Bug Summary

File:llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp
Warning:line 2238, 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 -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 -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen -I include -I /build/llvm-toolchain-snapshot-14~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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-2021-09-26-234817-15343-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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~++20210926122410+d23fd8ae8906/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 MOs.back().setIsDebug();
550 break;
551 case MachineLocKind::SpillLocKind: {
552 // Spills are indirect DBG_VALUEs, with a base register and offset.
553 // Use the original DBG_VALUEs expression to build the spilt location
554 // on top of. FIXME: spill locations created before this pass runs
555 // are not recognized, and not handled here.
556 unsigned Base = Loc.SpillLocation.SpillBase;
557 auto *TRI = MF.getSubtarget().getRegisterInfo();
558 if (MI.isNonListDebugValue()) {
559 auto Deref = Indirect ? DIExpression::DerefAfter : 0;
560 DIExpr = TRI->prependOffsetExpression(
561 DIExpr, DIExpression::ApplyOffset | Deref,
562 Loc.SpillLocation.SpillOffset);
563 Indirect = true;
564 } else {
565 SmallVector<uint64_t, 4> Ops;
566 TRI->getOffsetOpcodes(Loc.SpillLocation.SpillOffset, Ops);
567 Ops.push_back(dwarf::DW_OP_deref);
568 DIExpr = DIExpression::appendOpsToArg(DIExpr, Ops, I);
569 }
570 MOs.push_back(MachineOperand::CreateReg(Base, false));
571 MOs.back().setIsDebug();
572 break;
573 }
574 case MachineLocKind::ImmediateKind: {
575 MOs.push_back(Orig);
576 break;
577 }
578 case MachineLocKind::InvalidKind:
579 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 579)
;
580 }
581 }
582 return BuildMI(MF, DbgLoc, IID, Indirect, MOs, Var, DIExpr);
583 }
584
585 /// Is the Loc field a constant or constant object?
586 bool isConstant(MachineLocKind Kind) const {
587 return Kind == MachineLocKind::ImmediateKind;
588 }
589
590 /// Check if the Loc field is an entry backup location.
591 bool isEntryBackupLoc() const {
592 return EVKind == EntryValueLocKind::EntryValueBackupKind ||
593 EVKind == EntryValueLocKind::EntryValueCopyBackupKind;
594 }
595
596 /// If this variable is described by register \p Reg holding the entry
597 /// value, return true.
598 bool isEntryValueBackupReg(Register Reg) const {
599 return EVKind == EntryValueLocKind::EntryValueBackupKind && usesReg(Reg);
600 }
601
602 /// If this variable is described by register \p Reg holding a copy of the
603 /// entry value, return true.
604 bool isEntryValueCopyBackupReg(Register Reg) const {
605 return EVKind == EntryValueLocKind::EntryValueCopyBackupKind &&
606 usesReg(Reg);
607 }
608
609 /// If this variable is described in whole or part by \p Reg, return true.
610 bool usesReg(Register Reg) const {
611 MachineLoc RegML;
612 RegML.Kind = MachineLocKind::RegisterKind;
613 RegML.Value.RegNo = Reg;
614 return is_contained(Locs, RegML);
615 }
616
617 /// If this variable is described in whole or part by \p Reg, return true.
618 unsigned getRegIdx(Register Reg) const {
619 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
620 if (Locs[Idx].Kind == MachineLocKind::RegisterKind &&
621 Locs[Idx].Value.RegNo == Reg)
622 return Idx;
623 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 623)
;
624 }
625
626 /// If this variable is described in whole or part by 1 or more registers,
627 /// add each of them to \p Regs and return true.
628 bool getDescribingRegs(SmallVectorImpl<uint32_t> &Regs) const {
629 bool AnyRegs = false;
630 for (const auto &Loc : Locs)
631 if (Loc.Kind == MachineLocKind::RegisterKind) {
632 Regs.push_back(Loc.Value.RegNo);
633 AnyRegs = true;
634 }
635 return AnyRegs;
636 }
637
638 bool containsSpillLocs() const {
639 return any_of(Locs, [](VarLoc::MachineLoc ML) {
640 return ML.Kind == VarLoc::MachineLocKind::SpillLocKind;
641 });
642 }
643
644 /// If this variable is described in whole or part by \p SpillLocation,
645 /// return true.
646 bool usesSpillLoc(SpillLoc SpillLocation) const {
647 MachineLoc SpillML;
648 SpillML.Kind = MachineLocKind::SpillLocKind;
649 SpillML.Value.SpillLocation = SpillLocation;
650 return is_contained(Locs, SpillML);
651 }
652
653 /// If this variable is described in whole or part by \p SpillLocation,
654 /// return the index .
655 unsigned getSpillLocIdx(SpillLoc SpillLocation) const {
656 for (unsigned Idx = 0; Idx < Locs.size(); ++Idx)
657 if (Locs[Idx].Kind == MachineLocKind::SpillLocKind &&
658 Locs[Idx].Value.SpillLocation == SpillLocation)
659 return Idx;
660 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 660)
;
661 }
662
663 /// Determine whether the lexical scope of this value's debug location
664 /// dominates MBB.
665 bool dominates(LexicalScopes &LS, MachineBasicBlock &MBB) const {
666 return LS.dominates(MI.getDebugLoc().get(), &MBB);
667 }
668
669#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
670 // TRI can be null.
671 void dump(const TargetRegisterInfo *TRI, raw_ostream &Out = dbgs()) const {
672 Out << "VarLoc(";
673 for (const MachineLoc &MLoc : Locs) {
674 if (Locs.begin() != &MLoc)
675 Out << ", ";
676 switch (MLoc.Kind) {
677 case MachineLocKind::RegisterKind:
678 Out << printReg(MLoc.Value.RegNo, TRI);
679 break;
680 case MachineLocKind::SpillLocKind:
681 Out << printReg(MLoc.Value.SpillLocation.SpillBase, TRI);
682 Out << "[" << MLoc.Value.SpillLocation.SpillOffset.getFixed() << " + "
683 << MLoc.Value.SpillLocation.SpillOffset.getScalable()
684 << "x vscale"
685 << "]";
686 break;
687 case MachineLocKind::ImmediateKind:
688 Out << MLoc.Value.Immediate;
689 break;
690 case MachineLocKind::InvalidKind:
691 llvm_unreachable("Invalid VarLoc in dump method")::llvm::llvm_unreachable_internal("Invalid VarLoc in dump method"
, "/build/llvm-toolchain-snapshot-14~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 691)
;
692 }
693 }
694
695 Out << ", \"" << Var.getVariable()->getName() << "\", " << *Expr << ", ";
696 if (Var.getInlinedAt())
697 Out << "!" << Var.getInlinedAt()->getMetadataID() << ")\n";
698 else
699 Out << "(null))";
700
701 if (isEntryBackupLoc())
702 Out << " (backup loc)\n";
703 else
704 Out << "\n";
705 }
706#endif
707
708 bool operator==(const VarLoc &Other) const {
709 return std::tie(EVKind, Var, Expr, Locs) ==
710 std::tie(Other.EVKind, Other.Var, Other.Expr, Other.Locs);
711 }
712
713 /// This operator guarantees that VarLocs are sorted by Variable first.
714 bool operator<(const VarLoc &Other) const {
715 return std::tie(Var, EVKind, Locs, Expr) <
716 std::tie(Other.Var, Other.EVKind, Other.Locs, Other.Expr);
717 }
718 };
719
720#ifndef NDEBUG
721 using VarVec = SmallVector<VarLoc, 32>;
722#endif
723
724 /// VarLocMap is used for two things:
725 /// 1) Assigning LocIndices to a VarLoc. The LocIndices can be used to
726 /// virtually insert a VarLoc into a VarLocSet.
727 /// 2) Given a LocIndex, look up the unique associated VarLoc.
728 class VarLocMap {
729 /// Map a VarLoc to an index within the vector reserved for its location
730 /// within Loc2Vars.
731 std::map<VarLoc, LocIndices> Var2Indices;
732
733 /// Map a location to a vector which holds VarLocs which live in that
734 /// location.
735 SmallDenseMap<LocIndex::u32_location_t, std::vector<VarLoc>> Loc2Vars;
736
737 public:
738 /// Retrieve LocIndices for \p VL.
739 LocIndices insert(const VarLoc &VL) {
740 LocIndices &Indices = Var2Indices[VL];
741 // If Indices is not empty, VL is already in the map.
742 if (!Indices.empty())
743 return Indices;
744 SmallVector<LocIndex::u32_location_t, 4> Locations;
745 // LocIndices are determined by EVKind and MLs; each Register has a
746 // unique location, while all SpillLocs use a single bucket, and any EV
747 // VarLocs use only the Backup bucket or none at all (except the
748 // compulsory entry at the universal location index). LocIndices will
749 // always have an index at the universal location index as the last index.
750 if (VL.EVKind == VarLoc::EntryValueLocKind::NonEntryValueKind) {
751 VL.getDescribingRegs(Locations);
752 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 756, __extension__ __PRETTY_FUNCTION__))
753 [](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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 756, __extension__ __PRETTY_FUNCTION__))
754 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 756, __extension__ __PRETTY_FUNCTION__))
755 }) &&(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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 756, __extension__ __PRETTY_FUNCTION__))
756 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 756, __extension__ __PRETTY_FUNCTION__))
;
757 if (VL.containsSpillLocs()) {
758 LocIndex::u32_location_t Loc = LocIndex::kSpillLocation;
759 Locations.push_back(Loc);
760 }
761 } else if (VL.EVKind != VarLoc::EntryValueLocKind::EntryValueKind) {
762 LocIndex::u32_location_t Loc = LocIndex::kEntryValueBackupLocation;
763 Locations.push_back(Loc);
764 }
765 Locations.push_back(LocIndex::kUniversalLocation);
766 for (LocIndex::u32_location_t Location : Locations) {
767 auto &Vars = Loc2Vars[Location];
768 Indices.push_back(
769 {Location, static_cast<LocIndex::u32_index_t>(Vars.size())});
770 Vars.push_back(VL);
771 }
772 return Indices;
773 }
774
775 LocIndices getAllIndices(const VarLoc &VL) const {
776 auto IndIt = Var2Indices.find(VL);
777 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 777, __extension__ __PRETTY_FUNCTION__))
;
778 return IndIt->second;
779 }
780
781 /// Retrieve the unique VarLoc associated with \p ID.
782 const VarLoc &operator[](LocIndex ID) const {
783 auto LocIt = Loc2Vars.find(ID.Location);
784 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 784, __extension__ __PRETTY_FUNCTION__))
;
785 return LocIt->second[ID.Index];
786 }
787 };
788
789 using VarLocInMBB =
790 SmallDenseMap<const MachineBasicBlock *, std::unique_ptr<VarLocSet>>;
791 struct TransferDebugPair {
792 MachineInstr *TransferInst; ///< Instruction where this transfer occurs.
793 LocIndex LocationID; ///< Location number for the transfer dest.
794 };
795 using TransferMap = SmallVector<TransferDebugPair, 4>;
796 // Types for recording Entry Var Locations emitted by a single MachineInstr,
797 // as well as recording MachineInstr which last defined a register.
798 using InstToEntryLocMap = std::multimap<const MachineInstr *, LocIndex>;
799 using RegDefToInstMap = DenseMap<Register, MachineInstr *>;
800
801 // Types for recording sets of variable fragments that overlap. For a given
802 // local variable, we record all other fragments of that variable that could
803 // overlap it, to reduce search time.
804 using FragmentOfVar =
805 std::pair<const DILocalVariable *, DIExpression::FragmentInfo>;
806 using OverlapMap =
807 DenseMap<FragmentOfVar, SmallVector<DIExpression::FragmentInfo, 1>>;
808
809 // Helper while building OverlapMap, a map of all fragments seen for a given
810 // DILocalVariable.
811 using VarToFragments =
812 DenseMap<const DILocalVariable *, SmallSet<FragmentInfo, 4>>;
813
814 /// Collects all VarLocs from \p CollectFrom. Each unique VarLoc is added
815 /// to \p Collected once, in order of insertion into \p VarLocIDs.
816 static void collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
817 const VarLocSet &CollectFrom,
818 const VarLocMap &VarLocIDs);
819
820 /// Get the registers which are used by VarLocs of kind RegisterKind tracked
821 /// by \p CollectFrom.
822 void getUsedRegs(const VarLocSet &CollectFrom,
823 SmallVectorImpl<Register> &UsedRegs) const;
824
825 /// This holds the working set of currently open ranges. For fast
826 /// access, this is done both as a set of VarLocIDs, and a map of
827 /// DebugVariable to recent VarLocID. Note that a DBG_VALUE ends all
828 /// previous open ranges for the same variable. In addition, we keep
829 /// two different maps (Vars/EntryValuesBackupVars), so erase/insert
830 /// methods act differently depending on whether a VarLoc is primary
831 /// location or backup one. In the case the VarLoc is backup location
832 /// we will erase/insert from the EntryValuesBackupVars map, otherwise
833 /// we perform the operation on the Vars.
834 class OpenRangesSet {
835 VarLocSet::Allocator &Alloc;
836 VarLocSet VarLocs;
837 // Map the DebugVariable to recent primary location ID.
838 SmallDenseMap<DebugVariable, LocIndices, 8> Vars;
839 // Map the DebugVariable to recent backup location ID.
840 SmallDenseMap<DebugVariable, LocIndices, 8> EntryValuesBackupVars;
841 OverlapMap &OverlappingFragments;
842
843 public:
844 OpenRangesSet(VarLocSet::Allocator &Alloc, OverlapMap &_OLapMap)
845 : Alloc(Alloc), VarLocs(Alloc), OverlappingFragments(_OLapMap) {}
846
847 const VarLocSet &getVarLocs() const { return VarLocs; }
848
849 // Fetches all VarLocs in \p VarLocIDs and inserts them into \p Collected.
850 // This method is needed to get every VarLoc once, as each VarLoc may have
851 // multiple indices in a VarLocMap (corresponding to each applicable
852 // location), but all VarLocs appear exactly once at the universal location
853 // index.
854 void getUniqueVarLocs(SmallVectorImpl<VarLoc> &Collected,
855 const VarLocMap &VarLocIDs) const {
856 collectAllVarLocs(Collected, VarLocs, VarLocIDs);
857 }
858
859 /// Terminate all open ranges for VL.Var by removing it from the set.
860 void erase(const VarLoc &VL);
861
862 /// Terminate all open ranges listed as indices in \c KillSet with
863 /// \c Location by removing them from the set.
864 void erase(const VarLocsInRange &KillSet, const VarLocMap &VarLocIDs,
865 LocIndex::u32_location_t Location);
866
867 /// Insert a new range into the set.
868 void insert(LocIndices VarLocIDs, const VarLoc &VL);
869
870 /// Insert a set of ranges.
871 void insertFromLocSet(const VarLocSet &ToLoad, const VarLocMap &Map);
872
873 llvm::Optional<LocIndices> getEntryValueBackup(DebugVariable Var);
874
875 /// Empty the set.
876 void clear() {
877 VarLocs.clear();
878 Vars.clear();
879 EntryValuesBackupVars.clear();
880 }
881
882 /// Return whether the set is empty or not.
883 bool empty() const {
884 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 886, __extension__ __PRETTY_FUNCTION__))
885 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 886, __extension__ __PRETTY_FUNCTION__))
886 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 886, __extension__ __PRETTY_FUNCTION__))
;
887 return VarLocs.empty();
888 }
889
890 /// Get an empty range of VarLoc IDs.
891 auto getEmptyVarLocRange() const {
892 return iterator_range<VarLocSet::const_iterator>(getVarLocs().end(),
893 getVarLocs().end());
894 }
895
896 /// Get all set IDs for VarLocs with MLs of kind RegisterKind in \p Reg.
897 auto getRegisterVarLocs(Register Reg) const {
898 return LocIndex::indexRangeForLocation(getVarLocs(), Reg);
899 }
900
901 /// Get all set IDs for VarLocs with MLs of kind SpillLocKind.
902 auto getSpillVarLocs() const {
903 return LocIndex::indexRangeForLocation(getVarLocs(),
904 LocIndex::kSpillLocation);
905 }
906
907 /// Get all set IDs for VarLocs of EVKind EntryValueBackupKind or
908 /// EntryValueCopyBackupKind.
909 auto getEntryValueBackupVarLocs() const {
910 return LocIndex::indexRangeForLocation(
911 getVarLocs(), LocIndex::kEntryValueBackupLocation);
912 }
913 };
914
915 /// Collect all VarLoc IDs from \p CollectFrom for VarLocs with MLs of kind
916 /// RegisterKind which are located in any reg in \p Regs. The IDs for each
917 /// VarLoc correspond to entries in the universal location bucket, which every
918 /// VarLoc has exactly 1 entry for. Insert collected IDs into \p Collected.
919 static void collectIDsForRegs(VarLocsInRange &Collected,
920 const DefinedRegsSet &Regs,
921 const VarLocSet &CollectFrom,
922 const VarLocMap &VarLocIDs);
923
924 VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB, VarLocInMBB &Locs) {
925 std::unique_ptr<VarLocSet> &VLS = Locs[MBB];
926 if (!VLS)
927 VLS = std::make_unique<VarLocSet>(Alloc);
928 return *VLS.get();
929 }
930
931 const VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB,
932 const VarLocInMBB &Locs) const {
933 auto It = Locs.find(MBB);
934 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 934, __extension__ __PRETTY_FUNCTION__))
;
935 return *It->second.get();
936 }
937
938 /// Tests whether this instruction is a spill to a stack location.
939 bool isSpillInstruction(const MachineInstr &MI, MachineFunction *MF);
940
941 /// Decide if @MI is a spill instruction and return true if it is. We use 2
942 /// criteria to make this decision:
943 /// - Is this instruction a store to a spill slot?
944 /// - Is there a register operand that is both used and killed?
945 /// TODO: Store optimization can fold spills into other stores (including
946 /// other spills). We do not handle this yet (more than one memory operand).
947 bool isLocationSpill(const MachineInstr &MI, MachineFunction *MF,
948 Register &Reg);
949
950 /// Returns true if the given machine instruction is a debug value which we
951 /// can emit entry values for.
952 ///
953 /// Currently, we generate debug entry values only for parameters that are
954 /// unmodified throughout the function and located in a register.
955 bool isEntryValueCandidate(const MachineInstr &MI,
956 const DefinedRegsSet &Regs) const;
957
958 /// If a given instruction is identified as a spill, return the spill location
959 /// and set \p Reg to the spilled register.
960 Optional<VarLoc::SpillLoc> isRestoreInstruction(const MachineInstr &MI,
961 MachineFunction *MF,
962 Register &Reg);
963 /// Given a spill instruction, extract the register and offset used to
964 /// address the spill location in a target independent way.
965 VarLoc::SpillLoc extractSpillBaseRegAndOffset(const MachineInstr &MI);
966 void insertTransferDebugPair(MachineInstr &MI, OpenRangesSet &OpenRanges,
967 TransferMap &Transfers, VarLocMap &VarLocIDs,
968 LocIndex OldVarID, TransferKind Kind,
969 const VarLoc::MachineLoc &OldLoc,
970 Register NewReg = Register());
971
972 void transferDebugValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
973 VarLocMap &VarLocIDs,
974 InstToEntryLocMap &EntryValTransfers,
975 RegDefToInstMap &RegSetInstrs);
976 void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
977 VarLocMap &VarLocIDs, TransferMap &Transfers);
978 void cleanupEntryValueTransfers(const MachineInstr *MI,
979 OpenRangesSet &OpenRanges,
980 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
981 InstToEntryLocMap &EntryValTransfers);
982 void removeEntryValue(const MachineInstr &MI, OpenRangesSet &OpenRanges,
983 VarLocMap &VarLocIDs, const VarLoc &EntryVL,
984 InstToEntryLocMap &EntryValTransfers,
985 RegDefToInstMap &RegSetInstrs);
986 void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
987 VarLocMap &VarLocIDs,
988 InstToEntryLocMap &EntryValTransfers,
989 VarLocsInRange &KillSet);
990 void recordEntryValue(const MachineInstr &MI,
991 const DefinedRegsSet &DefinedRegs,
992 OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs);
993 void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
994 VarLocMap &VarLocIDs, TransferMap &Transfers);
995 void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
996 VarLocMap &VarLocIDs,
997 InstToEntryLocMap &EntryValTransfers,
998 RegDefToInstMap &RegSetInstrs);
999 bool transferTerminator(MachineBasicBlock *MBB, OpenRangesSet &OpenRanges,
1000 VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
1001
1002 void process(MachineInstr &MI, OpenRangesSet &OpenRanges,
1003 VarLocMap &VarLocIDs, TransferMap &Transfers,
1004 InstToEntryLocMap &EntryValTransfers,
1005 RegDefToInstMap &RegSetInstrs);
1006
1007 void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
1008 OverlapMap &OLapMap);
1009
1010 bool join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1011 const VarLocMap &VarLocIDs,
1012 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1013 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks);
1014
1015 /// Create DBG_VALUE insts for inlocs that have been propagated but
1016 /// had their instruction creation deferred.
1017 void flushPendingLocs(VarLocInMBB &PendingInLocs, VarLocMap &VarLocIDs);
1018
1019 bool ExtendRanges(MachineFunction &MF, TargetPassConfig *TPC,
1020 unsigned InputBBLimit, unsigned InputDbgValLimit) override;
1021
1022public:
1023 /// Default construct and initialize the pass.
1024 VarLocBasedLDV();
1025
1026 ~VarLocBasedLDV();
1027
1028 /// Print to ostream with a message.
1029 void printVarLocInMBB(const MachineFunction &MF, const VarLocInMBB &V,
1030 const VarLocMap &VarLocIDs, const char *msg,
1031 raw_ostream &Out) const;
1032};
1033
1034} // end anonymous namespace
1035
1036//===----------------------------------------------------------------------===//
1037// Implementation
1038//===----------------------------------------------------------------------===//
1039
1040VarLocBasedLDV::VarLocBasedLDV() { }
1041
1042VarLocBasedLDV::~VarLocBasedLDV() { }
1043
1044/// Erase a variable from the set of open ranges, and additionally erase any
1045/// fragments that may overlap it. If the VarLoc is a backup location, erase
1046/// the variable from the EntryValuesBackupVars set, indicating we should stop
1047/// tracking its backup entry location. Otherwise, if the VarLoc is primary
1048/// location, erase the variable from the Vars set.
1049void VarLocBasedLDV::OpenRangesSet::erase(const VarLoc &VL) {
1050 // Erasure helper.
1051 auto DoErase = [VL, this](DebugVariable VarToErase) {
1052 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1053 auto It = EraseFrom->find(VarToErase);
1054 if (It != EraseFrom->end()) {
1055 LocIndices IDs = It->second;
1056 for (LocIndex ID : IDs)
1057 VarLocs.reset(ID.getAsRawInteger());
1058 EraseFrom->erase(It);
1059 }
1060 };
1061
1062 DebugVariable Var = VL.Var;
1063
1064 // Erase the variable/fragment that ends here.
1065 DoErase(Var);
1066
1067 // Extract the fragment. Interpret an empty fragment as one that covers all
1068 // possible bits.
1069 FragmentInfo ThisFragment = Var.getFragmentOrDefault();
1070
1071 // There may be fragments that overlap the designated fragment. Look them up
1072 // in the pre-computed overlap map, and erase them too.
1073 auto MapIt = OverlappingFragments.find({Var.getVariable(), ThisFragment});
1074 if (MapIt != OverlappingFragments.end()) {
1075 for (auto Fragment : MapIt->second) {
1076 VarLocBasedLDV::OptFragmentInfo FragmentHolder;
1077 if (!DebugVariable::isDefaultFragment(Fragment))
1078 FragmentHolder = VarLocBasedLDV::OptFragmentInfo(Fragment);
1079 DoErase({Var.getVariable(), FragmentHolder, Var.getInlinedAt()});
1080 }
1081 }
1082}
1083
1084void VarLocBasedLDV::OpenRangesSet::erase(const VarLocsInRange &KillSet,
1085 const VarLocMap &VarLocIDs,
1086 LocIndex::u32_location_t Location) {
1087 VarLocSet RemoveSet(Alloc);
1088 for (LocIndex::u32_index_t ID : KillSet) {
1089 const VarLoc &VL = VarLocIDs[LocIndex(Location, ID)];
1090 auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1091 EraseFrom->erase(VL.Var);
1092 LocIndices VLI = VarLocIDs.getAllIndices(VL);
1093 for (LocIndex ID : VLI)
1094 RemoveSet.set(ID.getAsRawInteger());
1095 }
1096 VarLocs.intersectWithComplement(RemoveSet);
1097}
1098
1099void VarLocBasedLDV::OpenRangesSet::insertFromLocSet(const VarLocSet &ToLoad,
1100 const VarLocMap &Map) {
1101 VarLocsInRange UniqueVarLocIDs;
1102 DefinedRegsSet Regs;
1103 Regs.insert(LocIndex::kUniversalLocation);
1104 collectIDsForRegs(UniqueVarLocIDs, Regs, ToLoad, Map);
1105 for (uint64_t ID : UniqueVarLocIDs) {
1106 LocIndex Idx = LocIndex::fromRawInteger(ID);
1107 const VarLoc &VarL = Map[Idx];
1108 const LocIndices Indices = Map.getAllIndices(VarL);
1109 insert(Indices, VarL);
1110 }
1111}
1112
1113void VarLocBasedLDV::OpenRangesSet::insert(LocIndices VarLocIDs,
1114 const VarLoc &VL) {
1115 auto *InsertInto = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars;
1116 for (LocIndex ID : VarLocIDs)
1117 VarLocs.set(ID.getAsRawInteger());
1118 InsertInto->insert({VL.Var, VarLocIDs});
1119}
1120
1121/// Return the Loc ID of an entry value backup location, if it exists for the
1122/// variable.
1123llvm::Optional<LocIndices>
1124VarLocBasedLDV::OpenRangesSet::getEntryValueBackup(DebugVariable Var) {
1125 auto It = EntryValuesBackupVars.find(Var);
1126 if (It != EntryValuesBackupVars.end())
1127 return It->second;
1128
1129 return llvm::None;
1130}
1131
1132void VarLocBasedLDV::collectIDsForRegs(VarLocsInRange &Collected,
1133 const DefinedRegsSet &Regs,
1134 const VarLocSet &CollectFrom,
1135 const VarLocMap &VarLocIDs) {
1136 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1136, __extension__ __PRETTY_FUNCTION__))
;
1137 SmallVector<Register, 32> SortedRegs;
1138 append_range(SortedRegs, Regs);
1139 array_pod_sort(SortedRegs.begin(), SortedRegs.end());
1140 auto It = CollectFrom.find(LocIndex::rawIndexForReg(SortedRegs.front()));
1141 auto End = CollectFrom.end();
1142 for (Register Reg : SortedRegs) {
1143 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains
1144 // all possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which
1145 // live in Reg.
1146 uint64_t FirstIndexForReg = LocIndex::rawIndexForReg(Reg);
1147 uint64_t FirstInvalidIndex = LocIndex::rawIndexForReg(Reg + 1);
1148 It.advanceToLowerBound(FirstIndexForReg);
1149
1150 // Iterate through that half-open interval and collect all the set IDs.
1151 for (; It != End && *It < FirstInvalidIndex; ++It) {
1152 LocIndex ItIdx = LocIndex::fromRawInteger(*It);
1153 const VarLoc &VL = VarLocIDs[ItIdx];
1154 LocIndices LI = VarLocIDs.getAllIndices(VL);
1155 // For now, the back index is always the universal location index.
1156 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1158, __extension__ __PRETTY_FUNCTION__))
1157 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1158, __extension__ __PRETTY_FUNCTION__))
1158 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1158, __extension__ __PRETTY_FUNCTION__))
;
1159 Collected.insert(LI.back().Index);
1160 }
1161
1162 if (It == End)
1163 return;
1164 }
1165}
1166
1167void VarLocBasedLDV::getUsedRegs(const VarLocSet &CollectFrom,
1168 SmallVectorImpl<Register> &UsedRegs) const {
1169 // All register-based VarLocs are assigned indices greater than or equal to
1170 // FirstRegIndex.
1171 uint64_t FirstRegIndex =
1172 LocIndex::rawIndexForReg(LocIndex::kFirstRegLocation);
1173 uint64_t FirstInvalidIndex =
1174 LocIndex::rawIndexForReg(LocIndex::kFirstInvalidRegLocation);
1175 for (auto It = CollectFrom.find(FirstRegIndex),
1176 End = CollectFrom.find(FirstInvalidIndex);
1177 It != End;) {
1178 // We found a VarLoc ID for a VarLoc that lives in a register. Figure out
1179 // which register and add it to UsedRegs.
1180 uint32_t FoundReg = LocIndex::fromRawInteger(*It).Location;
1181 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1182, __extension__ __PRETTY_FUNCTION__))
1182 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1182, __extension__ __PRETTY_FUNCTION__))
;
1183 UsedRegs.push_back(FoundReg);
1184
1185 // Skip to the next /set/ register. Note that this finds a lower bound, so
1186 // even if there aren't any VarLocs living in `FoundReg+1`, we're still
1187 // guaranteed to move on to the next register (or to end()).
1188 uint64_t NextRegIndex = LocIndex::rawIndexForReg(FoundReg + 1);
1189 It.advanceToLowerBound(NextRegIndex);
1190 }
1191}
1192
1193//===----------------------------------------------------------------------===//
1194// Debug Range Extension Implementation
1195//===----------------------------------------------------------------------===//
1196
1197#ifndef NDEBUG
1198void VarLocBasedLDV::printVarLocInMBB(const MachineFunction &MF,
1199 const VarLocInMBB &V,
1200 const VarLocMap &VarLocIDs,
1201 const char *msg,
1202 raw_ostream &Out) const {
1203 Out << '\n' << msg << '\n';
1204 for (const MachineBasicBlock &BB : MF) {
1205 if (!V.count(&BB))
1206 continue;
1207 const VarLocSet &L = getVarLocsInMBB(&BB, V);
1208 if (L.empty())
1209 continue;
1210 SmallVector<VarLoc, 32> VarLocs;
1211 collectAllVarLocs(VarLocs, L, VarLocIDs);
1212 Out << "MBB: " << BB.getNumber() << ":\n";
1213 for (const VarLoc &VL : VarLocs) {
1214 Out << " Var: " << VL.Var.getVariable()->getName();
1215 Out << " MI: ";
1216 VL.dump(TRI, Out);
1217 }
1218 }
1219 Out << "\n";
1220}
1221#endif
1222
1223VarLocBasedLDV::VarLoc::SpillLoc
1224VarLocBasedLDV::extractSpillBaseRegAndOffset(const MachineInstr &MI) {
1225 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1226, __extension__ __PRETTY_FUNCTION__))
1226 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1226, __extension__ __PRETTY_FUNCTION__))
;
1227 auto MMOI = MI.memoperands_begin();
1228 const PseudoSourceValue *PVal = (*MMOI)->getPseudoValue();
1229 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1230, __extension__ __PRETTY_FUNCTION__))
1230 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1230, __extension__ __PRETTY_FUNCTION__))
;
1231 int FI = cast<FixedStackPseudoSourceValue>(PVal)->getFrameIndex();
1232 const MachineBasicBlock *MBB = MI.getParent();
1233 Register Reg;
1234 StackOffset Offset = TFI->getFrameIndexReference(*MBB->getParent(), FI, Reg);
1235 return {Reg, Offset};
1236}
1237
1238/// Do cleanup of \p EntryValTransfers created by \p TRInst, by removing the
1239/// Transfer, which uses the to-be-deleted \p EntryVL.
1240void VarLocBasedLDV::cleanupEntryValueTransfers(
1241 const MachineInstr *TRInst, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
1242 const VarLoc &EntryVL, InstToEntryLocMap &EntryValTransfers) {
1243 if (EntryValTransfers.empty() || TRInst == nullptr)
1244 return;
1245
1246 auto TransRange = EntryValTransfers.equal_range(TRInst);
1247 for (auto TDPair : llvm::make_range(TransRange.first, TransRange.second)) {
1248 const VarLoc &EmittedEV = VarLocIDs[TDPair.second];
1249 if (std::tie(EntryVL.Var, EntryVL.Locs[0].Value.RegNo, EntryVL.Expr) ==
1250 std::tie(EmittedEV.Var, EmittedEV.Locs[0].Value.RegNo,
1251 EmittedEV.Expr)) {
1252 OpenRanges.erase(EmittedEV);
1253 EntryValTransfers.erase(TRInst);
1254 break;
1255 }
1256 }
1257}
1258
1259/// Try to salvage the debug entry value if we encounter a new debug value
1260/// describing the same parameter, otherwise stop tracking the value. Return
1261/// true if we should stop tracking the entry value and do the cleanup of
1262/// emitted Entry Value Transfers, otherwise return false.
1263void VarLocBasedLDV::removeEntryValue(const MachineInstr &MI,
1264 OpenRangesSet &OpenRanges,
1265 VarLocMap &VarLocIDs,
1266 const VarLoc &EntryVL,
1267 InstToEntryLocMap &EntryValTransfers,
1268 RegDefToInstMap &RegSetInstrs) {
1269 // Skip the DBG_VALUE which is the debug entry value itself.
1270 if (&MI == &EntryVL.MI)
1271 return;
1272
1273 // If the parameter's location is not register location, we can not track
1274 // the entry value any more. It doesn't have the TransferInst which defines
1275 // register, so no Entry Value Transfers have been emitted already.
1276 if (!MI.getDebugOperand(0).isReg())
1277 return;
1278
1279 // Try to get non-debug instruction responsible for the DBG_VALUE.
1280 const MachineInstr *TransferInst = nullptr;
1281 Register Reg = MI.getDebugOperand(0).getReg();
1282 if (Reg.isValid() && RegSetInstrs.find(Reg) != RegSetInstrs.end())
1283 TransferInst = RegSetInstrs.find(Reg)->second;
1284
1285 // Case of the parameter's DBG_VALUE at the start of entry MBB.
1286 if (!TransferInst && !LastNonDbgMI && MI.getParent()->isEntryBlock())
1287 return;
1288
1289 // If the debug expression from the DBG_VALUE is not empty, we can assume the
1290 // parameter's value has changed indicating that we should stop tracking its
1291 // entry value as well.
1292 if (MI.getDebugExpression()->getNumElements() == 0 && TransferInst) {
1293 // If the DBG_VALUE comes from a copy instruction that copies the entry
1294 // value, it means the parameter's value has not changed and we should be
1295 // able to use its entry value.
1296 // TODO: Try to keep tracking of an entry value if we encounter a propagated
1297 // DBG_VALUE describing the copy of the entry value. (Propagated entry value
1298 // does not indicate the parameter modification.)
1299 auto DestSrc = TII->isCopyInstr(*TransferInst);
1300 if (DestSrc) {
1301 const MachineOperand *SrcRegOp, *DestRegOp;
1302 SrcRegOp = DestSrc->Source;
1303 DestRegOp = DestSrc->Destination;
1304 if (Reg == DestRegOp->getReg()) {
1305 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1306 const VarLoc &VL = VarLocIDs[LocIndex::fromRawInteger(ID)];
1307 if (VL.isEntryValueCopyBackupReg(Reg) &&
1308 // Entry Values should not be variadic.
1309 VL.MI.getDebugOperand(0).getReg() == SrcRegOp->getReg())
1310 return;
1311 }
1312 }
1313 }
1314 }
1315
1316 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)
1317 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)
1318 /*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)
1319 /*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)
;
1320 cleanupEntryValueTransfers(TransferInst, OpenRanges, VarLocIDs, EntryVL,
1321 EntryValTransfers);
1322 OpenRanges.erase(EntryVL);
1323}
1324
1325/// End all previous ranges related to @MI and start a new range from @MI
1326/// if it is a DBG_VALUE instr.
1327void VarLocBasedLDV::transferDebugValue(const MachineInstr &MI,
1328 OpenRangesSet &OpenRanges,
1329 VarLocMap &VarLocIDs,
1330 InstToEntryLocMap &EntryValTransfers,
1331 RegDefToInstMap &RegSetInstrs) {
1332 if (!MI.isDebugValue())
1333 return;
1334 const DILocalVariable *Var = MI.getDebugVariable();
1335 const DIExpression *Expr = MI.getDebugExpression();
1336 const DILocation *DebugLoc = MI.getDebugLoc();
1337 const DILocation *InlinedAt = DebugLoc->getInlinedAt();
1338 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1339, __extension__ __PRETTY_FUNCTION__))
1339 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1339, __extension__ __PRETTY_FUNCTION__))
;
1340
1341 DebugVariable V(Var, Expr, InlinedAt);
1342
1343 // Check if this DBG_VALUE indicates a parameter's value changing.
1344 // If that is the case, we should stop tracking its entry value.
1345 auto EntryValBackupID = OpenRanges.getEntryValueBackup(V);
1346 if (Var->isParameter() && EntryValBackupID) {
1347 const VarLoc &EntryVL = VarLocIDs[EntryValBackupID->back()];
1348 removeEntryValue(MI, OpenRanges, VarLocIDs, EntryVL, EntryValTransfers,
1349 RegSetInstrs);
1350 }
1351
1352 if (all_of(MI.debug_operands(), [](const MachineOperand &MO) {
1353 return (MO.isReg() && MO.getReg()) || MO.isImm() || MO.isFPImm() ||
1354 MO.isCImm();
1355 })) {
1356 // Use normal VarLoc constructor for registers and immediates.
1357 VarLoc VL(MI, LS);
1358 // End all previous ranges of VL.Var.
1359 OpenRanges.erase(VL);
1360
1361 LocIndices IDs = VarLocIDs.insert(VL);
1362 // Add the VarLoc to OpenRanges from this DBG_VALUE.
1363 OpenRanges.insert(IDs, VL);
1364 } else if (MI.memoperands().size() > 0) {
1365 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1365)
;
1366 } else {
1367 // This must be an undefined location. If it has an open range, erase it.
1368 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1369, __extension__ __PRETTY_FUNCTION__))
1369 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1369, __extension__ __PRETTY_FUNCTION__))
;
1370 VarLoc VL(MI, LS);
1371 OpenRanges.erase(VL);
1372 }
1373}
1374
1375// This should be removed later, doesn't fit the new design.
1376void VarLocBasedLDV::collectAllVarLocs(SmallVectorImpl<VarLoc> &Collected,
1377 const VarLocSet &CollectFrom,
1378 const VarLocMap &VarLocIDs) {
1379 // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains all
1380 // possible VarLoc IDs for VarLocs with MLs of kind RegisterKind which live
1381 // in Reg.
1382 uint64_t FirstIndex = LocIndex::rawIndexForReg(LocIndex::kUniversalLocation);
1383 uint64_t FirstInvalidIndex =
1384 LocIndex::rawIndexForReg(LocIndex::kUniversalLocation + 1);
1385 // Iterate through that half-open interval and collect all the set IDs.
1386 for (auto It = CollectFrom.find(FirstIndex), End = CollectFrom.end();
1387 It != End && *It < FirstInvalidIndex; ++It) {
1388 LocIndex RegIdx = LocIndex::fromRawInteger(*It);
1389 Collected.push_back(VarLocIDs[RegIdx]);
1390 }
1391}
1392
1393/// Turn the entry value backup locations into primary locations.
1394void VarLocBasedLDV::emitEntryValues(MachineInstr &MI,
1395 OpenRangesSet &OpenRanges,
1396 VarLocMap &VarLocIDs,
1397 InstToEntryLocMap &EntryValTransfers,
1398 VarLocsInRange &KillSet) {
1399 // Do not insert entry value locations after a terminator.
1400 if (MI.isTerminator())
1401 return;
1402
1403 for (uint32_t ID : KillSet) {
1404 // The KillSet IDs are indices for the universal location bucket.
1405 LocIndex Idx = LocIndex(LocIndex::kUniversalLocation, ID);
1406 const VarLoc &VL = VarLocIDs[Idx];
1407 if (!VL.Var.getVariable()->isParameter())
1408 continue;
1409
1410 auto DebugVar = VL.Var;
1411 Optional<LocIndices> EntryValBackupIDs =
1412 OpenRanges.getEntryValueBackup(DebugVar);
1413
1414 // If the parameter has the entry value backup, it means we should
1415 // be able to use its entry value.
1416 if (!EntryValBackupIDs)
1417 continue;
1418
1419 const VarLoc &EntryVL = VarLocIDs[EntryValBackupIDs->back()];
1420 VarLoc EntryLoc = VarLoc::CreateEntryLoc(EntryVL.MI, LS, EntryVL.Expr,
1421 EntryVL.Locs[0].Value.RegNo);
1422 LocIndices EntryValueIDs = VarLocIDs.insert(EntryLoc);
1423 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1424, __extension__ __PRETTY_FUNCTION__))
1424 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1424, __extension__ __PRETTY_FUNCTION__))
;
1425 EntryValTransfers.insert({&MI, EntryValueIDs.back()});
1426 OpenRanges.insert(EntryValueIDs, EntryLoc);
1427 }
1428}
1429
1430/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
1431/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
1432/// new VarLoc. If \p NewReg is different than default zero value then the
1433/// new location will be register location created by the copy like instruction,
1434/// otherwise it is variable's location on the stack.
1435void VarLocBasedLDV::insertTransferDebugPair(
1436 MachineInstr &MI, OpenRangesSet &OpenRanges, TransferMap &Transfers,
1437 VarLocMap &VarLocIDs, LocIndex OldVarID, TransferKind Kind,
1438 const VarLoc::MachineLoc &OldLoc, Register NewReg) {
1439 const VarLoc &OldVarLoc = VarLocIDs[OldVarID];
1440
1441 auto ProcessVarLoc = [&MI, &OpenRanges, &Transfers, &VarLocIDs](VarLoc &VL) {
1442 LocIndices LocIds = VarLocIDs.insert(VL);
1443
1444 // Close this variable's previous location range.
1445 OpenRanges.erase(VL);
1446
1447 // Record the new location as an open range, and a postponed transfer
1448 // inserting a DBG_VALUE for this location.
1449 OpenRanges.insert(LocIds, VL);
1450 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1450, __extension__ __PRETTY_FUNCTION__))
;
1451 TransferDebugPair MIP = {&MI, LocIds.back()};
1452 Transfers.push_back(MIP);
1453 };
1454
1455 // End all previous ranges of VL.Var.
1456 OpenRanges.erase(VarLocIDs[OldVarID]);
1457 switch (Kind) {
1458 case TransferKind::TransferCopy: {
1459 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1460, __extension__ __PRETTY_FUNCTION__))
1460 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1460, __extension__ __PRETTY_FUNCTION__))
;
1461 // Create a DBG_VALUE instruction to describe the Var in its new
1462 // register location.
1463 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1464 ProcessVarLoc(VL);
1465 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1466 dbgs() << "Creating VarLoc for register copy:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1467 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
1468 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:"
; VL.dump(TRI); }; } } while (false)
;
1469 return;
1470 }
1471 case TransferKind::TransferSpill: {
1472 // Create a DBG_VALUE instruction to describe the Var in its spilled
1473 // location.
1474 VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI);
1475 VarLoc VL = VarLoc::CreateSpillLoc(
1476 OldVarLoc, OldLoc, SpillLocation.SpillBase, SpillLocation.SpillOffset);
1477 ProcessVarLoc(VL);
1478 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1479 dbgs() << "Creating VarLoc for spill:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1480 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
1481 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:"
; VL.dump(TRI); }; } } while (false)
;
1482 return;
1483 }
1484 case TransferKind::TransferRestore: {
1485 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1486, __extension__ __PRETTY_FUNCTION__))
1486 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1486, __extension__ __PRETTY_FUNCTION__))
;
1487 // DebugInstr refers to the pre-spill location, therefore we can reuse
1488 // its expression.
1489 VarLoc VL = VarLoc::CreateCopyLoc(OldVarLoc, OldLoc, NewReg);
1490 ProcessVarLoc(VL);
1491 LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1492 dbgs() << "Creating VarLoc for restore:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1493 VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
1494 })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:"
; VL.dump(TRI); }; } } while (false)
;
1495 return;
1496 }
1497 }
1498 llvm_unreachable("Invalid transfer kind")::llvm::llvm_unreachable_internal("Invalid transfer kind", "/build/llvm-toolchain-snapshot-14~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1498)
;
1499}
1500
1501/// A definition of a register may mark the end of a range.
1502void VarLocBasedLDV::transferRegisterDef(MachineInstr &MI,
1503 OpenRangesSet &OpenRanges,
1504 VarLocMap &VarLocIDs,
1505 InstToEntryLocMap &EntryValTransfers,
1506 RegDefToInstMap &RegSetInstrs) {
1507
1508 // Meta Instructions do not affect the debug liveness of any register they
1509 // define.
1510 if (MI.isMetaInstruction())
1511 return;
1512
1513 MachineFunction *MF = MI.getMF();
1514 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1515 Register SP = TLI->getStackPointerRegisterToSaveRestore();
1516
1517 // Find the regs killed by MI, and find regmasks of preserved regs.
1518 DefinedRegsSet DeadRegs;
1519 SmallVector<const uint32_t *, 4> RegMasks;
1520 for (const MachineOperand &MO : MI.operands()) {
1521 // Determine whether the operand is a register def.
1522 if (MO.isReg() && MO.isDef() && MO.getReg() &&
1523 Register::isPhysicalRegister(MO.getReg()) &&
1524 !(MI.isCall() && MO.getReg() == SP)) {
1525 // Remove ranges of all aliased registers.
1526 for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI)
1527 // FIXME: Can we break out of this loop early if no insertion occurs?
1528 DeadRegs.insert(*RAI);
1529 if (RegSetInstrs.find(MO.getReg()) != RegSetInstrs.end())
1530 RegSetInstrs.erase(MO.getReg());
1531 RegSetInstrs.insert({MO.getReg(), &MI});
1532 } else if (MO.isRegMask()) {
1533 RegMasks.push_back(MO.getRegMask());
1534 }
1535 }
1536
1537 // Erase VarLocs which reside in one of the dead registers. For performance
1538 // reasons, it's critical to not iterate over the full set of open VarLocs.
1539 // Iterate over the set of dying/used regs instead.
1540 if (!RegMasks.empty()) {
1541 SmallVector<Register, 32> UsedRegs;
1542 getUsedRegs(OpenRanges.getVarLocs(), UsedRegs);
1543 for (Register Reg : UsedRegs) {
1544 // Remove ranges of all clobbered registers. Register masks don't usually
1545 // list SP as preserved. Assume that call instructions never clobber SP,
1546 // because some backends (e.g., AArch64) never list SP in the regmask.
1547 // While the debug info may be off for an instruction or two around
1548 // callee-cleanup calls, transferring the DEBUG_VALUE across the call is
1549 // still a better user experience.
1550 if (Reg == SP)
1551 continue;
1552 bool AnyRegMaskKillsReg =
1553 any_of(RegMasks, [Reg](const uint32_t *RegMask) {
1554 return MachineOperand::clobbersPhysReg(RegMask, Reg);
1555 });
1556 if (AnyRegMaskKillsReg)
1557 DeadRegs.insert(Reg);
1558 if (AnyRegMaskKillsReg) {
1559 if (RegSetInstrs.find(Reg) != RegSetInstrs.end())
1560 RegSetInstrs.erase(Reg);
1561 RegSetInstrs.insert({Reg, &MI});
1562 }
1563 }
1564 }
1565
1566 if (DeadRegs.empty())
1567 return;
1568
1569 VarLocsInRange KillSet;
1570 collectIDsForRegs(KillSet, DeadRegs, OpenRanges.getVarLocs(), VarLocIDs);
1571 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kUniversalLocation);
1572
1573 if (TPC) {
1574 auto &TM = TPC->getTM<TargetMachine>();
1575 if (TM.Options.ShouldEmitDebugEntryValues())
1576 emitEntryValues(MI, OpenRanges, VarLocIDs, EntryValTransfers, KillSet);
1577 }
1578}
1579
1580bool VarLocBasedLDV::isSpillInstruction(const MachineInstr &MI,
1581 MachineFunction *MF) {
1582 // TODO: Handle multiple stores folded into one.
1583 if (!MI.hasOneMemOperand())
1584 return false;
1585
1586 if (!MI.getSpillSize(TII) && !MI.getFoldedSpillSize(TII))
1587 return false; // This is not a spill instruction, since no valid size was
1588 // returned from either function.
1589
1590 return true;
1591}
1592
1593bool VarLocBasedLDV::isLocationSpill(const MachineInstr &MI,
1594 MachineFunction *MF, Register &Reg) {
1595 if (!isSpillInstruction(MI, MF))
1596 return false;
1597
1598 auto isKilledReg = [&](const MachineOperand MO, Register &Reg) {
1599 if (!MO.isReg() || !MO.isUse()) {
1600 Reg = 0;
1601 return false;
1602 }
1603 Reg = MO.getReg();
1604 return MO.isKill();
1605 };
1606
1607 for (const MachineOperand &MO : MI.operands()) {
1608 // In a spill instruction generated by the InlineSpiller the spilled
1609 // register has its kill flag set.
1610 if (isKilledReg(MO, Reg))
1611 return true;
1612 if (Reg != 0) {
1613 // Check whether next instruction kills the spilled register.
1614 // FIXME: Current solution does not cover search for killed register in
1615 // bundles and instructions further down the chain.
1616 auto NextI = std::next(MI.getIterator());
1617 // Skip next instruction that points to basic block end iterator.
1618 if (MI.getParent()->end() == NextI)
1619 continue;
1620 Register RegNext;
1621 for (const MachineOperand &MONext : NextI->operands()) {
1622 // Return true if we came across the register from the
1623 // previous spill instruction that is killed in NextI.
1624 if (isKilledReg(MONext, RegNext) && RegNext == Reg)
1625 return true;
1626 }
1627 }
1628 }
1629 // Return false if we didn't find spilled register.
1630 return false;
1631}
1632
1633Optional<VarLocBasedLDV::VarLoc::SpillLoc>
1634VarLocBasedLDV::isRestoreInstruction(const MachineInstr &MI,
1635 MachineFunction *MF, Register &Reg) {
1636 if (!MI.hasOneMemOperand())
1637 return None;
1638
1639 // FIXME: Handle folded restore instructions with more than one memory
1640 // operand.
1641 if (MI.getRestoreSize(TII)) {
1642 Reg = MI.getOperand(0).getReg();
1643 return extractSpillBaseRegAndOffset(MI);
1644 }
1645 return None;
1646}
1647
1648/// A spilled register may indicate that we have to end the current range of
1649/// a variable and create a new one for the spill location.
1650/// A restored register may indicate the reverse situation.
1651/// We don't want to insert any instructions in process(), so we just create
1652/// the DBG_VALUE without inserting it and keep track of it in \p Transfers.
1653/// It will be inserted into the BB when we're done iterating over the
1654/// instructions.
1655void VarLocBasedLDV::transferSpillOrRestoreInst(MachineInstr &MI,
1656 OpenRangesSet &OpenRanges,
1657 VarLocMap &VarLocIDs,
1658 TransferMap &Transfers) {
1659 MachineFunction *MF = MI.getMF();
1660 TransferKind TKind;
1661 Register Reg;
1662 Optional<VarLoc::SpillLoc> Loc;
1663
1664 LLVM_DEBUG(dbgs() << "Examining instruction: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Examining instruction: "
; MI.dump();; } } while (false)
;
1665
1666 // First, if there are any DBG_VALUEs pointing at a spill slot that is
1667 // written to, then close the variable location. The value in memory
1668 // will have changed.
1669 VarLocsInRange KillSet;
1670 if (isSpillInstruction(MI, MF)) {
1671 Loc = extractSpillBaseRegAndOffset(MI);
1672 for (uint64_t ID : OpenRanges.getSpillVarLocs()) {
1673 LocIndex Idx = LocIndex::fromRawInteger(ID);
1674 const VarLoc &VL = VarLocIDs[Idx];
1675 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1675, __extension__ __PRETTY_FUNCTION__))
;
1676 if (VL.usesSpillLoc(*Loc)) {
1677 // This location is overwritten by the current instruction -- terminate
1678 // the open range, and insert an explicit DBG_VALUE $noreg.
1679 //
1680 // Doing this at a later stage would require re-interpreting all
1681 // DBG_VALUes and DIExpressions to identify whether they point at
1682 // memory, and then analysing all memory writes to see if they
1683 // overwrite that memory, which is expensive.
1684 //
1685 // At this stage, we already know which DBG_VALUEs are for spills and
1686 // where they are located; it's best to fix handle overwrites now.
1687 KillSet.insert(ID);
1688 unsigned SpillLocIdx = VL.getSpillLocIdx(*Loc);
1689 VarLoc::MachineLoc OldLoc = VL.Locs[SpillLocIdx];
1690 VarLoc UndefVL = VarLoc::CreateCopyLoc(VL, OldLoc, 0);
1691 LocIndices UndefLocIDs = VarLocIDs.insert(UndefVL);
1692 Transfers.push_back({&MI, UndefLocIDs.back()});
1693 }
1694 }
1695 OpenRanges.erase(KillSet, VarLocIDs, LocIndex::kSpillLocation);
1696 }
1697
1698 // Try to recognise spill and restore instructions that may create a new
1699 // variable location.
1700 if (isLocationSpill(MI, MF, Reg)) {
1701 TKind = TransferKind::TransferSpill;
1702 LLVM_DEBUG(dbgs() << "Recognized as spill: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as spill: "
; MI.dump();; } } while (false)
;
1703 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1704 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1705 } else {
1706 if (!(Loc = isRestoreInstruction(MI, MF, Reg)))
1707 return;
1708 TKind = TransferKind::TransferRestore;
1709 LLVM_DEBUG(dbgs() << "Recognized as restore: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Recognized as restore: "
; MI.dump();; } } while (false)
;
1710 LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
1711 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Register: " << Reg
<< " " << printReg(Reg, TRI) << "\n"; } } while
(false)
;
1712 }
1713 // Check if the register or spill location is the location of a debug value.
1714 auto TransferCandidates = OpenRanges.getEmptyVarLocRange();
1715 if (TKind == TransferKind::TransferSpill)
1716 TransferCandidates = OpenRanges.getRegisterVarLocs(Reg);
1717 else if (TKind == TransferKind::TransferRestore)
1718 TransferCandidates = OpenRanges.getSpillVarLocs();
1719 for (uint64_t ID : TransferCandidates) {
1720 LocIndex Idx = LocIndex::fromRawInteger(ID);
1721 const VarLoc &VL = VarLocIDs[Idx];
1722 unsigned LocIdx;
1723 if (TKind == TransferKind::TransferSpill) {
1724 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1724, __extension__ __PRETTY_FUNCTION__))
;
1725 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)
1726 << 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)
;
1727 LocIdx = VL.getRegIdx(Reg);
1728 } else {
1729 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1730, __extension__ __PRETTY_FUNCTION__))
1730 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1730, __extension__ __PRETTY_FUNCTION__))
;
1731 if (!VL.usesSpillLoc(*Loc))
1732 // The spill location is not the location of a debug value.
1733 continue;
1734 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)
1735 << 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)
;
1736 LocIdx = VL.getSpillLocIdx(*Loc);
1737 }
1738 VarLoc::MachineLoc MLoc = VL.Locs[LocIdx];
1739 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx, TKind,
1740 MLoc, Reg);
1741 // FIXME: A comment should explain why it's correct to return early here,
1742 // if that is in fact correct.
1743 return;
1744 }
1745}
1746
1747/// If \p MI is a register copy instruction, that copies a previously tracked
1748/// value from one register to another register that is callee saved, we
1749/// create new DBG_VALUE instruction described with copy destination register.
1750void VarLocBasedLDV::transferRegisterCopy(MachineInstr &MI,
1751 OpenRangesSet &OpenRanges,
1752 VarLocMap &VarLocIDs,
1753 TransferMap &Transfers) {
1754 auto DestSrc = TII->isCopyInstr(MI);
1755 if (!DestSrc)
1756 return;
1757
1758 const MachineOperand *DestRegOp = DestSrc->Destination;
1759 const MachineOperand *SrcRegOp = DestSrc->Source;
1760
1761 if (!DestRegOp->isDef())
1762 return;
1763
1764 auto isCalleeSavedReg = [&](Register Reg) {
1765 for (MCRegAliasIterator RAI(Reg, TRI, true); RAI.isValid(); ++RAI)
1766 if (CalleeSavedRegs.test(*RAI))
1767 return true;
1768 return false;
1769 };
1770
1771 Register SrcReg = SrcRegOp->getReg();
1772 Register DestReg = DestRegOp->getReg();
1773
1774 // We want to recognize instructions where destination register is callee
1775 // saved register. If register that could be clobbered by the call is
1776 // included, there would be a great chance that it is going to be clobbered
1777 // soon. It is more likely that previous register location, which is callee
1778 // saved, is going to stay unclobbered longer, even if it is killed.
1779 if (!isCalleeSavedReg(DestReg))
1780 return;
1781
1782 // Remember an entry value movement. If we encounter a new debug value of
1783 // a parameter describing only a moving of the value around, rather then
1784 // modifying it, we are still able to use the entry value if needed.
1785 if (isRegOtherThanSPAndFP(*DestRegOp, MI, TRI)) {
1786 for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) {
1787 LocIndex Idx = LocIndex::fromRawInteger(ID);
1788 const VarLoc &VL = VarLocIDs[Idx];
1789 if (VL.isEntryValueBackupReg(SrcReg)) {
1790 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)
;
1791 VarLoc EntryValLocCopyBackup =
1792 VarLoc::CreateEntryCopyBackupLoc(VL.MI, LS, VL.Expr, DestReg);
1793 // Stop tracking the original entry value.
1794 OpenRanges.erase(VL);
1795
1796 // Start tracking the entry value copy.
1797 LocIndices EntryValCopyLocIDs = VarLocIDs.insert(EntryValLocCopyBackup);
1798 OpenRanges.insert(EntryValCopyLocIDs, EntryValLocCopyBackup);
1799 break;
1800 }
1801 }
1802 }
1803
1804 if (!SrcRegOp->isKill())
1805 return;
1806
1807 for (uint64_t ID : OpenRanges.getRegisterVarLocs(SrcReg)) {
1808 LocIndex Idx = LocIndex::fromRawInteger(ID);
1809 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1809, __extension__ __PRETTY_FUNCTION__))
;
1810 VarLoc::MachineLocValue Loc;
1811 Loc.RegNo = SrcReg;
1812 VarLoc::MachineLoc MLoc{VarLoc::MachineLocKind::RegisterKind, Loc};
1813 insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx,
1814 TransferKind::TransferCopy, MLoc, DestReg);
1815 // FIXME: A comment should explain why it's correct to return early here,
1816 // if that is in fact correct.
1817 return;
1818 }
1819}
1820
1821/// Terminate all open ranges at the end of the current basic block.
1822bool VarLocBasedLDV::transferTerminator(MachineBasicBlock *CurMBB,
1823 OpenRangesSet &OpenRanges,
1824 VarLocInMBB &OutLocs,
1825 const VarLocMap &VarLocIDs) {
1826 bool Changed = false;
1827 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)
1828 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)
1829 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)
1830 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)
1831 // 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)
1832 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)
1833 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)
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 })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)
;
1836 VarLocSet &VLS = getVarLocsInMBB(CurMBB, OutLocs);
1837 Changed = VLS != OpenRanges.getVarLocs();
1838 // New OutLocs set may be different due to spill, restore or register
1839 // copy instruction processing.
1840 if (Changed)
1841 VLS = OpenRanges.getVarLocs();
1842 OpenRanges.clear();
1843 return Changed;
1844}
1845
1846/// Accumulate a mapping between each DILocalVariable fragment and other
1847/// fragments of that DILocalVariable which overlap. This reduces work during
1848/// the data-flow stage from "Find any overlapping fragments" to "Check if the
1849/// known-to-overlap fragments are present".
1850/// \param MI A previously unprocessed DEBUG_VALUE instruction to analyze for
1851/// fragment usage.
1852/// \param SeenFragments Map from DILocalVariable to all fragments of that
1853/// Variable which are known to exist.
1854/// \param OverlappingFragments The overlap map being constructed, from one
1855/// Var/Fragment pair to a vector of fragments known to overlap.
1856void VarLocBasedLDV::accumulateFragmentMap(MachineInstr &MI,
1857 VarToFragments &SeenFragments,
1858 OverlapMap &OverlappingFragments) {
1859 DebugVariable MIVar(MI.getDebugVariable(), MI.getDebugExpression(),
1860 MI.getDebugLoc()->getInlinedAt());
1861 FragmentInfo ThisFragment = MIVar.getFragmentOrDefault();
1862
1863 // If this is the first sighting of this variable, then we are guaranteed
1864 // there are currently no overlapping fragments either. Initialize the set
1865 // of seen fragments, record no overlaps for the current one, and return.
1866 auto SeenIt = SeenFragments.find(MIVar.getVariable());
1867 if (SeenIt == SeenFragments.end()) {
1868 SmallSet<FragmentInfo, 4> OneFragment;
1869 OneFragment.insert(ThisFragment);
1870 SeenFragments.insert({MIVar.getVariable(), OneFragment});
1871
1872 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1873 return;
1874 }
1875
1876 // If this particular Variable/Fragment pair already exists in the overlap
1877 // map, it has already been accounted for.
1878 auto IsInOLapMap =
1879 OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}});
1880 if (!IsInOLapMap.second)
1881 return;
1882
1883 auto &ThisFragmentsOverlaps = IsInOLapMap.first->second;
1884 auto &AllSeenFragments = SeenIt->second;
1885
1886 // Otherwise, examine all other seen fragments for this variable, with "this"
1887 // fragment being a previously unseen fragment. Record any pair of
1888 // overlapping fragments.
1889 for (auto &ASeenFragment : AllSeenFragments) {
1890 // Does this previously seen fragment overlap?
1891 if (DIExpression::fragmentsOverlap(ThisFragment, ASeenFragment)) {
1892 // Yes: Mark the current fragment as being overlapped.
1893 ThisFragmentsOverlaps.push_back(ASeenFragment);
1894 // Mark the previously seen fragment as being overlapped by the current
1895 // one.
1896 auto ASeenFragmentsOverlaps =
1897 OverlappingFragments.find({MIVar.getVariable(), ASeenFragment});
1898 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1899, __extension__ __PRETTY_FUNCTION__))
1899 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1899, __extension__ __PRETTY_FUNCTION__))
;
1900 ASeenFragmentsOverlaps->second.push_back(ThisFragment);
1901 }
1902 }
1903
1904 AllSeenFragments.insert(ThisFragment);
1905}
1906
1907/// This routine creates OpenRanges.
1908void VarLocBasedLDV::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
1909 VarLocMap &VarLocIDs, TransferMap &Transfers,
1910 InstToEntryLocMap &EntryValTransfers,
1911 RegDefToInstMap &RegSetInstrs) {
1912 if (!MI.isDebugInstr())
1913 LastNonDbgMI = &MI;
1914 transferDebugValue(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1915 RegSetInstrs);
1916 transferRegisterDef(MI, OpenRanges, VarLocIDs, EntryValTransfers,
1917 RegSetInstrs);
1918 transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
1919 transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
1920}
1921
1922/// This routine joins the analysis results of all incoming edges in @MBB by
1923/// inserting a new DBG_VALUE instruction at the start of the @MBB - if the same
1924/// source variable in all the predecessors of @MBB reside in the same location.
1925bool VarLocBasedLDV::join(
1926 MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs,
1927 const VarLocMap &VarLocIDs,
1928 SmallPtrSet<const MachineBasicBlock *, 16> &Visited,
1929 SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks) {
1930 LLVM_DEBUG(dbgs() << "join MBB: " << MBB.getNumber() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "join MBB: " << MBB
.getNumber() << "\n"; } } while (false)
;
1931
1932 VarLocSet InLocsT(Alloc); // Temporary incoming locations.
1933
1934 // For all predecessors of this MBB, find the set of VarLocs that
1935 // can be joined.
1936 int NumVisited = 0;
1937 for (auto p : MBB.predecessors()) {
1938 // Ignore backedges if we have not visited the predecessor yet. As the
1939 // predecessor hasn't yet had locations propagated into it, most locations
1940 // will not yet be valid, so treat them as all being uninitialized and
1941 // potentially valid. If a location guessed to be correct here is
1942 // invalidated later, we will remove it when we revisit this block.
1943 if (!Visited.count(p)) {
1944 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)
1945 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << " ignoring unvisited pred MBB: "
<< p->getNumber() << "\n"; } } while (false)
;
1946 continue;
1947 }
1948 auto OL = OutLocs.find(p);
1949 // Join is null in case of empty OutLocs from any of the pred.
1950 if (OL == OutLocs.end())
1951 return false;
1952
1953 // Just copy over the Out locs to incoming locs for the first visited
1954 // predecessor, and for all other predecessors join the Out locs.
1955 VarLocSet &OutLocVLS = *OL->second.get();
1956 if (!NumVisited)
1957 InLocsT = OutLocVLS;
1958 else
1959 InLocsT &= OutLocVLS;
1960
1961 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)
1962 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)
1963 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)
1964 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)
1965 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)
1966 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)
1967 << 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)
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 })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)
;
1970
1971 NumVisited++;
1972 }
1973
1974 // Filter out DBG_VALUES that are out of scope.
1975 VarLocSet KillSet(Alloc);
1976 bool IsArtificial = ArtificialBlocks.count(&MBB);
1977 if (!IsArtificial) {
1978 for (uint64_t ID : InLocsT) {
1979 LocIndex Idx = LocIndex::fromRawInteger(ID);
1980 if (!VarLocIDs[Idx].dominates(LS, MBB)) {
1981 KillSet.set(ID);
1982 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)
1983 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)
1984 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)
1985 })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)
;
1986 }
1987 }
1988 }
1989 InLocsT.intersectWithComplement(KillSet);
1990
1991 // As we are processing blocks in reverse post-order we
1992 // should have processed at least one predecessor, unless it
1993 // is the entry block which has no predecessor.
1994 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1995, __extension__ __PRETTY_FUNCTION__))
1995 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 1995, __extension__ __PRETTY_FUNCTION__))
;
1996
1997 VarLocSet &ILS = getVarLocsInMBB(&MBB, InLocs);
1998 bool Changed = false;
1999 if (ILS != InLocsT) {
2000 ILS = InLocsT;
2001 Changed = true;
2002 }
2003
2004 return Changed;
2005}
2006
2007void VarLocBasedLDV::flushPendingLocs(VarLocInMBB &PendingInLocs,
2008 VarLocMap &VarLocIDs) {
2009 // PendingInLocs records all locations propagated into blocks, which have
2010 // not had DBG_VALUE insts created. Go through and create those insts now.
2011 for (auto &Iter : PendingInLocs) {
2012 // Map is keyed on a constant pointer, unwrap it so we can insert insts.
2013 auto &MBB = const_cast<MachineBasicBlock &>(*Iter.first);
2014 VarLocSet &Pending = *Iter.second.get();
2015
2016 SmallVector<VarLoc, 32> VarLocs;
2017 collectAllVarLocs(VarLocs, Pending, VarLocIDs);
2018
2019 for (VarLoc DiffIt : VarLocs) {
2020 // The ID location is live-in to MBB -- work out what kind of machine
2021 // location it is and create a DBG_VALUE.
2022 if (DiffIt.isEntryBackupLoc())
2023 continue;
2024 MachineInstr *MI = DiffIt.BuildDbgValue(*MBB.getParent());
2025 MBB.insert(MBB.instr_begin(), MI);
2026
2027 (void)MI;
2028 LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Inserted: "; MI->dump
();; } } while (false)
;
2029 }
2030 }
2031}
2032
2033bool VarLocBasedLDV::isEntryValueCandidate(
2034 const MachineInstr &MI, const DefinedRegsSet &DefinedRegs) const {
2035 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2035, __extension__ __PRETTY_FUNCTION__))
;
2036
2037 // TODO: Add support for local variables that are expressed in terms of
2038 // parameters entry values.
2039 // TODO: Add support for modified arguments that can be expressed
2040 // by using its entry value.
2041 auto *DIVar = MI.getDebugVariable();
2042 if (!DIVar->isParameter())
2043 return false;
2044
2045 // Do not consider parameters that belong to an inlined function.
2046 if (MI.getDebugLoc()->getInlinedAt())
2047 return false;
2048
2049 // Only consider parameters that are described using registers. Parameters
2050 // that are passed on the stack are not yet supported, so ignore debug
2051 // values that are described by the frame or stack pointer.
2052 if (!isRegOtherThanSPAndFP(MI.getDebugOperand(0), MI, TRI))
2053 return false;
2054
2055 // If a parameter's value has been propagated from the caller, then the
2056 // parameter's DBG_VALUE may be described using a register defined by some
2057 // instruction in the entry block, in which case we shouldn't create an
2058 // entry value.
2059 if (DefinedRegs.count(MI.getDebugOperand(0).getReg()))
2060 return false;
2061
2062 // TODO: Add support for parameters that have a pre-existing debug expressions
2063 // (e.g. fragments).
2064 if (MI.getDebugExpression()->getNumElements() > 0)
2065 return false;
2066
2067 return true;
2068}
2069
2070/// Collect all register defines (including aliases) for the given instruction.
2071static void collectRegDefs(const MachineInstr &MI, DefinedRegsSet &Regs,
2072 const TargetRegisterInfo *TRI) {
2073 for (const MachineOperand &MO : MI.operands())
2074 if (MO.isReg() && MO.isDef() && MO.getReg())
2075 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI)
2076 Regs.insert(*AI);
2077}
2078
2079/// This routine records the entry values of function parameters. The values
2080/// could be used as backup values. If we loose the track of some unmodified
2081/// parameters, the backup values will be used as a primary locations.
2082void VarLocBasedLDV::recordEntryValue(const MachineInstr &MI,
2083 const DefinedRegsSet &DefinedRegs,
2084 OpenRangesSet &OpenRanges,
2085 VarLocMap &VarLocIDs) {
2086 if (TPC) {
2087 auto &TM = TPC->getTM<TargetMachine>();
2088 if (!TM.Options.ShouldEmitDebugEntryValues())
2089 return;
2090 }
2091
2092 DebugVariable V(MI.getDebugVariable(), MI.getDebugExpression(),
2093 MI.getDebugLoc()->getInlinedAt());
2094
2095 if (!isEntryValueCandidate(MI, DefinedRegs) ||
2096 OpenRanges.getEntryValueBackup(V))
2097 return;
2098
2099 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)
;
2100
2101 // Create the entry value and use it as a backup location until it is
2102 // valid. It is valid until a parameter is not changed.
2103 DIExpression *NewExpr =
2104 DIExpression::prepend(MI.getDebugExpression(), DIExpression::EntryValue);
2105 VarLoc EntryValLocAsBackup = VarLoc::CreateEntryBackupLoc(MI, LS, NewExpr);
2106 LocIndices EntryValLocIDs = VarLocIDs.insert(EntryValLocAsBackup);
2107 OpenRanges.insert(EntryValLocIDs, EntryValLocAsBackup);
2108}
2109
2110/// Calculate the liveness information for the given machine function and
2111/// extend ranges across basic blocks.
2112bool VarLocBasedLDV::ExtendRanges(MachineFunction &MF, TargetPassConfig *TPC,
2113 unsigned InputBBLimit,
2114 unsigned InputDbgValLimit) {
2115 LLVM_DEBUG(dbgs() << "\nDebug Range Extension\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "\nDebug Range Extension\n"
; } } while (false)
;
2116
2117 if (!MF.getFunction().getSubprogram())
2118 // VarLocBaseLDV will already have removed all DBG_VALUEs.
2119 return false;
2120
2121 // Skip functions from NoDebug compilation units.
2122 if (MF.getFunction().getSubprogram()->getUnit()->getEmissionKind() ==
2123 DICompileUnit::NoDebug)
2124 return false;
2125
2126 TRI = MF.getSubtarget().getRegisterInfo();
2127 TII = MF.getSubtarget().getInstrInfo();
2128 TFI = MF.getSubtarget().getFrameLowering();
2129 TFI->getCalleeSaves(MF, CalleeSavedRegs);
2130 this->TPC = TPC;
2131 LS.initialize(MF);
2132
2133 bool Changed = false;
2134 bool OLChanged = false;
2135 bool MBBJoined = false;
2136
2137 VarLocMap VarLocIDs; // Map VarLoc<>unique ID for use in bitvectors.
2138 OverlapMap OverlapFragments; // Map of overlapping variable fragments.
2139 OpenRangesSet OpenRanges(Alloc, OverlapFragments);
2140 // Ranges that are open until end of bb.
2141 VarLocInMBB OutLocs; // Ranges that exist beyond bb.
2142 VarLocInMBB InLocs; // Ranges that are incoming after joining.
2143 TransferMap Transfers; // DBG_VALUEs associated with transfers (such as
2144 // spills, copies and restores).
2145 // Map responsible MI to attached Transfer emitted from Backup Entry Value.
2146 InstToEntryLocMap EntryValTransfers;
2147 // Map a Register to the last MI which clobbered it.
2148 RegDefToInstMap RegSetInstrs;
2149
2150 VarToFragments SeenFragments;
2151
2152 // Blocks which are artificial, i.e. blocks which exclusively contain
2153 // instructions without locations, or with line 0 locations.
2154 SmallPtrSet<const MachineBasicBlock *, 16> ArtificialBlocks;
2155
2156 DenseMap<unsigned int, MachineBasicBlock *> OrderToBB;
2157 DenseMap<MachineBasicBlock *, unsigned int> BBToOrder;
2158 std::priority_queue<unsigned int, std::vector<unsigned int>,
2159 std::greater<unsigned int>>
2160 Worklist;
2161 std::priority_queue<unsigned int, std::vector<unsigned int>,
2162 std::greater<unsigned int>>
2163 Pending;
2164
2165 // Set of register defines that are seen when traversing the entry block
2166 // looking for debug entry value candidates.
2167 DefinedRegsSet DefinedRegs;
2168
2169 // Only in the case of entry MBB collect DBG_VALUEs representing
2170 // function parameters in order to generate debug entry values for them.
2171 MachineBasicBlock &First_MBB = *(MF.begin());
2172 for (auto &MI : First_MBB) {
2173 collectRegDefs(MI, DefinedRegs, TRI);
2174 if (MI.isDebugValue())
2175 recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs);
2176 }
2177
2178 // Initialize per-block structures and scan for fragment overlaps.
2179 for (auto &MBB : MF)
2180 for (auto &MI : MBB)
2181 if (MI.isDebugValue())
2182 accumulateFragmentMap(MI, SeenFragments, OverlapFragments);
2183
2184 auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
2185 if (const DebugLoc &DL = MI.getDebugLoc())
2186 return DL.getLine() != 0;
2187 return false;
2188 };
2189 for (auto &MBB : MF)
2190 if (none_of(MBB.instrs(), hasNonArtificialLocation))
2191 ArtificialBlocks.insert(&MBB);
2192
2193 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
2194 "OutLocs after initialization", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after initialization", dbgs()); } } while (false)
;
2195
2196 ReversePostOrderTraversal<MachineFunction *> RPOT(&MF);
2197 unsigned int RPONumber = 0;
2198 for (MachineBasicBlock *MBB : RPOT) {
2199 OrderToBB[RPONumber] = MBB;
2200 BBToOrder[MBB] = RPONumber;
2201 Worklist.push(RPONumber);
2202 ++RPONumber;
2203 }
2204
2205 if (RPONumber > InputBBLimit) {
2206 unsigned NumInputDbgValues = 0;
2207 for (auto &MBB : MF)
2208 for (auto &MI : MBB)
2209 if (MI.isDebugValue())
2210 ++NumInputDbgValues;
2211 if (NumInputDbgValues > InputDbgValLimit) {
2212 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)
2213 << " 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)
2214 << 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)
2215 << " 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)
;
2216 return false;
2217 }
2218 }
2219
2220 // This is a standard "union of predecessor outs" dataflow problem.
2221 // To solve it, we perform join() and process() using the two worklist method
2222 // until the ranges converge.
2223 // Ranges have converged when both worklists are empty.
2224 SmallPtrSet<const MachineBasicBlock *, 16> Visited;
2225 while (!Worklist.empty() || !Pending.empty()) {
2226 // We track what is on the pending worklist to avoid inserting the same
2227 // thing twice. We could avoid this with a custom priority queue, but this
2228 // is probably not worth it.
2229 SmallPtrSet<MachineBasicBlock *, 16> OnPending;
2230 LLVM_DEBUG(dbgs() << "Processing Worklist\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { dbgs() << "Processing Worklist\n"
; } } while (false)
;
2231 while (!Worklist.empty()) {
2232 MachineBasicBlock *MBB = OrderToBB[Worklist.top()];
2233 Worklist.pop();
2234 MBBJoined = join(*MBB, OutLocs, InLocs, VarLocIDs, Visited,
2235 ArtificialBlocks);
2236 MBBJoined |= Visited.insert(MBB).second;
2237 if (MBBJoined) {
2238 MBBJoined = false;
Value stored to 'MBBJoined' is never read
2239 Changed = true;
2240 // Now that we have started to extend ranges across BBs we need to
2241 // examine spill, copy and restore instructions to see whether they
2242 // operate with registers that correspond to user variables.
2243 // First load any pending inlocs.
2244 OpenRanges.insertFromLocSet(getVarLocsInMBB(MBB, InLocs), VarLocIDs);
2245 LastNonDbgMI = nullptr;
2246 RegSetInstrs.clear();
2247 for (auto &MI : *MBB)
2248 process(MI, OpenRanges, VarLocIDs, Transfers, EntryValTransfers,
2249 RegSetInstrs);
2250 OLChanged |= transferTerminator(MBB, OpenRanges, OutLocs, VarLocIDs);
2251
2252 LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
2253 "OutLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs
, "OutLocs after propagating", dbgs()); } } while (false)
;
2254 LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
2255 "InLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs
, "InLocs after propagating", dbgs()); } } while (false)
;
2256
2257 if (OLChanged) {
2258 OLChanged = false;
2259 for (auto s : MBB->successors())
2260 if (OnPending.insert(s).second) {
2261 Pending.push(BBToOrder[s]);
2262 }
2263 }
2264 }
2265 }
2266 Worklist.swap(Pending);
2267 // At this point, pending must be empty, since it was just the empty
2268 // worklist
2269 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2269, __extension__ __PRETTY_FUNCTION__))
;
2270 }
2271
2272 // Add any DBG_VALUE instructions created by location transfers.
2273 for (auto &TR : Transfers) {
2274 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2275, __extension__ __PRETTY_FUNCTION__))
2275 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2275, __extension__ __PRETTY_FUNCTION__))
;
2276 MachineBasicBlock *MBB = TR.TransferInst->getParent();
2277 const VarLoc &VL = VarLocIDs[TR.LocationID];
2278 MachineInstr *MI = VL.BuildDbgValue(MF);
2279 MBB->insertAfterBundle(TR.TransferInst->getIterator(), MI);
2280 }
2281 Transfers.clear();
2282
2283 // Add DBG_VALUEs created using Backup Entry Value location.
2284 for (auto &TR : EntryValTransfers) {
2285 MachineInstr *TRInst = const_cast<MachineInstr *>(TR.first);
2286 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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2287, __extension__ __PRETTY_FUNCTION__))
2287 "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~++20210926122410+d23fd8ae8906/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp"
, 2287, __extension__ __PRETTY_FUNCTION__))
;
2288 MachineBasicBlock *MBB = TRInst->getParent();
2289 const VarLoc &VL = VarLocIDs[TR.second];
2290 MachineInstr *MI = VL.BuildDbgValue(MF);
2291 MBB->insertAfterBundle(TRInst->getIterator(), MI);
2292 }
2293 EntryValTransfers.clear();
2294
2295 // Deferred inlocs will not have had any DBG_VALUE insts created; do
2296 // that now.
2297 flushPendingLocs(InLocs, VarLocIDs);
2298
2299 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)
;
2300 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)
;
2301 return Changed;
2302}
2303
2304LDVImpl *
2305llvm::makeVarLocBasedLiveDebugValues()
2306{
2307 return new VarLocBasedLDV();
2308}