File: | llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp |
Warning: | line 1939, column 9 Value stored to 'MBBJoined' is never read |
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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, its current |
80 | /// machine-location, and the DBG_VALUE inst that specifies the location. Each |
81 | /// VarLoc is indexed in the (function-scope) \p VarLocMap, giving each VarLoc a |
82 | /// unique index. Rather than operate directly on machine locations, the |
83 | /// dataflow analysis in this pass identifies locations by their index in the |
84 | /// VarLocMap, meaning all the variable locations in a block can be described |
85 | /// by a sparse vector of VarLocMap indicies. |
86 | /// |
87 | /// All the storage for the dataflow analysis is local to the ExtendRanges |
88 | /// method and passed down to helper methods. "OutLocs" and "InLocs" record the |
89 | /// in and out lattice values for each block. "OpenRanges" maintains a list of |
90 | /// variable locations and, with the "process" method, evaluates the transfer |
91 | /// function of each block. "flushPendingLocs" installs DBG_VALUEs for each |
92 | /// live-in location at the start of blocks, while "Transfers" records |
93 | /// transfers of values between machine-locations. |
94 | /// |
95 | /// We avoid explicitly representing the "Unknown" (\top) lattice value in the |
96 | /// implementation. Instead, unvisited blocks implicitly have all lattice |
97 | /// values set as "Unknown". After being visited, there will be path back to |
98 | /// the entry block where the lattice value is "False", and as the transfer |
99 | /// function cannot make new "Unknown" locations, there are no scenarios where |
100 | /// a block can have an "Unknown" location after being visited. Similarly, we |
101 | /// don't enumerate all possible variable locations before exploring the |
102 | /// function: when a new location is discovered, all blocks previously explored |
103 | /// were implicitly "False" but unrecorded, and become explicitly "False" when |
104 | /// a new VarLoc is created with its bit not set in predecessor InLocs or |
105 | /// OutLocs. |
106 | /// |
107 | //===----------------------------------------------------------------------===// |
108 | |
109 | #include "LiveDebugValues.h" |
110 | |
111 | #include "llvm/ADT/CoalescingBitVector.h" |
112 | #include "llvm/ADT/DenseMap.h" |
113 | #include "llvm/ADT/PostOrderIterator.h" |
114 | #include "llvm/ADT/SmallPtrSet.h" |
115 | #include "llvm/ADT/SmallSet.h" |
116 | #include "llvm/ADT/SmallVector.h" |
117 | #include "llvm/ADT/Statistic.h" |
118 | #include "llvm/ADT/UniqueVector.h" |
119 | #include "llvm/CodeGen/LexicalScopes.h" |
120 | #include "llvm/CodeGen/MachineBasicBlock.h" |
121 | #include "llvm/CodeGen/MachineFrameInfo.h" |
122 | #include "llvm/CodeGen/MachineFunction.h" |
123 | #include "llvm/CodeGen/MachineFunctionPass.h" |
124 | #include "llvm/CodeGen/MachineInstr.h" |
125 | #include "llvm/CodeGen/MachineInstrBuilder.h" |
126 | #include "llvm/CodeGen/MachineMemOperand.h" |
127 | #include "llvm/CodeGen/MachineOperand.h" |
128 | #include "llvm/CodeGen/PseudoSourceValue.h" |
129 | #include "llvm/CodeGen/RegisterScavenging.h" |
130 | #include "llvm/CodeGen/TargetFrameLowering.h" |
131 | #include "llvm/CodeGen/TargetInstrInfo.h" |
132 | #include "llvm/CodeGen/TargetLowering.h" |
133 | #include "llvm/CodeGen/TargetPassConfig.h" |
134 | #include "llvm/CodeGen/TargetRegisterInfo.h" |
135 | #include "llvm/CodeGen/TargetSubtargetInfo.h" |
136 | #include "llvm/Config/llvm-config.h" |
137 | #include "llvm/IR/DIBuilder.h" |
138 | #include "llvm/IR/DebugInfoMetadata.h" |
139 | #include "llvm/IR/DebugLoc.h" |
140 | #include "llvm/IR/Function.h" |
141 | #include "llvm/IR/Module.h" |
142 | #include "llvm/InitializePasses.h" |
143 | #include "llvm/MC/MCRegisterInfo.h" |
144 | #include "llvm/Pass.h" |
145 | #include "llvm/Support/Casting.h" |
146 | #include "llvm/Support/Compiler.h" |
147 | #include "llvm/Support/Debug.h" |
148 | #include "llvm/Support/TypeSize.h" |
149 | #include "llvm/Support/raw_ostream.h" |
150 | #include "llvm/Target/TargetMachine.h" |
151 | #include <algorithm> |
152 | #include <cassert> |
153 | #include <cstdint> |
154 | #include <functional> |
155 | #include <queue> |
156 | #include <tuple> |
157 | #include <utility> |
158 | #include <vector> |
159 | |
160 | using namespace llvm; |
161 | |
162 | #define DEBUG_TYPE"livedebugvalues" "livedebugvalues" |
163 | |
164 | STATISTIC(NumInserted, "Number of DBG_VALUE instructions inserted")static llvm::Statistic NumInserted = {"livedebugvalues", "NumInserted" , "Number of DBG_VALUE instructions inserted"}; |
165 | |
166 | // Options to prevent pathological compile-time behavior. If InputBBLimit and |
167 | // InputDbgValueLimit are both exceeded, range extension is disabled. |
168 | static cl::opt<unsigned> InputBBLimit( |
169 | "livedebugvalues-input-bb-limit", |
170 | cl::desc("Maximum input basic blocks before DBG_VALUE limit applies"), |
171 | cl::init(10000), cl::Hidden); |
172 | static cl::opt<unsigned> InputDbgValueLimit( |
173 | "livedebugvalues-input-dbg-value-limit", |
174 | cl::desc( |
175 | "Maximum input DBG_VALUE insts supported by debug range extension"), |
176 | cl::init(50000), cl::Hidden); |
177 | |
178 | // If @MI is a DBG_VALUE with debug value described by a defined |
179 | // register, returns the number of this register. In the other case, returns 0. |
180 | static Register isDbgValueDescribedByReg(const MachineInstr &MI) { |
181 | assert(MI.isDebugValue() && "expected a DBG_VALUE")((MI.isDebugValue() && "expected a DBG_VALUE") ? static_cast <void> (0) : __assert_fail ("MI.isDebugValue() && \"expected a DBG_VALUE\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 181, __PRETTY_FUNCTION__)); |
182 | assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE")((MI.getNumOperands() == 4 && "malformed DBG_VALUE") ? static_cast<void> (0) : __assert_fail ("MI.getNumOperands() == 4 && \"malformed DBG_VALUE\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 182, __PRETTY_FUNCTION__)); |
183 | // If location of variable is described using a register (directly |
184 | // or indirectly), this register is always a first operand. |
185 | return MI.getDebugOperand(0).isReg() ? MI.getDebugOperand(0).getReg() |
186 | : Register(); |
187 | } |
188 | |
189 | /// If \p Op is a stack or frame register return true, otherwise return false. |
190 | /// This is used to avoid basing the debug entry values on the registers, since |
191 | /// we do not support it at the moment. |
192 | static bool isRegOtherThanSPAndFP(const MachineOperand &Op, |
193 | const MachineInstr &MI, |
194 | const TargetRegisterInfo *TRI) { |
195 | if (!Op.isReg()) |
196 | return false; |
197 | |
198 | const MachineFunction *MF = MI.getParent()->getParent(); |
199 | const TargetLowering *TLI = MF->getSubtarget().getTargetLowering(); |
200 | Register SP = TLI->getStackPointerRegisterToSaveRestore(); |
201 | Register FP = TRI->getFrameRegister(*MF); |
202 | Register Reg = Op.getReg(); |
203 | |
204 | return Reg && Reg != SP && Reg != FP; |
205 | } |
206 | |
207 | namespace { |
208 | |
209 | // Max out the number of statically allocated elements in DefinedRegsSet, as |
210 | // this prevents fallback to std::set::count() operations. |
211 | using DefinedRegsSet = SmallSet<Register, 32>; |
212 | |
213 | using VarLocSet = CoalescingBitVector<uint64_t>; |
214 | |
215 | /// A type-checked pair of {Register Location (or 0), Index}, used to index |
216 | /// into a \ref VarLocMap. This can be efficiently converted to a 64-bit int |
217 | /// for insertion into a \ref VarLocSet, and efficiently converted back. The |
218 | /// type-checker helps ensure that the conversions aren't lossy. |
219 | /// |
220 | /// Why encode a location /into/ the VarLocMap index? This makes it possible |
221 | /// to find the open VarLocs killed by a register def very quickly. This is a |
222 | /// performance-critical operation for LiveDebugValues. |
223 | struct LocIndex { |
224 | using u32_location_t = uint32_t; |
225 | using u32_index_t = uint32_t; |
226 | |
227 | u32_location_t Location; // Physical registers live in the range [1;2^30) (see |
228 | // \ref MCRegister), so we have plenty of range left |
229 | // here to encode non-register locations. |
230 | u32_index_t Index; |
231 | |
232 | /// The first location greater than 0 that is not reserved for VarLocs of |
233 | /// kind RegisterKind. |
234 | static constexpr u32_location_t kFirstInvalidRegLocation = 1 << 30; |
235 | |
236 | /// A special location reserved for VarLocs of kind SpillLocKind. |
237 | static constexpr u32_location_t kSpillLocation = kFirstInvalidRegLocation; |
238 | |
239 | /// A special location reserved for VarLocs of kind EntryValueBackupKind and |
240 | /// EntryValueCopyBackupKind. |
241 | static constexpr u32_location_t kEntryValueBackupLocation = |
242 | kFirstInvalidRegLocation + 1; |
243 | |
244 | LocIndex(u32_location_t Location, u32_index_t Index) |
245 | : Location(Location), Index(Index) {} |
246 | |
247 | uint64_t getAsRawInteger() const { |
248 | return (static_cast<uint64_t>(Location) << 32) | Index; |
249 | } |
250 | |
251 | template<typename IntT> static LocIndex fromRawInteger(IntT ID) { |
252 | static_assert(std::is_unsigned<IntT>::value && |
253 | sizeof(ID) == sizeof(uint64_t), |
254 | "Cannot convert raw integer to LocIndex"); |
255 | return {static_cast<u32_location_t>(ID >> 32), |
256 | static_cast<u32_index_t>(ID)}; |
257 | } |
258 | |
259 | /// Get the start of the interval reserved for VarLocs of kind RegisterKind |
260 | /// which reside in \p Reg. The end is at rawIndexForReg(Reg+1)-1. |
261 | static uint64_t rawIndexForReg(uint32_t Reg) { |
262 | return LocIndex(Reg, 0).getAsRawInteger(); |
263 | } |
264 | |
265 | /// Return a range covering all set indices in the interval reserved for |
266 | /// \p Location in \p Set. |
267 | static auto indexRangeForLocation(const VarLocSet &Set, |
268 | u32_location_t Location) { |
269 | uint64_t Start = LocIndex(Location, 0).getAsRawInteger(); |
270 | uint64_t End = LocIndex(Location + 1, 0).getAsRawInteger(); |
271 | return Set.half_open_range(Start, End); |
272 | } |
273 | }; |
274 | |
275 | class VarLocBasedLDV : public LDVImpl { |
276 | private: |
277 | const TargetRegisterInfo *TRI; |
278 | const TargetInstrInfo *TII; |
279 | const TargetFrameLowering *TFI; |
280 | TargetPassConfig *TPC; |
281 | BitVector CalleeSavedRegs; |
282 | LexicalScopes LS; |
283 | VarLocSet::Allocator Alloc; |
284 | |
285 | enum struct TransferKind { TransferCopy, TransferSpill, TransferRestore }; |
286 | |
287 | using FragmentInfo = DIExpression::FragmentInfo; |
288 | using OptFragmentInfo = Optional<DIExpression::FragmentInfo>; |
289 | |
290 | /// A pair of debug variable and value location. |
291 | struct VarLoc { |
292 | // The location at which a spilled variable resides. It consists of a |
293 | // register and an offset. |
294 | struct SpillLoc { |
295 | unsigned SpillBase; |
296 | StackOffset SpillOffset; |
297 | bool operator==(const SpillLoc &Other) const { |
298 | return SpillBase == Other.SpillBase && SpillOffset == Other.SpillOffset; |
299 | } |
300 | bool operator!=(const SpillLoc &Other) const { |
301 | return !(*this == Other); |
302 | } |
303 | }; |
304 | |
305 | /// Identity of the variable at this location. |
306 | const DebugVariable Var; |
307 | |
308 | /// The expression applied to this location. |
309 | const DIExpression *Expr; |
310 | |
311 | /// DBG_VALUE to clone var/expr information from if this location |
312 | /// is moved. |
313 | const MachineInstr &MI; |
314 | |
315 | enum VarLocKind { |
316 | InvalidKind = 0, |
317 | RegisterKind, |
318 | SpillLocKind, |
319 | ImmediateKind, |
320 | EntryValueKind, |
321 | EntryValueBackupKind, |
322 | EntryValueCopyBackupKind |
323 | } Kind = InvalidKind; |
324 | |
325 | /// The value location. Stored separately to avoid repeatedly |
326 | /// extracting it from MI. |
327 | union LocUnion { |
328 | uint64_t RegNo; |
329 | SpillLoc SpillLocation; |
330 | uint64_t Hash; |
331 | int64_t Immediate; |
332 | const ConstantFP *FPImm; |
333 | const ConstantInt *CImm; |
334 | LocUnion() : Hash(0) {} |
335 | } Loc; |
336 | |
337 | VarLoc(const MachineInstr &MI, LexicalScopes &LS) |
338 | : Var(MI.getDebugVariable(), MI.getDebugExpression(), |
339 | MI.getDebugLoc()->getInlinedAt()), |
340 | Expr(MI.getDebugExpression()), MI(MI) { |
341 | assert(MI.isDebugValue() && "not a DBG_VALUE")((MI.isDebugValue() && "not a DBG_VALUE") ? static_cast <void> (0) : __assert_fail ("MI.isDebugValue() && \"not a DBG_VALUE\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 341, __PRETTY_FUNCTION__)); |
342 | assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE")((MI.getNumOperands() == 4 && "malformed DBG_VALUE") ? static_cast<void> (0) : __assert_fail ("MI.getNumOperands() == 4 && \"malformed DBG_VALUE\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 342, __PRETTY_FUNCTION__)); |
343 | if (int RegNo = isDbgValueDescribedByReg(MI)) { |
344 | Kind = RegisterKind; |
345 | Loc.RegNo = RegNo; |
346 | } else if (MI.getDebugOperand(0).isImm()) { |
347 | Kind = ImmediateKind; |
348 | Loc.Immediate = MI.getDebugOperand(0).getImm(); |
349 | } else if (MI.getDebugOperand(0).isFPImm()) { |
350 | Kind = ImmediateKind; |
351 | Loc.FPImm = MI.getDebugOperand(0).getFPImm(); |
352 | } else if (MI.getDebugOperand(0).isCImm()) { |
353 | Kind = ImmediateKind; |
354 | Loc.CImm = MI.getDebugOperand(0).getCImm(); |
355 | } |
356 | |
357 | // We create the debug entry values from the factory functions rather than |
358 | // from this ctor. |
359 | assert(Kind != EntryValueKind && !isEntryBackupLoc())((Kind != EntryValueKind && !isEntryBackupLoc()) ? static_cast <void> (0) : __assert_fail ("Kind != EntryValueKind && !isEntryBackupLoc()" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 359, __PRETTY_FUNCTION__)); |
360 | } |
361 | |
362 | /// Take the variable and machine-location in DBG_VALUE MI, and build an |
363 | /// entry location using the given expression. |
364 | static VarLoc CreateEntryLoc(const MachineInstr &MI, LexicalScopes &LS, |
365 | const DIExpression *EntryExpr, Register Reg) { |
366 | VarLoc VL(MI, LS); |
367 | assert(VL.Kind == RegisterKind)((VL.Kind == RegisterKind) ? static_cast<void> (0) : __assert_fail ("VL.Kind == RegisterKind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 367, __PRETTY_FUNCTION__)); |
368 | VL.Kind = EntryValueKind; |
369 | VL.Expr = EntryExpr; |
370 | VL.Loc.RegNo = Reg; |
371 | return VL; |
372 | } |
373 | |
374 | /// Take the variable and machine-location from the DBG_VALUE (from the |
375 | /// function entry), and build an entry value backup location. The backup |
376 | /// location will turn into the normal location if the backup is valid at |
377 | /// the time of the primary location clobbering. |
378 | static VarLoc CreateEntryBackupLoc(const MachineInstr &MI, |
379 | LexicalScopes &LS, |
380 | const DIExpression *EntryExpr) { |
381 | VarLoc VL(MI, LS); |
382 | assert(VL.Kind == RegisterKind)((VL.Kind == RegisterKind) ? static_cast<void> (0) : __assert_fail ("VL.Kind == RegisterKind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 382, __PRETTY_FUNCTION__)); |
383 | VL.Kind = EntryValueBackupKind; |
384 | VL.Expr = EntryExpr; |
385 | return VL; |
386 | } |
387 | |
388 | /// Take the variable and machine-location from the DBG_VALUE (from the |
389 | /// function entry), and build a copy of an entry value backup location by |
390 | /// setting the register location to NewReg. |
391 | static VarLoc CreateEntryCopyBackupLoc(const MachineInstr &MI, |
392 | LexicalScopes &LS, |
393 | const DIExpression *EntryExpr, |
394 | Register NewReg) { |
395 | VarLoc VL(MI, LS); |
396 | assert(VL.Kind == RegisterKind)((VL.Kind == RegisterKind) ? static_cast<void> (0) : __assert_fail ("VL.Kind == RegisterKind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 396, __PRETTY_FUNCTION__)); |
397 | VL.Kind = EntryValueCopyBackupKind; |
398 | VL.Expr = EntryExpr; |
399 | VL.Loc.RegNo = NewReg; |
400 | return VL; |
401 | } |
402 | |
403 | /// Copy the register location in DBG_VALUE MI, updating the register to |
404 | /// be NewReg. |
405 | static VarLoc CreateCopyLoc(const MachineInstr &MI, LexicalScopes &LS, |
406 | Register NewReg) { |
407 | VarLoc VL(MI, LS); |
408 | assert(VL.Kind == RegisterKind)((VL.Kind == RegisterKind) ? static_cast<void> (0) : __assert_fail ("VL.Kind == RegisterKind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 408, __PRETTY_FUNCTION__)); |
409 | VL.Loc.RegNo = NewReg; |
410 | return VL; |
411 | } |
412 | |
413 | /// Take the variable described by DBG_VALUE MI, and create a VarLoc |
414 | /// locating it in the specified spill location. |
415 | static VarLoc CreateSpillLoc(const MachineInstr &MI, unsigned SpillBase, |
416 | StackOffset SpillOffset, LexicalScopes &LS) { |
417 | VarLoc VL(MI, LS); |
418 | assert(VL.Kind == RegisterKind)((VL.Kind == RegisterKind) ? static_cast<void> (0) : __assert_fail ("VL.Kind == RegisterKind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 418, __PRETTY_FUNCTION__)); |
419 | VL.Kind = SpillLocKind; |
420 | VL.Loc.SpillLocation = {SpillBase, SpillOffset}; |
421 | return VL; |
422 | } |
423 | |
424 | /// Create a DBG_VALUE representing this VarLoc in the given function. |
425 | /// Copies variable-specific information such as DILocalVariable and |
426 | /// inlining information from the original DBG_VALUE instruction, which may |
427 | /// have been several transfers ago. |
428 | MachineInstr *BuildDbgValue(MachineFunction &MF) const { |
429 | const DebugLoc &DbgLoc = MI.getDebugLoc(); |
430 | bool Indirect = MI.isIndirectDebugValue(); |
431 | const auto &IID = MI.getDesc(); |
432 | const DILocalVariable *Var = MI.getDebugVariable(); |
433 | const DIExpression *DIExpr = MI.getDebugExpression(); |
434 | NumInserted++; |
435 | |
436 | switch (Kind) { |
437 | case EntryValueKind: |
438 | // An entry value is a register location -- but with an updated |
439 | // expression. The register location of such DBG_VALUE is always the one |
440 | // from the entry DBG_VALUE, it does not matter if the entry value was |
441 | // copied in to another register due to some optimizations. |
442 | return BuildMI(MF, DbgLoc, IID, Indirect, |
443 | MI.getDebugOperand(0).getReg(), Var, Expr); |
444 | case RegisterKind: |
445 | // Register locations are like the source DBG_VALUE, but with the |
446 | // register number from this VarLoc. |
447 | return BuildMI(MF, DbgLoc, IID, Indirect, Loc.RegNo, Var, DIExpr); |
448 | case SpillLocKind: { |
449 | // Spills are indirect DBG_VALUEs, with a base register and offset. |
450 | // Use the original DBG_VALUEs expression to build the spilt location |
451 | // on top of. FIXME: spill locations created before this pass runs |
452 | // are not recognized, and not handled here. |
453 | auto *TRI = MF.getSubtarget().getRegisterInfo(); |
454 | auto *SpillExpr = TRI->prependOffsetExpression( |
455 | DIExpr, DIExpression::ApplyOffset, Loc.SpillLocation.SpillOffset); |
456 | unsigned Base = Loc.SpillLocation.SpillBase; |
457 | return BuildMI(MF, DbgLoc, IID, true, Base, Var, SpillExpr); |
458 | } |
459 | case ImmediateKind: { |
460 | MachineOperand MO = MI.getDebugOperand(0); |
461 | return BuildMI(MF, DbgLoc, IID, Indirect, MO, Var, DIExpr); |
462 | } |
463 | case EntryValueBackupKind: |
464 | case EntryValueCopyBackupKind: |
465 | case InvalidKind: |
466 | llvm_unreachable(::llvm::llvm_unreachable_internal("Tried to produce DBG_VALUE for invalid or backup VarLoc" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 467) |
467 | "Tried to produce DBG_VALUE for invalid or backup VarLoc")::llvm::llvm_unreachable_internal("Tried to produce DBG_VALUE for invalid or backup VarLoc" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 467); |
468 | } |
469 | llvm_unreachable("Unrecognized VarLocBasedLDV.VarLoc.Kind enum")::llvm::llvm_unreachable_internal("Unrecognized VarLocBasedLDV.VarLoc.Kind enum" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 469); |
470 | } |
471 | |
472 | /// Is the Loc field a constant or constant object? |
473 | bool isConstant() const { return Kind == ImmediateKind; } |
474 | |
475 | /// Check if the Loc field is an entry backup location. |
476 | bool isEntryBackupLoc() const { |
477 | return Kind == EntryValueBackupKind || Kind == EntryValueCopyBackupKind; |
478 | } |
479 | |
480 | /// If this variable is described by a register holding the entry value, |
481 | /// return it, otherwise return 0. |
482 | unsigned getEntryValueBackupReg() const { |
483 | if (Kind == EntryValueBackupKind) |
484 | return Loc.RegNo; |
485 | return 0; |
486 | } |
487 | |
488 | /// If this variable is described by a register holding the copy of the |
489 | /// entry value, return it, otherwise return 0. |
490 | unsigned getEntryValueCopyBackupReg() const { |
491 | if (Kind == EntryValueCopyBackupKind) |
492 | return Loc.RegNo; |
493 | return 0; |
494 | } |
495 | |
496 | /// If this variable is described by a register, return it, |
497 | /// otherwise return 0. |
498 | unsigned isDescribedByReg() const { |
499 | if (Kind == RegisterKind) |
500 | return Loc.RegNo; |
501 | return 0; |
502 | } |
503 | |
504 | /// Determine whether the lexical scope of this value's debug location |
505 | /// dominates MBB. |
506 | bool dominates(LexicalScopes &LS, MachineBasicBlock &MBB) const { |
507 | return LS.dominates(MI.getDebugLoc().get(), &MBB); |
508 | } |
509 | |
510 | #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) |
511 | // TRI can be null. |
512 | void dump(const TargetRegisterInfo *TRI, raw_ostream &Out = dbgs()) const { |
513 | Out << "VarLoc("; |
514 | switch (Kind) { |
515 | case RegisterKind: |
516 | case EntryValueKind: |
517 | case EntryValueBackupKind: |
518 | case EntryValueCopyBackupKind: |
519 | Out << printReg(Loc.RegNo, TRI); |
520 | break; |
521 | case SpillLocKind: |
522 | Out << printReg(Loc.SpillLocation.SpillBase, TRI); |
523 | Out << "[" << Loc.SpillLocation.SpillOffset.getFixed() << " + " |
524 | << Loc.SpillLocation.SpillOffset.getScalable() << "x vscale" |
525 | << "]"; |
526 | break; |
527 | case ImmediateKind: |
528 | Out << Loc.Immediate; |
529 | break; |
530 | case InvalidKind: |
531 | llvm_unreachable("Invalid VarLoc in dump method")::llvm::llvm_unreachable_internal("Invalid VarLoc in dump method" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 531); |
532 | } |
533 | |
534 | Out << ", \"" << Var.getVariable()->getName() << "\", " << *Expr << ", "; |
535 | if (Var.getInlinedAt()) |
536 | Out << "!" << Var.getInlinedAt()->getMetadataID() << ")\n"; |
537 | else |
538 | Out << "(null))"; |
539 | |
540 | if (isEntryBackupLoc()) |
541 | Out << " (backup loc)\n"; |
542 | else |
543 | Out << "\n"; |
544 | } |
545 | #endif |
546 | |
547 | bool operator==(const VarLoc &Other) const { |
548 | if (Kind != Other.Kind || !(Var == Other.Var) || Expr != Other.Expr) |
549 | return false; |
550 | |
551 | switch (Kind) { |
552 | case SpillLocKind: |
553 | return Loc.SpillLocation == Other.Loc.SpillLocation; |
554 | case RegisterKind: |
555 | case ImmediateKind: |
556 | case EntryValueKind: |
557 | case EntryValueBackupKind: |
558 | case EntryValueCopyBackupKind: |
559 | return Loc.Hash == Other.Loc.Hash; |
560 | default: |
561 | llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 561); |
562 | } |
563 | } |
564 | |
565 | /// This operator guarantees that VarLocs are sorted by Variable first. |
566 | bool operator<(const VarLoc &Other) const { |
567 | switch (Kind) { |
568 | case SpillLocKind: |
569 | return std::make_tuple(Var, Kind, Loc.SpillLocation.SpillBase, |
570 | Loc.SpillLocation.SpillOffset.getFixed(), |
571 | Loc.SpillLocation.SpillOffset.getScalable(), |
572 | Expr) < |
573 | std::make_tuple( |
574 | Other.Var, Other.Kind, Other.Loc.SpillLocation.SpillBase, |
575 | Other.Loc.SpillLocation.SpillOffset.getFixed(), |
576 | Other.Loc.SpillLocation.SpillOffset.getScalable(), |
577 | Other.Expr); |
578 | case RegisterKind: |
579 | case ImmediateKind: |
580 | case EntryValueKind: |
581 | case EntryValueBackupKind: |
582 | case EntryValueCopyBackupKind: |
583 | return std::tie(Var, Kind, Loc.Hash, Expr) < |
584 | std::tie(Other.Var, Other.Kind, Other.Loc.Hash, Other.Expr); |
585 | default: |
586 | llvm_unreachable("Invalid kind")::llvm::llvm_unreachable_internal("Invalid kind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 586); |
587 | } |
588 | } |
589 | }; |
590 | |
591 | /// VarLocMap is used for two things: |
592 | /// 1) Assigning a unique LocIndex to a VarLoc. This LocIndex can be used to |
593 | /// virtually insert a VarLoc into a VarLocSet. |
594 | /// 2) Given a LocIndex, look up the unique associated VarLoc. |
595 | class VarLocMap { |
596 | /// Map a VarLoc to an index within the vector reserved for its location |
597 | /// within Loc2Vars. |
598 | std::map<VarLoc, LocIndex::u32_index_t> Var2Index; |
599 | |
600 | /// Map a location to a vector which holds VarLocs which live in that |
601 | /// location. |
602 | SmallDenseMap<LocIndex::u32_location_t, std::vector<VarLoc>> Loc2Vars; |
603 | |
604 | /// Determine the 32-bit location reserved for \p VL, based on its kind. |
605 | static LocIndex::u32_location_t getLocationForVar(const VarLoc &VL) { |
606 | switch (VL.Kind) { |
607 | case VarLoc::RegisterKind: |
608 | assert((VL.Loc.RegNo < LocIndex::kFirstInvalidRegLocation) &&(((VL.Loc.RegNo < LocIndex::kFirstInvalidRegLocation) && "Physreg out of range?") ? static_cast<void> (0) : __assert_fail ("(VL.Loc.RegNo < LocIndex::kFirstInvalidRegLocation) && \"Physreg out of range?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 609, __PRETTY_FUNCTION__)) |
609 | "Physreg out of range?")(((VL.Loc.RegNo < LocIndex::kFirstInvalidRegLocation) && "Physreg out of range?") ? static_cast<void> (0) : __assert_fail ("(VL.Loc.RegNo < LocIndex::kFirstInvalidRegLocation) && \"Physreg out of range?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 609, __PRETTY_FUNCTION__)); |
610 | return VL.Loc.RegNo; |
611 | case VarLoc::SpillLocKind: |
612 | return LocIndex::kSpillLocation; |
613 | case VarLoc::EntryValueBackupKind: |
614 | case VarLoc::EntryValueCopyBackupKind: |
615 | return LocIndex::kEntryValueBackupLocation; |
616 | default: |
617 | return 0; |
618 | } |
619 | } |
620 | |
621 | public: |
622 | /// Retrieve a unique LocIndex for \p VL. |
623 | LocIndex insert(const VarLoc &VL) { |
624 | LocIndex::u32_location_t Location = getLocationForVar(VL); |
625 | LocIndex::u32_index_t &Index = Var2Index[VL]; |
626 | if (!Index) { |
627 | auto &Vars = Loc2Vars[Location]; |
628 | Vars.push_back(VL); |
629 | Index = Vars.size(); |
630 | } |
631 | return {Location, Index - 1}; |
632 | } |
633 | |
634 | /// Retrieve the unique VarLoc associated with \p ID. |
635 | const VarLoc &operator[](LocIndex ID) const { |
636 | auto LocIt = Loc2Vars.find(ID.Location); |
637 | assert(LocIt != Loc2Vars.end() && "Location not tracked")((LocIt != Loc2Vars.end() && "Location not tracked") ? static_cast<void> (0) : __assert_fail ("LocIt != Loc2Vars.end() && \"Location not tracked\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 637, __PRETTY_FUNCTION__)); |
638 | return LocIt->second[ID.Index]; |
639 | } |
640 | }; |
641 | |
642 | using VarLocInMBB = |
643 | SmallDenseMap<const MachineBasicBlock *, std::unique_ptr<VarLocSet>>; |
644 | struct TransferDebugPair { |
645 | MachineInstr *TransferInst; ///< Instruction where this transfer occurs. |
646 | LocIndex LocationID; ///< Location number for the transfer dest. |
647 | }; |
648 | using TransferMap = SmallVector<TransferDebugPair, 4>; |
649 | |
650 | // Types for recording sets of variable fragments that overlap. For a given |
651 | // local variable, we record all other fragments of that variable that could |
652 | // overlap it, to reduce search time. |
653 | using FragmentOfVar = |
654 | std::pair<const DILocalVariable *, DIExpression::FragmentInfo>; |
655 | using OverlapMap = |
656 | DenseMap<FragmentOfVar, SmallVector<DIExpression::FragmentInfo, 1>>; |
657 | |
658 | // Helper while building OverlapMap, a map of all fragments seen for a given |
659 | // DILocalVariable. |
660 | using VarToFragments = |
661 | DenseMap<const DILocalVariable *, SmallSet<FragmentInfo, 4>>; |
662 | |
663 | /// This holds the working set of currently open ranges. For fast |
664 | /// access, this is done both as a set of VarLocIDs, and a map of |
665 | /// DebugVariable to recent VarLocID. Note that a DBG_VALUE ends all |
666 | /// previous open ranges for the same variable. In addition, we keep |
667 | /// two different maps (Vars/EntryValuesBackupVars), so erase/insert |
668 | /// methods act differently depending on whether a VarLoc is primary |
669 | /// location or backup one. In the case the VarLoc is backup location |
670 | /// we will erase/insert from the EntryValuesBackupVars map, otherwise |
671 | /// we perform the operation on the Vars. |
672 | class OpenRangesSet { |
673 | VarLocSet VarLocs; |
674 | // Map the DebugVariable to recent primary location ID. |
675 | SmallDenseMap<DebugVariable, LocIndex, 8> Vars; |
676 | // Map the DebugVariable to recent backup location ID. |
677 | SmallDenseMap<DebugVariable, LocIndex, 8> EntryValuesBackupVars; |
678 | OverlapMap &OverlappingFragments; |
679 | |
680 | public: |
681 | OpenRangesSet(VarLocSet::Allocator &Alloc, OverlapMap &_OLapMap) |
682 | : VarLocs(Alloc), OverlappingFragments(_OLapMap) {} |
683 | |
684 | const VarLocSet &getVarLocs() const { return VarLocs; } |
685 | |
686 | /// Terminate all open ranges for VL.Var by removing it from the set. |
687 | void erase(const VarLoc &VL); |
688 | |
689 | /// Terminate all open ranges listed in \c KillSet by removing |
690 | /// them from the set. |
691 | void erase(const VarLocSet &KillSet, const VarLocMap &VarLocIDs); |
692 | |
693 | /// Insert a new range into the set. |
694 | void insert(LocIndex VarLocID, const VarLoc &VL); |
695 | |
696 | /// Insert a set of ranges. |
697 | void insertFromLocSet(const VarLocSet &ToLoad, const VarLocMap &Map) { |
698 | for (uint64_t ID : ToLoad) { |
699 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
700 | const VarLoc &VarL = Map[Idx]; |
701 | insert(Idx, VarL); |
702 | } |
703 | } |
704 | |
705 | llvm::Optional<LocIndex> getEntryValueBackup(DebugVariable Var); |
706 | |
707 | /// Empty the set. |
708 | void clear() { |
709 | VarLocs.clear(); |
710 | Vars.clear(); |
711 | EntryValuesBackupVars.clear(); |
712 | } |
713 | |
714 | /// Return whether the set is empty or not. |
715 | bool empty() const { |
716 | assert(Vars.empty() == EntryValuesBackupVars.empty() &&((Vars.empty() == EntryValuesBackupVars.empty() && Vars .empty() == VarLocs.empty() && "open ranges are inconsistent" ) ? static_cast<void> (0) : __assert_fail ("Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 718, __PRETTY_FUNCTION__)) |
717 | Vars.empty() == VarLocs.empty() &&((Vars.empty() == EntryValuesBackupVars.empty() && Vars .empty() == VarLocs.empty() && "open ranges are inconsistent" ) ? static_cast<void> (0) : __assert_fail ("Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 718, __PRETTY_FUNCTION__)) |
718 | "open ranges are inconsistent")((Vars.empty() == EntryValuesBackupVars.empty() && Vars .empty() == VarLocs.empty() && "open ranges are inconsistent" ) ? static_cast<void> (0) : __assert_fail ("Vars.empty() == EntryValuesBackupVars.empty() && Vars.empty() == VarLocs.empty() && \"open ranges are inconsistent\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 718, __PRETTY_FUNCTION__)); |
719 | return VarLocs.empty(); |
720 | } |
721 | |
722 | /// Get an empty range of VarLoc IDs. |
723 | auto getEmptyVarLocRange() const { |
724 | return iterator_range<VarLocSet::const_iterator>(getVarLocs().end(), |
725 | getVarLocs().end()); |
726 | } |
727 | |
728 | /// Get all set IDs for VarLocs of kind RegisterKind in \p Reg. |
729 | auto getRegisterVarLocs(Register Reg) const { |
730 | return LocIndex::indexRangeForLocation(getVarLocs(), Reg); |
731 | } |
732 | |
733 | /// Get all set IDs for VarLocs of kind SpillLocKind. |
734 | auto getSpillVarLocs() const { |
735 | return LocIndex::indexRangeForLocation(getVarLocs(), |
736 | LocIndex::kSpillLocation); |
737 | } |
738 | |
739 | /// Get all set IDs for VarLocs of kind EntryValueBackupKind or |
740 | /// EntryValueCopyBackupKind. |
741 | auto getEntryValueBackupVarLocs() const { |
742 | return LocIndex::indexRangeForLocation( |
743 | getVarLocs(), LocIndex::kEntryValueBackupLocation); |
744 | } |
745 | }; |
746 | |
747 | /// Collect all VarLoc IDs from \p CollectFrom for VarLocs of kind |
748 | /// RegisterKind which are located in any reg in \p Regs. Insert collected IDs |
749 | /// into \p Collected. |
750 | void collectIDsForRegs(VarLocSet &Collected, const DefinedRegsSet &Regs, |
751 | const VarLocSet &CollectFrom) const; |
752 | |
753 | /// Get the registers which are used by VarLocs of kind RegisterKind tracked |
754 | /// by \p CollectFrom. |
755 | void getUsedRegs(const VarLocSet &CollectFrom, |
756 | SmallVectorImpl<uint32_t> &UsedRegs) const; |
757 | |
758 | VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB, VarLocInMBB &Locs) { |
759 | std::unique_ptr<VarLocSet> &VLS = Locs[MBB]; |
760 | if (!VLS) |
761 | VLS = std::make_unique<VarLocSet>(Alloc); |
762 | return *VLS.get(); |
763 | } |
764 | |
765 | const VarLocSet &getVarLocsInMBB(const MachineBasicBlock *MBB, |
766 | const VarLocInMBB &Locs) const { |
767 | auto It = Locs.find(MBB); |
768 | assert(It != Locs.end() && "MBB not in map")((It != Locs.end() && "MBB not in map") ? static_cast <void> (0) : __assert_fail ("It != Locs.end() && \"MBB not in map\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 768, __PRETTY_FUNCTION__)); |
769 | return *It->second.get(); |
770 | } |
771 | |
772 | /// Tests whether this instruction is a spill to a stack location. |
773 | bool isSpillInstruction(const MachineInstr &MI, MachineFunction *MF); |
774 | |
775 | /// Decide if @MI is a spill instruction and return true if it is. We use 2 |
776 | /// criteria to make this decision: |
777 | /// - Is this instruction a store to a spill slot? |
778 | /// - Is there a register operand that is both used and killed? |
779 | /// TODO: Store optimization can fold spills into other stores (including |
780 | /// other spills). We do not handle this yet (more than one memory operand). |
781 | bool isLocationSpill(const MachineInstr &MI, MachineFunction *MF, |
782 | Register &Reg); |
783 | |
784 | /// Returns true if the given machine instruction is a debug value which we |
785 | /// can emit entry values for. |
786 | /// |
787 | /// Currently, we generate debug entry values only for parameters that are |
788 | /// unmodified throughout the function and located in a register. |
789 | bool isEntryValueCandidate(const MachineInstr &MI, |
790 | const DefinedRegsSet &Regs) const; |
791 | |
792 | /// If a given instruction is identified as a spill, return the spill location |
793 | /// and set \p Reg to the spilled register. |
794 | Optional<VarLoc::SpillLoc> isRestoreInstruction(const MachineInstr &MI, |
795 | MachineFunction *MF, |
796 | Register &Reg); |
797 | /// Given a spill instruction, extract the register and offset used to |
798 | /// address the spill location in a target independent way. |
799 | VarLoc::SpillLoc extractSpillBaseRegAndOffset(const MachineInstr &MI); |
800 | void insertTransferDebugPair(MachineInstr &MI, OpenRangesSet &OpenRanges, |
801 | TransferMap &Transfers, VarLocMap &VarLocIDs, |
802 | LocIndex OldVarID, TransferKind Kind, |
803 | Register NewReg = Register()); |
804 | |
805 | void transferDebugValue(const MachineInstr &MI, OpenRangesSet &OpenRanges, |
806 | VarLocMap &VarLocIDs); |
807 | void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges, |
808 | VarLocMap &VarLocIDs, TransferMap &Transfers); |
809 | bool removeEntryValue(const MachineInstr &MI, OpenRangesSet &OpenRanges, |
810 | VarLocMap &VarLocIDs, const VarLoc &EntryVL); |
811 | void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges, |
812 | VarLocMap &VarLocIDs, TransferMap &Transfers, |
813 | VarLocSet &KillSet); |
814 | void recordEntryValue(const MachineInstr &MI, |
815 | const DefinedRegsSet &DefinedRegs, |
816 | OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs); |
817 | void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges, |
818 | VarLocMap &VarLocIDs, TransferMap &Transfers); |
819 | void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges, |
820 | VarLocMap &VarLocIDs, TransferMap &Transfers); |
821 | bool transferTerminator(MachineBasicBlock *MBB, OpenRangesSet &OpenRanges, |
822 | VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs); |
823 | |
824 | void process(MachineInstr &MI, OpenRangesSet &OpenRanges, |
825 | VarLocMap &VarLocIDs, TransferMap &Transfers); |
826 | |
827 | void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments, |
828 | OverlapMap &OLapMap); |
829 | |
830 | bool join(MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs, |
831 | const VarLocMap &VarLocIDs, |
832 | SmallPtrSet<const MachineBasicBlock *, 16> &Visited, |
833 | SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks); |
834 | |
835 | /// Create DBG_VALUE insts for inlocs that have been propagated but |
836 | /// had their instruction creation deferred. |
837 | void flushPendingLocs(VarLocInMBB &PendingInLocs, VarLocMap &VarLocIDs); |
838 | |
839 | bool ExtendRanges(MachineFunction &MF, TargetPassConfig *TPC) override; |
840 | |
841 | public: |
842 | /// Default construct and initialize the pass. |
843 | VarLocBasedLDV(); |
844 | |
845 | ~VarLocBasedLDV(); |
846 | |
847 | /// Print to ostream with a message. |
848 | void printVarLocInMBB(const MachineFunction &MF, const VarLocInMBB &V, |
849 | const VarLocMap &VarLocIDs, const char *msg, |
850 | raw_ostream &Out) const; |
851 | }; |
852 | |
853 | } // end anonymous namespace |
854 | |
855 | //===----------------------------------------------------------------------===// |
856 | // Implementation |
857 | //===----------------------------------------------------------------------===// |
858 | |
859 | VarLocBasedLDV::VarLocBasedLDV() { } |
860 | |
861 | VarLocBasedLDV::~VarLocBasedLDV() { } |
862 | |
863 | /// Erase a variable from the set of open ranges, and additionally erase any |
864 | /// fragments that may overlap it. If the VarLoc is a backup location, erase |
865 | /// the variable from the EntryValuesBackupVars set, indicating we should stop |
866 | /// tracking its backup entry location. Otherwise, if the VarLoc is primary |
867 | /// location, erase the variable from the Vars set. |
868 | void VarLocBasedLDV::OpenRangesSet::erase(const VarLoc &VL) { |
869 | // Erasure helper. |
870 | auto DoErase = [VL, this](DebugVariable VarToErase) { |
871 | auto *EraseFrom = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars; |
872 | auto It = EraseFrom->find(VarToErase); |
873 | if (It != EraseFrom->end()) { |
874 | LocIndex ID = It->second; |
875 | VarLocs.reset(ID.getAsRawInteger()); |
876 | EraseFrom->erase(It); |
877 | } |
878 | }; |
879 | |
880 | DebugVariable Var = VL.Var; |
881 | |
882 | // Erase the variable/fragment that ends here. |
883 | DoErase(Var); |
884 | |
885 | // Extract the fragment. Interpret an empty fragment as one that covers all |
886 | // possible bits. |
887 | FragmentInfo ThisFragment = Var.getFragmentOrDefault(); |
888 | |
889 | // There may be fragments that overlap the designated fragment. Look them up |
890 | // in the pre-computed overlap map, and erase them too. |
891 | auto MapIt = OverlappingFragments.find({Var.getVariable(), ThisFragment}); |
892 | if (MapIt != OverlappingFragments.end()) { |
893 | for (auto Fragment : MapIt->second) { |
894 | VarLocBasedLDV::OptFragmentInfo FragmentHolder; |
895 | if (!DebugVariable::isDefaultFragment(Fragment)) |
896 | FragmentHolder = VarLocBasedLDV::OptFragmentInfo(Fragment); |
897 | DoErase({Var.getVariable(), FragmentHolder, Var.getInlinedAt()}); |
898 | } |
899 | } |
900 | } |
901 | |
902 | void VarLocBasedLDV::OpenRangesSet::erase(const VarLocSet &KillSet, |
903 | const VarLocMap &VarLocIDs) { |
904 | VarLocs.intersectWithComplement(KillSet); |
905 | for (uint64_t ID : KillSet) { |
906 | const VarLoc *VL = &VarLocIDs[LocIndex::fromRawInteger(ID)]; |
907 | auto *EraseFrom = VL->isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars; |
908 | EraseFrom->erase(VL->Var); |
909 | } |
910 | } |
911 | |
912 | void VarLocBasedLDV::OpenRangesSet::insert(LocIndex VarLocID, |
913 | const VarLoc &VL) { |
914 | auto *InsertInto = VL.isEntryBackupLoc() ? &EntryValuesBackupVars : &Vars; |
915 | VarLocs.set(VarLocID.getAsRawInteger()); |
916 | InsertInto->insert({VL.Var, VarLocID}); |
917 | } |
918 | |
919 | /// Return the Loc ID of an entry value backup location, if it exists for the |
920 | /// variable. |
921 | llvm::Optional<LocIndex> |
922 | VarLocBasedLDV::OpenRangesSet::getEntryValueBackup(DebugVariable Var) { |
923 | auto It = EntryValuesBackupVars.find(Var); |
924 | if (It != EntryValuesBackupVars.end()) |
925 | return It->second; |
926 | |
927 | return llvm::None; |
928 | } |
929 | |
930 | void VarLocBasedLDV::collectIDsForRegs(VarLocSet &Collected, |
931 | const DefinedRegsSet &Regs, |
932 | const VarLocSet &CollectFrom) const { |
933 | assert(!Regs.empty() && "Nothing to collect")((!Regs.empty() && "Nothing to collect") ? static_cast <void> (0) : __assert_fail ("!Regs.empty() && \"Nothing to collect\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 933, __PRETTY_FUNCTION__)); |
934 | SmallVector<uint32_t, 32> SortedRegs; |
935 | for (Register Reg : Regs) |
936 | SortedRegs.push_back(Reg); |
937 | array_pod_sort(SortedRegs.begin(), SortedRegs.end()); |
938 | auto It = CollectFrom.find(LocIndex::rawIndexForReg(SortedRegs.front())); |
939 | auto End = CollectFrom.end(); |
940 | for (uint32_t Reg : SortedRegs) { |
941 | // The half-open interval [FirstIndexForReg, FirstInvalidIndex) contains all |
942 | // possible VarLoc IDs for VarLocs of kind RegisterKind which live in Reg. |
943 | uint64_t FirstIndexForReg = LocIndex::rawIndexForReg(Reg); |
944 | uint64_t FirstInvalidIndex = LocIndex::rawIndexForReg(Reg + 1); |
945 | It.advanceToLowerBound(FirstIndexForReg); |
946 | |
947 | // Iterate through that half-open interval and collect all the set IDs. |
948 | for (; It != End && *It < FirstInvalidIndex; ++It) |
949 | Collected.set(*It); |
950 | |
951 | if (It == End) |
952 | return; |
953 | } |
954 | } |
955 | |
956 | void VarLocBasedLDV::getUsedRegs(const VarLocSet &CollectFrom, |
957 | SmallVectorImpl<uint32_t> &UsedRegs) const { |
958 | // All register-based VarLocs are assigned indices greater than or equal to |
959 | // FirstRegIndex. |
960 | uint64_t FirstRegIndex = LocIndex::rawIndexForReg(1); |
961 | uint64_t FirstInvalidIndex = |
962 | LocIndex::rawIndexForReg(LocIndex::kFirstInvalidRegLocation); |
963 | for (auto It = CollectFrom.find(FirstRegIndex), |
964 | End = CollectFrom.find(FirstInvalidIndex); |
965 | It != End;) { |
966 | // We found a VarLoc ID for a VarLoc that lives in a register. Figure out |
967 | // which register and add it to UsedRegs. |
968 | uint32_t FoundReg = LocIndex::fromRawInteger(*It).Location; |
969 | assert((UsedRegs.empty() || FoundReg != UsedRegs.back()) &&(((UsedRegs.empty() || FoundReg != UsedRegs.back()) && "Duplicate used reg") ? static_cast<void> (0) : __assert_fail ("(UsedRegs.empty() || FoundReg != UsedRegs.back()) && \"Duplicate used reg\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 970, __PRETTY_FUNCTION__)) |
970 | "Duplicate used reg")(((UsedRegs.empty() || FoundReg != UsedRegs.back()) && "Duplicate used reg") ? static_cast<void> (0) : __assert_fail ("(UsedRegs.empty() || FoundReg != UsedRegs.back()) && \"Duplicate used reg\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 970, __PRETTY_FUNCTION__)); |
971 | UsedRegs.push_back(FoundReg); |
972 | |
973 | // Skip to the next /set/ register. Note that this finds a lower bound, so |
974 | // even if there aren't any VarLocs living in `FoundReg+1`, we're still |
975 | // guaranteed to move on to the next register (or to end()). |
976 | uint64_t NextRegIndex = LocIndex::rawIndexForReg(FoundReg + 1); |
977 | It.advanceToLowerBound(NextRegIndex); |
978 | } |
979 | } |
980 | |
981 | //===----------------------------------------------------------------------===// |
982 | // Debug Range Extension Implementation |
983 | //===----------------------------------------------------------------------===// |
984 | |
985 | #ifndef NDEBUG |
986 | void VarLocBasedLDV::printVarLocInMBB(const MachineFunction &MF, |
987 | const VarLocInMBB &V, |
988 | const VarLocMap &VarLocIDs, |
989 | const char *msg, |
990 | raw_ostream &Out) const { |
991 | Out << '\n' << msg << '\n'; |
992 | for (const MachineBasicBlock &BB : MF) { |
993 | if (!V.count(&BB)) |
994 | continue; |
995 | const VarLocSet &L = getVarLocsInMBB(&BB, V); |
996 | if (L.empty()) |
997 | continue; |
998 | Out << "MBB: " << BB.getNumber() << ":\n"; |
999 | for (uint64_t VLL : L) { |
1000 | const VarLoc &VL = VarLocIDs[LocIndex::fromRawInteger(VLL)]; |
1001 | Out << " Var: " << VL.Var.getVariable()->getName(); |
1002 | Out << " MI: "; |
1003 | VL.dump(TRI, Out); |
1004 | } |
1005 | } |
1006 | Out << "\n"; |
1007 | } |
1008 | #endif |
1009 | |
1010 | VarLocBasedLDV::VarLoc::SpillLoc |
1011 | VarLocBasedLDV::extractSpillBaseRegAndOffset(const MachineInstr &MI) { |
1012 | assert(MI.hasOneMemOperand() &&((MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?" ) ? static_cast<void> (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1013, __PRETTY_FUNCTION__)) |
1013 | "Spill instruction does not have exactly one memory operand?")((MI.hasOneMemOperand() && "Spill instruction does not have exactly one memory operand?" ) ? static_cast<void> (0) : __assert_fail ("MI.hasOneMemOperand() && \"Spill instruction does not have exactly one memory operand?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1013, __PRETTY_FUNCTION__)); |
1014 | auto MMOI = MI.memoperands_begin(); |
1015 | const PseudoSourceValue *PVal = (*MMOI)->getPseudoValue(); |
1016 | assert(PVal->kind() == PseudoSourceValue::FixedStack &&((PVal->kind() == PseudoSourceValue::FixedStack && "Inconsistent memory operand in spill instruction") ? static_cast <void> (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1017, __PRETTY_FUNCTION__)) |
1017 | "Inconsistent memory operand in spill instruction")((PVal->kind() == PseudoSourceValue::FixedStack && "Inconsistent memory operand in spill instruction") ? static_cast <void> (0) : __assert_fail ("PVal->kind() == PseudoSourceValue::FixedStack && \"Inconsistent memory operand in spill instruction\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1017, __PRETTY_FUNCTION__)); |
1018 | int FI = cast<FixedStackPseudoSourceValue>(PVal)->getFrameIndex(); |
1019 | const MachineBasicBlock *MBB = MI.getParent(); |
1020 | Register Reg; |
1021 | StackOffset Offset = TFI->getFrameIndexReference(*MBB->getParent(), FI, Reg); |
1022 | return {Reg, Offset}; |
1023 | } |
1024 | |
1025 | /// Try to salvage the debug entry value if we encounter a new debug value |
1026 | /// describing the same parameter, otherwise stop tracking the value. Return |
1027 | /// true if we should stop tracking the entry value, otherwise return false. |
1028 | bool VarLocBasedLDV::removeEntryValue(const MachineInstr &MI, |
1029 | OpenRangesSet &OpenRanges, |
1030 | VarLocMap &VarLocIDs, |
1031 | const VarLoc &EntryVL) { |
1032 | // Skip the DBG_VALUE which is the debug entry value itself. |
1033 | if (MI.isIdenticalTo(EntryVL.MI)) |
1034 | return false; |
1035 | |
1036 | // If the parameter's location is not register location, we can not track |
1037 | // the entry value any more. In addition, if the debug expression from the |
1038 | // DBG_VALUE is not empty, we can assume the parameter's value has changed |
1039 | // indicating that we should stop tracking its entry value as well. |
1040 | if (!MI.getDebugOperand(0).isReg() || |
1041 | MI.getDebugExpression()->getNumElements() != 0) |
1042 | return true; |
1043 | |
1044 | // If the DBG_VALUE comes from a copy instruction that copies the entry value, |
1045 | // it means the parameter's value has not changed and we should be able to use |
1046 | // its entry value. |
1047 | bool TrySalvageEntryValue = false; |
1048 | Register Reg = MI.getDebugOperand(0).getReg(); |
1049 | auto I = std::next(MI.getReverseIterator()); |
1050 | const MachineOperand *SrcRegOp, *DestRegOp; |
1051 | if (I != MI.getParent()->rend()) { |
1052 | // TODO: Try to keep tracking of an entry value if we encounter a propagated |
1053 | // DBG_VALUE describing the copy of the entry value. (Propagated entry value |
1054 | // does not indicate the parameter modification.) |
1055 | auto DestSrc = TII->isCopyInstr(*I); |
1056 | if (!DestSrc) |
1057 | return true; |
1058 | |
1059 | SrcRegOp = DestSrc->Source; |
1060 | DestRegOp = DestSrc->Destination; |
1061 | if (Reg != DestRegOp->getReg()) |
1062 | return true; |
1063 | TrySalvageEntryValue = true; |
1064 | } |
1065 | |
1066 | if (TrySalvageEntryValue) { |
1067 | for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) { |
1068 | const VarLoc &VL = VarLocIDs[LocIndex::fromRawInteger(ID)]; |
1069 | if (VL.getEntryValueCopyBackupReg() == Reg && |
1070 | VL.MI.getDebugOperand(0).getReg() == SrcRegOp->getReg()) |
1071 | return false; |
1072 | } |
1073 | } |
1074 | |
1075 | return true; |
1076 | } |
1077 | |
1078 | /// End all previous ranges related to @MI and start a new range from @MI |
1079 | /// if it is a DBG_VALUE instr. |
1080 | void VarLocBasedLDV::transferDebugValue(const MachineInstr &MI, |
1081 | OpenRangesSet &OpenRanges, |
1082 | VarLocMap &VarLocIDs) { |
1083 | if (!MI.isDebugValue()) |
1084 | return; |
1085 | const DILocalVariable *Var = MI.getDebugVariable(); |
1086 | const DIExpression *Expr = MI.getDebugExpression(); |
1087 | const DILocation *DebugLoc = MI.getDebugLoc(); |
1088 | const DILocation *InlinedAt = DebugLoc->getInlinedAt(); |
1089 | assert(Var->isValidLocationForIntrinsic(DebugLoc) &&((Var->isValidLocationForIntrinsic(DebugLoc) && "Expected inlined-at fields to agree" ) ? static_cast<void> (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1090, __PRETTY_FUNCTION__)) |
1090 | "Expected inlined-at fields to agree")((Var->isValidLocationForIntrinsic(DebugLoc) && "Expected inlined-at fields to agree" ) ? static_cast<void> (0) : __assert_fail ("Var->isValidLocationForIntrinsic(DebugLoc) && \"Expected inlined-at fields to agree\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1090, __PRETTY_FUNCTION__)); |
1091 | |
1092 | DebugVariable V(Var, Expr, InlinedAt); |
1093 | |
1094 | // Check if this DBG_VALUE indicates a parameter's value changing. |
1095 | // If that is the case, we should stop tracking its entry value. |
1096 | auto EntryValBackupID = OpenRanges.getEntryValueBackup(V); |
1097 | if (Var->isParameter() && EntryValBackupID) { |
1098 | const VarLoc &EntryVL = VarLocIDs[*EntryValBackupID]; |
1099 | if (removeEntryValue(MI, OpenRanges, VarLocIDs, EntryVL)) { |
1100 | 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) |
1101 | 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) |
1102 | /*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) |
1103 | /*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); |
1104 | OpenRanges.erase(EntryVL); |
1105 | } |
1106 | } |
1107 | |
1108 | if (isDbgValueDescribedByReg(MI) || MI.getDebugOperand(0).isImm() || |
1109 | MI.getDebugOperand(0).isFPImm() || MI.getDebugOperand(0).isCImm()) { |
1110 | // Use normal VarLoc constructor for registers and immediates. |
1111 | VarLoc VL(MI, LS); |
1112 | // End all previous ranges of VL.Var. |
1113 | OpenRanges.erase(VL); |
1114 | |
1115 | LocIndex ID = VarLocIDs.insert(VL); |
1116 | // Add the VarLoc to OpenRanges from this DBG_VALUE. |
1117 | OpenRanges.insert(ID, VL); |
1118 | } else if (MI.hasOneMemOperand()) { |
1119 | 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-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1119); |
1120 | } else { |
1121 | // This must be an undefined location. If it has an open range, erase it. |
1122 | assert(MI.getDebugOperand(0).isReg() &&((MI.getDebugOperand(0).isReg() && MI.getDebugOperand (0).getReg() == 0 && "Unexpected non-undef DBG_VALUE encountered" ) ? static_cast<void> (0) : __assert_fail ("MI.getDebugOperand(0).isReg() && MI.getDebugOperand(0).getReg() == 0 && \"Unexpected non-undef DBG_VALUE encountered\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1124, __PRETTY_FUNCTION__)) |
1123 | MI.getDebugOperand(0).getReg() == 0 &&((MI.getDebugOperand(0).isReg() && MI.getDebugOperand (0).getReg() == 0 && "Unexpected non-undef DBG_VALUE encountered" ) ? static_cast<void> (0) : __assert_fail ("MI.getDebugOperand(0).isReg() && MI.getDebugOperand(0).getReg() == 0 && \"Unexpected non-undef DBG_VALUE encountered\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1124, __PRETTY_FUNCTION__)) |
1124 | "Unexpected non-undef DBG_VALUE encountered")((MI.getDebugOperand(0).isReg() && MI.getDebugOperand (0).getReg() == 0 && "Unexpected non-undef DBG_VALUE encountered" ) ? static_cast<void> (0) : __assert_fail ("MI.getDebugOperand(0).isReg() && MI.getDebugOperand(0).getReg() == 0 && \"Unexpected non-undef DBG_VALUE encountered\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1124, __PRETTY_FUNCTION__)); |
1125 | VarLoc VL(MI, LS); |
1126 | OpenRanges.erase(VL); |
1127 | } |
1128 | } |
1129 | |
1130 | /// Turn the entry value backup locations into primary locations. |
1131 | void VarLocBasedLDV::emitEntryValues(MachineInstr &MI, |
1132 | OpenRangesSet &OpenRanges, |
1133 | VarLocMap &VarLocIDs, |
1134 | TransferMap &Transfers, |
1135 | VarLocSet &KillSet) { |
1136 | // Do not insert entry value locations after a terminator. |
1137 | if (MI.isTerminator()) |
1138 | return; |
1139 | |
1140 | for (uint64_t ID : KillSet) { |
1141 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1142 | const VarLoc &VL = VarLocIDs[Idx]; |
1143 | if (!VL.Var.getVariable()->isParameter()) |
1144 | continue; |
1145 | |
1146 | auto DebugVar = VL.Var; |
1147 | Optional<LocIndex> EntryValBackupID = |
1148 | OpenRanges.getEntryValueBackup(DebugVar); |
1149 | |
1150 | // If the parameter has the entry value backup, it means we should |
1151 | // be able to use its entry value. |
1152 | if (!EntryValBackupID) |
1153 | continue; |
1154 | |
1155 | const VarLoc &EntryVL = VarLocIDs[*EntryValBackupID]; |
1156 | VarLoc EntryLoc = |
1157 | VarLoc::CreateEntryLoc(EntryVL.MI, LS, EntryVL.Expr, EntryVL.Loc.RegNo); |
1158 | LocIndex EntryValueID = VarLocIDs.insert(EntryLoc); |
1159 | Transfers.push_back({&MI, EntryValueID}); |
1160 | OpenRanges.insert(EntryValueID, EntryLoc); |
1161 | } |
1162 | } |
1163 | |
1164 | /// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc |
1165 | /// with \p OldVarID should be deleted form \p OpenRanges and replaced with |
1166 | /// new VarLoc. If \p NewReg is different than default zero value then the |
1167 | /// new location will be register location created by the copy like instruction, |
1168 | /// otherwise it is variable's location on the stack. |
1169 | void VarLocBasedLDV::insertTransferDebugPair( |
1170 | MachineInstr &MI, OpenRangesSet &OpenRanges, TransferMap &Transfers, |
1171 | VarLocMap &VarLocIDs, LocIndex OldVarID, TransferKind Kind, |
1172 | Register NewReg) { |
1173 | const MachineInstr *DebugInstr = &VarLocIDs[OldVarID].MI; |
1174 | |
1175 | auto ProcessVarLoc = [&MI, &OpenRanges, &Transfers, &VarLocIDs](VarLoc &VL) { |
1176 | LocIndex LocId = VarLocIDs.insert(VL); |
1177 | |
1178 | // Close this variable's previous location range. |
1179 | OpenRanges.erase(VL); |
1180 | |
1181 | // Record the new location as an open range, and a postponed transfer |
1182 | // inserting a DBG_VALUE for this location. |
1183 | OpenRanges.insert(LocId, VL); |
1184 | assert(!MI.isTerminator() && "Cannot insert DBG_VALUE after terminator")((!MI.isTerminator() && "Cannot insert DBG_VALUE after terminator" ) ? static_cast<void> (0) : __assert_fail ("!MI.isTerminator() && \"Cannot insert DBG_VALUE after terminator\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1184, __PRETTY_FUNCTION__)); |
1185 | TransferDebugPair MIP = {&MI, LocId}; |
1186 | Transfers.push_back(MIP); |
1187 | }; |
1188 | |
1189 | // End all previous ranges of VL.Var. |
1190 | OpenRanges.erase(VarLocIDs[OldVarID]); |
1191 | switch (Kind) { |
1192 | case TransferKind::TransferCopy: { |
1193 | assert(NewReg &&((NewReg && "No register supplied when handling a copy of a debug value" ) ? static_cast<void> (0) : __assert_fail ("NewReg && \"No register supplied when handling a copy of a debug value\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1194, __PRETTY_FUNCTION__)) |
1194 | "No register supplied when handling a copy of a debug value")((NewReg && "No register supplied when handling a copy of a debug value" ) ? static_cast<void> (0) : __assert_fail ("NewReg && \"No register supplied when handling a copy of a debug value\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1194, __PRETTY_FUNCTION__)); |
1195 | // Create a DBG_VALUE instruction to describe the Var in its new |
1196 | // register location. |
1197 | VarLoc VL = VarLoc::CreateCopyLoc(*DebugInstr, LS, NewReg); |
1198 | ProcessVarLoc(VL); |
1199 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:" ; VL.dump(TRI); }; } } while (false) |
1200 | dbgs() << "Creating VarLoc for register copy:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:" ; VL.dump(TRI); }; } } while (false) |
1201 | VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:" ; VL.dump(TRI); }; } } while (false) |
1202 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for register copy:" ; VL.dump(TRI); }; } } while (false); |
1203 | return; |
1204 | } |
1205 | case TransferKind::TransferSpill: { |
1206 | // Create a DBG_VALUE instruction to describe the Var in its spilled |
1207 | // location. |
1208 | VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI); |
1209 | VarLoc VL = VarLoc::CreateSpillLoc(*DebugInstr, SpillLocation.SpillBase, |
1210 | SpillLocation.SpillOffset, LS); |
1211 | ProcessVarLoc(VL); |
1212 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:" ; VL.dump(TRI); }; } } while (false) |
1213 | dbgs() << "Creating VarLoc for spill:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:" ; VL.dump(TRI); }; } } while (false) |
1214 | VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:" ; VL.dump(TRI); }; } } while (false) |
1215 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for spill:" ; VL.dump(TRI); }; } } while (false); |
1216 | return; |
1217 | } |
1218 | case TransferKind::TransferRestore: { |
1219 | assert(NewReg &&((NewReg && "No register supplied when handling a restore of a debug value" ) ? static_cast<void> (0) : __assert_fail ("NewReg && \"No register supplied when handling a restore of a debug value\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1220, __PRETTY_FUNCTION__)) |
1220 | "No register supplied when handling a restore of a debug value")((NewReg && "No register supplied when handling a restore of a debug value" ) ? static_cast<void> (0) : __assert_fail ("NewReg && \"No register supplied when handling a restore of a debug value\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1220, __PRETTY_FUNCTION__)); |
1221 | // DebugInstr refers to the pre-spill location, therefore we can reuse |
1222 | // its expression. |
1223 | VarLoc VL = VarLoc::CreateCopyLoc(*DebugInstr, LS, NewReg); |
1224 | ProcessVarLoc(VL); |
1225 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:" ; VL.dump(TRI); }; } } while (false) |
1226 | dbgs() << "Creating VarLoc for restore:";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:" ; VL.dump(TRI); }; } } while (false) |
1227 | VL.dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:" ; VL.dump(TRI); }; } } while (false) |
1228 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { dbgs() << "Creating VarLoc for restore:" ; VL.dump(TRI); }; } } while (false); |
1229 | return; |
1230 | } |
1231 | } |
1232 | llvm_unreachable("Invalid transfer kind")::llvm::llvm_unreachable_internal("Invalid transfer kind", "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1232); |
1233 | } |
1234 | |
1235 | /// A definition of a register may mark the end of a range. |
1236 | void VarLocBasedLDV::transferRegisterDef( |
1237 | MachineInstr &MI, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs, |
1238 | TransferMap &Transfers) { |
1239 | |
1240 | // Meta Instructions do not affect the debug liveness of any register they |
1241 | // define. |
1242 | if (MI.isMetaInstruction()) |
1243 | return; |
1244 | |
1245 | MachineFunction *MF = MI.getMF(); |
1246 | const TargetLowering *TLI = MF->getSubtarget().getTargetLowering(); |
1247 | Register SP = TLI->getStackPointerRegisterToSaveRestore(); |
1248 | |
1249 | // Find the regs killed by MI, and find regmasks of preserved regs. |
1250 | DefinedRegsSet DeadRegs; |
1251 | SmallVector<const uint32_t *, 4> RegMasks; |
1252 | for (const MachineOperand &MO : MI.operands()) { |
1253 | // Determine whether the operand is a register def. |
1254 | if (MO.isReg() && MO.isDef() && MO.getReg() && |
1255 | Register::isPhysicalRegister(MO.getReg()) && |
1256 | !(MI.isCall() && MO.getReg() == SP)) { |
1257 | // Remove ranges of all aliased registers. |
1258 | for (MCRegAliasIterator RAI(MO.getReg(), TRI, true); RAI.isValid(); ++RAI) |
1259 | // FIXME: Can we break out of this loop early if no insertion occurs? |
1260 | DeadRegs.insert(*RAI); |
1261 | } else if (MO.isRegMask()) { |
1262 | RegMasks.push_back(MO.getRegMask()); |
1263 | } |
1264 | } |
1265 | |
1266 | // Erase VarLocs which reside in one of the dead registers. For performance |
1267 | // reasons, it's critical to not iterate over the full set of open VarLocs. |
1268 | // Iterate over the set of dying/used regs instead. |
1269 | if (!RegMasks.empty()) { |
1270 | SmallVector<uint32_t, 32> UsedRegs; |
1271 | getUsedRegs(OpenRanges.getVarLocs(), UsedRegs); |
1272 | for (uint32_t Reg : UsedRegs) { |
1273 | // Remove ranges of all clobbered registers. Register masks don't usually |
1274 | // list SP as preserved. Assume that call instructions never clobber SP, |
1275 | // because some backends (e.g., AArch64) never list SP in the regmask. |
1276 | // While the debug info may be off for an instruction or two around |
1277 | // callee-cleanup calls, transferring the DEBUG_VALUE across the call is |
1278 | // still a better user experience. |
1279 | if (Reg == SP) |
1280 | continue; |
1281 | bool AnyRegMaskKillsReg = |
1282 | any_of(RegMasks, [Reg](const uint32_t *RegMask) { |
1283 | return MachineOperand::clobbersPhysReg(RegMask, Reg); |
1284 | }); |
1285 | if (AnyRegMaskKillsReg) |
1286 | DeadRegs.insert(Reg); |
1287 | } |
1288 | } |
1289 | |
1290 | if (DeadRegs.empty()) |
1291 | return; |
1292 | |
1293 | VarLocSet KillSet(Alloc); |
1294 | collectIDsForRegs(KillSet, DeadRegs, OpenRanges.getVarLocs()); |
1295 | OpenRanges.erase(KillSet, VarLocIDs); |
1296 | |
1297 | if (TPC) { |
1298 | auto &TM = TPC->getTM<TargetMachine>(); |
1299 | if (TM.Options.ShouldEmitDebugEntryValues()) |
1300 | emitEntryValues(MI, OpenRanges, VarLocIDs, Transfers, KillSet); |
1301 | } |
1302 | } |
1303 | |
1304 | bool VarLocBasedLDV::isSpillInstruction(const MachineInstr &MI, |
1305 | MachineFunction *MF) { |
1306 | // TODO: Handle multiple stores folded into one. |
1307 | if (!MI.hasOneMemOperand()) |
1308 | return false; |
1309 | |
1310 | if (!MI.getSpillSize(TII) && !MI.getFoldedSpillSize(TII)) |
1311 | return false; // This is not a spill instruction, since no valid size was |
1312 | // returned from either function. |
1313 | |
1314 | return true; |
1315 | } |
1316 | |
1317 | bool VarLocBasedLDV::isLocationSpill(const MachineInstr &MI, |
1318 | MachineFunction *MF, Register &Reg) { |
1319 | if (!isSpillInstruction(MI, MF)) |
1320 | return false; |
1321 | |
1322 | auto isKilledReg = [&](const MachineOperand MO, Register &Reg) { |
1323 | if (!MO.isReg() || !MO.isUse()) { |
1324 | Reg = 0; |
1325 | return false; |
1326 | } |
1327 | Reg = MO.getReg(); |
1328 | return MO.isKill(); |
1329 | }; |
1330 | |
1331 | for (const MachineOperand &MO : MI.operands()) { |
1332 | // In a spill instruction generated by the InlineSpiller the spilled |
1333 | // register has its kill flag set. |
1334 | if (isKilledReg(MO, Reg)) |
1335 | return true; |
1336 | if (Reg != 0) { |
1337 | // Check whether next instruction kills the spilled register. |
1338 | // FIXME: Current solution does not cover search for killed register in |
1339 | // bundles and instructions further down the chain. |
1340 | auto NextI = std::next(MI.getIterator()); |
1341 | // Skip next instruction that points to basic block end iterator. |
1342 | if (MI.getParent()->end() == NextI) |
1343 | continue; |
1344 | Register RegNext; |
1345 | for (const MachineOperand &MONext : NextI->operands()) { |
1346 | // Return true if we came across the register from the |
1347 | // previous spill instruction that is killed in NextI. |
1348 | if (isKilledReg(MONext, RegNext) && RegNext == Reg) |
1349 | return true; |
1350 | } |
1351 | } |
1352 | } |
1353 | // Return false if we didn't find spilled register. |
1354 | return false; |
1355 | } |
1356 | |
1357 | Optional<VarLocBasedLDV::VarLoc::SpillLoc> |
1358 | VarLocBasedLDV::isRestoreInstruction(const MachineInstr &MI, |
1359 | MachineFunction *MF, Register &Reg) { |
1360 | if (!MI.hasOneMemOperand()) |
1361 | return None; |
1362 | |
1363 | // FIXME: Handle folded restore instructions with more than one memory |
1364 | // operand. |
1365 | if (MI.getRestoreSize(TII)) { |
1366 | Reg = MI.getOperand(0).getReg(); |
1367 | return extractSpillBaseRegAndOffset(MI); |
1368 | } |
1369 | return None; |
1370 | } |
1371 | |
1372 | /// A spilled register may indicate that we have to end the current range of |
1373 | /// a variable and create a new one for the spill location. |
1374 | /// A restored register may indicate the reverse situation. |
1375 | /// We don't want to insert any instructions in process(), so we just create |
1376 | /// the DBG_VALUE without inserting it and keep track of it in \p Transfers. |
1377 | /// It will be inserted into the BB when we're done iterating over the |
1378 | /// instructions. |
1379 | void VarLocBasedLDV::transferSpillOrRestoreInst(MachineInstr &MI, |
1380 | OpenRangesSet &OpenRanges, |
1381 | VarLocMap &VarLocIDs, |
1382 | TransferMap &Transfers) { |
1383 | MachineFunction *MF = MI.getMF(); |
1384 | TransferKind TKind; |
1385 | Register Reg; |
1386 | Optional<VarLoc::SpillLoc> Loc; |
1387 | |
1388 | LLVM_DEBUG(dbgs() << "Examining instruction: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Examining instruction: " ; MI.dump();; } } while (false); |
1389 | |
1390 | // First, if there are any DBG_VALUEs pointing at a spill slot that is |
1391 | // written to, then close the variable location. The value in memory |
1392 | // will have changed. |
1393 | VarLocSet KillSet(Alloc); |
1394 | if (isSpillInstruction(MI, MF)) { |
1395 | Loc = extractSpillBaseRegAndOffset(MI); |
1396 | for (uint64_t ID : OpenRanges.getSpillVarLocs()) { |
1397 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1398 | const VarLoc &VL = VarLocIDs[Idx]; |
1399 | assert(VL.Kind == VarLoc::SpillLocKind && "Broken VarLocSet?")((VL.Kind == VarLoc::SpillLocKind && "Broken VarLocSet?" ) ? static_cast<void> (0) : __assert_fail ("VL.Kind == VarLoc::SpillLocKind && \"Broken VarLocSet?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1399, __PRETTY_FUNCTION__)); |
1400 | if (VL.Loc.SpillLocation == *Loc) { |
1401 | // This location is overwritten by the current instruction -- terminate |
1402 | // the open range, and insert an explicit DBG_VALUE $noreg. |
1403 | // |
1404 | // Doing this at a later stage would require re-interpreting all |
1405 | // DBG_VALUes and DIExpressions to identify whether they point at |
1406 | // memory, and then analysing all memory writes to see if they |
1407 | // overwrite that memory, which is expensive. |
1408 | // |
1409 | // At this stage, we already know which DBG_VALUEs are for spills and |
1410 | // where they are located; it's best to fix handle overwrites now. |
1411 | KillSet.set(ID); |
1412 | VarLoc UndefVL = VarLoc::CreateCopyLoc(VL.MI, LS, 0); |
1413 | LocIndex UndefLocID = VarLocIDs.insert(UndefVL); |
1414 | Transfers.push_back({&MI, UndefLocID}); |
1415 | } |
1416 | } |
1417 | OpenRanges.erase(KillSet, VarLocIDs); |
1418 | } |
1419 | |
1420 | // Try to recognise spill and restore instructions that may create a new |
1421 | // variable location. |
1422 | if (isLocationSpill(MI, MF, Reg)) { |
1423 | TKind = TransferKind::TransferSpill; |
1424 | LLVM_DEBUG(dbgs() << "Recognized as spill: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Recognized as spill: " ; MI.dump();; } } while (false); |
1425 | LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI) << "\n"; } } while (false) |
1426 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI) << "\n"; } } while (false); |
1427 | } else { |
1428 | if (!(Loc = isRestoreInstruction(MI, MF, Reg))) |
1429 | return; |
1430 | TKind = TransferKind::TransferRestore; |
1431 | LLVM_DEBUG(dbgs() << "Recognized as restore: "; MI.dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Recognized as restore: " ; MI.dump();; } } while (false); |
1432 | LLVM_DEBUG(dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI) << "\n"; } } while (false) |
1433 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Register: " << Reg << " " << printReg(Reg, TRI) << "\n"; } } while (false); |
1434 | } |
1435 | // Check if the register or spill location is the location of a debug value. |
1436 | auto TransferCandidates = OpenRanges.getEmptyVarLocRange(); |
1437 | if (TKind == TransferKind::TransferSpill) |
1438 | TransferCandidates = OpenRanges.getRegisterVarLocs(Reg); |
1439 | else if (TKind == TransferKind::TransferRestore) |
1440 | TransferCandidates = OpenRanges.getSpillVarLocs(); |
1441 | for (uint64_t ID : TransferCandidates) { |
1442 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1443 | const VarLoc &VL = VarLocIDs[Idx]; |
1444 | if (TKind == TransferKind::TransferSpill) { |
1445 | assert(VL.isDescribedByReg() == Reg && "Broken VarLocSet?")((VL.isDescribedByReg() == Reg && "Broken VarLocSet?" ) ? static_cast<void> (0) : __assert_fail ("VL.isDescribedByReg() == Reg && \"Broken VarLocSet?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1445, __PRETTY_FUNCTION__)); |
1446 | 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) |
1447 | << 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); |
1448 | } else { |
1449 | assert(TKind == TransferKind::TransferRestore &&((TKind == TransferKind::TransferRestore && VL.Kind == VarLoc::SpillLocKind && "Broken VarLocSet?") ? static_cast <void> (0) : __assert_fail ("TKind == TransferKind::TransferRestore && VL.Kind == VarLoc::SpillLocKind && \"Broken VarLocSet?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1450, __PRETTY_FUNCTION__)) |
1450 | VL.Kind == VarLoc::SpillLocKind && "Broken VarLocSet?")((TKind == TransferKind::TransferRestore && VL.Kind == VarLoc::SpillLocKind && "Broken VarLocSet?") ? static_cast <void> (0) : __assert_fail ("TKind == TransferKind::TransferRestore && VL.Kind == VarLoc::SpillLocKind && \"Broken VarLocSet?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1450, __PRETTY_FUNCTION__)); |
1451 | if (VL.Loc.SpillLocation != *Loc) |
1452 | // The spill location is not the location of a debug value. |
1453 | continue; |
1454 | 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) |
1455 | << 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); |
1456 | } |
1457 | insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx, TKind, |
1458 | Reg); |
1459 | // FIXME: A comment should explain why it's correct to return early here, |
1460 | // if that is in fact correct. |
1461 | return; |
1462 | } |
1463 | } |
1464 | |
1465 | /// If \p MI is a register copy instruction, that copies a previously tracked |
1466 | /// value from one register to another register that is callee saved, we |
1467 | /// create new DBG_VALUE instruction described with copy destination register. |
1468 | void VarLocBasedLDV::transferRegisterCopy(MachineInstr &MI, |
1469 | OpenRangesSet &OpenRanges, |
1470 | VarLocMap &VarLocIDs, |
1471 | TransferMap &Transfers) { |
1472 | auto DestSrc = TII->isCopyInstr(MI); |
1473 | if (!DestSrc) |
1474 | return; |
1475 | |
1476 | const MachineOperand *DestRegOp = DestSrc->Destination; |
1477 | const MachineOperand *SrcRegOp = DestSrc->Source; |
1478 | |
1479 | if (!DestRegOp->isDef()) |
1480 | return; |
1481 | |
1482 | auto isCalleeSavedReg = [&](Register Reg) { |
1483 | for (MCRegAliasIterator RAI(Reg, TRI, true); RAI.isValid(); ++RAI) |
1484 | if (CalleeSavedRegs.test(*RAI)) |
1485 | return true; |
1486 | return false; |
1487 | }; |
1488 | |
1489 | Register SrcReg = SrcRegOp->getReg(); |
1490 | Register DestReg = DestRegOp->getReg(); |
1491 | |
1492 | // We want to recognize instructions where destination register is callee |
1493 | // saved register. If register that could be clobbered by the call is |
1494 | // included, there would be a great chance that it is going to be clobbered |
1495 | // soon. It is more likely that previous register location, which is callee |
1496 | // saved, is going to stay unclobbered longer, even if it is killed. |
1497 | if (!isCalleeSavedReg(DestReg)) |
1498 | return; |
1499 | |
1500 | // Remember an entry value movement. If we encounter a new debug value of |
1501 | // a parameter describing only a moving of the value around, rather then |
1502 | // modifying it, we are still able to use the entry value if needed. |
1503 | if (isRegOtherThanSPAndFP(*DestRegOp, MI, TRI)) { |
1504 | for (uint64_t ID : OpenRanges.getEntryValueBackupVarLocs()) { |
1505 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1506 | const VarLoc &VL = VarLocIDs[Idx]; |
1507 | if (VL.getEntryValueBackupReg() == SrcReg) { |
1508 | 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); |
1509 | VarLoc EntryValLocCopyBackup = |
1510 | VarLoc::CreateEntryCopyBackupLoc(VL.MI, LS, VL.Expr, DestReg); |
1511 | |
1512 | // Stop tracking the original entry value. |
1513 | OpenRanges.erase(VL); |
1514 | |
1515 | // Start tracking the entry value copy. |
1516 | LocIndex EntryValCopyLocID = VarLocIDs.insert(EntryValLocCopyBackup); |
1517 | OpenRanges.insert(EntryValCopyLocID, EntryValLocCopyBackup); |
1518 | break; |
1519 | } |
1520 | } |
1521 | } |
1522 | |
1523 | if (!SrcRegOp->isKill()) |
1524 | return; |
1525 | |
1526 | for (uint64_t ID : OpenRanges.getRegisterVarLocs(SrcReg)) { |
1527 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1528 | assert(VarLocIDs[Idx].isDescribedByReg() == SrcReg && "Broken VarLocSet?")((VarLocIDs[Idx].isDescribedByReg() == SrcReg && "Broken VarLocSet?" ) ? static_cast<void> (0) : __assert_fail ("VarLocIDs[Idx].isDescribedByReg() == SrcReg && \"Broken VarLocSet?\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1528, __PRETTY_FUNCTION__)); |
1529 | insertTransferDebugPair(MI, OpenRanges, Transfers, VarLocIDs, Idx, |
1530 | TransferKind::TransferCopy, DestReg); |
1531 | // FIXME: A comment should explain why it's correct to return early here, |
1532 | // if that is in fact correct. |
1533 | return; |
1534 | } |
1535 | } |
1536 | |
1537 | /// Terminate all open ranges at the end of the current basic block. |
1538 | bool VarLocBasedLDV::transferTerminator(MachineBasicBlock *CurMBB, |
1539 | OpenRangesSet &OpenRanges, |
1540 | VarLocInMBB &OutLocs, |
1541 | const VarLocMap &VarLocIDs) { |
1542 | bool Changed = false; |
1543 | |
1544 | LLVM_DEBUG(for (uint64_t IDdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false) |
1545 | : OpenRanges.getVarLocs()) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false) |
1546 | // Copy OpenRanges to OutLocs, if not already present.do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false) |
1547 | dbgs() << "Add to OutLocs in MBB #" << CurMBB->getNumber() << ": ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false) |
1548 | VarLocIDs[LocIndex::fromRawInteger(ID)].dump(TRI);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false) |
1549 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { for (uint64_t ID : OpenRanges.getVarLocs ()) { dbgs() << "Add to OutLocs in MBB #" << CurMBB ->getNumber() << ": "; VarLocIDs[LocIndex::fromRawInteger (ID)].dump(TRI); }; } } while (false); |
1550 | VarLocSet &VLS = getVarLocsInMBB(CurMBB, OutLocs); |
1551 | Changed = VLS != OpenRanges.getVarLocs(); |
1552 | // New OutLocs set may be different due to spill, restore or register |
1553 | // copy instruction processing. |
1554 | if (Changed) |
1555 | VLS = OpenRanges.getVarLocs(); |
1556 | OpenRanges.clear(); |
1557 | return Changed; |
1558 | } |
1559 | |
1560 | /// Accumulate a mapping between each DILocalVariable fragment and other |
1561 | /// fragments of that DILocalVariable which overlap. This reduces work during |
1562 | /// the data-flow stage from "Find any overlapping fragments" to "Check if the |
1563 | /// known-to-overlap fragments are present". |
1564 | /// \param MI A previously unprocessed DEBUG_VALUE instruction to analyze for |
1565 | /// fragment usage. |
1566 | /// \param SeenFragments Map from DILocalVariable to all fragments of that |
1567 | /// Variable which are known to exist. |
1568 | /// \param OverlappingFragments The overlap map being constructed, from one |
1569 | /// Var/Fragment pair to a vector of fragments known to overlap. |
1570 | void VarLocBasedLDV::accumulateFragmentMap(MachineInstr &MI, |
1571 | VarToFragments &SeenFragments, |
1572 | OverlapMap &OverlappingFragments) { |
1573 | DebugVariable MIVar(MI.getDebugVariable(), MI.getDebugExpression(), |
1574 | MI.getDebugLoc()->getInlinedAt()); |
1575 | FragmentInfo ThisFragment = MIVar.getFragmentOrDefault(); |
1576 | |
1577 | // If this is the first sighting of this variable, then we are guaranteed |
1578 | // there are currently no overlapping fragments either. Initialize the set |
1579 | // of seen fragments, record no overlaps for the current one, and return. |
1580 | auto SeenIt = SeenFragments.find(MIVar.getVariable()); |
1581 | if (SeenIt == SeenFragments.end()) { |
1582 | SmallSet<FragmentInfo, 4> OneFragment; |
1583 | OneFragment.insert(ThisFragment); |
1584 | SeenFragments.insert({MIVar.getVariable(), OneFragment}); |
1585 | |
1586 | OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}}); |
1587 | return; |
1588 | } |
1589 | |
1590 | // If this particular Variable/Fragment pair already exists in the overlap |
1591 | // map, it has already been accounted for. |
1592 | auto IsInOLapMap = |
1593 | OverlappingFragments.insert({{MIVar.getVariable(), ThisFragment}, {}}); |
1594 | if (!IsInOLapMap.second) |
1595 | return; |
1596 | |
1597 | auto &ThisFragmentsOverlaps = IsInOLapMap.first->second; |
1598 | auto &AllSeenFragments = SeenIt->second; |
1599 | |
1600 | // Otherwise, examine all other seen fragments for this variable, with "this" |
1601 | // fragment being a previously unseen fragment. Record any pair of |
1602 | // overlapping fragments. |
1603 | for (auto &ASeenFragment : AllSeenFragments) { |
1604 | // Does this previously seen fragment overlap? |
1605 | if (DIExpression::fragmentsOverlap(ThisFragment, ASeenFragment)) { |
1606 | // Yes: Mark the current fragment as being overlapped. |
1607 | ThisFragmentsOverlaps.push_back(ASeenFragment); |
1608 | // Mark the previously seen fragment as being overlapped by the current |
1609 | // one. |
1610 | auto ASeenFragmentsOverlaps = |
1611 | OverlappingFragments.find({MIVar.getVariable(), ASeenFragment}); |
1612 | assert(ASeenFragmentsOverlaps != OverlappingFragments.end() &&((ASeenFragmentsOverlaps != OverlappingFragments.end() && "Previously seen var fragment has no vector of overlaps") ? static_cast <void> (0) : __assert_fail ("ASeenFragmentsOverlaps != OverlappingFragments.end() && \"Previously seen var fragment has no vector of overlaps\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1613, __PRETTY_FUNCTION__)) |
1613 | "Previously seen var fragment has no vector of overlaps")((ASeenFragmentsOverlaps != OverlappingFragments.end() && "Previously seen var fragment has no vector of overlaps") ? static_cast <void> (0) : __assert_fail ("ASeenFragmentsOverlaps != OverlappingFragments.end() && \"Previously seen var fragment has no vector of overlaps\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1613, __PRETTY_FUNCTION__)); |
1614 | ASeenFragmentsOverlaps->second.push_back(ThisFragment); |
1615 | } |
1616 | } |
1617 | |
1618 | AllSeenFragments.insert(ThisFragment); |
1619 | } |
1620 | |
1621 | /// This routine creates OpenRanges. |
1622 | void VarLocBasedLDV::process(MachineInstr &MI, OpenRangesSet &OpenRanges, |
1623 | VarLocMap &VarLocIDs, TransferMap &Transfers) { |
1624 | transferDebugValue(MI, OpenRanges, VarLocIDs); |
1625 | transferRegisterDef(MI, OpenRanges, VarLocIDs, Transfers); |
1626 | transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers); |
1627 | transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers); |
1628 | } |
1629 | |
1630 | /// This routine joins the analysis results of all incoming edges in @MBB by |
1631 | /// inserting a new DBG_VALUE instruction at the start of the @MBB - if the same |
1632 | /// source variable in all the predecessors of @MBB reside in the same location. |
1633 | bool VarLocBasedLDV::join( |
1634 | MachineBasicBlock &MBB, VarLocInMBB &OutLocs, VarLocInMBB &InLocs, |
1635 | const VarLocMap &VarLocIDs, |
1636 | SmallPtrSet<const MachineBasicBlock *, 16> &Visited, |
1637 | SmallPtrSetImpl<const MachineBasicBlock *> &ArtificialBlocks) { |
1638 | LLVM_DEBUG(dbgs() << "join MBB: " << MBB.getNumber() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "join MBB: " << MBB .getNumber() << "\n"; } } while (false); |
1639 | |
1640 | VarLocSet InLocsT(Alloc); // Temporary incoming locations. |
1641 | |
1642 | // For all predecessors of this MBB, find the set of VarLocs that |
1643 | // can be joined. |
1644 | int NumVisited = 0; |
1645 | for (auto p : MBB.predecessors()) { |
1646 | // Ignore backedges if we have not visited the predecessor yet. As the |
1647 | // predecessor hasn't yet had locations propagated into it, most locations |
1648 | // will not yet be valid, so treat them as all being uninitialized and |
1649 | // potentially valid. If a location guessed to be correct here is |
1650 | // invalidated later, we will remove it when we revisit this block. |
1651 | if (!Visited.count(p)) { |
1652 | 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) |
1653 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << " ignoring unvisited pred MBB: " << p->getNumber() << "\n"; } } while (false); |
1654 | continue; |
1655 | } |
1656 | auto OL = OutLocs.find(p); |
1657 | // Join is null in case of empty OutLocs from any of the pred. |
1658 | if (OL == OutLocs.end()) |
1659 | return false; |
1660 | |
1661 | // Just copy over the Out locs to incoming locs for the first visited |
1662 | // predecessor, and for all other predecessors join the Out locs. |
1663 | VarLocSet &OutLocVLS = *OL->second.get(); |
1664 | if (!NumVisited) |
1665 | InLocsT = OutLocVLS; |
1666 | else |
1667 | InLocsT &= OutLocVLS; |
1668 | |
1669 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1670 | if (!InLocsT.empty()) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1671 | for (uint64_t ID : InLocsT)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1672 | dbgs() << " gathered candidate incoming var: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1673 | << VarLocIDs[LocIndex::fromRawInteger(ID)]do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1674 | .Var.getVariable()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1675 | ->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1676 | << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1677 | }do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false) |
1678 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { { if (!InLocsT.empty()) { for (uint64_t ID : InLocsT) dbgs() << " gathered candidate incoming var: " << VarLocIDs[LocIndex::fromRawInteger(ID)] .Var.getVariable () ->getName() << "\n"; } }; } } while (false); |
1679 | |
1680 | NumVisited++; |
1681 | } |
1682 | |
1683 | // Filter out DBG_VALUES that are out of scope. |
1684 | VarLocSet KillSet(Alloc); |
1685 | bool IsArtificial = ArtificialBlocks.count(&MBB); |
1686 | if (!IsArtificial) { |
1687 | for (uint64_t ID : InLocsT) { |
1688 | LocIndex Idx = LocIndex::fromRawInteger(ID); |
1689 | if (!VarLocIDs[Idx].dominates(LS, MBB)) { |
1690 | KillSet.set(ID); |
1691 | 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) |
1692 | 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) |
1693 | 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) |
1694 | })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); |
1695 | } |
1696 | } |
1697 | } |
1698 | InLocsT.intersectWithComplement(KillSet); |
1699 | |
1700 | // As we are processing blocks in reverse post-order we |
1701 | // should have processed at least one predecessor, unless it |
1702 | // is the entry block which has no predecessor. |
1703 | assert((NumVisited || MBB.pred_empty()) &&(((NumVisited || MBB.pred_empty()) && "Should have processed at least one predecessor" ) ? static_cast<void> (0) : __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1704, __PRETTY_FUNCTION__)) |
1704 | "Should have processed at least one predecessor")(((NumVisited || MBB.pred_empty()) && "Should have processed at least one predecessor" ) ? static_cast<void> (0) : __assert_fail ("(NumVisited || MBB.pred_empty()) && \"Should have processed at least one predecessor\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1704, __PRETTY_FUNCTION__)); |
1705 | |
1706 | VarLocSet &ILS = getVarLocsInMBB(&MBB, InLocs); |
1707 | bool Changed = false; |
1708 | if (ILS != InLocsT) { |
1709 | ILS = InLocsT; |
1710 | Changed = true; |
1711 | } |
1712 | |
1713 | return Changed; |
1714 | } |
1715 | |
1716 | void VarLocBasedLDV::flushPendingLocs(VarLocInMBB &PendingInLocs, |
1717 | VarLocMap &VarLocIDs) { |
1718 | // PendingInLocs records all locations propagated into blocks, which have |
1719 | // not had DBG_VALUE insts created. Go through and create those insts now. |
1720 | for (auto &Iter : PendingInLocs) { |
1721 | // Map is keyed on a constant pointer, unwrap it so we can insert insts. |
1722 | auto &MBB = const_cast<MachineBasicBlock &>(*Iter.first); |
1723 | VarLocSet &Pending = *Iter.second.get(); |
1724 | |
1725 | for (uint64_t ID : Pending) { |
1726 | // The ID location is live-in to MBB -- work out what kind of machine |
1727 | // location it is and create a DBG_VALUE. |
1728 | const VarLoc &DiffIt = VarLocIDs[LocIndex::fromRawInteger(ID)]; |
1729 | if (DiffIt.isEntryBackupLoc()) |
1730 | continue; |
1731 | MachineInstr *MI = DiffIt.BuildDbgValue(*MBB.getParent()); |
1732 | MBB.insert(MBB.instr_begin(), MI); |
1733 | |
1734 | (void)MI; |
1735 | LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump();)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Inserted: "; MI->dump ();; } } while (false); |
1736 | } |
1737 | } |
1738 | } |
1739 | |
1740 | bool VarLocBasedLDV::isEntryValueCandidate( |
1741 | const MachineInstr &MI, const DefinedRegsSet &DefinedRegs) const { |
1742 | assert(MI.isDebugValue() && "This must be DBG_VALUE.")((MI.isDebugValue() && "This must be DBG_VALUE.") ? static_cast <void> (0) : __assert_fail ("MI.isDebugValue() && \"This must be DBG_VALUE.\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1742, __PRETTY_FUNCTION__)); |
1743 | |
1744 | // TODO: Add support for local variables that are expressed in terms of |
1745 | // parameters entry values. |
1746 | // TODO: Add support for modified arguments that can be expressed |
1747 | // by using its entry value. |
1748 | auto *DIVar = MI.getDebugVariable(); |
1749 | if (!DIVar->isParameter()) |
1750 | return false; |
1751 | |
1752 | // Do not consider parameters that belong to an inlined function. |
1753 | if (MI.getDebugLoc()->getInlinedAt()) |
1754 | return false; |
1755 | |
1756 | // Only consider parameters that are described using registers. Parameters |
1757 | // that are passed on the stack are not yet supported, so ignore debug |
1758 | // values that are described by the frame or stack pointer. |
1759 | if (!isRegOtherThanSPAndFP(MI.getDebugOperand(0), MI, TRI)) |
1760 | return false; |
1761 | |
1762 | // If a parameter's value has been propagated from the caller, then the |
1763 | // parameter's DBG_VALUE may be described using a register defined by some |
1764 | // instruction in the entry block, in which case we shouldn't create an |
1765 | // entry value. |
1766 | if (DefinedRegs.count(MI.getDebugOperand(0).getReg())) |
1767 | return false; |
1768 | |
1769 | // TODO: Add support for parameters that have a pre-existing debug expressions |
1770 | // (e.g. fragments). |
1771 | if (MI.getDebugExpression()->getNumElements() > 0) |
1772 | return false; |
1773 | |
1774 | return true; |
1775 | } |
1776 | |
1777 | /// Collect all register defines (including aliases) for the given instruction. |
1778 | static void collectRegDefs(const MachineInstr &MI, DefinedRegsSet &Regs, |
1779 | const TargetRegisterInfo *TRI) { |
1780 | for (const MachineOperand &MO : MI.operands()) |
1781 | if (MO.isReg() && MO.isDef() && MO.getReg()) |
1782 | for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI) |
1783 | Regs.insert(*AI); |
1784 | } |
1785 | |
1786 | /// This routine records the entry values of function parameters. The values |
1787 | /// could be used as backup values. If we loose the track of some unmodified |
1788 | /// parameters, the backup values will be used as a primary locations. |
1789 | void VarLocBasedLDV::recordEntryValue(const MachineInstr &MI, |
1790 | const DefinedRegsSet &DefinedRegs, |
1791 | OpenRangesSet &OpenRanges, |
1792 | VarLocMap &VarLocIDs) { |
1793 | if (TPC) { |
1794 | auto &TM = TPC->getTM<TargetMachine>(); |
1795 | if (!TM.Options.ShouldEmitDebugEntryValues()) |
1796 | return; |
1797 | } |
1798 | |
1799 | DebugVariable V(MI.getDebugVariable(), MI.getDebugExpression(), |
1800 | MI.getDebugLoc()->getInlinedAt()); |
1801 | |
1802 | if (!isEntryValueCandidate(MI, DefinedRegs) || |
1803 | OpenRanges.getEntryValueBackup(V)) |
1804 | return; |
1805 | |
1806 | 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); |
1807 | |
1808 | // Create the entry value and use it as a backup location until it is |
1809 | // valid. It is valid until a parameter is not changed. |
1810 | DIExpression *NewExpr = |
1811 | DIExpression::prepend(MI.getDebugExpression(), DIExpression::EntryValue); |
1812 | VarLoc EntryValLocAsBackup = VarLoc::CreateEntryBackupLoc(MI, LS, NewExpr); |
1813 | LocIndex EntryValLocID = VarLocIDs.insert(EntryValLocAsBackup); |
1814 | OpenRanges.insert(EntryValLocID, EntryValLocAsBackup); |
1815 | } |
1816 | |
1817 | /// Calculate the liveness information for the given machine function and |
1818 | /// extend ranges across basic blocks. |
1819 | bool VarLocBasedLDV::ExtendRanges(MachineFunction &MF, TargetPassConfig *TPC) { |
1820 | LLVM_DEBUG(dbgs() << "\nDebug Range Extension\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "\nDebug Range Extension\n" ; } } while (false); |
1821 | |
1822 | if (!MF.getFunction().getSubprogram()) |
1823 | // VarLocBaseLDV will already have removed all DBG_VALUEs. |
1824 | return false; |
1825 | |
1826 | // Skip functions from NoDebug compilation units. |
1827 | if (MF.getFunction().getSubprogram()->getUnit()->getEmissionKind() == |
1828 | DICompileUnit::NoDebug) |
1829 | return false; |
1830 | |
1831 | TRI = MF.getSubtarget().getRegisterInfo(); |
1832 | TII = MF.getSubtarget().getInstrInfo(); |
1833 | TFI = MF.getSubtarget().getFrameLowering(); |
1834 | TFI->getCalleeSaves(MF, CalleeSavedRegs); |
1835 | this->TPC = TPC; |
1836 | LS.initialize(MF); |
1837 | |
1838 | bool Changed = false; |
1839 | bool OLChanged = false; |
1840 | bool MBBJoined = false; |
1841 | |
1842 | VarLocMap VarLocIDs; // Map VarLoc<>unique ID for use in bitvectors. |
1843 | OverlapMap OverlapFragments; // Map of overlapping variable fragments. |
1844 | OpenRangesSet OpenRanges(Alloc, OverlapFragments); |
1845 | // Ranges that are open until end of bb. |
1846 | VarLocInMBB OutLocs; // Ranges that exist beyond bb. |
1847 | VarLocInMBB InLocs; // Ranges that are incoming after joining. |
1848 | TransferMap Transfers; // DBG_VALUEs associated with transfers (such as |
1849 | // spills, copies and restores). |
1850 | |
1851 | VarToFragments SeenFragments; |
1852 | |
1853 | // Blocks which are artificial, i.e. blocks which exclusively contain |
1854 | // instructions without locations, or with line 0 locations. |
1855 | SmallPtrSet<const MachineBasicBlock *, 16> ArtificialBlocks; |
1856 | |
1857 | DenseMap<unsigned int, MachineBasicBlock *> OrderToBB; |
1858 | DenseMap<MachineBasicBlock *, unsigned int> BBToOrder; |
1859 | std::priority_queue<unsigned int, std::vector<unsigned int>, |
1860 | std::greater<unsigned int>> |
1861 | Worklist; |
1862 | std::priority_queue<unsigned int, std::vector<unsigned int>, |
1863 | std::greater<unsigned int>> |
1864 | Pending; |
1865 | |
1866 | // Set of register defines that are seen when traversing the entry block |
1867 | // looking for debug entry value candidates. |
1868 | DefinedRegsSet DefinedRegs; |
1869 | |
1870 | // Only in the case of entry MBB collect DBG_VALUEs representing |
1871 | // function parameters in order to generate debug entry values for them. |
1872 | MachineBasicBlock &First_MBB = *(MF.begin()); |
1873 | for (auto &MI : First_MBB) { |
1874 | collectRegDefs(MI, DefinedRegs, TRI); |
1875 | if (MI.isDebugValue()) |
1876 | recordEntryValue(MI, DefinedRegs, OpenRanges, VarLocIDs); |
1877 | } |
1878 | |
1879 | // Initialize per-block structures and scan for fragment overlaps. |
1880 | for (auto &MBB : MF) |
1881 | for (auto &MI : MBB) |
1882 | if (MI.isDebugValue()) |
1883 | accumulateFragmentMap(MI, SeenFragments, OverlapFragments); |
1884 | |
1885 | auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool { |
1886 | if (const DebugLoc &DL = MI.getDebugLoc()) |
1887 | return DL.getLine() != 0; |
1888 | return false; |
1889 | }; |
1890 | for (auto &MBB : MF) |
1891 | if (none_of(MBB.instrs(), hasNonArtificialLocation)) |
1892 | ArtificialBlocks.insert(&MBB); |
1893 | |
1894 | LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs , "OutLocs after initialization", dbgs()); } } while (false) |
1895 | "OutLocs after initialization", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs , "OutLocs after initialization", dbgs()); } } while (false); |
1896 | |
1897 | ReversePostOrderTraversal<MachineFunction *> RPOT(&MF); |
1898 | unsigned int RPONumber = 0; |
1899 | for (auto RI = RPOT.begin(), RE = RPOT.end(); RI != RE; ++RI) { |
1900 | OrderToBB[RPONumber] = *RI; |
1901 | BBToOrder[*RI] = RPONumber; |
1902 | Worklist.push(RPONumber); |
1903 | ++RPONumber; |
1904 | } |
1905 | |
1906 | if (RPONumber > InputBBLimit) { |
1907 | unsigned NumInputDbgValues = 0; |
1908 | for (auto &MBB : MF) |
1909 | for (auto &MI : MBB) |
1910 | if (MI.isDebugValue()) |
1911 | ++NumInputDbgValues; |
1912 | if (NumInputDbgValues > InputDbgValueLimit) { |
1913 | 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) |
1914 | << " 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) |
1915 | << 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) |
1916 | << " 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); |
1917 | return false; |
1918 | } |
1919 | } |
1920 | |
1921 | // This is a standard "union of predecessor outs" dataflow problem. |
1922 | // To solve it, we perform join() and process() using the two worklist method |
1923 | // until the ranges converge. |
1924 | // Ranges have converged when both worklists are empty. |
1925 | SmallPtrSet<const MachineBasicBlock *, 16> Visited; |
1926 | while (!Worklist.empty() || !Pending.empty()) { |
1927 | // We track what is on the pending worklist to avoid inserting the same |
1928 | // thing twice. We could avoid this with a custom priority queue, but this |
1929 | // is probably not worth it. |
1930 | SmallPtrSet<MachineBasicBlock *, 16> OnPending; |
1931 | LLVM_DEBUG(dbgs() << "Processing Worklist\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { dbgs() << "Processing Worklist\n" ; } } while (false); |
1932 | while (!Worklist.empty()) { |
1933 | MachineBasicBlock *MBB = OrderToBB[Worklist.top()]; |
1934 | Worklist.pop(); |
1935 | MBBJoined = join(*MBB, OutLocs, InLocs, VarLocIDs, Visited, |
1936 | ArtificialBlocks); |
1937 | MBBJoined |= Visited.insert(MBB).second; |
1938 | if (MBBJoined) { |
1939 | MBBJoined = false; |
Value stored to 'MBBJoined' is never read | |
1940 | Changed = true; |
1941 | // Now that we have started to extend ranges across BBs we need to |
1942 | // examine spill, copy and restore instructions to see whether they |
1943 | // operate with registers that correspond to user variables. |
1944 | // First load any pending inlocs. |
1945 | OpenRanges.insertFromLocSet(getVarLocsInMBB(MBB, InLocs), VarLocIDs); |
1946 | for (auto &MI : *MBB) |
1947 | process(MI, OpenRanges, VarLocIDs, Transfers); |
1948 | OLChanged |= transferTerminator(MBB, OpenRanges, OutLocs, VarLocIDs); |
1949 | |
1950 | LLVM_DEBUG(printVarLocInMBB(MF, OutLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs , "OutLocs after propagating", dbgs()); } } while (false) |
1951 | "OutLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, OutLocs, VarLocIDs , "OutLocs after propagating", dbgs()); } } while (false); |
1952 | LLVM_DEBUG(printVarLocInMBB(MF, InLocs, VarLocIDs,do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs , "InLocs after propagating", dbgs()); } } while (false) |
1953 | "InLocs after propagating", dbgs()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("livedebugvalues")) { printVarLocInMBB(MF, InLocs, VarLocIDs , "InLocs after propagating", dbgs()); } } while (false); |
1954 | |
1955 | if (OLChanged) { |
1956 | OLChanged = false; |
1957 | for (auto s : MBB->successors()) |
1958 | if (OnPending.insert(s).second) { |
1959 | Pending.push(BBToOrder[s]); |
1960 | } |
1961 | } |
1962 | } |
1963 | } |
1964 | Worklist.swap(Pending); |
1965 | // At this point, pending must be empty, since it was just the empty |
1966 | // worklist |
1967 | assert(Pending.empty() && "Pending should be empty")((Pending.empty() && "Pending should be empty") ? static_cast <void> (0) : __assert_fail ("Pending.empty() && \"Pending should be empty\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1967, __PRETTY_FUNCTION__)); |
1968 | } |
1969 | |
1970 | // Add any DBG_VALUE instructions created by location transfers. |
1971 | for (auto &TR : Transfers) { |
1972 | assert(!TR.TransferInst->isTerminator() &&((!TR.TransferInst->isTerminator() && "Cannot insert DBG_VALUE after terminator" ) ? static_cast<void> (0) : __assert_fail ("!TR.TransferInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1973, __PRETTY_FUNCTION__)) |
1973 | "Cannot insert DBG_VALUE after terminator")((!TR.TransferInst->isTerminator() && "Cannot insert DBG_VALUE after terminator" ) ? static_cast<void> (0) : __assert_fail ("!TR.TransferInst->isTerminator() && \"Cannot insert DBG_VALUE after terminator\"" , "/build/llvm-toolchain-snapshot-12~++20210124100612+2afaf072f5c1/llvm/lib/CodeGen/LiveDebugValues/VarLocBasedImpl.cpp" , 1973, __PRETTY_FUNCTION__)); |
1974 | MachineBasicBlock *MBB = TR.TransferInst->getParent(); |
1975 | const VarLoc &VL = VarLocIDs[TR.LocationID]; |
1976 | MachineInstr *MI = VL.BuildDbgValue(MF); |
1977 | MBB->insertAfterBundle(TR.TransferInst->getIterator(), MI); |
1978 | } |
1979 | Transfers.clear(); |
1980 | |
1981 | // Deferred inlocs will not have had any DBG_VALUE insts created; do |
1982 | // that now. |
1983 | flushPendingLocs(InLocs, VarLocIDs); |
1984 | |
1985 | 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); |
1986 | 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); |
1987 | return Changed; |
1988 | } |
1989 | |
1990 | LDVImpl * |
1991 | llvm::makeVarLocBasedLiveDebugValues() |
1992 | { |
1993 | return new VarLocBasedLDV(); |
1994 | } |