1787 const VarLoc &VL = VarLocIDs[Idx];
1788 if (VL.isEntryValueBackupReg(SrcReg)) {
1789 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)
;
1790 VarLoc EntryValLocCopyBackup =
1791 VarLoc::CreateEntryCopyBackupLoc(VL.MI, LS, VL.Expr, DestReg);
1792 // Stop tracking the original entry value.
1793 OpenRanges.erase(VL);
1794
1795 // Start tracking the entry value copy.
1796 LocIndices EntryValCopyLocIDs = VarLocIDs.insert(EntryValLocCopyBackup);
1797 OpenRanges.insert(EntryValCopyLocIDs, EntryValLocCopyBackup);
1798 break;
1799 }
1800 }
1801 }
1802
1803 if (!SrcRegOp->isKill())
1804 return;
1805
1806 for (uint64_t ID : OpenRanges.getRegisterVarLocs(SrcReg)) {
1807 LocIndex Idx = LocIndex::fromRawInteger(ID);
1808 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?\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1808, __extension__ __PRETTY_FUNCTION__))
;
1809 VarLoc::MachineLocValue Loc;
1810 Loc.RegNo = SrcReg;
1811 VarLoc::MachineLoc MLoc{VarLoc::MachineLocKind::RegisterKind, Loc};
1812 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx,
1813 TransferKind::TransferCopy, MLoc, DestReg);
1814 // FIXME: A comment should explain why it's correct to return early here,
1815 // if that is in fact correct.
1816 return;
1817 }
1818}
1819
1820/// Terminate all open ranges at the end of the current basic block.
1821bool VarLocBasedLDV::transferTerminator(MachineBasicBlock *CurMBB,
1822 OpenRangesSet &OpenRanges,
1823 VarLocInMBB &OutLocs,
1824 const VarLocMap &VarLocIDs) {
1825 bool Changed = false;
1826 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)
1827 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)
1828 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)
1829 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)
1830 // 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)
1831 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)
1832 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)
1833 }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)
1834 })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)
;
1835 VarLocSet &VLS = getVarLocsInMBB(CurMBB, OutLocs);
1836 Changed = VLS != OpenRanges.getVarLocs();
1837 // New OutLocs set may be different due to spill, restore or register
1838 // copy instruction processing.
1839 if (Changed)
1840 VLS = OpenRanges.getVarLocs();
1841 OpenRanges.clear();
1842 return Changed;
1843}
1844
1845/// Accumulate a mapping between each DILocalVariable fragment and other
1846/// fragments of that DILocalVariable which overlap. This reduces work during
1847/// the data-flow stage from "Find any overlapping fragments" to "Check if the
1848/// known-to-overlap fragments are present".
1849/// \param MI A previously unprocessed DEBUG_VALUE instruction to analyze for
1850/// fragment usage.
1851/// \param SeenFragments Map from DILocalVariable to all fragments of that
1852/// Variable which are known to exist.
1853/// \param OverlappingFragments The overlap map being constructed, from one
1854/// Var/Fragment pair to a vector of fragments known to overlap.
1855void VarLocBasedLDV::accumulateFragmentMap(MachineInstr &MI,
1856 VarToFragments &SeenFragments,
1857 OverlapMap &OverlappingFragments) {
1858 DebugVariable MIVar(MI.getDebugVariable(), MI.getDebugExpression(),
1859 MI.getDebugLoc()->getInlinedAt());
1860 FragmentInfo ThisFragment = MIVar.getFragmentOrDefault();
1861
1862 // If this is the first sighting of this variable, then we are guaranteed
1863 // there are currently no overlapping fragments either. Initialize the set
1864 // of seen fragments, record no overlaps for the current one, and return.
1865 auto SeenIt = SeenFragments.find(MIVar.getVariable());
1866 if (SeenIt == SeenFragments.end()) {
1867 SmallSet<FragmentInfo, 4> OneFragment;
1868 OneFragment.insert(ThisFragment);
1869 SeenFragments.insert({MIVar.getVariable(), OneFragment});
1870
1871 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1872 return;
1873 }
1874
1875 // If this particular Variable/Fragment pair already exists in the overlap
1876 // map, it has already been accounted for.
1877 auto IsInOLapMap =
1878 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1879 if (!IsInOLapMap.second)
1880 return;
1881
1882 auto &ThisFragmentsOverlaps = IsInOLapMap.first->second;
1883 auto &AllSeenFragments = SeenIt->second;
1884
1885 // Otherwise, examine all other seen fragments for this variable, with "this"
1886 // fragment being a previously unseen fragment. Record any pair of
1887 // overlapping fragments.
1888 for (auto &ASeenFragment : AllSeenFragments) {
1889 // Does this previously seen fragment overlap?
1890 if (DIExpression::fragmentsOverlap(ThisFragment, ASeenFragment)) {
1891 // Yes: Mark the current fragment as being overlapped.
1892 ThisFragmentsOverlaps.push_back(ASeenFragment);
1893 // Mark the previously seen fragment as being overlapped by the current
1894 // one.
1895 auto ASeenFragmentsOverlaps =
1896 OverlappingFragments.find({MIVar.getVariable(), ASeenFragment});
1897 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1898, __extension__ __PRETTY_FUNCTION__))
1898 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1898, __extension__ __PRETTY_FUNCTION__))
;
1899 ASeenFragmentsOverlaps->second.push_back(ThisFragment);
1900 }
1901 }
1902
1903 AllSeenFragments.insert(ThisFragment);
1904}
1905
1906/// This routine creates OpenRanges.
1907void VarLocBasedLDV::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
1908 VarLocMap &VarLocIDs, TransferMap &Transfers,
1909 InstToEntryLocMap &EntryValTransfers,
1910 RegDefToInstMap &RegSetInstrs) {
1911 if (!MI.isDebugInstr())
1912 LastNonDbgMI = &MI;
1913 transferDebugValue(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1914 RegSetInstrs);
1915 transferRegisterDef(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1916 RegSetInstrs);
1917 transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
1918 transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
1919}
1920
1921/// This routine joins the analysis results of all incoming edges in @MBB by
1922/// inserting a new DBG_VALUE instruction at the start of the @MBB - if the same
1923/// source variable in all the predecessors of @MBB reside in the same location.
1924bool VarLocBasedLDV::join(
1925 MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1926 const VarLocMap &VarLocIDs,
1927 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1928 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks) {
1929 LLVM_DEBUG(dbgs() << "join MBB: " << MBB.getNumber() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "join MBB: " << MBB
.getNumber() << "\n"; } } while (false)
;
1930
1931 VarLocSet InLocsT(Alloc); // Temporary incoming locations.
1932
1933 // For all predecessors of this MBB, find the set of VarLocs that
1934 // can be joined.
1935 int NumVisited = 0;
1936 for (auto p : MBB.predecessors()) {
1937 // Ignore backedges if we have not visited the predecessor yet. As the
1938 // predecessor hasn't yet had locations propagated into it, most locations
1939 // will not yet be valid, so treat them as all being uninitialized and
1940 // potentially valid. If a location guessed to be correct here is
1941 // invalidated later, we will remove it when we revisit this block.
1942 if (!Visited.count(p)) {
1943 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)
1944 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << " ignoring unvisited pred MBB: "
<< p->getNumber() << "\n"; } } while (false)
;
1945 continue;
1946 }
1947 auto OL = OutLocs.find(p);
1948 // Join is null in case of empty OutLocs from any of the pred.
1949 if (OL == OutLocs.end())
1950 return false;
1951
1952 // Just copy over the Out locs to incoming locs for the first visited
1953 // predecessor, and for all other predecessors join the Out locs.
1954 VarLocSet &OutLocVLS = *OL->second.get();
1955 if (!NumVisited)
1956 InLocsT = OutLocVLS;
1957 else
1958 InLocsT &= OutLocVLS;
1959
1960 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)
1961 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)
1962 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)
1963 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)
1964 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)
1965 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)
1966 << 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)
1967 }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)
1968 })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)
;
1969
1970 NumVisited++;
1971 }
1972
1973 // Filter out DBG_VALUES that are out of scope.
1974 VarLocSet KillSet(Alloc);
1975 bool IsArtificial = ArtificialBlocks.count(&MBB);
1976 if (!IsArtificial) {
1977 for (uint64_t ID : InLocsT) {
1978 LocIndex Idx = LocIndex::fromRawInteger(ID);
1979 if (!VarLocIDs[Idx].dominates(LS, MBB)) {
1980 KillSet.set(ID);
1981 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)
1982 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)
1983 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)
1984 })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)
;
1985 }
1986 }
1987 }
1988 InLocsT.intersectWithComplement(KillSet);
1989
1990 // As we are processing blocks in reverse post-order we
1991 // should have processed at least one predecessor, unless it
1992 // is the entry block which has no predecessor.
1993 assert((NumVisited || MBB.pred_empty()) &&(static_cast <bool> ((NumVisited || MBB.pred_empty()) &&
"Should have processed at least one predecessor") ? void (0)
: __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1994, __extension__ __PRETTY_FUNCTION__))
1994 "Should have processed at least one predecessor")(static_cast <bool> ((NumVisited || MBB.pred_empty()) &&
"Should have processed at least one predecessor") ? void (0)
: __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1994, __extension__ __PRETTY_FUNCTION__))
;
1995
1996 VarLocSet &ILS = getVarLocsInMBB(&MBB, InLocs);
1997 bool Changed = false;
1998 if (ILS != InLocsT) {
1999 ILS = InLocsT;
2000 Changed = true;
2001 }
2002
2003 return Changed;
2004}
2005
2006void VarLocBasedLDV::flushPendingLocs(VarLocInMBB &PendingInLocs,
2007 VarLocMap &VarLocIDs) {
2008 // PendingInLocs records all locations propagated into blocks, which have
2009 // not had DBG_VALUE insts created. Go through and create those insts now.
2010 for (auto &Iter : PendingInLocs) {
2011 // Map is keyed on a constant pointer, unwrap it so we can insert insts.
2012 auto &MBB = const_cast<MachineBasicBlock &>(*Iter.first);
2013 VarLocSet &Pending = *Iter.second.get();
2014
2015 SmallVector<VarLoc, 32> VarLocs;
2016 collectAllVarLocs(VarLocs, Pending, VarLocIDs);
2017
2018 for (VarLoc DiffIt : VarLocs) {
2019 // The ID location is live-in to MBB -- work out what kind of machine
2020 // location it is and create a DBG_VALUE.
2021 if (DiffIt.isEntryBackupLoc())
2022 continue;
2023 MachineInstr *MI = DiffIt.BuildDbgValue(*MBB.getParent());
2024 MBB.insert(MBB.instr_begin(), MI);
2025
2026 (void)MI;
2027 LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Inserted: "; MI->dump
();; } } while (false)
;
2028 }
2029 }
2030}
2031
2032bool VarLocBasedLDV::isEntryValueCandidate(
2033 const MachineInstr &MI, const DefinedRegsSet &DefinedRegs) const {
2034 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.\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2034, __extension__ __PRETTY_FUNCTION__))
;
2035
2036 // TODO: Add support for local variables that are expressed in terms of
2037 // parameters entry values.
2038 // TODO: Add support for modified arguments that can be expressed
2039 // by using its entry value.
2040 auto *DIVar = MI.getDebugVariable();
2041 if (!DIVar->isParameter())
2042 return false;
2043
2044 // Do not consider parameters that belong to an inlined function.
2045 if (MI.getDebugLoc()->getInlinedAt())
2046 return false;
2047
2048 // Only consider parameters that are described using registers. Parameters
2049 // that are passed on the stack are not yet supported, so ignore debug
2050 // values that are described by the frame or stack pointer.
2051 if (!isRegOtherThanSPAndFP(MI.getDebugOperand(0), MI, TRI))
2052 return false;
2053
2054 // If a parameter's value has been propagated from the caller, then the
2055 // parameter's DBG_VALUE may be described using a register defined by some
2056 // instruction in the entry block, in which case we shouldn't create an
2057 // entry value.
2058 if (DefinedRegs.count(MI.getDebugOperand(0).getReg()))
2059 return false;
2060
2061 // TODO: Add support for parameters that have a pre-existing debug expressions
2062 // (e.g. fragments).
2063 if (MI.getDebugExpression()->getNumElements() > 0)
2064 return false;
2065
2066 return true;
2067}
2068
2069/// Collect all register defines (including aliases) for the given instruction.
2070static void collectRegDefs(const MachineInstr &MI, DefinedRegsSet &Regs,
2071 const TargetRegisterInfo *TRI) {
2072 for (const MachineOperand &MO : MI.operands())
2073 if (MO.isReg() && MO.isDef() && MO.getReg())
2074 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI)
2075 Regs.insert(*AI);
2076}
2077
2078/// This routine records the entry values of function parameters. The values
2079/// could be used as backup values. If we loose the track of some unmodified
2080/// parameters, the backup values will be used as a primary locations.
2081void VarLocBasedLDV::recordEntryValue(const MachineInstr &MI,
2082 const DefinedRegsSet &DefinedRegs,
2083 OpenRangesSet &OpenRanges,
2084 VarLocMap &VarLocIDs) {
2085 if (TPC) {
2086 auto &TM = TPC->getTM<TargetMachine>();
2087 if (!TM.Options.ShouldEmitDebugEntryValues())
2088 return;
2089 }
2090
2091 DebugVariable V(MI.getDebugVariable(), MI.getDebugExpression(),
2092 MI.getDebugLoc()->getInlinedAt());
2093
2094 if (!isEntryValueCandidate(MI, DefinedRegs) ||
2095 OpenRanges.getEntryValueBackup(V))
2096 return;
2097
2098 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)
;
2099
2100 // Create the entry value and use it as a backup location until it is
2101 // valid. It is valid until a parameter is not changed.
2102 DIExpression *NewExpr =
2103 DIExpression::prepend(MI.getDebugExpression(), DIExpression::EntryValue);
2104 VarLoc EntryValLocAsBackup = VarLoc::CreateEntryBackupLoc(MI, LS, NewExpr);
2105 LocIndices EntryValLocIDs = VarLocIDs.insert(EntryValLocAsBackup);
2106 OpenRanges.insert(EntryValLocIDs, EntryValLocAsBackup);
2107}
2108
2109/// Calculate the liveness information for the given machine function and
2110/// extend ranges across basic blocks.
2111bool VarLocBasedLDV::ExtendRanges(MachineFunction &MF,
2112 MachineDominatorTree *DomTree,
2113 TargetPassConfig *TPC, unsigned InputBBLimit,
2114 unsigned InputDbgValLimit) {
2115 (void)DomTree;
2116 LLVM_DEBUG(dbgs() << "\nDebug Range Extension\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "\nDebug Range Extension\n"
; } } while (false)
;
2117
2118 if (!MF.getFunction().getSubprogram())
2119 // VarLocBaseLDV will already have removed all DBG_VALUEs.
2120 return false;
2121
2122 // Skip functions from NoDebug compilation units.
2123 if (MF.getFunction().getSubprogram()->getUnit()->getEmissionKind() ==
2124 DICompileUnit::NoDebug)
2125 return false;
2126
2127 TRI = MF.getSubtarget().getRegisterInfo();
2128 TII = MF.getSubtarget().getInstrInfo();
2129 TFI = MF.getSubtarget().getFrameLowering();
2130 TFI->getCalleeSaves(MF, CalleeSavedRegs);
2131 this->TPC = TPC;
2132 LS.initialize(MF);
2133
2134 bool Changed = false;
2135 bool OLChanged = false;
2136 bool MBBJoined = false;
2137
2138 VarLocMap VarLocIDs; // Map VarLoc<>unique ID for use in bitvectors.
2139 OverlapMap OverlapFragments; // Map of overlapping variable fragments.
2140 OpenRangesSet OpenRanges(Alloc, OverlapFragments);
2141 // Ranges that are open until end of bb.
2142 VarLocInMBB OutLocs; // Ranges that exist beyond bb.
2143 VarLocInMBB InLocs; // Ranges that are incoming after joining.
2144 TransferMap Transfers; // DBG_VALUEs associated with transfers (such as
2145 // spills, copies and restores).
2146 // Map responsible MI to attached Transfer emitted from Backup Entry Value.
2147 InstToEntryLocMap EntryValTransfers;
2148 // Map a Register to the last MI which clobbered it.
2149 RegDefToInstMap RegSetInstrs;
2150
2151 VarToFragments SeenFragments;
2152
2153 // Blocks which are artificial, i.e. blocks which exclusively contain
2154 // instructions without locations, or with line 0 locations.
2155 SmallPtrSet<const MachineBasicBlock *, 16> ArtificialBlocks;
2156
2157 DenseMap<unsigned int, MachineBasicBlock *> OrderToBB;
2158 DenseMap<MachineBasicBlock *, unsigned int> BBToOrder;
2159 std::priority_queue<unsigned int, std::vector<unsigned int>,
2160 std::greater<unsigned int>>
2161 Worklist;
2162 std::priority_queue<unsigned int, std::vector<unsigned int>,
2163 std::greater<unsigned int>>
2164 Pending;
2165
2166 // Set of register defines that are seen when traversing the entry block
2167 // looking for debug entry value candidates.
2168 DefinedRegsSet DefinedRegs;
2169
2170 // Only in the case of entry MBB collect DBG_VALUEs representing
2171 // function parameters in order to generate debug entry values for them.
2172 MachineBasicBlock &First_MBB = *(MF.begin());
2173 for (auto &MI : First_MBB) {
2174 collectRegDefs(MI, DefinedRegs, TRI);
2175 if (MI.isDebugValue())
2176 recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs);
2177 }
2178
2179 // Initialize per-block structures and scan for fragment overlaps.
2180 for (auto &MBB : MF)
2181 for (auto &MI : MBB)
2182 if (MI.isDebugValue())
2183 accumulateFragmentMap(MI, SeenFragments, OverlapFragments);
2184
2185 auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
2186 if (const DebugLoc &DL = MI.getDebugLoc())
2187 return DL.getLine() != 0;
2188 return false;
2189 };
2190 for (auto &MBB : MF)
2191 if (none_of(MBB.instrs(), hasNonArtificialLocation))
2192 ArtificialBlocks.insert(&MBB);
2193
2194 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
2195 "OutLocs after initialization", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
;
2196
2197 ReversePostOrderTraversal<MachineFunction *> RPOT(&MF);
2198 unsigned int RPONumber = 0;
2199 for (MachineBasicBlock *MBB : RPOT) {
2200 OrderToBB[RPONumber] = MBB;
2201 BBToOrder[MBB] = RPONumber;
2202 Worklist.push(RPONumber);
2203 ++RPONumber;
2204 }
2205
2206 if (RPONumber > InputBBLimit) {
2207 unsigned NumInputDbgValues = 0;
2208 for (auto &MBB : MF)
2209 for (auto &MI : MBB)
2210 if (MI.isDebugValue())
2211 ++NumInputDbgValues;
2212 if (NumInputDbgValues > InputDbgValLimit) {
2213 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)
2214 << " 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)
2215 << 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)
2216 << " 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)
;
2217 return false;
2218 }
2219 }
2220
2221 // This is a standard "union of predecessor outs" dataflow problem.
2222 // To solve it, we perform join() and process() using the two worklist method
2223 // until the ranges converge.
2224 // Ranges have converged when both worklists are empty.
2225 SmallPtrSet<const MachineBasicBlock *, 16> Visited;
2226 while (!Worklist.empty() || !Pending.empty()) {
2227 // We track what is on the pending worklist to avoid inserting the same
2228 // thing twice. We could avoid this with a custom priority queue, but this
2229 // is probably not worth it.
2230 SmallPtrSet<MachineBasicBlock *, 16> OnPending;
2231 LLVM_DEBUG(dbgs() << "Processing Worklist\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Processing Worklist\n"
; } } while (false)
;
2232 while (!Worklist.empty()) {
2233 MachineBasicBlock *MBB = OrderToBB[Worklist.top()];
2234 Worklist.pop();
2235 MBBJoined = join(*MBB, OutLocs, InLocs, VarLocIDs, Visited,
2236 ArtificialBlocks);
2237 MBBJoined |= Visited.insert(MBB).second;
2238 if (MBBJoined) {
2239 MBBJoined = false;
Value stored to 'MBBJoined' is never read
2240 Changed = true;
2241 // Now that we have started to extend ranges across BBs we need to
2242 // examine spill, copy and restore instructions to see whether they
2243 // operate with registers that correspond to user variables.
2244 // First load any pending inlocs.
2245 OpenRanges.insertFromLocSet(getVarLocsInMBB(MBB, InLocs), VarLocIDs);
2246 LastNonDbgMI = nullptr;
2247 RegSetInstrs.clear();
2248 for (auto &MI : *MBB)
2249 process(MI, OpenRanges, VarLocIDs, Transfers, EntryValTransfers,
2250 RegSetInstrs);
2251 OLChanged |= transferTerminator(MBB, OpenRanges, OutLocs, VarLocIDs);
2252
2253 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
2254 "OutLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
;
2255 LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
2256 "InLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
;
2257
2258 if (OLChanged) {
2259 OLChanged = false;
2260 for (auto s : MBB->successors())
2261 if (OnPending.insert(s).second) {
2262 Pending.push(BBToOrder[s]);
2263 }
2264 }
2265 }
2266 }
2267 Worklist.swap(Pending);
2268 // At this point, pending must be empty, since it was just the empty
2269 // worklist
2270 assert(Pending.empty() && "Pending should be empty")(static_cast <bool> (Pending.empty() && "Pending should be empty"
) ? void (0) : __assert_fail ("Pending.empty() && \"Pending should be empty\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2270, __extension__ __PRETTY_FUNCTION__))
;
2271 }
2272
2273 // Add any DBG_VALUE instructions created by location transfers.
2274 for (auto &TR : Transfers) {
2275 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2276, __extension__ __PRETTY_FUNCTION__))
2276 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2276, __extension__ __PRETTY_FUNCTION__))
;
2277 MachineBasicBlock *MBB = TR.TransferInst->getParent();
2278 const VarLoc &VL = VarLocIDs[TR.LocationID];
2279 MachineInstr *MI = VL.BuildDbgValue(MF);
2280 MBB->insertAfterBundle(TR.TransferInst->getIterator(), MI);
2281 }
2282 Transfers.clear();
2283
2284 // Add DBG_VALUEs created using Backup Entry Value location.
2285 for (auto &TR : EntryValTransfers) {
2286 MachineInstr *TRInst = const_cast<MachineInstr *>(TR.first);
2287 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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2288, __extension__ __PRETTY_FUNCTION__))
2288 "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\""
, "/build/llvm-toolchain-snapshot-14~++20211016100712+8e1d532707fd/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2288, __extension__ __PRETTY_FUNCTION__))
;
2289 MachineBasicBlock *MBB = TRInst->getParent();
2290 const VarLoc &VL = VarLocIDs[TR.second];
2291 MachineInstr *MI = VL.BuildDbgValue(MF);
2292 MBB->insertAfterBundle(TRInst->getIterator(), MI);
2293 }
2294 EntryValTransfers.clear();
2295
2296 // Deferred inlocs will not have had any DBG_VALUE insts created; do
2297 // that now.
2298 flushPendingLocs(InLocs, VarLocIDs);
2299
2300 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)
;
2301 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)
;
2302 return Changed;
2303}
2304
2305LDVImpl *
2306llvm::makeVarLocBasedLiveDebugValues()
2307{
2308 return new VarLocBasedLDV();
2309}