Bug Summary

File:llvm/include/llvm/MC/MCRegisterInfo.h
Warning:line 217, column 21
Dereference of null pointer

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CriticalAntiDepBreaker.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/CodeGen -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/CodeGen -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/CodeGen -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/CodeGen/CriticalAntiDepBreaker.cpp

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/CodeGen/CriticalAntiDepBreaker.cpp

→
1//===- CriticalAntiDepBreaker.cpp - Anti-dep breaker ----------------------===//
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// This file implements the CriticalAntiDepBreaker class, which
10// implements register anti-dependence breaking along a blocks
11// critical path during post-RA scheduler.
12//
13//===----------------------------------------------------------------------===//
14
15#include "CriticalAntiDepBreaker.h"
16#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/DenseMap.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/CodeGen/MachineBasicBlock.h"
20#include "llvm/CodeGen/MachineFrameInfo.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/CodeGen/MachineInstr.h"
23#include "llvm/CodeGen/MachineOperand.h"
24#include "llvm/CodeGen/MachineRegisterInfo.h"
25#include "llvm/CodeGen/RegisterClassInfo.h"
26#include "llvm/CodeGen/ScheduleDAG.h"
27#include "llvm/CodeGen/TargetInstrInfo.h"
28#include "llvm/CodeGen/TargetRegisterInfo.h"
29#include "llvm/CodeGen/TargetSubtargetInfo.h"
30#include "llvm/MC/MCInstrDesc.h"
31#include "llvm/MC/MCRegisterInfo.h"
32#include "llvm/Support/Debug.h"
33#include "llvm/Support/raw_ostream.h"
34#include <cassert>
35#include <utility>
36
37using namespace llvm;
38
39#define DEBUG_TYPE"post-RA-sched" "post-RA-sched"
40
41CriticalAntiDepBreaker::CriticalAntiDepBreaker(MachineFunction &MFi,
42 const RegisterClassInfo &RCI)
43 : AntiDepBreaker(), MF(MFi), MRI(MF.getRegInfo()),
44 TII(MF.getSubtarget().getInstrInfo()),
45 TRI(MF.getSubtarget().getRegisterInfo()), RegClassInfo(RCI),
46 Classes(TRI->getNumRegs(), nullptr), KillIndices(TRI->getNumRegs(), 0),
47 DefIndices(TRI->getNumRegs(), 0), KeepRegs(TRI->getNumRegs(), false) {}
48
49CriticalAntiDepBreaker::~CriticalAntiDepBreaker() = default;
50
51void CriticalAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
52 const unsigned BBSize = BB->size();
53 for (unsigned i = 0, e = TRI->getNumRegs(); i != e; ++i) {
54 // Clear out the register class data.
55 Classes[i] = nullptr;
56
57 // Initialize the indices to indicate that no registers are live.
58 KillIndices[i] = ~0u;
59 DefIndices[i] = BBSize;
60 }
61
62 // Clear "do not change" set.
63 KeepRegs.reset();
64
65 bool IsReturnBlock = BB->isReturnBlock();
66
67 // Examine the live-in regs of all successors.
68 for (const MachineBasicBlock *Succ : BB->successors())
69 for (const auto &LI : Succ->liveins()) {
70 for (MCRegAliasIterator AI(LI.PhysReg, TRI, true); AI.isValid(); ++AI) {
71 unsigned Reg = *AI;
72 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
73 KillIndices[Reg] = BBSize;
74 DefIndices[Reg] = ~0u;
75 }
76 }
77
78 // Mark live-out callee-saved registers. In a return block this is
79 // all callee-saved registers. In non-return this is any
80 // callee-saved register that is not saved in the prolog.
81 const MachineFrameInfo &MFI = MF.getFrameInfo();
82 BitVector Pristine = MFI.getPristineRegs(MF);
83 for (const MCPhysReg *I = MF.getRegInfo().getCalleeSavedRegs(); *I;
84 ++I) {
85 unsigned Reg = *I;
86 if (!IsReturnBlock && !Pristine.test(Reg))
87 continue;
88 for (MCRegAliasIterator AI(*I, TRI, true); AI.isValid(); ++AI) {
89 unsigned Reg = *AI;
90 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
91 KillIndices[Reg] = BBSize;
92 DefIndices[Reg] = ~0u;
93 }
94 }
95}
96
97void CriticalAntiDepBreaker::FinishBlock() {
98 RegRefs.clear();
99 KeepRegs.reset();
100}
101
102void CriticalAntiDepBreaker::Observe(MachineInstr &MI, unsigned Count,
103 unsigned InsertPosIndex) {
104 // Kill instructions can define registers but are really nops, and there might
105 // be a real definition earlier that needs to be paired with uses dominated by
106 // this kill.
107
108 // FIXME: It may be possible to remove the isKill() restriction once PR18663
109 // has been properly fixed. There can be value in processing kills as seen in
110 // the AggressiveAntiDepBreaker class.
111 if (MI.isDebugInstr() || MI.isKill())
112 return;
113 assert(Count < InsertPosIndex && "Instruction index out of expected range!")(static_cast<void> (0));
114
115 for (unsigned Reg = 0; Reg != TRI->getNumRegs(); ++Reg) {
116 if (KillIndices[Reg] != ~0u) {
117 // If Reg is currently live, then mark that it can't be renamed as
118 // we don't know the extent of its live-range anymore (now that it
119 // has been scheduled).
120 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
121 KillIndices[Reg] = Count;
122 } else if (DefIndices[Reg] < InsertPosIndex && DefIndices[Reg] >= Count) {
123 // Any register which was defined within the previous scheduling region
124 // may have been rescheduled and its lifetime may overlap with registers
125 // in ways not reflected in our current liveness state. For each such
126 // register, adjust the liveness state to be conservatively correct.
127 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
128
129 // Move the def index to the end of the previous region, to reflect
130 // that the def could theoretically have been scheduled at the end.
131 DefIndices[Reg] = InsertPosIndex;
132 }
133 }
134
135 PrescanInstruction(MI);
136 ScanInstruction(MI, Count);
137}
138
139/// CriticalPathStep - Return the next SUnit after SU on the bottom-up
140/// critical path.
141static const SDep *CriticalPathStep(const SUnit *SU) {
142 const SDep *Next = nullptr;
143 unsigned NextDepth = 0;
144 // Find the predecessor edge with the greatest depth.
145 for (const SDep &P : SU->Preds) {
146 const SUnit *PredSU = P.getSUnit();
147 unsigned PredLatency = P.getLatency();
148 unsigned PredTotalLatency = PredSU->getDepth() + PredLatency;
149 // In the case of a latency tie, prefer an anti-dependency edge over
150 // other types of edges.
151 if (NextDepth < PredTotalLatency ||
152 (NextDepth == PredTotalLatency && P.getKind() == SDep::Anti)) {
153 NextDepth = PredTotalLatency;
154 Next = &P;
155 }
156 }
157 return Next;
158}
159
160void CriticalAntiDepBreaker::PrescanInstruction(MachineInstr &MI) {
161 // It's not safe to change register allocation for source operands of
162 // instructions that have special allocation requirements. Also assume all
163 // registers used in a call must not be changed (ABI).
164 // FIXME: The issue with predicated instruction is more complex. We are being
165 // conservative here because the kill markers cannot be trusted after
166 // if-conversion:
167 // %r6 = LDR %sp, %reg0, 92, 14, %reg0; mem:LD4[FixedStack14]
168 // ...
169 // STR %r0, killed %r6, %reg0, 0, 0, %cpsr; mem:ST4[%395]
170 // %r6 = LDR %sp, %reg0, 100, 0, %cpsr; mem:LD4[FixedStack12]
171 // STR %r0, killed %r6, %reg0, 0, 14, %reg0; mem:ST4[%396](align=8)
172 //
173 // The first R6 kill is not really a kill since it's killed by a predicated
174 // instruction which may not be executed. The second R6 def may or may not
175 // re-define R6 so it's not safe to change it since the last R6 use cannot be
176 // changed.
177 bool Special =
178 MI.isCall() || MI.hasExtraSrcRegAllocReq() || TII->isPredicated(MI);
179
180 // Scan the register operands for this instruction and update
181 // Classes and RegRefs.
182 for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
183 MachineOperand &MO = MI.getOperand(i);
184 if (!MO.isReg()) continue;
185 Register Reg = MO.getReg();
186 if (Reg == 0) continue;
187 const TargetRegisterClass *NewRC = nullptr;
188
189 if (i < MI.getDesc().getNumOperands())
190 NewRC = TII->getRegClass(MI.getDesc(), i, TRI, MF);
191
192 // For now, only allow the register to be changed if its register
193 // class is consistent across all uses.
194 if (!Classes[Reg] && NewRC)
195 Classes[Reg] = NewRC;
196 else if (!NewRC || Classes[Reg] != NewRC)
197 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
198
199 // Now check for aliases.
200 for (MCRegAliasIterator AI(Reg, TRI, false); AI.isValid(); ++AI) {
201 // If an alias of the reg is used during the live range, give up.
202 // Note that this allows us to skip checking if AntiDepReg
203 // overlaps with any of the aliases, among other things.
204 unsigned AliasReg = *AI;
205 if (Classes[AliasReg]) {
206 Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
207 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
208 }
209 }
210
211 // If we're still willing to consider this register, note the reference.
212 if (Classes[Reg] != reinterpret_cast<TargetRegisterClass *>(-1))
213 RegRefs.insert(std::make_pair(Reg, &MO));
214
215 // If this reg is tied and live (Classes[Reg] is set to -1), we can't change
216 // it or any of its sub or super regs. We need to use KeepRegs to mark the
217 // reg because not all uses of the same reg within an instruction are
218 // necessarily tagged as tied.
219 // Example: an x86 "xor %eax, %eax" will have one source operand tied to the
220 // def register but not the second (see PR20020 for details).
221 // FIXME: can this check be relaxed to account for undef uses
222 // of a register? In the above 'xor' example, the uses of %eax are undef, so
223 // earlier instructions could still replace %eax even though the 'xor'
224 // itself can't be changed.
225 if (MI.isRegTiedToUseOperand(i) &&
226 Classes[Reg] == reinterpret_cast<TargetRegisterClass *>(-1)) {
227 for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
228 SubRegs.isValid(); ++SubRegs) {
229 KeepRegs.set(*SubRegs);
230 }
231 for (MCSuperRegIterator SuperRegs(Reg, TRI);
232 SuperRegs.isValid(); ++SuperRegs) {
233 KeepRegs.set(*SuperRegs);
234 }
235 }
236
237 if (MO.isUse() && Special) {
238 if (!KeepRegs.test(Reg)) {
239 for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
240 SubRegs.isValid(); ++SubRegs)
241 KeepRegs.set(*SubRegs);
242 }
243 }
244 }
245}
246
247void CriticalAntiDepBreaker::ScanInstruction(MachineInstr &MI, unsigned Count) {
248 // Update liveness.
249 // Proceeding upwards, registers that are defed but not used in this
250 // instruction are now dead.
251 assert(!MI.isKill() && "Attempting to scan a kill instruction")(static_cast<void> (0));
252
253 if (!TII->isPredicated(MI)) {
20
←
Assuming the condition is true
→
21
←
Taking true branch
→
254 // Predicated defs are modeled as read + write, i.e. similar to two
255 // address updates.
256 for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
22
←
Loop condition is true. Entering loop body
→
257 MachineOperand &MO = MI.getOperand(i);
258
259 if (MO.isRegMask()) {
23
←
Taking true branch
→
260 auto ClobbersPhysRegAndSubRegs = [&](unsigned PhysReg) {
261 for (MCSubRegIterator SRI(PhysReg, TRI, true); SRI.isValid(); ++SRI)
262 if (!MO.clobbersPhysReg(*SRI))
263 return false;
264
265 return true;
266 };
267
268 for (unsigned i = 0, e = TRI->getNumRegs(); i != e; ++i) {
24
←
Assuming 'i' is not equal to 'e'
→
25
←
Loop condition is true. Entering loop body
→
28
←
Assuming 'i' is equal to 'e'
→
29
←
Loop condition is false. Execution continues on line 279
→
269 if (ClobbersPhysRegAndSubRegs(i)) {
26
←
Assuming the condition is false
→
27
←
Taking false branch
→
270 DefIndices[i] = Count;
271 KillIndices[i] = ~0u;
272 KeepRegs.reset(i);
273 Classes[i] = nullptr;
274 RegRefs.erase(i);
275 }
276 }
277 }
278
279 if (!MO.isReg()) continue;
30
←
Taking false branch
→
280 Register Reg = MO.getReg();
281 if (Reg == 0) continue;
31
←
Taking false branch
→
282 if (!MO.isDef()) continue;
32
←
Assuming the condition is false
→
33
←
Taking false branch
→
283
284 // Ignore two-addr defs.
285 if (MI.isRegTiedToUseOperand(i))
34
←
Taking false branch
→
286 continue;
287
288 // If we've already marked this reg as unchangeable, don't remove
289 // it or any of its subregs from KeepRegs.
290 bool Keep = KeepRegs.test(Reg);
291
292 // For the reg itself and all subregs: update the def to current;
293 // reset the kill state, any restrictions, and references.
294 for (MCSubRegIterator SRI(Reg, TRI, true); SRI.isValid(); ++SRI) {
35
←
Loop condition is false. Execution continues on line 304
→
295 unsigned SubregReg = *SRI;
296 DefIndices[SubregReg] = Count;
297 KillIndices[SubregReg] = ~0u;
298 Classes[SubregReg] = nullptr;
299 RegRefs.erase(SubregReg);
300 if (!Keep)
301 KeepRegs.reset(SubregReg);
302 }
303 // Conservatively mark super-registers as unusable.
304 for (MCSuperRegIterator SR(Reg, TRI); SR.isValid(); ++SR)
36
←
Calling constructor for 'MCSuperRegIterator'
→
305 Classes[*SR] = reinterpret_cast<TargetRegisterClass *>(-1);
306 }
307 }
308 for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
309 MachineOperand &MO = MI.getOperand(i);
310 if (!MO.isReg()) continue;
311 Register Reg = MO.getReg();
312 if (Reg == 0) continue;
313 if (!MO.isUse()) continue;
314
315 const TargetRegisterClass *NewRC = nullptr;
316 if (i < MI.getDesc().getNumOperands())
317 NewRC = TII->getRegClass(MI.getDesc(), i, TRI, MF);
318
319 // For now, only allow the register to be changed if its register
320 // class is consistent across all uses.
321 if (!Classes[Reg] && NewRC)
322 Classes[Reg] = NewRC;
323 else if (!NewRC || Classes[Reg] != NewRC)
324 Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
325
326 RegRefs.insert(std::make_pair(Reg, &MO));
327
328 // It wasn't previously live but now it is, this is a kill.
329 // Repeat for all aliases.
330 for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
331 unsigned AliasReg = *AI;
332 if (KillIndices[AliasReg] == ~0u) {
333 KillIndices[AliasReg] = Count;
334 DefIndices[AliasReg] = ~0u;
335 }
336 }
337 }
338}
339
340// Check all machine operands that reference the antidependent register and must
341// be replaced by NewReg. Return true if any of their parent instructions may
342// clobber the new register.
343//
344// Note: AntiDepReg may be referenced by a two-address instruction such that
345// it's use operand is tied to a def operand. We guard against the case in which
346// the two-address instruction also defines NewReg, as may happen with
347// pre/postincrement loads. In this case, both the use and def operands are in
348// RegRefs because the def is inserted by PrescanInstruction and not erased
349// during ScanInstruction. So checking for an instruction with definitions of
350// both NewReg and AntiDepReg covers it.
351bool
352CriticalAntiDepBreaker::isNewRegClobberedByRefs(RegRefIter RegRefBegin,
353 RegRefIter RegRefEnd,
354 unsigned NewReg) {
355 for (RegRefIter I = RegRefBegin; I != RegRefEnd; ++I ) {
356 MachineOperand *RefOper = I->second;
357
358 // Don't allow the instruction defining AntiDepReg to earlyclobber its
359 // operands, in case they may be assigned to NewReg. In this case antidep
360 // breaking must fail, but it's too rare to bother optimizing.
361 if (RefOper->isDef() && RefOper->isEarlyClobber())
362 return true;
363
364 // Handle cases in which this instruction defines NewReg.
365 MachineInstr *MI = RefOper->getParent();
366 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
367 const MachineOperand &CheckOper = MI->getOperand(i);
368
369 if (CheckOper.isRegMask() && CheckOper.clobbersPhysReg(NewReg))
370 return true;
371
372 if (!CheckOper.isReg() || !CheckOper.isDef() ||
373 CheckOper.getReg() != NewReg)
374 continue;
375
376 // Don't allow the instruction to define NewReg and AntiDepReg.
377 // When AntiDepReg is renamed it will be an illegal op.
378 if (RefOper->isDef())
379 return true;
380
381 // Don't allow an instruction using AntiDepReg to be earlyclobbered by
382 // NewReg.
383 if (CheckOper.isEarlyClobber())
384 return true;
385
386 // Don't allow inline asm to define NewReg at all. Who knows what it's
387 // doing with it.
388 if (MI->isInlineAsm())
389 return true;
390 }
391 }
392 return false;
393}
394
395unsigned CriticalAntiDepBreaker::
396findSuitableFreeRegister(RegRefIter RegRefBegin,
397 RegRefIter RegRefEnd,
398 unsigned AntiDepReg,
399 unsigned LastNewReg,
400 const TargetRegisterClass *RC,
401 SmallVectorImpl<unsigned> &Forbid) {
402 ArrayRef<MCPhysReg> Order = RegClassInfo.getOrder(RC);
403 for (unsigned i = 0; i != Order.size(); ++i) {
404 unsigned NewReg = Order[i];
405 // Don't replace a register with itself.
406 if (NewReg == AntiDepReg) continue;
407 // Don't replace a register with one that was recently used to repair
408 // an anti-dependence with this AntiDepReg, because that would
409 // re-introduce that anti-dependence.
410 if (NewReg == LastNewReg) continue;
411 // If any instructions that define AntiDepReg also define the NewReg, it's
412 // not suitable. For example, Instruction with multiple definitions can
413 // result in this condition.
414 if (isNewRegClobberedByRefs(RegRefBegin, RegRefEnd, NewReg)) continue;
415 // If NewReg is dead and NewReg's most recent def is not before
416 // AntiDepReg's kill, it's safe to replace AntiDepReg with NewReg.
417 assert(((KillIndices[AntiDepReg] == ~0u) != (DefIndices[AntiDepReg] == ~0u))(static_cast<void> (0))
418 && "Kill and Def maps aren't consistent for AntiDepReg!")(static_cast<void> (0));
419 assert(((KillIndices[NewReg] == ~0u) != (DefIndices[NewReg] == ~0u))(static_cast<void> (0))
420 && "Kill and Def maps aren't consistent for NewReg!")(static_cast<void> (0));
421 if (KillIndices[NewReg] != ~0u ||
422 Classes[NewReg] == reinterpret_cast<TargetRegisterClass *>(-1) ||
423 KillIndices[AntiDepReg] > DefIndices[NewReg])
424 continue;
425 // If NewReg overlaps any of the forbidden registers, we can't use it.
426 bool Forbidden = false;
427 for (unsigned R : Forbid)
428 if (TRI->regsOverlap(NewReg, R)) {
429 Forbidden = true;
430 break;
431 }
432 if (Forbidden) continue;
433 return NewReg;
434 }
435
436 // No registers are free and available!
437 return 0;
438}
439
440unsigned CriticalAntiDepBreaker::
441BreakAntiDependencies(const std::vector<SUnit> &SUnits,
442 MachineBasicBlock::iterator Begin,
443 MachineBasicBlock::iterator End,
444 unsigned InsertPosIndex,
445 DbgValueVector &DbgValues) {
446 // The code below assumes that there is at least one instruction,
447 // so just duck out immediately if the block is empty.
448 if (SUnits.empty()) return 0;
1
Assuming the condition is false
→
2
←
Taking false branch
→
449
450 // Keep a map of the MachineInstr*'s back to the SUnit representing them.
451 // This is used for updating debug information.
452 //
453 // FIXME: Replace this with the existing map in ScheduleDAGInstrs::MISUnitMap
454 DenseMap<MachineInstr *, const SUnit *> MISUnitMap;
455
456 // Find the node at the bottom of the critical path.
457 const SUnit *Max = nullptr;
458 for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
3
←
Assuming 'i' is not equal to 'e'
→
4
←
Loop condition is true. Entering loop body
→
5
←
Assuming 'i' is equal to 'e'
→
6
←
Loop condition is false. Execution continues on line 464
→
459 const SUnit *SU = &SUnits[i];
460 MISUnitMap[SU->getInstr()] = SU;
461 if (!Max
4.1
'Max' is null
4.1
'Max' is null
4.1
'Max' is null
 || SU->getDepth() + SU->Latency > Max->getDepth() + Max->Latency)
462 Max = SU;
463 }
464 assert(Max && "Failed to find bottom of the critical path")(static_cast<void> (0));
465
466#ifndef NDEBUG1
467 {
468 LLVM_DEBUG(dbgs() << "Critical path has total latency "do { } while (false)
469 << (Max->getDepth() + Max->Latency) << "\n")do { } while (false);
470 LLVM_DEBUG(dbgs() << "Available regs:")do { } while (false);
471 for (unsigned Reg = 0; Reg < TRI->getNumRegs(); ++Reg) {
472 if (KillIndices[Reg] == ~0u)
473 LLVM_DEBUG(dbgs() << " " << printReg(Reg, TRI))do { } while (false);
474 }
475 LLVM_DEBUG(dbgs() << '\n')do { } while (false);
476 }
477#endif
478
479 // Track progress along the critical path through the SUnit graph as we walk
480 // the instructions.
481 const SUnit *CriticalPathSU = Max;
482 MachineInstr *CriticalPathMI = CriticalPathSU->getInstr();
483
484 // Consider this pattern:
485 // A = ...
486 // ... = A
487 // A = ...
488 // ... = A
489 // A = ...
490 // ... = A
491 // A = ...
492 // ... = A
493 // There are three anti-dependencies here, and without special care,
494 // we'd break all of them using the same register:
495 // A = ...
496 // ... = A
497 // B = ...
498 // ... = B
499 // B = ...
500 // ... = B
501 // B = ...
502 // ... = B
503 // because at each anti-dependence, B is the first register that
504 // isn't A which is free. This re-introduces anti-dependencies
505 // at all but one of the original anti-dependencies that we were
506 // trying to break. To avoid this, keep track of the most recent
507 // register that each register was replaced with, avoid
508 // using it to repair an anti-dependence on the same register.
509 // This lets us produce this:
510 // A = ...
511 // ... = A
512 // B = ...
513 // ... = B
514 // C = ...
515 // ... = C
516 // B = ...
517 // ... = B
518 // This still has an anti-dependence on B, but at least it isn't on the
519 // original critical path.
520 //
521 // TODO: If we tracked more than one register here, we could potentially
522 // fix that remaining critical edge too. This is a little more involved,
523 // because unlike the most recent register, less recent registers should
524 // still be considered, though only if no other registers are available.
525 std::vector<unsigned> LastNewReg(TRI->getNumRegs(), 0);
526
527 // Attempt to break anti-dependence edges on the critical path. Walk the
528 // instructions from the bottom up, tracking information about liveness
529 // as we go to help determine which registers are available.
530 unsigned Broken = 0;
531 unsigned Count = InsertPosIndex - 1;
532 for (MachineBasicBlock::iterator I = End, E = Begin; I != E; --Count) {
7
←
Loop condition is true. Entering loop body
→
533 MachineInstr &MI = *--I;
534 // Kill instructions can define registers but are really nops, and there
535 // might be a real definition earlier that needs to be paired with uses
536 // dominated by this kill.
537
538 // FIXME: It may be possible to remove the isKill() restriction once PR18663
539 // has been properly fixed. There can be value in processing kills as seen
540 // in the AggressiveAntiDepBreaker class.
541 if (MI.isDebugInstr() || MI.isKill())
8
←
Taking false branch
→
542 continue;
543
544 // Check if this instruction has a dependence on the critical path that
545 // is an anti-dependence that we may be able to break. If it is, set
546 // AntiDepReg to the non-zero register associated with the anti-dependence.
547 //
548 // We limit our attention to the critical path as a heuristic to avoid
549 // breaking anti-dependence edges that aren't going to significantly
550 // impact the overall schedule. There are a limited number of registers
551 // and we want to save them for the important edges.
552 //
553 // TODO: Instructions with multiple defs could have multiple
554 // anti-dependencies. The current code here only knows how to break one
555 // edge per instruction. Note that we'd have to be able to break all of
556 // the anti-dependencies in an instruction in order to be effective.
557 unsigned AntiDepReg = 0;
558 if (&MI == CriticalPathMI) {
9
←
Assuming the condition is false
→
10
←
Taking false branch
→
559 if (const SDep *Edge = CriticalPathStep(CriticalPathSU)) {
560 const SUnit *NextSU = Edge->getSUnit();
561
562 // Only consider anti-dependence edges.
563 if (Edge->getKind() == SDep::Anti) {
564 AntiDepReg = Edge->getReg();
565 assert(AntiDepReg != 0 && "Anti-dependence on reg0?")(static_cast<void> (0));
566 if (!MRI.isAllocatable(AntiDepReg))
567 // Don't break anti-dependencies on non-allocatable registers.
568 AntiDepReg = 0;
569 else if (KeepRegs.test(AntiDepReg))
570 // Don't break anti-dependencies if a use down below requires
571 // this exact register.
572 AntiDepReg = 0;
573 else {
574 // If the SUnit has other dependencies on the SUnit that it
575 // anti-depends on, don't bother breaking the anti-dependency
576 // since those edges would prevent such units from being
577 // scheduled past each other regardless.
578 //
579 // Also, if there are dependencies on other SUnits with the
580 // same register as the anti-dependency, don't attempt to
581 // break it.
582 for (const SDep &P : CriticalPathSU->Preds)
583 if (P.getSUnit() == NextSU
584 ? (P.getKind() != SDep::Anti || P.getReg() != AntiDepReg)
585 : (P.getKind() == SDep::Data &&
586 P.getReg() == AntiDepReg)) {
587 AntiDepReg = 0;
588 break;
589 }
590 }
591 }
592 CriticalPathSU = NextSU;
593 CriticalPathMI = CriticalPathSU->getInstr();
594 } else {
595 // We've reached the end of the critical path.
596 CriticalPathSU = nullptr;
597 CriticalPathMI = nullptr;
598 }
599 }
600
601 PrescanInstruction(MI);
602
603 SmallVector<unsigned, 2> ForbidRegs;
604
605 // If MI's defs have a special allocation requirement, don't allow
606 // any def registers to be changed. Also assume all registers
607 // defined in a call must not be changed (ABI).
608 if (MI.isCall() || MI.hasExtraDefRegAllocReq() || TII->isPredicated(MI))
11
←
Assuming the condition is false
→
12
←
Assuming the condition is false
→
13
←
Assuming the condition is false
→
14
←
Taking false branch
→
609 // If this instruction's defs have special allocation requirement, don't
610 // break this anti-dependency.
611 AntiDepReg = 0;
612 else if (AntiDepReg
14.1
'AntiDepReg' is 0
14.1
'AntiDepReg' is 0
14.1
'AntiDepReg' is 0
) {
613 // If this instruction has a use of AntiDepReg, breaking it
614 // is invalid. If the instruction defines other registers,
615 // save a list of them so that we don't pick a new register
616 // that overlaps any of them.
617 for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
618 MachineOperand &MO = MI.getOperand(i);
619 if (!MO.isReg()) continue;
620 Register Reg = MO.getReg();
621 if (Reg == 0) continue;
622 if (MO.isUse() && TRI->regsOverlap(AntiDepReg, Reg)) {
623 AntiDepReg = 0;
624 break;
625 }
626 if (MO.isDef() && Reg != AntiDepReg)
627 ForbidRegs.push_back(Reg);
628 }
629 }
630
631 // Determine AntiDepReg's register class, if it is live and is
632 // consistently used within a single class.
633 const TargetRegisterClass *RC = AntiDepReg
15.1
'AntiDepReg' is equal to 0
15.1
'AntiDepReg' is equal to 0
15.1
'AntiDepReg' is equal to 0
 != 0 ? Classes[AntiDepReg]
15
←
Taking false branch
→
16
←
'?' condition is false
→
634 : nullptr;
635 assert((AntiDepReg == 0 || RC != nullptr) &&(static_cast<void> (0))
636 "Register should be live if it's causing an anti-dependence!")(static_cast<void> (0));
637 if (RC == reinterpret_cast<TargetRegisterClass *>(-1))
17
←
Taking false branch
→
638 AntiDepReg = 0;
639
640 // Look for a suitable register to use to break the anti-dependence.
641 //
642 // TODO: Instead of picking the first free register, consider which might
643 // be the best.
644 if (AntiDepReg
17.1
'AntiDepReg' is equal to 0
17.1
'AntiDepReg' is equal to 0
17.1
'AntiDepReg' is equal to 0
 != 0) {
18
←
Taking false branch
→
645 std::pair<std::multimap<unsigned, MachineOperand *>::iterator,
646 std::multimap<unsigned, MachineOperand *>::iterator>
647 Range = RegRefs.equal_range(AntiDepReg);
648 if (unsigned NewReg = findSuitableFreeRegister(Range.first, Range.second,
649 AntiDepReg,
650 LastNewReg[AntiDepReg],
651 RC, ForbidRegs)) {
652 LLVM_DEBUG(dbgs() << "Breaking anti-dependence edge on "do { } while (false)
653 << printReg(AntiDepReg, TRI) << " with "do { } while (false)
654 << RegRefs.count(AntiDepReg) << " references"do { } while (false)
655 << " using " << printReg(NewReg, TRI) << "!\n")do { } while (false);
656
657 // Update the references to the old register to refer to the new
658 // register.
659 for (std::multimap<unsigned, MachineOperand *>::iterator
660 Q = Range.first, QE = Range.second; Q != QE; ++Q) {
661 Q->second->setReg(NewReg);
662 // If the SU for the instruction being updated has debug information
663 // related to the anti-dependency register, make sure to update that
664 // as well.
665 const SUnit *SU = MISUnitMap[Q->second->getParent()];
666 if (!SU) continue;
667 UpdateDbgValues(DbgValues, Q->second->getParent(),
668 AntiDepReg, NewReg);
669 }
670
671 // We just went back in time and modified history; the
672 // liveness information for the anti-dependence reg is now
673 // inconsistent. Set the state as if it were dead.
674 Classes[NewReg] = Classes[AntiDepReg];
675 DefIndices[NewReg] = DefIndices[AntiDepReg];
676 KillIndices[NewReg] = KillIndices[AntiDepReg];
677 assert(((KillIndices[NewReg] == ~0u) !=(static_cast<void> (0))
678 (DefIndices[NewReg] == ~0u)) &&(static_cast<void> (0))
679 "Kill and Def maps aren't consistent for NewReg!")(static_cast<void> (0));
680
681 Classes[AntiDepReg] = nullptr;
682 DefIndices[AntiDepReg] = KillIndices[AntiDepReg];
683 KillIndices[AntiDepReg] = ~0u;
684 assert(((KillIndices[AntiDepReg] == ~0u) !=(static_cast<void> (0))
685 (DefIndices[AntiDepReg] == ~0u)) &&(static_cast<void> (0))
686 "Kill and Def maps aren't consistent for AntiDepReg!")(static_cast<void> (0));
687
688 RegRefs.erase(AntiDepReg);
689 LastNewReg[AntiDepReg] = NewReg;
690 ++Broken;
691 }
692 }
693
694 ScanInstruction(MI, Count);
19
←
Calling 'CriticalAntiDepBreaker::ScanInstruction'
→
695 }
696
697 return Broken;
698}
699
700AntiDepBreaker *
701llvm::createCriticalAntiDepBreaker(MachineFunction &MFi,
702 const RegisterClassInfo &RCI) {
703 return new CriticalAntiDepBreaker(MFi, RCI);
704}
←

/usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/stl_vector.h

→
1// Vector implementation -*- C++ -*-
2
3// Copyright (C) 2001-2020 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_vector.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{vector}
54 */
55
56#ifndef _STL_VECTOR_H1
57#define _STL_VECTOR_H1 1
58
59#include <bits/stl_iterator_base_funcs.h>
60#include <bits/functexcept.h>
61#include <bits/concept_check.h>
62#if __cplusplus201402L >= 201103L
63#include <initializer_list>
64#endif
65#if __cplusplus201402L > 201703L
66# include <compare>
67#endif
68
69#include <debug/assertions.h>
70
71#if _GLIBCXX_SANITIZE_STD_ALLOCATOR && _GLIBCXX_SANITIZE_VECTOR
72extern "C" void
73__sanitizer_annotate_contiguous_container(const void*, const void*,
74 const void*, const void*);
75#endif
76
77namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
78{
79_GLIBCXX_BEGIN_NAMESPACE_VERSION
80_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
81
82 /// See bits/stl_deque.h's _Deque_base for an explanation.
83 template<typename _Tp, typename _Alloc>
84 struct _Vector_base
85 {
86 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
87 rebind<_Tp>::other _Tp_alloc_type;
88 typedef typename __gnu_cxx::__alloc_traits<_Tp_alloc_type>::pointer
89 pointer;
90
91 struct _Vector_impl_data
92 {
93 pointer _M_start;
94 pointer _M_finish;
95 pointer _M_end_of_storage;
96
97 _Vector_impl_data() _GLIBCXX_NOEXCEPTnoexcept
98 : _M_start(), _M_finish(), _M_end_of_storage()
99 { }
100
101#if __cplusplus201402L >= 201103L
102 _Vector_impl_data(_Vector_impl_data&& __x) noexcept
103 : _M_start(__x._M_start), _M_finish(__x._M_finish),
104 _M_end_of_storage(__x._M_end_of_storage)
105 { __x._M_start = __x._M_finish = __x._M_end_of_storage = pointer(); }
106#endif
107
108 void
109 _M_copy_data(_Vector_impl_data const& __x) _GLIBCXX_NOEXCEPTnoexcept
110 {
111 _M_start = __x._M_start;
112 _M_finish = __x._M_finish;
113 _M_end_of_storage = __x._M_end_of_storage;
114 }
115
116 void
117 _M_swap_data(_Vector_impl_data& __x) _GLIBCXX_NOEXCEPTnoexcept
118 {
119 // Do not use std::swap(_M_start, __x._M_start), etc as it loses
120 // information used by TBAA.
121 _Vector_impl_data __tmp;
122 __tmp._M_copy_data(*this);
123 _M_copy_data(__x);
124 __x._M_copy_data(__tmp);
125 }
126 };
127
128 struct _Vector_impl
129 : public _Tp_alloc_type, public _Vector_impl_data
130 {
131 _Vector_impl() _GLIBCXX_NOEXCEPT_IF(noexcept(is_nothrow_default_constructible<_Tp_alloc_type>
::value)
132 is_nothrow_default_constructible<_Tp_alloc_type>::value)noexcept(is_nothrow_default_constructible<_Tp_alloc_type>
::value)
133 : _Tp_alloc_type()
134 { }
135
136 _Vector_impl(_Tp_alloc_type const& __a) _GLIBCXX_NOEXCEPTnoexcept
137 : _Tp_alloc_type(__a)
138 { }
139
140#if __cplusplus201402L >= 201103L
141 // Not defaulted, to enforce noexcept(true) even when
142 // !is_nothrow_move_constructible<_Tp_alloc_type>.
143 _Vector_impl(_Vector_impl&& __x) noexcept
144 : _Tp_alloc_type(std::move(__x)), _Vector_impl_data(std::move(__x))
145 { }
146
147 _Vector_impl(_Tp_alloc_type&& __a) noexcept
148 : _Tp_alloc_type(std::move(__a))
149 { }
150
151 _Vector_impl(_Tp_alloc_type&& __a, _Vector_impl&& __rv) noexcept
152 : _Tp_alloc_type(std::move(__a)), _Vector_impl_data(std::move(__rv))
153 { }
154#endif
155
156#if _GLIBCXX_SANITIZE_STD_ALLOCATOR && _GLIBCXX_SANITIZE_VECTOR
157 template<typename = _Tp_alloc_type>
158 struct _Asan
159 {
160 typedef typename __gnu_cxx::__alloc_traits<_Tp_alloc_type>
161 ::size_type size_type;
162
163 static void _S_shrink(_Vector_impl&, size_type) { }
164 static void _S_on_dealloc(_Vector_impl&) { }
165
166 typedef _Vector_impl& _Reinit;
167
168 struct _Grow
169 {
170 _Grow(_Vector_impl&, size_type) { }
171 void _M_grew(size_type) { }
172 };
173 };
174
175 // Enable ASan annotations for memory obtained from std::allocator.
176 template<typename _Up>
177 struct _Asan<allocator<_Up> >
178 {
179 typedef typename __gnu_cxx::__alloc_traits<_Tp_alloc_type>
180 ::size_type size_type;
181
182 // Adjust ASan annotation for [_M_start, _M_end_of_storage) to
183 // mark end of valid region as __curr instead of __prev.
184 static void
185 _S_adjust(_Vector_impl& __impl, pointer __prev, pointer __curr)
186 {
187 __sanitizer_annotate_contiguous_container(__impl._M_start,
188 __impl._M_end_of_storage, __prev, __curr);
189 }
190
191 static void
192 _S_grow(_Vector_impl& __impl, size_type __n)
193 { _S_adjust(__impl, __impl._M_finish, __impl._M_finish + __n); }
194
195 static void
196 _S_shrink(_Vector_impl& __impl, size_type __n)
197 { _S_adjust(__impl, __impl._M_finish + __n, __impl._M_finish); }
198
199 static void
200 _S_on_dealloc(_Vector_impl& __impl)
201 {
202 if (__impl._M_start)
203 _S_adjust(__impl, __impl._M_finish, __impl._M_end_of_storage);
204 }
205
206 // Used on reallocation to tell ASan unused capacity is invalid.
207 struct _Reinit
208 {
209 explicit _Reinit(_Vector_impl& __impl) : _M_impl(__impl)
210 {
211 // Mark unused capacity as valid again before deallocating it.
212 _S_on_dealloc(_M_impl);
213 }
214
215 ~_Reinit()
216 {
217 // Mark unused capacity as invalid after reallocation.
218 if (_M_impl._M_start)
219 _S_adjust(_M_impl, _M_impl._M_end_of_storage,
220 _M_impl._M_finish);
221 }
222
223 _Vector_impl& _M_impl;
224
225#if __cplusplus201402L >= 201103L
226 _Reinit(const _Reinit&) = delete;
227 _Reinit& operator=(const _Reinit&) = delete;
228#endif
229 };
230
231 // Tell ASan when unused capacity is initialized to be valid.
232 struct _Grow
233 {
234 _Grow(_Vector_impl& __impl, size_type __n)
235 : _M_impl(__impl), _M_n(__n)
236 { _S_grow(_M_impl, __n); }
237
238 ~_Grow() { if (_M_n) _S_shrink(_M_impl, _M_n); }
239
240 void _M_grew(size_type __n) { _M_n -= __n; }
241
242#if __cplusplus201402L >= 201103L
243 _Grow(const _Grow&) = delete;
244 _Grow& operator=(const _Grow&) = delete;
245#endif
246 private:
247 _Vector_impl& _M_impl;
248 size_type _M_n;
249 };
250 };
251
252#define _GLIBCXX_ASAN_ANNOTATE_REINIT \
253 typename _Base::_Vector_impl::template _Asan<>::_Reinit const \
254 __attribute__((__unused__)) __reinit_guard(this->_M_impl)
255#define _GLIBCXX_ASAN_ANNOTATE_GROW(n) \
256 typename _Base::_Vector_impl::template _Asan<>::_Grow \
257 __attribute__((__unused__)) __grow_guard(this->_M_impl, (n))
258#define _GLIBCXX_ASAN_ANNOTATE_GREW(n) __grow_guard._M_grew(n)
259#define _GLIBCXX_ASAN_ANNOTATE_SHRINK(n) \
260 _Base::_Vector_impl::template _Asan<>::_S_shrink(this->_M_impl, n)
261#define _GLIBCXX_ASAN_ANNOTATE_BEFORE_DEALLOC \
262 _Base::_Vector_impl::template _Asan<>::_S_on_dealloc(this->_M_impl)
263#else // ! (_GLIBCXX_SANITIZE_STD_ALLOCATOR && _GLIBCXX_SANITIZE_VECTOR)
264#define _GLIBCXX_ASAN_ANNOTATE_REINIT
265#define _GLIBCXX_ASAN_ANNOTATE_GROW(n)
266#define _GLIBCXX_ASAN_ANNOTATE_GREW(n)
267#define _GLIBCXX_ASAN_ANNOTATE_SHRINK(n)
268#define _GLIBCXX_ASAN_ANNOTATE_BEFORE_DEALLOC
269#endif // _GLIBCXX_SANITIZE_STD_ALLOCATOR && _GLIBCXX_SANITIZE_VECTOR
270 };
271
272 public:
273 typedef _Alloc allocator_type;
274
275 _Tp_alloc_type&
276 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPTnoexcept
277 { return this->_M_impl; }
278
279 const _Tp_alloc_type&
280 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPTnoexcept
281 { return this->_M_impl; }
282
283 allocator_type
284 get_allocator() const _GLIBCXX_NOEXCEPTnoexcept
285 { return allocator_type(_M_get_Tp_allocator()); }
286
287#if __cplusplus201402L >= 201103L
288 _Vector_base() = default;
289#else
290 _Vector_base() { }
291#endif
292
293 _Vector_base(const allocator_type& __a) _GLIBCXX_NOEXCEPTnoexcept
294 : _M_impl(__a) { }
295
296 // Kept for ABI compatibility.
297#if !_GLIBCXX_INLINE_VERSION0
298 _Vector_base(size_t __n)
299 : _M_impl()
300 { _M_create_storage(__n); }
301#endif
302
303 _Vector_base(size_t __n, const allocator_type& __a)
304 : _M_impl(__a)
305 { _M_create_storage(__n); }
306
307#if __cplusplus201402L >= 201103L
308 _Vector_base(_Vector_base&&) = default;
309
310 // Kept for ABI compatibility.
311# if !_GLIBCXX_INLINE_VERSION0
312 _Vector_base(_Tp_alloc_type&& __a) noexcept
313 : _M_impl(std::move(__a)) { }
314
315 _Vector_base(_Vector_base&& __x, const allocator_type& __a)
316 : _M_impl(__a)
317 {
318 if (__x.get_allocator() == __a)
319 this->_M_impl._M_swap_data(__x._M_impl);
320 else
321 {
322 size_t __n = __x._M_impl._M_finish - __x._M_impl._M_start;
323 _M_create_storage(__n);
324 }
325 }
326# endif
327
328 _Vector_base(const allocator_type& __a, _Vector_base&& __x)
329 : _M_impl(_Tp_alloc_type(__a), std::move(__x._M_impl))
330 { }
331#endif
332
333 ~_Vector_base() _GLIBCXX_NOEXCEPTnoexcept
334 {
335 _M_deallocate(_M_impl._M_start,
336 _M_impl._M_end_of_storage - _M_impl._M_start);
337 }
338
339 public:
340 _Vector_impl _M_impl;
341
342 pointer
343 _M_allocate(size_t __n)
344 {
345 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Tr;
346 return __n != 0 ? _Tr::allocate(_M_impl, __n) : pointer();
347 }
348
349 void
350 _M_deallocate(pointer __p, size_t __n)
351 {
352 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Tr;
353 if (__p)
354 _Tr::deallocate(_M_impl, __p, __n);
355 }
356
357 protected:
358 void
359 _M_create_storage(size_t __n)
360 {
361 this->_M_impl._M_start = this->_M_allocate(__n);
362 this->_M_impl._M_finish = this->_M_impl._M_start;
363 this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
364 }
365 };
366
367 /**
368 * @brief A standard container which offers fixed time access to
369 * individual elements in any order.
370 *
371 * @ingroup sequences
372 *
373 * @tparam _Tp Type of element.
374 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
375 *
376 * Meets the requirements of a <a href="tables.html#65">container</a>, a
377 * <a href="tables.html#66">reversible container</a>, and a
378 * <a href="tables.html#67">sequence</a>, including the
379 * <a href="tables.html#68">optional sequence requirements</a> with the
380 * %exception of @c push_front and @c pop_front.
381 *
382 * In some terminology a %vector can be described as a dynamic
383 * C-style array, it offers fast and efficient access to individual
384 * elements in any order and saves the user from worrying about
385 * memory and size allocation. Subscripting ( @c [] ) access is
386 * also provided as with C-style arrays.
387 */
388 template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
389 class vector : protected _Vector_base<_Tp, _Alloc>
390 {
391#ifdef _GLIBCXX_CONCEPT_CHECKS
392 // Concept requirements.
393 typedef typename _Alloc::value_type _Alloc_value_type;
394# if __cplusplus201402L < 201103L
395 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
396# endif
397 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
398#endif
399
400#if __cplusplus201402L >= 201103L
401 static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value,
402 "std::vector must have a non-const, non-volatile value_type");
403# if __cplusplus201402L > 201703L || defined __STRICT_ANSI__1
404 static_assert(is_same<typename _Alloc::value_type, _Tp>::value,
405 "std::vector must have the same value_type as its allocator");
406# endif
407#endif
408
409 typedef _Vector_base<_Tp, _Alloc> _Base;
410 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
411 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
412
413 public:
414 typedef _Tp value_type;
415 typedef typename _Base::pointer pointer;
416 typedef typename _Alloc_traits::const_pointer const_pointer;
417 typedef typename _Alloc_traits::reference reference;
418 typedef typename _Alloc_traits::const_reference const_reference;
419 typedef __gnu_cxx::__normal_iterator<pointer, vector> iterator;
420 typedef __gnu_cxx::__normal_iterator<const_pointer, vector>
421 const_iterator;
422 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
423 typedef std::reverse_iterator<iterator> reverse_iterator;
424 typedef size_t size_type;
425 typedef ptrdiff_t difference_type;
426 typedef _Alloc allocator_type;
427
428 private:
429#if __cplusplus201402L >= 201103L
430 static constexpr bool
431 _S_nothrow_relocate(true_type)
432 {
433 return noexcept(std::__relocate_a(std::declval<pointer>(),
434 std::declval<pointer>(),
435 std::declval<pointer>(),
436 std::declval<_Tp_alloc_type&>()));
437 }
438
439 static constexpr bool
440 _S_nothrow_relocate(false_type)
441 { return false; }
442
443 static constexpr bool
444 _S_use_relocate()
445 {
446 // Instantiating std::__relocate_a might cause an error outside the
447 // immediate context (in __relocate_object_a's noexcept-specifier),
448 // so only do it if we know the type can be move-inserted into *this.
449 return _S_nothrow_relocate(__is_move_insertable<_Tp_alloc_type>{});
450 }
451
452 static pointer
453 _S_do_relocate(pointer __first, pointer __last, pointer __result,
454 _Tp_alloc_type& __alloc, true_type) noexcept
455 {
456 return std::__relocate_a(__first, __last, __result, __alloc);
457 }
458
459 static pointer
460 _S_do_relocate(pointer, pointer, pointer __result,
461 _Tp_alloc_type&, false_type) noexcept
462 { return __result; }
463
464 static pointer
465 _S_relocate(pointer __first, pointer __last, pointer __result,
466 _Tp_alloc_type& __alloc) noexcept
467 {
468 using __do_it = __bool_constant<_S_use_relocate()>;
469 return _S_do_relocate(__first, __last, __result, __alloc, __do_it{});
470 }
471#endif // C++11
472
473 protected:
474 using _Base::_M_allocate;
475 using _Base::_M_deallocate;
476 using _Base::_M_impl;
477 using _Base::_M_get_Tp_allocator;
478
479 public:
480 // [23.2.4.1] construct/copy/destroy
481 // (assign() and get_allocator() are also listed in this section)
482
483 /**
484 * @brief Creates a %vector with no elements.
485 */
486#if __cplusplus201402L >= 201103L
487 vector() = default;
488#else
489 vector() { }
490#endif
491
492 /**
493 * @brief Creates a %vector with no elements.
494 * @param __a An allocator object.
495 */
496 explicit
497 vector(const allocator_type& __a) _GLIBCXX_NOEXCEPTnoexcept
498 : _Base(__a) { }
499
500#if __cplusplus201402L >= 201103L
501 /**
502 * @brief Creates a %vector with default constructed elements.
503 * @param __n The number of elements to initially create.
504 * @param __a An allocator.
505 *
506 * This constructor fills the %vector with @a __n default
507 * constructed elements.
508 */
509 explicit
510 vector(size_type __n, const allocator_type& __a = allocator_type())
511 : _Base(_S_check_init_len(__n, __a), __a)
512 { _M_default_initialize(__n); }
513
514 /**
515 * @brief Creates a %vector with copies of an exemplar element.
516 * @param __n The number of elements to initially create.
517 * @param __value An element to copy.
518 * @param __a An allocator.
519 *
520 * This constructor fills the %vector with @a __n copies of @a __value.
521 */
522 vector(size_type __n, const value_type& __value,
523 const allocator_type& __a = allocator_type())
524 : _Base(_S_check_init_len(__n, __a), __a)
525 { _M_fill_initialize(__n, __value); }
526#else
527 /**
528 * @brief Creates a %vector with copies of an exemplar element.
529 * @param __n The number of elements to initially create.
530 * @param __value An element to copy.
531 * @param __a An allocator.
532 *
533 * This constructor fills the %vector with @a __n copies of @a __value.
534 */
535 explicit
536 vector(size_type __n, const value_type& __value = value_type(),
537 const allocator_type& __a = allocator_type())
538 : _Base(_S_check_init_len(__n, __a), __a)
539 { _M_fill_initialize(__n, __value); }
540#endif
541
542 /**
543 * @brief %Vector copy constructor.
544 * @param __x A %vector of identical element and allocator types.
545 *
546 * All the elements of @a __x are copied, but any unused capacity in
547 * @a __x will not be copied
548 * (i.e. capacity() == size() in the new %vector).
549 *
550 * The newly-created %vector uses a copy of the allocator object used
551 * by @a __x (unless the allocator traits dictate a different object).
552 */
553 vector(const vector& __x)
554 : _Base(__x.size(),
555 _Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()))
556 {
557 this->_M_impl._M_finish =
558 std::__uninitialized_copy_a(__x.begin(), __x.end(),
559 this->_M_impl._M_start,
560 _M_get_Tp_allocator());
561 }
562
563#if __cplusplus201402L >= 201103L
564 /**
565 * @brief %Vector move constructor.
566 *
567 * The newly-created %vector contains the exact contents of the
568 * moved instance.
569 * The contents of the moved instance are a valid, but unspecified
570 * %vector.
571 */
572 vector(vector&&) noexcept = default;
573
574 /// Copy constructor with alternative allocator
575 vector(const vector& __x, const allocator_type& __a)
576 : _Base(__x.size(), __a)
577 {
578 this->_M_impl._M_finish =
579 std::__uninitialized_copy_a(__x.begin(), __x.end(),
580 this->_M_impl._M_start,
581 _M_get_Tp_allocator());
582 }
583
584 private:
585 vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
586 : _Base(__m, std::move(__rv))
587 { }
588
589 vector(vector&& __rv, const allocator_type& __m, false_type)
590 : _Base(__m)
591 {
592 if (__rv.get_allocator() == __m)
593 this->_M_impl._M_swap_data(__rv._M_impl);
594 else if (!__rv.empty())
595 {
596 this->_M_create_storage(__rv.size());
597 this->_M_impl._M_finish =
598 std::__uninitialized_move_a(__rv.begin(), __rv.end(),
599 this->_M_impl._M_start,
600 _M_get_Tp_allocator());
601 __rv.clear();
602 }
603 }
604
605 public:
606 /// Move constructor with alternative allocator
607 vector(vector&& __rv, const allocator_type& __m)
608 noexcept( noexcept(
609 vector(std::declval<vector&&>(), std::declval<const allocator_type&>(),
610 std::declval<typename _Alloc_traits::is_always_equal>())) )
611 : vector(std::move(__rv), __m, typename _Alloc_traits::is_always_equal{})
612 { }
613
614 /**
615 * @brief Builds a %vector from an initializer list.
616 * @param __l An initializer_list.
617 * @param __a An allocator.
618 *
619 * Create a %vector consisting of copies of the elements in the
620 * initializer_list @a __l.
621 *
622 * This will call the element type's copy constructor N times
623 * (where N is @a __l.size()) and do no memory reallocation.
624 */
625 vector(initializer_list<value_type> __l,
626 const allocator_type& __a = allocator_type())
627 : _Base(__a)
628 {
629 _M_range_initialize(__l.begin(), __l.end(),
630 random_access_iterator_tag());
631 }
632#endif
633
634 /**
635 * @brief Builds a %vector from a range.
636 * @param __first An input iterator.
637 * @param __last An input iterator.
638 * @param __a An allocator.
639 *
640 * Create a %vector consisting of copies of the elements from
641 * [first,last).
642 *
643 * If the iterators are forward, bidirectional, or
644 * random-access, then this will call the elements' copy
645 * constructor N times (where N is distance(first,last)) and do
646 * no memory reallocation. But if only input iterators are
647 * used, then this will do at most 2N calls to the copy
648 * constructor, and logN memory reallocations.
649 */
650#if __cplusplus201402L >= 201103L
651 template<typename _InputIterator,
652 typename = std::_RequireInputIter<_InputIterator>>
653 vector(_InputIterator __first, _InputIterator __last,
654 const allocator_type& __a = allocator_type())
655 : _Base(__a)
656 {
657 _M_range_initialize(__first, __last,
658 std::__iterator_category(__first));
659 }
660#else
661 template<typename _InputIterator>
662 vector(_InputIterator __first, _InputIterator __last,
663 const allocator_type& __a = allocator_type())
664 : _Base(__a)
665 {
666 // Check whether it's an integral type. If so, it's not an iterator.
667 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
668 _M_initialize_dispatch(__first, __last, _Integral());
669 }
670#endif
671
672 /**
673 * The dtor only erases the elements, and note that if the
674 * elements themselves are pointers, the pointed-to memory is
675 * not touched in any way. Managing the pointer is the user's
676 * responsibility.
677 */
678 ~vector() _GLIBCXX_NOEXCEPTnoexcept
679 {
680 std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
681 _M_get_Tp_allocator());
682 _GLIBCXX_ASAN_ANNOTATE_BEFORE_DEALLOC;
683 }
684
685 /**
686 * @brief %Vector assignment operator.
687 * @param __x A %vector of identical element and allocator types.
688 *
689 * All the elements of @a __x are copied, but any unused capacity in
690 * @a __x will not be copied.
691 *
692 * Whether the allocator is copied depends on the allocator traits.
693 */
694 vector&
695 operator=(const vector& __x);
696
697#if __cplusplus201402L >= 201103L
698 /**
699 * @brief %Vector move assignment operator.
700 * @param __x A %vector of identical element and allocator types.
701 *
702 * The contents of @a __x are moved into this %vector (without copying,
703 * if the allocators permit it).
704 * Afterwards @a __x is a valid, but unspecified %vector.
705 *
706 * Whether the allocator is moved depends on the allocator traits.
707 */
708 vector&
709 operator=(vector&& __x) noexcept(_Alloc_traits::_S_nothrow_move())
710 {
711 constexpr bool __move_storage =
712 _Alloc_traits::_S_propagate_on_move_assign()
713 || _Alloc_traits::_S_always_equal();
714 _M_move_assign(std::move(__x), __bool_constant<__move_storage>());
715 return *this;
716 }
717
718 /**
719 * @brief %Vector list assignment operator.
720 * @param __l An initializer_list.
721 *
722 * This function fills a %vector with copies of the elements in the
723 * initializer list @a __l.
724 *
725 * Note that the assignment completely changes the %vector and
726 * that the resulting %vector's size is the same as the number
727 * of elements assigned.
728 */
729 vector&
730 operator=(initializer_list<value_type> __l)
731 {
732 this->_M_assign_aux(__l.begin(), __l.end(),
733 random_access_iterator_tag());
734 return *this;
735 }
736#endif
737
738 /**
739 * @brief Assigns a given value to a %vector.
740 * @param __n Number of elements to be assigned.
741 * @param __val Value to be assigned.
742 *
743 * This function fills a %vector with @a __n copies of the given
744 * value. Note that the assignment completely changes the
745 * %vector and that the resulting %vector's size is the same as
746 * the number of elements assigned.
747 */
748 void
749 assign(size_type __n, const value_type& __val)
750 { _M_fill_assign(__n, __val); }
751
752 /**
753 * @brief Assigns a range to a %vector.
754 * @param __first An input iterator.
755 * @param __last An input iterator.
756 *
757 * This function fills a %vector with copies of the elements in the
758 * range [__first,__last).
759 *
760 * Note that the assignment completely changes the %vector and
761 * that the resulting %vector's size is the same as the number
762 * of elements assigned.
763 */
764#if __cplusplus201402L >= 201103L
765 template<typename _InputIterator,
766 typename = std::_RequireInputIter<_InputIterator>>
767 void
768 assign(_InputIterator __first, _InputIterator __last)
769 { _M_assign_dispatch(__first, __last, __false_type()); }
770#else
771 template<typename _InputIterator>
772 void
773 assign(_InputIterator __first, _InputIterator __last)
774 {
775 // Check whether it's an integral type. If so, it's not an iterator.
776 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
777 _M_assign_dispatch(__first, __last, _Integral());
778 }
779#endif
780
781#if __cplusplus201402L >= 201103L
782 /**
783 * @brief Assigns an initializer list to a %vector.
784 * @param __l An initializer_list.
785 *
786 * This function fills a %vector with copies of the elements in the
787 * initializer list @a __l.
788 *
789 * Note that the assignment completely changes the %vector and
790 * that the resulting %vector's size is the same as the number
791 * of elements assigned.
792 */
793 void
794 assign(initializer_list<value_type> __l)
795 {
796 this->_M_assign_aux(__l.begin(), __l.end(),
797 random_access_iterator_tag());
798 }
799#endif
800
801 /// Get a copy of the memory allocation object.
802 using _Base::get_allocator;
803
804 // iterators
805 /**
806 * Returns a read/write iterator that points to the first
807 * element in the %vector. Iteration is done in ordinary
808 * element order.
809 */
810 iterator
811 begin() _GLIBCXX_NOEXCEPTnoexcept
812 { return iterator(this->_M_impl._M_start); }
813
814 /**
815 * Returns a read-only (constant) iterator that points to the
816 * first element in the %vector. Iteration is done in ordinary
817 * element order.
818 */
819 const_iterator
820 begin() const _GLIBCXX_NOEXCEPTnoexcept
821 { return const_iterator(this->_M_impl._M_start); }
822
823 /**
824 * Returns a read/write iterator that points one past the last
825 * element in the %vector. Iteration is done in ordinary
826 * element order.
827 */
828 iterator
829 end() _GLIBCXX_NOEXCEPTnoexcept
830 { return iterator(this->_M_impl._M_finish); }
831
832 /**
833 * Returns a read-only (constant) iterator that points one past
834 * the last element in the %vector. Iteration is done in
835 * ordinary element order.
836 */
837 const_iterator
838 end() const _GLIBCXX_NOEXCEPTnoexcept
839 { return const_iterator(this->_M_impl._M_finish); }
840
841 /**
842 * Returns a read/write reverse iterator that points to the
843 * last element in the %vector. Iteration is done in reverse
844 * element order.
845 */
846 reverse_iterator
847 rbegin() _GLIBCXX_NOEXCEPTnoexcept
848 { return reverse_iterator(end()); }
849
850 /**
851 * Returns a read-only (constant) reverse iterator that points
852 * to the last element in the %vector. Iteration is done in
853 * reverse element order.
854 */
855 const_reverse_iterator
856 rbegin() const _GLIBCXX_NOEXCEPTnoexcept
857 { return const_reverse_iterator(end()); }
858
859 /**
860 * Returns a read/write reverse iterator that points to one
861 * before the first element in the %vector. Iteration is done
862 * in reverse element order.
863 */
864 reverse_iterator
865 rend() _GLIBCXX_NOEXCEPTnoexcept
866 { return reverse_iterator(begin()); }
867
868 /**
869 * Returns a read-only (constant) reverse iterator that points
870 * to one before the first element in the %vector. Iteration
871 * is done in reverse element order.
872 */
873 const_reverse_iterator
874 rend() const _GLIBCXX_NOEXCEPTnoexcept
875 { return const_reverse_iterator(begin()); }
876
877#if __cplusplus201402L >= 201103L
878 /**
879 * Returns a read-only (constant) iterator that points to the
880 * first element in the %vector. Iteration is done in ordinary
881 * element order.
882 */
883 const_iterator
884 cbegin() const noexcept
885 { return const_iterator(this->_M_impl._M_start); }
886
887 /**
888 * Returns a read-only (constant) iterator that points one past
889 * the last element in the %vector. Iteration is done in
890 * ordinary element order.
891 */
892 const_iterator
893 cend() const noexcept
894 { return const_iterator(this->_M_impl._M_finish); }
895
896 /**
897 * Returns a read-only (constant) reverse iterator that points
898 * to the last element in the %vector. Iteration is done in
899 * reverse element order.
900 */
901 const_reverse_iterator
902 crbegin() const noexcept
903 { return const_reverse_iterator(end()); }
904
905 /**
906 * Returns a read-only (constant) reverse iterator that points
907 * to one before the first element in the %vector. Iteration
908 * is done in reverse element order.
909 */
910 const_reverse_iterator
911 crend() const noexcept
912 { return const_reverse_iterator(begin()); }
913#endif
914
915 // [23.2.4.2] capacity
916 /** Returns the number of elements in the %vector. */
917 size_type
918 size() const _GLIBCXX_NOEXCEPTnoexcept
919 { return size_type(this->_M_impl._M_finish - this->_M_impl._M_start); }
920
921 /** Returns the size() of the largest possible %vector. */
922 size_type
923 max_size() const _GLIBCXX_NOEXCEPTnoexcept
924 { return _S_max_size(_M_get_Tp_allocator()); }
925
926#if __cplusplus201402L >= 201103L
927 /**
928 * @brief Resizes the %vector to the specified number of elements.
929 * @param __new_size Number of elements the %vector should contain.
930 *
931 * This function will %resize the %vector to the specified
932 * number of elements. If the number is smaller than the
933 * %vector's current size the %vector is truncated, otherwise
934 * default constructed elements are appended.
935 */
936 void
937 resize(size_type __new_size)
938 {
939 if (__new_size > size())
940 _M_default_append(__new_size - size());
941 else if (__new_size < size())
942 _M_erase_at_end(this->_M_impl._M_start + __new_size);
943 }
944
945 /**
946 * @brief Resizes the %vector to the specified number of elements.
947 * @param __new_size Number of elements the %vector should contain.
948 * @param __x Data with which new elements should be populated.
949 *
950 * This function will %resize the %vector to the specified
951 * number of elements. If the number is smaller than the
952 * %vector's current size the %vector is truncated, otherwise
953 * the %vector is extended and new elements are populated with
954 * given data.
955 */
956 void
957 resize(size_type __new_size, const value_type& __x)
958 {
959 if (__new_size > size())
960 _M_fill_insert(end(), __new_size - size(), __x);
961 else if (__new_size < size())
962 _M_erase_at_end(this->_M_impl._M_start + __new_size);
963 }
964#else
965 /**
966 * @brief Resizes the %vector to the specified number of elements.
967 * @param __new_size Number of elements the %vector should contain.
968 * @param __x Data with which new elements should be populated.
969 *
970 * This function will %resize the %vector to the specified
971 * number of elements. If the number is smaller than the
972 * %vector's current size the %vector is truncated, otherwise
973 * the %vector is extended and new elements are populated with
974 * given data.
975 */
976 void
977 resize(size_type __new_size, value_type __x = value_type())
978 {
979 if (__new_size > size())
980 _M_fill_insert(end(), __new_size - size(), __x);
981 else if (__new_size < size())
982 _M_erase_at_end(this->_M_impl._M_start + __new_size);
983 }
984#endif
985
986#if __cplusplus201402L >= 201103L
987 /** A non-binding request to reduce capacity() to size(). */
988 void
989 shrink_to_fit()
990 { _M_shrink_to_fit(); }
991#endif
992
993 /**
994 * Returns the total number of elements that the %vector can
995 * hold before needing to allocate more memory.
996 */
997 size_type
998 capacity() const _GLIBCXX_NOEXCEPTnoexcept
999 { return size_type(this->_M_impl._M_end_of_storage
1000 - this->_M_impl._M_start); }
1001
1002 /**
1003 * Returns true if the %vector is empty. (Thus begin() would
1004 * equal end().)
1005 */
1006 _GLIBCXX_NODISCARD bool
1007 empty() const _GLIBCXX_NOEXCEPTnoexcept
1008 { return begin() == end(); }
1009
1010 /**
1011 * @brief Attempt to preallocate enough memory for specified number of
1012 * elements.
1013 * @param __n Number of elements required.
1014 * @throw std::length_error If @a n exceeds @c max_size().
1015 *
1016 * This function attempts to reserve enough memory for the
1017 * %vector to hold the specified number of elements. If the
1018 * number requested is more than max_size(), length_error is
1019 * thrown.
1020 *
1021 * The advantage of this function is that if optimal code is a
1022 * necessity and the user can determine the number of elements
1023 * that will be required, the user can reserve the memory in
1024 * %advance, and thus prevent a possible reallocation of memory
1025 * and copying of %vector data.
1026 */
1027 void
1028 reserve(size_type __n);
1029
1030 // element access
1031 /**
1032 * @brief Subscript access to the data contained in the %vector.
1033 * @param __n The index of the element for which data should be
1034 * accessed.
1035 * @return Read/write reference to data.
1036 *
1037 * This operator allows for easy, array-style, data access.
1038 * Note that data access with this operator is unchecked and
1039 * out_of_range lookups are not defined. (For checked lookups
1040 * see at().)
1041 */
1042 reference
1043 operator[](size_type __n) _GLIBCXX_NOEXCEPTnoexcept
1044 {
1045 __glibcxx_requires_subscript(__n);
1046 return *(this->_M_impl._M_start + __n);
1047 }
1048
1049 /**
1050 * @brief Subscript access to the data contained in the %vector.
1051 * @param __n The index of the element for which data should be
1052 * accessed.
1053 * @return Read-only (constant) reference to data.
1054 *
1055 * This operator allows for easy, array-style, data access.
1056 * Note that data access with this operator is unchecked and
1057 * out_of_range lookups are not defined. (For checked lookups
1058 * see at().)
1059 */
1060 const_reference
1061 operator[](size_type __n) const _GLIBCXX_NOEXCEPTnoexcept
1062 {
1063 __glibcxx_requires_subscript(__n);
1064 return *(this->_M_impl._M_start + __n);
1065 }
1066
1067 protected:
1068 /// Safety check used only from at().
1069 void
1070 _M_range_check(size_type __n) const
1071 {
1072 if (__n >= this->size())
1073 __throw_out_of_range_fmt(__N("vector::_M_range_check: __n "("vector::_M_range_check: __n " "(which is %zu) >= this->size() "
"(which is %zu)")
1074 "(which is %zu) >= this->size() "("vector::_M_range_check: __n " "(which is %zu) >= this->size() "
"(which is %zu)")
1075 "(which is %zu)")("vector::_M_range_check: __n " "(which is %zu) >= this->size() "
"(which is %zu)"),
1076 __n, this->size());
1077 }
1078
1079 public:
1080 /**
1081 * @brief Provides access to the data contained in the %vector.
1082 * @param __n The index of the element for which data should be
1083 * accessed.
1084 * @return Read/write reference to data.
1085 * @throw std::out_of_range If @a __n is an invalid index.
1086 *
1087 * This function provides for safer data access. The parameter
1088 * is first checked that it is in the range of the vector. The
1089 * function throws out_of_range if the check fails.
1090 */
1091 reference
1092 at(size_type __n)
1093 {
1094 _M_range_check(__n);
1095 return (*this)[__n];
1096 }
1097
1098 /**
1099 * @brief Provides access to the data contained in the %vector.
1100 * @param __n The index of the element for which data should be
1101 * accessed.
1102 * @return Read-only (constant) reference to data.
1103 * @throw std::out_of_range If @a __n is an invalid index.
1104 *
1105 * This function provides for safer data access. The parameter
1106 * is first checked that it is in the range of the vector. The
1107 * function throws out_of_range if the check fails.
1108 */
1109 const_reference
1110 at(size_type __n) const
1111 {
1112 _M_range_check(__n);
1113 return (*this)[__n];
1114 }
1115
1116 /**
1117 * Returns a read/write reference to the data at the first
1118 * element of the %vector.
1119 */
1120 reference
1121 front() _GLIBCXX_NOEXCEPTnoexcept
1122 {
1123 __glibcxx_requires_nonempty();
1124 return *begin();
1125 }
1126
1127 /**
1128 * Returns a read-only (constant) reference to the data at the first
1129 * element of the %vector.
1130 */
1131 const_reference
1132 front() const _GLIBCXX_NOEXCEPTnoexcept
1133 {
1134 __glibcxx_requires_nonempty();
1135 return *begin();
1136 }
1137
1138 /**
1139 * Returns a read/write reference to the data at the last
1140 * element of the %vector.
1141 */
1142 reference
1143 back() _GLIBCXX_NOEXCEPTnoexcept
1144 {
1145 __glibcxx_requires_nonempty();
1146 return *(end() - 1);
1147 }
1148
1149 /**
1150 * Returns a read-only (constant) reference to the data at the
1151 * last element of the %vector.
1152 */
1153 const_reference
1154 back() const _GLIBCXX_NOEXCEPTnoexcept
1155 {
1156 __glibcxx_requires_nonempty();
1157 return *(end() - 1);
1158 }
1159
1160 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1161 // DR 464. Suggestion for new member functions in standard containers.
1162 // data access
1163 /**
1164 * Returns a pointer such that [data(), data() + size()) is a valid
1165 * range. For a non-empty %vector, data() == &front().
1166 */
1167 _Tp*
1168 data() _GLIBCXX_NOEXCEPTnoexcept
1169 { return _M_data_ptr(this->_M_impl._M_start); }
1170
1171 const _Tp*
1172 data() const _GLIBCXX_NOEXCEPTnoexcept
1173 { return _M_data_ptr(this->_M_impl._M_start); }
1174
1175 // [23.2.4.3] modifiers
1176 /**
1177 * @brief Add data to the end of the %vector.
1178 * @param __x Data to be added.
1179 *
1180 * This is a typical stack operation. The function creates an
1181 * element at the end of the %vector and assigns the given data
1182 * to it. Due to the nature of a %vector this operation can be
1183 * done in constant time if the %vector has preallocated space
1184 * available.
1185 */
1186 void
1187 push_back(const value_type& __x)
1188 {
1189 if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)
1190 {
1191 _GLIBCXX_ASAN_ANNOTATE_GROW(1);
1192 _Alloc_traits::construct(this->_M_impl, this->_M_impl._M_finish,
1193 __x);
1194 ++this->_M_impl._M_finish;
1195 _GLIBCXX_ASAN_ANNOTATE_GREW(1);
1196 }
1197 else
1198 _M_realloc_insert(end(), __x);
1199 }
1200
1201#if __cplusplus201402L >= 201103L
1202 void
1203 push_back(value_type&& __x)
1204 { emplace_back(std::move(__x)); }
1205
1206 template<typename... _Args>
1207#if __cplusplus201402L > 201402L
1208 reference
1209#else
1210 void
1211#endif
1212 emplace_back(_Args&&... __args);
1213#endif
1214
1215 /**
1216 * @brief Removes last element.
1217 *
1218 * This is a typical stack operation. It shrinks the %vector by one.
1219 *
1220 * Note that no data is returned, and if the last element's
1221 * data is needed, it should be retrieved before pop_back() is
1222 * called.
1223 */
1224 void
1225 pop_back() _GLIBCXX_NOEXCEPTnoexcept
1226 {
1227 __glibcxx_requires_nonempty();
1228 --this->_M_impl._M_finish;
1229 _Alloc_traits::destroy(this->_M_impl, this->_M_impl._M_finish);
1230 _GLIBCXX_ASAN_ANNOTATE_SHRINK(1);
1231 }
1232
1233#if __cplusplus201402L >= 201103L
1234 /**
1235 * @brief Inserts an object in %vector before specified iterator.
1236 * @param __position A const_iterator into the %vector.
1237 * @param __args Arguments.
1238 * @return An iterator that points to the inserted data.
1239 *
1240 * This function will insert an object of type T constructed
1241 * with T(std::forward<Args>(args)...) before the specified location.
1242 * Note that this kind of operation could be expensive for a %vector
1243 * and if it is frequently used the user should consider using
1244 * std::list.
1245 */
1246 template<typename... _Args>
1247 iterator
1248 emplace(const_iterator __position, _Args&&... __args)
1249 { return _M_emplace_aux(__position, std::forward<_Args>(__args)...); }
1250
1251 /**
1252 * @brief Inserts given value into %vector before specified iterator.
1253 * @param __position A const_iterator into the %vector.
1254 * @param __x Data to be inserted.
1255 * @return An iterator that points to the inserted data.
1256 *
1257 * This function will insert a copy of the given value before
1258 * the specified location. Note that this kind of operation
1259 * could be expensive for a %vector and if it is frequently
1260 * used the user should consider using std::list.
1261 */
1262 iterator
1263 insert(const_iterator __position, const value_type& __x);
1264#else
1265 /**
1266 * @brief Inserts given value into %vector before specified iterator.
1267 * @param __position An iterator into the %vector.
1268 * @param __x Data to be inserted.
1269 * @return An iterator that points to the inserted data.
1270 *
1271 * This function will insert a copy of the given value before
1272 * the specified location. Note that this kind of operation
1273 * could be expensive for a %vector and if it is frequently
1274 * used the user should consider using std::list.
1275 */
1276 iterator
1277 insert(iterator __position, const value_type& __x);
1278#endif
1279
1280#if __cplusplus201402L >= 201103L
1281 /**
1282 * @brief Inserts given rvalue into %vector before specified iterator.
1283 * @param __position A const_iterator into the %vector.
1284 * @param __x Data to be inserted.
1285 * @return An iterator that points to the inserted data.
1286 *
1287 * This function will insert a copy of the given rvalue before
1288 * the specified location. Note that this kind of operation
1289 * could be expensive for a %vector and if it is frequently
1290 * used the user should consider using std::list.
1291 */
1292 iterator
1293 insert(const_iterator __position, value_type&& __x)
1294 { return _M_insert_rval(__position, std::move(__x)); }
1295
1296 /**
1297 * @brief Inserts an initializer_list into the %vector.
1298 * @param __position An iterator into the %vector.
1299 * @param __l An initializer_list.
1300 *
1301 * This function will insert copies of the data in the
1302 * initializer_list @a l into the %vector before the location
1303 * specified by @a position.
1304 *
1305 * Note that this kind of operation could be expensive for a
1306 * %vector and if it is frequently used the user should
1307 * consider using std::list.
1308 */
1309 iterator
1310 insert(const_iterator __position, initializer_list<value_type> __l)
1311 {
1312 auto __offset = __position - cbegin();
1313 _M_range_insert(begin() + __offset, __l.begin(), __l.end(),
1314 std::random_access_iterator_tag());
1315 return begin() + __offset;
1316 }
1317#endif
1318
1319#if __cplusplus201402L >= 201103L
1320 /**
1321 * @brief Inserts a number of copies of given data into the %vector.
1322 * @param __position A const_iterator into the %vector.
1323 * @param __n Number of elements to be inserted.
1324 * @param __x Data to be inserted.
1325 * @return An iterator that points to the inserted data.
1326 *
1327 * This function will insert a specified number of copies of
1328 * the given data before the location specified by @a position.
1329 *
1330 * Note that this kind of operation could be expensive for a
1331 * %vector and if it is frequently used the user should
1332 * consider using std::list.
1333 */
1334 iterator
1335 insert(const_iterator __position, size_type __n, const value_type& __x)
1336 {
1337 difference_type __offset = __position - cbegin();
1338 _M_fill_insert(begin() + __offset, __n, __x);
1339 return begin() + __offset;
1340 }
1341#else
1342 /**
1343 * @brief Inserts a number of copies of given data into the %vector.
1344 * @param __position An iterator into the %vector.
1345 * @param __n Number of elements to be inserted.
1346 * @param __x Data to be inserted.
1347 *
1348 * This function will insert a specified number of copies of
1349 * the given data before the location specified by @a position.
1350 *
1351 * Note that this kind of operation could be expensive for a
1352 * %vector and if it is frequently used the user should
1353 * consider using std::list.
1354 */
1355 void
1356 insert(iterator __position, size_type __n, const value_type& __x)
1357 { _M_fill_insert(__position, __n, __x); }
1358#endif
1359
1360#if __cplusplus201402L >= 201103L
1361 /**
1362 * @brief Inserts a range into the %vector.
1363 * @param __position A const_iterator into the %vector.
1364 * @param __first An input iterator.
1365 * @param __last An input iterator.
1366 * @return An iterator that points to the inserted data.
1367 *
1368 * This function will insert copies of the data in the range
1369 * [__first,__last) into the %vector before the location specified
1370 * by @a pos.
1371 *
1372 * Note that this kind of operation could be expensive for a
1373 * %vector and if it is frequently used the user should
1374 * consider using std::list.
1375 */
1376 template<typename _InputIterator,
1377 typename = std::_RequireInputIter<_InputIterator>>
1378 iterator
1379 insert(const_iterator __position, _InputIterator __first,
1380 _InputIterator __last)
1381 {
1382 difference_type __offset = __position - cbegin();
1383 _M_insert_dispatch(begin() + __offset,
1384 __first, __last, __false_type());
1385 return begin() + __offset;
1386 }
1387#else
1388 /**
1389 * @brief Inserts a range into the %vector.
1390 * @param __position An iterator into the %vector.
1391 * @param __first An input iterator.
1392 * @param __last An input iterator.
1393 *
1394 * This function will insert copies of the data in the range
1395 * [__first,__last) into the %vector before the location specified
1396 * by @a pos.
1397 *
1398 * Note that this kind of operation could be expensive for a
1399 * %vector and if it is frequently used the user should
1400 * consider using std::list.
1401 */
1402 template<typename _InputIterator>
1403 void
1404 insert(iterator __position, _InputIterator __first,
1405 _InputIterator __last)
1406 {
1407 // Check whether it's an integral type. If so, it's not an iterator.
1408 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1409 _M_insert_dispatch(__position, __first, __last, _Integral());
1410 }
1411#endif
1412
1413 /**
1414 * @brief Remove element at given position.
1415 * @param __position Iterator pointing to element to be erased.
1416 * @return An iterator pointing to the next element (or end()).
1417 *
1418 * This function will erase the element at the given position and thus
1419 * shorten the %vector by one.
1420 *
1421 * Note This operation could be expensive and if it is
1422 * frequently used the user should consider using std::list.
1423 * The user is also cautioned that this function only erases
1424 * the element, and that if the element is itself a pointer,
1425 * the pointed-to memory is not touched in any way. Managing
1426 * the pointer is the user's responsibility.
1427 */
1428 iterator
1429#if __cplusplus201402L >= 201103L
1430 erase(const_iterator __position)
1431 { return _M_erase(begin() + (__position - cbegin())); }
1432#else
1433 erase(iterator __position)
1434 { return _M_erase(__position); }
1435#endif
1436
1437 /**
1438 * @brief Remove a range of elements.
1439 * @param __first Iterator pointing to the first element to be erased.
1440 * @param __last Iterator pointing to one past the last element to be
1441 * erased.
1442 * @return An iterator pointing to the element pointed to by @a __last
1443 * prior to erasing (or end()).
1444 *
1445 * This function will erase the elements in the range
1446 * [__first,__last) and shorten the %vector accordingly.
1447 *
1448 * Note This operation could be expensive and if it is
1449 * frequently used the user should consider using std::list.
1450 * The user is also cautioned that this function only erases
1451 * the elements, and that if the elements themselves are
1452 * pointers, the pointed-to memory is not touched in any way.
1453 * Managing the pointer is the user's responsibility.
1454 */
1455 iterator
1456#if __cplusplus201402L >= 201103L
1457 erase(const_iterator __first, const_iterator __last)
1458 {
1459 const auto __beg = begin();
1460 const auto __cbeg = cbegin();
1461 return _M_erase(__beg + (__first - __cbeg), __beg + (__last - __cbeg));
1462 }
1463#else
1464 erase(iterator __first, iterator __last)
1465 { return _M_erase(__first, __last); }
1466#endif
1467
1468 /**
1469 * @brief Swaps data with another %vector.
1470 * @param __x A %vector of the same element and allocator types.
1471 *
1472 * This exchanges the elements between two vectors in constant time.
1473 * (Three pointers, so it should be quite fast.)
1474 * Note that the global std::swap() function is specialized such that
1475 * std::swap(v1,v2) will feed to this function.
1476 *
1477 * Whether the allocators are swapped depends on the allocator traits.
1478 */
1479 void
1480 swap(vector& __x) _GLIBCXX_NOEXCEPTnoexcept
1481 {
1482#if __cplusplus201402L >= 201103L
1483 __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value
1484 || _M_get_Tp_allocator() == __x._M_get_Tp_allocator());
1485#endif
1486 this->_M_impl._M_swap_data(__x._M_impl);
1487 _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1488 __x._M_get_Tp_allocator());
1489 }
1490
1491 /**
1492 * Erases all the elements. Note that this function only erases the
1493 * elements, and that if the elements themselves are pointers, the
1494 * pointed-to memory is not touched in any way. Managing the pointer is
1495 * the user's responsibility.
1496 */
1497 void
1498 clear() _GLIBCXX_NOEXCEPTnoexcept
1499 { _M_erase_at_end(this->_M_impl._M_start); }
1500
1501 protected:
1502 /**
1503 * Memory expansion handler. Uses the member allocation function to
1504 * obtain @a n bytes of memory, and then copies [first,last) into it.
1505 */
1506 template<typename _ForwardIterator>
1507 pointer
1508 _M_allocate_and_copy(size_type __n,
1509 _ForwardIterator __first, _ForwardIterator __last)
1510 {
1511 pointer __result = this->_M_allocate(__n);
1512 __tryif (true)
1513 {
1514 std::__uninitialized_copy_a(__first, __last, __result,
1515 _M_get_Tp_allocator());
1516 return __result;
1517 }
1518 __catch(...)if (false)
1519 {
1520 _M_deallocate(__result, __n);
1521 __throw_exception_again;
1522 }
1523 }
1524
1525
1526 // Internal constructor functions follow.
1527
1528 // Called by the range constructor to implement [23.1.1]/9
1529
1530#if __cplusplus201402L < 201103L
1531 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1532 // 438. Ambiguity in the "do the right thing" clause
1533 template<typename _Integer>
1534 void
1535 _M_initialize_dispatch(_Integer __n, _Integer __value, __true_type)
1536 {
1537 this->_M_impl._M_start = _M_allocate(_S_check_init_len(
1538 static_cast<size_type>(__n), _M_get_Tp_allocator()));
1539 this->_M_impl._M_end_of_storage =
1540 this->_M_impl._M_start + static_cast<size_type>(__n);
1541 _M_fill_initialize(static_cast<size_type>(__n), __value);
1542 }
1543
1544 // Called by the range constructor to implement [23.1.1]/9
1545 template<typename _InputIterator>
1546 void
1547 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1548 __false_type)
1549 {
1550 _M_range_initialize(__first, __last,
1551 std::__iterator_category(__first));
1552 }
1553#endif
1554
1555 // Called by the second initialize_dispatch above
1556 template<typename _InputIterator>
1557 void
1558 _M_range_initialize(_InputIterator __first, _InputIterator __last,
1559 std::input_iterator_tag)
1560 {
1561 __tryif (true) {
1562 for (; __first != __last; ++__first)
1563#if __cplusplus201402L >= 201103L
1564 emplace_back(*__first);
1565#else
1566 push_back(*__first);
1567#endif
1568 } __catch(...)if (false) {
1569 clear();
1570 __throw_exception_again;
1571 }
1572 }
1573
1574 // Called by the second initialize_dispatch above
1575 template<typename _ForwardIterator>
1576 void
1577 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1578 std::forward_iterator_tag)
1579 {
1580 const size_type __n = std::distance(__first, __last);
1581 this->_M_impl._M_start
1582 = this->_M_allocate(_S_check_init_len(__n, _M_get_Tp_allocator()));
1583 this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
1584 this->_M_impl._M_finish =
1585 std::__uninitialized_copy_a(__first, __last,
1586 this->_M_impl._M_start,
1587 _M_get_Tp_allocator());
1588 }
1589
1590 // Called by the first initialize_dispatch above and by the
1591 // vector(n,value,a) constructor.
1592 void
1593 _M_fill_initialize(size_type __n, const value_type& __value)
1594 {
1595 this->_M_impl._M_finish =
1596 std::__uninitialized_fill_n_a(this->_M_impl._M_start, __n, __value,
1597 _M_get_Tp_allocator());
1598 }
1599
1600#if __cplusplus201402L >= 201103L
1601 // Called by the vector(n) constructor.
1602 void
1603 _M_default_initialize(size_type __n)
1604 {
1605 this->_M_impl._M_finish =
1606 std::__uninitialized_default_n_a(this->_M_impl._M_start, __n,
1607 _M_get_Tp_allocator());
1608 }
1609#endif
1610
1611 // Internal assign functions follow. The *_aux functions do the actual
1612 // assignment work for the range versions.
1613
1614 // Called by the range assign to implement [23.1.1]/9
1615
1616 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1617 // 438. Ambiguity in the "do the right thing" clause
1618 template<typename _Integer>
1619 void
1620 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1621 { _M_fill_assign(__n, __val); }
1622
1623 // Called by the range assign to implement [23.1.1]/9
1624 template<typename _InputIterator>
1625 void
1626 _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1627 __false_type)
1628 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
1629
1630 // Called by the second assign_dispatch above
1631 template<typename _InputIterator>
1632 void
1633 _M_assign_aux(_InputIterator __first, _InputIterator __last,
1634 std::input_iterator_tag);
1635
1636 // Called by the second assign_dispatch above
1637 template<typename _ForwardIterator>
1638 void
1639 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1640 std::forward_iterator_tag);
1641
1642 // Called by assign(n,t), and the range assign when it turns out
1643 // to be the same thing.
1644 void
1645 _M_fill_assign(size_type __n, const value_type& __val);
1646
1647 // Internal insert functions follow.
1648
1649 // Called by the range insert to implement [23.1.1]/9
1650
1651 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1652 // 438. Ambiguity in the "do the right thing" clause
1653 template<typename _Integer>
1654 void
1655 _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __val,
1656 __true_type)
1657 { _M_fill_insert(__pos, __n, __val); }
1658
1659 // Called by the range insert to implement [23.1.1]/9
1660 template<typename _InputIterator>
1661 void
1662 _M_insert_dispatch(iterator __pos, _InputIterator __first,
1663 _InputIterator __last, __false_type)
1664 {
1665 _M_range_insert(__pos, __first, __last,
1666 std::__iterator_category(__first));
1667 }
1668
1669 // Called by the second insert_dispatch above
1670 template<typename _InputIterator>
1671 void
1672 _M_range_insert(iterator __pos, _InputIterator __first,
1673 _InputIterator __last, std::input_iterator_tag);
1674
1675 // Called by the second insert_dispatch above
1676 template<typename _ForwardIterator>
1677 void
1678 _M_range_insert(iterator __pos, _ForwardIterator __first,
1679 _ForwardIterator __last, std::forward_iterator_tag);
1680
1681 // Called by insert(p,n,x), and the range insert when it turns out to be
1682 // the same thing.
1683 void
1684 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
1685
1686#if __cplusplus201402L >= 201103L
1687 // Called by resize(n).
1688 void
1689 _M_default_append(size_type __n);
1690
1691 bool
1692 _M_shrink_to_fit();
1693#endif
1694
1695#if __cplusplus201402L < 201103L
1696 // Called by insert(p,x)
1697 void
1698 _M_insert_aux(iterator __position, const value_type& __x);
1699
1700 void
1701 _M_realloc_insert(iterator __position, const value_type& __x);
1702#else
1703 // A value_type object constructed with _Alloc_traits::construct()
1704 // and destroyed with _Alloc_traits::destroy().
1705 struct _Temporary_value
1706 {
1707 template<typename... _Args>
1708 explicit
1709 _Temporary_value(vector* __vec, _Args&&... __args) : _M_this(__vec)
1710 {
1711 _Alloc_traits::construct(_M_this->_M_impl, _M_ptr(),
1712 std::forward<_Args>(__args)...);
1713 }
1714
1715 ~_Temporary_value()
1716 { _Alloc_traits::destroy(_M_this->_M_impl, _M_ptr()); }
1717
1718 value_type&
1719 _M_val() { return *_M_ptr(); }
1720
1721 private:
1722 _Tp*
1723 _M_ptr() { return reinterpret_cast<_Tp*>(&__buf); }
1724
1725 vector* _M_this;
1726 typename aligned_storage<sizeof(_Tp), alignof(_Tp)>::type __buf;
1727 };
1728
1729 // Called by insert(p,x) and other functions when insertion needs to
1730 // reallocate or move existing elements. _Arg is either _Tp& or _Tp.
1731 template<typename _Arg>
1732 void
1733 _M_insert_aux(iterator __position, _Arg&& __arg);
1734
1735 template<typename... _Args>
1736 void
1737 _M_realloc_insert(iterator __position, _Args&&... __args);
1738
1739 // Either move-construct at the end, or forward to _M_insert_aux.
1740 iterator
1741 _M_insert_rval(const_iterator __position, value_type&& __v);
1742
1743 // Try to emplace at the end, otherwise forward to _M_insert_aux.
1744 template<typename... _Args>
1745 iterator
1746 _M_emplace_aux(const_iterator __position, _Args&&... __args);
1747
1748 // Emplacing an rvalue of the correct type can use _M_insert_rval.
1749 iterator
1750 _M_emplace_aux(const_iterator __position, value_type&& __v)
1751 { return _M_insert_rval(__position, std::move(__v)); }
1752#endif
1753
1754 // Called by _M_fill_insert, _M_insert_aux etc.
1755 size_type
1756 _M_check_len(size_type __n, const char* __s) const
1757 {
1758 if (max_size() - size() < __n)
1759 __throw_length_error(__N(__s)(__s));
1760
1761 const size_type __len = size() + (std::max)(size(), __n);
1762 return (__len < size() || __len > max_size()) ? max_size() : __len;
1763 }
1764
1765 // Called by constructors to check initial size.
1766 static size_type
1767 _S_check_init_len(size_type __n, const allocator_type& __a)
1768 {
1769 if (__n > _S_max_size(_Tp_alloc_type(__a)))
1770 __throw_length_error(
1771 __N("cannot create std::vector larger than max_size()")("cannot create std::vector larger than max_size()"));
1772 return __n;
1773 }
1774
1775 static size_type
1776 _S_max_size(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPTnoexcept
1777 {
1778 // std::distance(begin(), end()) cannot be greater than PTRDIFF_MAX,
1779 // and realistically we can't store more than PTRDIFF_MAX/sizeof(T)
1780 // (even if std::allocator_traits::max_size says we can).
1781 const size_t __diffmax
1782 = __gnu_cxx::__numeric_traits<ptrdiff_t>::__max / sizeof(_Tp);
1783 const size_t __allocmax = _Alloc_traits::max_size(__a);
1784 return (std::min)(__diffmax, __allocmax);
1785 }
1786
1787 // Internal erase functions follow.
1788
1789 // Called by erase(q1,q2), clear(), resize(), _M_fill_assign,
1790 // _M_assign_aux.
1791 void
1792 _M_erase_at_end(pointer __pos) _GLIBCXX_NOEXCEPTnoexcept
1793 {
1794 if (size_type __n = this->_M_impl._M_finish - __pos)
1795 {
1796 std::_Destroy(__pos, this->_M_impl._M_finish,
1797 _M_get_Tp_allocator());
1798 this->_M_impl._M_finish = __pos;
1799 _GLIBCXX_ASAN_ANNOTATE_SHRINK(__n);
1800 }
1801 }
1802
1803 iterator
1804 _M_erase(iterator __position);
1805
1806 iterator
1807 _M_erase(iterator __first, iterator __last);
1808
1809#if __cplusplus201402L >= 201103L
1810 private:
1811 // Constant-time move assignment when source object's memory can be
1812 // moved, either because the source's allocator will move too
1813 // or because the allocators are equal.
1814 void
1815 _M_move_assign(vector&& __x, true_type) noexcept
1816 {
1817 vector __tmp(get_allocator());
1818 this->_M_impl._M_swap_data(__x._M_impl);
1819 __tmp._M_impl._M_swap_data(__x._M_impl);
1820 std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
1821 }
1822
1823 // Do move assignment when it might not be possible to move source
1824 // object's memory, resulting in a linear-time operation.
1825 void
1826 _M_move_assign(vector&& __x, false_type)
1827 {
1828 if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
1829 _M_move_assign(std::move(__x), true_type());
1830 else
1831 {
1832 // The rvalue's allocator cannot be moved and is not equal,
1833 // so we need to individually move each element.
1834 this->_M_assign_aux(std::make_move_iterator(__x.begin()),
1835 std::make_move_iterator(__x.end()),
1836 std::random_access_iterator_tag());
1837 __x.clear();
1838 }
1839 }
1840#endif
1841
1842 template<typename _Up>
1843 _Up*
1844 _M_data_ptr(_Up* __ptr) const _GLIBCXX_NOEXCEPTnoexcept
1845 { return __ptr; }
1846
1847#if __cplusplus201402L >= 201103L
1848 template<typename _Ptr>
1849 typename std::pointer_traits<_Ptr>::element_type*
1850 _M_data_ptr(_Ptr __ptr) const
1851 { return empty() ? nullptr : std::__to_address(__ptr); }
1852#else
1853 template<typename _Up>
1854 _Up*
1855 _M_data_ptr(_Up* __ptr) _GLIBCXX_NOEXCEPTnoexcept
1856 { return __ptr; }
1857
1858 template<typename _Ptr>
1859 value_type*
1860 _M_data_ptr(_Ptr __ptr)
1861 { return empty() ? (value_type*)0 : __ptr.operator->(); }
1862
1863 template<typename _Ptr>
1864 const value_type*
1865 _M_data_ptr(_Ptr __ptr) const
1866 { return empty() ? (const value_type*)0 : __ptr.operator->(); }
1867#endif
1868 };
1869
1870#if __cpp_deduction_guides >= 201606
1871 template<typename _InputIterator, typename _ValT
1872 = typename iterator_traits<_InputIterator>::value_type,
1873 typename _Allocator = allocator<_ValT>,
1874 typename = _RequireInputIter<_InputIterator>,
1875 typename = _RequireAllocator<_Allocator>>
1876 vector(_InputIterator, _InputIterator, _Allocator = _Allocator())
1877 -> vector<_ValT, _Allocator>;
1878#endif
1879
1880 /**
1881 * @brief Vector equality comparison.
1882 * @param __x A %vector.
1883 * @param __y A %vector of the same type as @a __x.
1884 * @return True iff the size and elements of the vectors are equal.
1885 *
1886 * This is an equivalence relation. It is linear in the size of the
1887 * vectors. Vectors are considered equivalent if their sizes are equal,
1888 * and if corresponding elements compare equal.
1889 */
1890 template<typename _Tp, typename _Alloc>
1891 inline bool
1892 operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1893 { return (__x.size() == __y.size()
1894 && std::equal(__x.begin(), __x.end(), __y.begin())); }
1895
1896#if __cpp_lib_three_way_comparison
1897 /**
1898 * @brief Vector ordering relation.
1899 * @param __x A `vector`.
1900 * @param __y A `vector` of the same type as `__x`.
1901 * @return A value indicating whether `__x` is less than, equal to,
1902 * greater than, or incomparable with `__y`.
1903 *
1904 * See `std::lexicographical_compare_three_way()` for how the determination
1905 * is made. This operator is used to synthesize relational operators like
1906 * `<` and `>=` etc.
1907 */
1908 template<typename _Tp, typename _Alloc>
1909 inline __detail::__synth3way_t<_Tp>
1910 operator<=>(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1911 {
1912 return std::lexicographical_compare_three_way(__x.begin(), __x.end(),
1913 __y.begin(), __y.end(),
1914 __detail::__synth3way);
1915 }
1916#else
1917 /**
1918 * @brief Vector ordering relation.
1919 * @param __x A %vector.
1920 * @param __y A %vector of the same type as @a __x.
1921 * @return True iff @a __x is lexicographically less than @a __y.
1922 *
1923 * This is a total ordering relation. It is linear in the size of the
1924 * vectors. The elements must be comparable with @c <.
1925 *
1926 * See std::lexicographical_compare() for how the determination is made.
1927 */
1928 template<typename _Tp, typename _Alloc>
1929 inline bool
1930 operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1931 { return std::lexicographical_compare(__x.begin(), __x.end(),
1932 __y.begin(), __y.end()); }
1933
1934 /// Based on operator==
1935 template<typename _Tp, typename _Alloc>
1936 inline bool
1937 operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1938 { return !(__x == __y); }
1939
1940 /// Based on operator<
1941 template<typename _Tp, typename _Alloc>
1942 inline bool
1943 operator>(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1944 { return __y < __x; }
1945
1946 /// Based on operator<
1947 template<typename _Tp, typename _Alloc>
1948 inline bool
1949 operator<=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1950 { return !(__y < __x); }
1951
1952 /// Based on operator<
1953 template<typename _Tp, typename _Alloc>
1954 inline bool
1955 operator>=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
1956 { return !(__x < __y); }
1957#endif // three-way comparison
1958
1959 /// See std::vector::swap().
1960 template<typename _Tp, typename _Alloc>
1961 inline void
1962 swap(vector<_Tp, _Alloc>& __x, vector<_Tp, _Alloc>& __y)
1963 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))noexcept(noexcept(__x.swap(__y)))
1964 { __x.swap(__y); }
1965
1966_GLIBCXX_END_NAMESPACE_CONTAINER
1967
1968#if __cplusplus201402L >= 201703L
1969 namespace __detail::__variant
1970 {
1971 template<typename> struct _Never_valueless_alt; // see <variant>
1972
1973 // Provide the strong exception-safety guarantee when emplacing a
1974 // vector into a variant, but only if move assignment cannot throw.
1975 template<typename _Tp, typename _Alloc>
1976 struct _Never_valueless_alt<_GLIBCXX_STD_Cstd::vector<_Tp, _Alloc>>
1977 : std::is_nothrow_move_assignable<_GLIBCXX_STD_Cstd::vector<_Tp, _Alloc>>
1978 { };
1979 } // namespace __detail::__variant
1980#endif // C++17
1981
1982_GLIBCXX_END_NAMESPACE_VERSION
1983} // namespace std
1984
1985#endif /* _STL_VECTOR_H */
←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include/llvm/MC/MCRegisterInfo.h

1//===- MC/MCRegisterInfo.h - Target Register Description --------*- C++ -*-===//
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// This file describes an abstract interface used to get information about a
10// target machines register file. This information is used for a variety of
11// purposed, especially register allocation.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_MC_MCREGISTERINFO_H
16#define LLVM_MC_MCREGISTERINFO_H
17
18#include "llvm/ADT/DenseMap.h"
19#include "llvm/ADT/iterator.h"
20#include "llvm/ADT/iterator_range.h"
21#include "llvm/MC/LaneBitmask.h"
22#include "llvm/MC/MCRegister.h"
23#include <cassert>
24#include <cstdint>
25#include <iterator>
26#include <utility>
27
28namespace llvm {
29
30/// MCRegisterClass - Base class of TargetRegisterClass.
31class MCRegisterClass {
32public:
33 using iterator = const MCPhysReg*;
34 using const_iterator = const MCPhysReg*;
35
36 const iterator RegsBegin;
37 const uint8_t *const RegSet;
38 const uint32_t NameIdx;
39 const uint16_t RegsSize;
40 const uint16_t RegSetSize;
41 const uint16_t ID;
42 const uint16_t RegSizeInBits;
43 const int8_t CopyCost;
44 const bool Allocatable;
45
46 /// getID() - Return the register class ID number.
47 ///
48 unsigned getID() const { return ID; }
49
50 /// begin/end - Return all of the registers in this class.
51 ///
52 iterator begin() const { return RegsBegin; }
53 iterator end() const { return RegsBegin + RegsSize; }
54
55 /// getNumRegs - Return the number of registers in this class.
56 ///
57 unsigned getNumRegs() const { return RegsSize; }
58
59 /// getRegister - Return the specified register in the class.
60 ///
61 unsigned getRegister(unsigned i) const {
62 assert(i < getNumRegs() && "Register number out of range!")(static_cast<void> (0));
63 return RegsBegin[i];
64 }
65
66 /// contains - Return true if the specified register is included in this
67 /// register class. This does not include virtual registers.
68 bool contains(MCRegister Reg) const {
69 unsigned RegNo = unsigned(Reg);
70 unsigned InByte = RegNo % 8;
71 unsigned Byte = RegNo / 8;
72 if (Byte >= RegSetSize)
73 return false;
74 return (RegSet[Byte] & (1 << InByte)) != 0;
75 }
76
77 /// contains - Return true if both registers are in this class.
78 bool contains(MCRegister Reg1, MCRegister Reg2) const {
79 return contains(Reg1) && contains(Reg2);
80 }
81
82 /// Return the size of the physical register in bits if we are able to
83 /// determine it. This always returns zero for registers of targets that use
84 /// HW modes, as we need more information to determine the size of registers
85 /// in such cases. Use TargetRegisterInfo to cover them.
86 unsigned getSizeInBits() const { return RegSizeInBits; }
87
88 /// getCopyCost - Return the cost of copying a value between two registers in
89 /// this class. A negative number means the register class is very expensive
90 /// to copy e.g. status flag register classes.
91 int getCopyCost() const { return CopyCost; }
92
93 /// isAllocatable - Return true if this register class may be used to create
94 /// virtual registers.
95 bool isAllocatable() const { return Allocatable; }
96};
97
98/// MCRegisterDesc - This record contains information about a particular
99/// register. The SubRegs field is a zero terminated array of registers that
100/// are sub-registers of the specific register, e.g. AL, AH are sub-registers
101/// of AX. The SuperRegs field is a zero terminated array of registers that are
102/// super-registers of the specific register, e.g. RAX, EAX, are
103/// super-registers of AX.
104///
105struct MCRegisterDesc {
106 uint32_t Name; // Printable name for the reg (for debugging)
107 uint32_t SubRegs; // Sub-register set, described above
108 uint32_t SuperRegs; // Super-register set, described above
109
110 // Offset into MCRI::SubRegIndices of a list of sub-register indices for each
111 // sub-register in SubRegs.
112 uint32_t SubRegIndices;
113
114 // RegUnits - Points to the list of register units. The low 4 bits holds the
115 // Scale, the high bits hold an offset into DiffLists. See MCRegUnitIterator.
116 uint32_t RegUnits;
117
118 /// Index into list with lane mask sequences. The sequence contains a lanemask
119 /// for every register unit.
120 uint16_t RegUnitLaneMasks;
121};
122
123/// MCRegisterInfo base class - We assume that the target defines a static
124/// array of MCRegisterDesc objects that represent all of the machine
125/// registers that the target has. As such, we simply have to track a pointer
126/// to this array so that we can turn register number into a register
127/// descriptor.
128///
129/// Note this class is designed to be a base class of TargetRegisterInfo, which
130/// is the interface used by codegen. However, specific targets *should never*
131/// specialize this class. MCRegisterInfo should only contain getters to access
132/// TableGen generated physical register data. It must not be extended with
133/// virtual methods.
134///
135class MCRegisterInfo {
136public:
137 using regclass_iterator = const MCRegisterClass *;
138
139 /// DwarfLLVMRegPair - Emitted by tablegen so Dwarf<->LLVM reg mappings can be
140 /// performed with a binary search.
141 struct DwarfLLVMRegPair {
142 unsigned FromReg;
143 unsigned ToReg;
144
145 bool operator<(DwarfLLVMRegPair RHS) const { return FromReg < RHS.FromReg; }
146 };
147
148 /// SubRegCoveredBits - Emitted by tablegen: bit range covered by a subreg
149 /// index, -1 in any being invalid.
150 struct SubRegCoveredBits {
151 uint16_t Offset;
152 uint16_t Size;
153 };
154
155private:
156 const MCRegisterDesc *Desc; // Pointer to the descriptor array
157 unsigned NumRegs; // Number of entries in the array
158 MCRegister RAReg; // Return address register
159 MCRegister PCReg; // Program counter register
160 const MCRegisterClass *Classes; // Pointer to the regclass array
161 unsigned NumClasses; // Number of entries in the array
162 unsigned NumRegUnits; // Number of regunits.
163 const MCPhysReg (*RegUnitRoots)[2]; // Pointer to regunit root table.
164 const MCPhysReg *DiffLists; // Pointer to the difflists array
165 const LaneBitmask *RegUnitMaskSequences; // Pointer to lane mask sequences
166 // for register units.
167 const char *RegStrings; // Pointer to the string table.
168 const char *RegClassStrings; // Pointer to the class strings.
169 const uint16_t *SubRegIndices; // Pointer to the subreg lookup
170 // array.
171 const SubRegCoveredBits *SubRegIdxRanges; // Pointer to the subreg covered
172 // bit ranges array.
173 unsigned NumSubRegIndices; // Number of subreg indices.
174 const uint16_t *RegEncodingTable; // Pointer to array of register
175 // encodings.
176
177 unsigned L2DwarfRegsSize;
178 unsigned EHL2DwarfRegsSize;
179 unsigned Dwarf2LRegsSize;
180 unsigned EHDwarf2LRegsSize;
181 const DwarfLLVMRegPair *L2DwarfRegs; // LLVM to Dwarf regs mapping
182 const DwarfLLVMRegPair *EHL2DwarfRegs; // LLVM to Dwarf regs mapping EH
183 const DwarfLLVMRegPair *Dwarf2LRegs; // Dwarf to LLVM regs mapping
184 const DwarfLLVMRegPair *EHDwarf2LRegs; // Dwarf to LLVM regs mapping EH
185 DenseMap<MCRegister, int> L2SEHRegs; // LLVM to SEH regs mapping
186 DenseMap<MCRegister, int> L2CVRegs; // LLVM to CV regs mapping
187
188public:
189 // Forward declaration to become a friend class of DiffListIterator.
190 template <class SubT> class mc_difflist_iterator;
191
192 /// DiffListIterator - Base iterator class that can traverse the
193 /// differentially encoded register and regunit lists in DiffLists.
194 /// Don't use this class directly, use one of the specialized sub-classes
195 /// defined below.
196 class DiffListIterator {
197 uint16_t Val = 0;
198 const MCPhysReg *List = nullptr;
199
200 protected:
201 /// Create an invalid iterator. Call init() to point to something useful.
202 DiffListIterator() = default;
203
204 /// init - Point the iterator to InitVal, decoding subsequent values from
205 /// DiffList. The iterator will initially point to InitVal, sub-classes are
206 /// responsible for skipping the seed value if it is not part of the list.
207 void init(MCPhysReg InitVal, const MCPhysReg *DiffList) {
208 Val = InitVal;
209 List = DiffList;
210 }
211
212 /// advance - Move to the next list position, return the applied
213 /// differential. This function does not detect the end of the list, that
214 /// is the caller's responsibility (by checking for a 0 return value).
215 MCRegister advance() {
216 assert(isValid() && "Cannot move off the end of the list.")(static_cast<void> (0));
217 MCPhysReg D = *List++;
40
←
Dereference of null pointer
218 Val += D;
219 return D;
220 }
221
222 public:
223 /// isValid - returns true if this iterator is not yet at the end.
224 bool isValid() const { return List; }
225
226 /// Dereference the iterator to get the value at the current position.
227 MCRegister operator*() const { return Val; }
228
229 /// Pre-increment to move to the next position.
230 void operator++() {
231 // The end of the list is encoded as a 0 differential.
232 if (!advance())
39
←
Calling 'DiffListIterator::advance'
→
233 List = nullptr;
234 }
235
236 template <class SubT> friend class MCRegisterInfo::mc_difflist_iterator;
237 };
238
239 /// Forward iterator using DiffListIterator.
240 template <class SubT>
241 class mc_difflist_iterator
242 : public iterator_facade_base<mc_difflist_iterator<SubT>,
243 std::forward_iterator_tag, MCPhysReg> {
244 MCRegisterInfo::DiffListIterator Iter;
245 /// Current value as MCPhysReg, so we can return a reference to it.
246 MCPhysReg Val;
247
248 protected:
249 mc_difflist_iterator(MCRegisterInfo::DiffListIterator Iter) : Iter(Iter) {}
250
251 // Allow conversion between instantiations where valid.
252 mc_difflist_iterator(MCRegister Reg, const MCPhysReg *DiffList) {
253 Iter.init(Reg, DiffList);
254 Val = *Iter;
255 }
256
257 public:
258 // Allow default construction to build variables, but this doesn't build
259 // a useful iterator.
260 mc_difflist_iterator() = default;
261
262 /// Return an iterator past the last element.
263 static SubT end() {
264 SubT End;
265 End.Iter.List = nullptr;
266 return End;
267 }
268
269 bool operator==(const mc_difflist_iterator &Arg) const {
270 return Iter.List == Arg.Iter.List;
271 }
272
273 const MCPhysReg &operator*() const { return Val; }
274
275 using mc_difflist_iterator::iterator_facade_base::operator++;
276 void operator++() {
277 assert(Iter.List && "Cannot increment the end iterator!")(static_cast<void> (0));
278 ++Iter;
279 Val = *Iter;
280 }
281 };
282
283 /// Forward iterator over all sub-registers.
284 /// TODO: Replace remaining uses of MCSubRegIterator.
285 class mc_subreg_iterator : public mc_difflist_iterator<mc_subreg_iterator> {
286 public:
287 mc_subreg_iterator(MCRegisterInfo::DiffListIterator Iter)
288 : mc_difflist_iterator(Iter) {}
289 mc_subreg_iterator() = default;
290 mc_subreg_iterator(MCRegister Reg, const MCRegisterInfo *MCRI)
291 : mc_difflist_iterator(Reg, MCRI->DiffLists + MCRI->get(Reg).SubRegs) {}
292 };
293
294 /// Forward iterator over all super-registers.
295 /// TODO: Replace remaining uses of MCSuperRegIterator.
296 class mc_superreg_iterator
297 : public mc_difflist_iterator<mc_superreg_iterator> {
298 public:
299 mc_superreg_iterator(MCRegisterInfo::DiffListIterator Iter)
300 : mc_difflist_iterator(Iter) {}
301 mc_superreg_iterator() = default;
302 mc_superreg_iterator(MCRegister Reg, const MCRegisterInfo *MCRI)
303 : mc_difflist_iterator(Reg,
304 MCRI->DiffLists + MCRI->get(Reg).SuperRegs) {}
305 };
306
307 /// Return an iterator range over all sub-registers of \p Reg, excluding \p
308 /// Reg.
309 iterator_range<mc_subreg_iterator> subregs(MCRegister Reg) const {
310 return make_range(std::next(mc_subreg_iterator(Reg, this)),
311 mc_subreg_iterator::end());
312 }
313
314 /// Return an iterator range over all sub-registers of \p Reg, including \p
315 /// Reg.
316 iterator_range<mc_subreg_iterator> subregs_inclusive(MCRegister Reg) const {
317 return make_range({Reg, this}, mc_subreg_iterator::end());
318 }
319
320 /// Return an iterator range over all super-registers of \p Reg, excluding \p
321 /// Reg.
322 iterator_range<mc_superreg_iterator> superregs(MCRegister Reg) const {
323 return make_range(std::next(mc_superreg_iterator(Reg, this)),
324 mc_superreg_iterator::end());
325 }
326
327 /// Return an iterator range over all super-registers of \p Reg, including \p
328 /// Reg.
329 iterator_range<mc_superreg_iterator>
330 superregs_inclusive(MCRegister Reg) const {
331 return make_range({Reg, this}, mc_superreg_iterator::end());
332 }
333
334 /// Return an iterator range over all sub- and super-registers of \p Reg,
335 /// including \p Reg.
336 detail::concat_range<const MCPhysReg, iterator_range<mc_subreg_iterator>,
337 iterator_range<mc_superreg_iterator>>
338 sub_and_superregs_inclusive(MCRegister Reg) const {
339 return concat<const MCPhysReg>(subregs_inclusive(Reg), superregs(Reg));
340 }
341
342 // These iterators are allowed to sub-class DiffListIterator and access
343 // internal list pointers.
344 friend class MCSubRegIterator;
345 friend class MCSubRegIndexIterator;
346 friend class MCSuperRegIterator;
347 friend class MCRegUnitIterator;
348 friend class MCRegUnitMaskIterator;
349 friend class MCRegUnitRootIterator;
350
351 /// Initialize MCRegisterInfo, called by TableGen
352 /// auto-generated routines. *DO NOT USE*.
353 void InitMCRegisterInfo(const MCRegisterDesc *D, unsigned NR, unsigned RA,
354 unsigned PC,
355 const MCRegisterClass *C, unsigned NC,
356 const MCPhysReg (*RURoots)[2],
357 unsigned NRU,
358 const MCPhysReg *DL,
359 const LaneBitmask *RUMS,
360 const char *Strings,
361 const char *ClassStrings,
362 const uint16_t *SubIndices,
363 unsigned NumIndices,
364 const SubRegCoveredBits *SubIdxRanges,
365 const uint16_t *RET) {
366 Desc = D;
367 NumRegs = NR;
368 RAReg = RA;
369 PCReg = PC;
370 Classes = C;
371 DiffLists = DL;
372 RegUnitMaskSequences = RUMS;
373 RegStrings = Strings;
374 RegClassStrings = ClassStrings;
375 NumClasses = NC;
376 RegUnitRoots = RURoots;
377 NumRegUnits = NRU;
378 SubRegIndices = SubIndices;
379 NumSubRegIndices = NumIndices;
380 SubRegIdxRanges = SubIdxRanges;
381 RegEncodingTable = RET;
382
383 // Initialize DWARF register mapping variables
384 EHL2DwarfRegs = nullptr;
385 EHL2DwarfRegsSize = 0;
386 L2DwarfRegs = nullptr;
387 L2DwarfRegsSize = 0;
388 EHDwarf2LRegs = nullptr;
389 EHDwarf2LRegsSize = 0;
390 Dwarf2LRegs = nullptr;
391 Dwarf2LRegsSize = 0;
392 }
393
394 /// Used to initialize LLVM register to Dwarf
395 /// register number mapping. Called by TableGen auto-generated routines.
396 /// *DO NOT USE*.
397 void mapLLVMRegsToDwarfRegs(const DwarfLLVMRegPair *Map, unsigned Size,
398 bool isEH) {
399 if (isEH) {
400 EHL2DwarfRegs = Map;
401 EHL2DwarfRegsSize = Size;
402 } else {
403 L2DwarfRegs = Map;
404 L2DwarfRegsSize = Size;
405 }
406 }
407
408 /// Used to initialize Dwarf register to LLVM
409 /// register number mapping. Called by TableGen auto-generated routines.
410 /// *DO NOT USE*.
411 void mapDwarfRegsToLLVMRegs(const DwarfLLVMRegPair *Map, unsigned Size,
412 bool isEH) {
413 if (isEH) {
414 EHDwarf2LRegs = Map;
415 EHDwarf2LRegsSize = Size;
416 } else {
417 Dwarf2LRegs = Map;
418 Dwarf2LRegsSize = Size;
419 }
420 }
421
422 /// mapLLVMRegToSEHReg - Used to initialize LLVM register to SEH register
423 /// number mapping. By default the SEH register number is just the same
424 /// as the LLVM register number.
425 /// FIXME: TableGen these numbers. Currently this requires target specific
426 /// initialization code.
427 void mapLLVMRegToSEHReg(MCRegister LLVMReg, int SEHReg) {
428 L2SEHRegs[LLVMReg] = SEHReg;
429 }
430
431 void mapLLVMRegToCVReg(MCRegister LLVMReg, int CVReg) {
432 L2CVRegs[LLVMReg] = CVReg;
433 }
434
435 /// This method should return the register where the return
436 /// address can be found.
437 MCRegister getRARegister() const {
438 return RAReg;
439 }
440
441 /// Return the register which is the program counter.
442 MCRegister getProgramCounter() const {
443 return PCReg;
444 }
445
446 const MCRegisterDesc &operator[](MCRegister RegNo) const {
447 assert(RegNo < NumRegs &&(static_cast<void> (0))
448 "Attempting to access record for invalid register number!")(static_cast<void> (0));
449 return Desc[RegNo];
450 }
451
452 /// Provide a get method, equivalent to [], but more useful with a
453 /// pointer to this object.
454 const MCRegisterDesc &get(MCRegister RegNo) const {
455 return operator[](RegNo);
456 }
457
458 /// Returns the physical register number of sub-register "Index"
459 /// for physical register RegNo. Return zero if the sub-register does not
460 /// exist.
461 MCRegister getSubReg(MCRegister Reg, unsigned Idx) const;
462
463 /// Return a super-register of the specified register
464 /// Reg so its sub-register of index SubIdx is Reg.
465 MCRegister getMatchingSuperReg(MCRegister Reg, unsigned SubIdx,
466 const MCRegisterClass *RC) const;
467
468 /// For a given register pair, return the sub-register index
469 /// if the second register is a sub-register of the first. Return zero
470 /// otherwise.
471 unsigned getSubRegIndex(MCRegister RegNo, MCRegister SubRegNo) const;
472
473 /// Get the size of the bit range covered by a sub-register index.
474 /// If the index isn't continuous, return the sum of the sizes of its parts.
475 /// If the index is used to access subregisters of different sizes, return -1.
476 unsigned getSubRegIdxSize(unsigned Idx) const;
477
478 /// Get the offset of the bit range covered by a sub-register index.
479 /// If an Offset doesn't make sense (the index isn't continuous, or is used to
480 /// access sub-registers at different offsets), return -1.
481 unsigned getSubRegIdxOffset(unsigned Idx) const;
482
483 /// Return the human-readable symbolic target-specific name for the
484 /// specified physical register.
485 const char *getName(MCRegister RegNo) const {
486 return RegStrings + get(RegNo).Name;
487 }
488
489 /// Return the number of registers this target has (useful for
490 /// sizing arrays holding per register information)
491 unsigned getNumRegs() const {
492 return NumRegs;
493 }
494
495 /// Return the number of sub-register indices
496 /// understood by the target. Index 0 is reserved for the no-op sub-register,
497 /// while 1 to getNumSubRegIndices() - 1 represent real sub-registers.
498 unsigned getNumSubRegIndices() const {
499 return NumSubRegIndices;
500 }
501
502 /// Return the number of (native) register units in the
503 /// target. Register units are numbered from 0 to getNumRegUnits() - 1. They
504 /// can be accessed through MCRegUnitIterator defined below.
505 unsigned getNumRegUnits() const {
506 return NumRegUnits;
507 }
508
509 /// Map a target register to an equivalent dwarf register
510 /// number. Returns -1 if there is no equivalent value. The second
511 /// parameter allows targets to use different numberings for EH info and
512 /// debugging info.
513 int getDwarfRegNum(MCRegister RegNum, bool isEH) const;
514
515 /// Map a dwarf register back to a target register. Returns None is there is
516 /// no mapping.
517 Optional<unsigned> getLLVMRegNum(unsigned RegNum, bool isEH) const;
518
519 /// Map a target EH register number to an equivalent DWARF register
520 /// number.
521 int getDwarfRegNumFromDwarfEHRegNum(unsigned RegNum) const;
522
523 /// Map a target register to an equivalent SEH register
524 /// number. Returns LLVM register number if there is no equivalent value.
525 int getSEHRegNum(MCRegister RegNum) const;
526
527 /// Map a target register to an equivalent CodeView register
528 /// number.
529 int getCodeViewRegNum(MCRegister RegNum) const;
530
531 regclass_iterator regclass_begin() const { return Classes; }
532 regclass_iterator regclass_end() const { return Classes+NumClasses; }
533 iterator_range<regclass_iterator> regclasses() const {
534 return make_range(regclass_begin(), regclass_end());
535 }
536
537 unsigned getNumRegClasses() const {
538 return (unsigned)(regclass_end()-regclass_begin());
539 }
540
541 /// Returns the register class associated with the enumeration
542 /// value. See class MCOperandInfo.
543 const MCRegisterClass& getRegClass(unsigned i) const {
544 assert(i < getNumRegClasses() && "Register Class ID out of range")(static_cast<void> (0));
545 return Classes[i];
546 }
547
548 const char *getRegClassName(const MCRegisterClass *Class) const {
549 return RegClassStrings + Class->NameIdx;
550 }
551
552 /// Returns the encoding for RegNo
553 uint16_t getEncodingValue(MCRegister RegNo) const {
554 assert(RegNo < NumRegs &&(static_cast<void> (0))
555 "Attempting to get encoding for invalid register number!")(static_cast<void> (0));
556 return RegEncodingTable[RegNo];
557 }
558
559 /// Returns true if RegB is a sub-register of RegA.
560 bool isSubRegister(MCRegister RegA, MCRegister RegB) const {
561 return isSuperRegister(RegB, RegA);
562 }
563
564 /// Returns true if RegB is a super-register of RegA.
565 bool isSuperRegister(MCRegister RegA, MCRegister RegB) const;
566
567 /// Returns true if RegB is a sub-register of RegA or if RegB == RegA.
568 bool isSubRegisterEq(MCRegister RegA, MCRegister RegB) const {
569 return isSuperRegisterEq(RegB, RegA);
570 }
571
572 /// Returns true if RegB is a super-register of RegA or if
573 /// RegB == RegA.
574 bool isSuperRegisterEq(MCRegister RegA, MCRegister RegB) const {
575 return RegA == RegB || isSuperRegister(RegA, RegB);
576 }
577
578 /// Returns true if RegB is a super-register or sub-register of RegA
579 /// or if RegB == RegA.
580 bool isSuperOrSubRegisterEq(MCRegister RegA, MCRegister RegB) const {
581 return isSubRegisterEq(RegA, RegB) || isSuperRegister(RegA, RegB);
582 }
583};
584
585//===----------------------------------------------------------------------===//
586// Register List Iterators
587//===----------------------------------------------------------------------===//
588
589// MCRegisterInfo provides lists of super-registers, sub-registers, and
590// aliasing registers. Use these iterator classes to traverse the lists.
591
592/// MCSubRegIterator enumerates all sub-registers of Reg.
593/// If IncludeSelf is set, Reg itself is included in the list.
594class MCSubRegIterator : public MCRegisterInfo::DiffListIterator {
595public:
596 MCSubRegIterator(MCRegister Reg, const MCRegisterInfo *MCRI,
597 bool IncludeSelf = false) {
598 init(Reg, MCRI->DiffLists + MCRI->get(Reg).SubRegs);
599 // Initially, the iterator points to Reg itself.
600 if (!IncludeSelf)
601 ++*this;
602 }
603};
604
605/// Iterator that enumerates the sub-registers of a Reg and the associated
606/// sub-register indices.
607class MCSubRegIndexIterator {
608 MCSubRegIterator SRIter;
609 const uint16_t *SRIndex;
610
611public:
612 /// Constructs an iterator that traverses subregisters and their
613 /// associated subregister indices.
614 MCSubRegIndexIterator(MCRegister Reg, const MCRegisterInfo *MCRI)
615 : SRIter(Reg, MCRI) {
616 SRIndex = MCRI->SubRegIndices + MCRI->get(Reg).SubRegIndices;
617 }
618
619 /// Returns current sub-register.
620 MCRegister getSubReg() const {
621 return *SRIter;
622 }
623
624 /// Returns sub-register index of the current sub-register.
625 unsigned getSubRegIndex() const {
626 return *SRIndex;
627 }
628
629 /// Returns true if this iterator is not yet at the end.
630 bool isValid() const { return SRIter.isValid(); }
631
632 /// Moves to the next position.
633 void operator++() {
634 ++SRIter;
635 ++SRIndex;
636 }
637};
638
639/// MCSuperRegIterator enumerates all super-registers of Reg.
640/// If IncludeSelf is set, Reg itself is included in the list.
641class MCSuperRegIterator : public MCRegisterInfo::DiffListIterator {
642public:
643 MCSuperRegIterator() = default;
644
645 MCSuperRegIterator(MCRegister Reg, const MCRegisterInfo *MCRI,
646 bool IncludeSelf = false) {
647 init(Reg, MCRI->DiffLists + MCRI->get(Reg).SuperRegs);
648 // Initially, the iterator points to Reg itself.
649 if (!IncludeSelf
36.1
'IncludeSelf' is false
36.1
'IncludeSelf' is false
36.1
'IncludeSelf' is false
)
37
←
Taking true branch
→
650 ++*this;
38
←
Calling 'DiffListIterator::operator++'
→
651 }
652};
653
654// Definition for isSuperRegister. Put it down here since it needs the
655// iterator defined above in addition to the MCRegisterInfo class itself.
656inline bool MCRegisterInfo::isSuperRegister(MCRegister RegA, MCRegister RegB) const{
657 for (MCSuperRegIterator I(RegA, this); I.isValid(); ++I)
658 if (*I == RegB)
659 return true;
660 return false;
661}
662
663//===----------------------------------------------------------------------===//
664// Register Units
665//===----------------------------------------------------------------------===//
666
667// Register units are used to compute register aliasing. Every register has at
668// least one register unit, but it can have more. Two registers overlap if and
669// only if they have a common register unit.
670//
671// A target with a complicated sub-register structure will typically have many
672// fewer register units than actual registers. MCRI::getNumRegUnits() returns
673// the number of register units in the target.
674
675// MCRegUnitIterator enumerates a list of register units for Reg. The list is
676// in ascending numerical order.
677class MCRegUnitIterator : public MCRegisterInfo::DiffListIterator {
678public:
679 /// MCRegUnitIterator - Create an iterator that traverses the register units
680 /// in Reg.
681 MCRegUnitIterator() = default;
682
683 MCRegUnitIterator(MCRegister Reg, const MCRegisterInfo *MCRI) {
684 assert(Reg && "Null register has no regunits")(static_cast<void> (0));
685 assert(MCRegister::isPhysicalRegister(Reg.id()))(static_cast<void> (0));
686 // Decode the RegUnits MCRegisterDesc field.
687 unsigned RU = MCRI->get(Reg).RegUnits;
688 unsigned Scale = RU & 15;
689 unsigned Offset = RU >> 4;
690
691 // Initialize the iterator to Reg * Scale, and the List pointer to
692 // DiffLists + Offset.
693 init(Reg * Scale, MCRI->DiffLists + Offset);
694
695 // That may not be a valid unit, we need to advance by one to get the real
696 // unit number. The first differential can be 0 which would normally
697 // terminate the list, but since we know every register has at least one
698 // unit, we can allow a 0 differential here.
699 advance();
700 }
701};
702
703/// MCRegUnitMaskIterator enumerates a list of register units and their
704/// associated lane masks for Reg. The register units are in ascending
705/// numerical order.
706class MCRegUnitMaskIterator {
707 MCRegUnitIterator RUIter;
708 const LaneBitmask *MaskListIter;
709
710public:
711 MCRegUnitMaskIterator() = default;
712
713 /// Constructs an iterator that traverses the register units and their
714 /// associated LaneMasks in Reg.
715 MCRegUnitMaskIterator(MCRegister Reg, const MCRegisterInfo *MCRI)
716 : RUIter(Reg, MCRI) {
717 uint16_t Idx = MCRI->get(Reg).RegUnitLaneMasks;
718 MaskListIter = &MCRI->RegUnitMaskSequences[Idx];
719 }
720
721 /// Returns a (RegUnit, LaneMask) pair.
722 std::pair<unsigned,LaneBitmask> operator*() const {
723 return std::make_pair(*RUIter, *MaskListIter);
724 }
725
726 /// Returns true if this iterator is not yet at the end.
727 bool isValid() const { return RUIter.isValid(); }
728
729 /// Moves to the next position.
730 void operator++() {
731 ++MaskListIter;
732 ++RUIter;
733 }
734};
735
736// Each register unit has one or two root registers. The complete set of
737// registers containing a register unit is the union of the roots and their
738// super-registers. All registers aliasing Unit can be visited like this:
739//
740// for (MCRegUnitRootIterator RI(Unit, MCRI); RI.isValid(); ++RI) {
741// for (MCSuperRegIterator SI(*RI, MCRI, true); SI.isValid(); ++SI)
742// visit(*SI);
743// }
744
745/// MCRegUnitRootIterator enumerates the root registers of a register unit.
746class MCRegUnitRootIterator {
747 uint16_t Reg0 = 0;
748 uint16_t Reg1 = 0;
749
750public:
751 MCRegUnitRootIterator() = default;
752
753 MCRegUnitRootIterator(unsigned RegUnit, const MCRegisterInfo *MCRI) {
754 assert(RegUnit < MCRI->getNumRegUnits() && "Invalid register unit")(static_cast<void> (0));
755 Reg0 = MCRI->RegUnitRoots[RegUnit][0];
756 Reg1 = MCRI->RegUnitRoots[RegUnit][1];
757 }
758
759 /// Dereference to get the current root register.
760 unsigned operator*() const {
761 return Reg0;
762 }
763
764 /// Check if the iterator is at the end of the list.
765 bool isValid() const {
766 return Reg0;
767 }
768
769 /// Preincrement to move to the next root register.
770 void operator++() {
771 assert(isValid() && "Cannot move off the end of the list.")(static_cast<void> (0));
772 Reg0 = Reg1;
773 Reg1 = 0;
774 }
775};
776
777/// MCRegAliasIterator enumerates all registers aliasing Reg. If IncludeSelf is
778/// set, Reg itself is included in the list. This iterator does not guarantee
779/// any ordering or that entries are unique.
780class MCRegAliasIterator {
781private:
782 MCRegister Reg;
783 const MCRegisterInfo *MCRI;
784 bool IncludeSelf;
785
786 MCRegUnitIterator RI;
787 MCRegUnitRootIterator RRI;
788 MCSuperRegIterator SI;
789
790public:
791 MCRegAliasIterator(MCRegister Reg, const MCRegisterInfo *MCRI,
792 bool IncludeSelf)
793 : Reg(Reg), MCRI(MCRI), IncludeSelf(IncludeSelf) {
794 // Initialize the iterators.
795 for (RI = MCRegUnitIterator(Reg, MCRI); RI.isValid(); ++RI) {
796 for (RRI = MCRegUnitRootIterator(*RI, MCRI); RRI.isValid(); ++RRI) {
797 for (SI = MCSuperRegIterator(*RRI, MCRI, true); SI.isValid(); ++SI) {
798 if (!(!IncludeSelf && Reg == *SI))
799 return;
800 }
801 }
802 }
803 }
804
805 bool isValid() const { return RI.isValid(); }
806
807 MCRegister operator*() const {
808 assert(SI.isValid() && "Cannot dereference an invalid iterator.")(static_cast<void> (0));
809 return *SI;
810 }
811
812 void advance() {
813 // Assuming SI is valid.
814 ++SI;
815 if (SI.isValid()) return;
816
817 ++RRI;
818 if (RRI.isValid()) {
819 SI = MCSuperRegIterator(*RRI, MCRI, true);
820 return;
821 }
822
823 ++RI;
824 if (RI.isValid()) {
825 RRI = MCRegUnitRootIterator(*RI, MCRI);
826 SI = MCSuperRegIterator(*RRI, MCRI, true);
827 }
828 }
829
830 void operator++() {
831 assert(isValid() && "Cannot move off the end of the list.")(static_cast<void> (0));
832 do advance();
833 while (!IncludeSelf && isValid() && *SI == Reg);
834 }
835};
836
837} // end namespace llvm
838
839#endif // LLVM_MC_MCREGISTERINFO_H