Line data Source code
1 : //===- StatepointLowering.cpp - SDAGBuilder's statepoint code -------------===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // This file includes support code use by SelectionDAGBuilder when lowering a
11 : // statepoint sequence in SelectionDAG IR.
12 : //
13 : //===----------------------------------------------------------------------===//
14 :
15 : #include "StatepointLowering.h"
16 : #include "SelectionDAGBuilder.h"
17 : #include "llvm/ADT/ArrayRef.h"
18 : #include "llvm/ADT/DenseMap.h"
19 : #include "llvm/ADT/None.h"
20 : #include "llvm/ADT/Optional.h"
21 : #include "llvm/ADT/STLExtras.h"
22 : #include "llvm/ADT/SmallVector.h"
23 : #include "llvm/ADT/Statistic.h"
24 : #include "llvm/CodeGen/FunctionLoweringInfo.h"
25 : #include "llvm/CodeGen/GCMetadata.h"
26 : #include "llvm/CodeGen/GCStrategy.h"
27 : #include "llvm/CodeGen/ISDOpcodes.h"
28 : #include "llvm/CodeGen/MachineFrameInfo.h"
29 : #include "llvm/CodeGen/MachineFunction.h"
30 : #include "llvm/CodeGen/MachineMemOperand.h"
31 : #include "llvm/CodeGen/RuntimeLibcalls.h"
32 : #include "llvm/CodeGen/SelectionDAG.h"
33 : #include "llvm/CodeGen/SelectionDAGNodes.h"
34 : #include "llvm/CodeGen/StackMaps.h"
35 : #include "llvm/CodeGen/TargetLowering.h"
36 : #include "llvm/CodeGen/TargetOpcodes.h"
37 : #include "llvm/IR/CallingConv.h"
38 : #include "llvm/IR/DerivedTypes.h"
39 : #include "llvm/IR/Instruction.h"
40 : #include "llvm/IR/Instructions.h"
41 : #include "llvm/IR/LLVMContext.h"
42 : #include "llvm/IR/Statepoint.h"
43 : #include "llvm/IR/Type.h"
44 : #include "llvm/Support/Casting.h"
45 : #include "llvm/Support/MachineValueType.h"
46 : #include "llvm/Target/TargetMachine.h"
47 : #include "llvm/Target/TargetOptions.h"
48 : #include <cassert>
49 : #include <cstddef>
50 : #include <cstdint>
51 : #include <iterator>
52 : #include <tuple>
53 : #include <utility>
54 :
55 : using namespace llvm;
56 :
57 : #define DEBUG_TYPE "statepoint-lowering"
58 :
59 : STATISTIC(NumSlotsAllocatedForStatepoints,
60 : "Number of stack slots allocated for statepoints");
61 : STATISTIC(NumOfStatepoints, "Number of statepoint nodes encountered");
62 : STATISTIC(StatepointMaxSlotsRequired,
63 : "Maximum number of stack slots required for a singe statepoint");
64 :
65 284 : static void pushStackMapConstant(SmallVectorImpl<SDValue>& Ops,
66 : SelectionDAGBuilder &Builder, uint64_t Value) {
67 284 : SDLoc L = Builder.getCurSDLoc();
68 284 : Ops.push_back(Builder.DAG.getTargetConstant(StackMaps::ConstantOp, L,
69 284 : MVT::i64));
70 284 : Ops.push_back(Builder.DAG.getTargetConstant(Value, L, MVT::i64));
71 284 : }
72 :
73 70 : void StatepointLoweringState::startNewStatepoint(SelectionDAGBuilder &Builder) {
74 : // Consistency check
75 : assert(PendingGCRelocateCalls.empty() &&
76 : "Trying to visit statepoint before finished processing previous one");
77 70 : Locations.clear();
78 70 : NextSlotToAllocate = 0;
79 : // Need to resize this on each safepoint - we need the two to stay in sync and
80 : // the clear patterns of a SelectionDAGBuilder have no relation to
81 : // FunctionLoweringInfo. Also need to ensure used bits get cleared.
82 70 : AllocatedStackSlots.clear();
83 70 : AllocatedStackSlots.resize(Builder.FuncInfo.StatepointStackSlots.size());
84 70 : }
85 :
86 1269117 : void StatepointLoweringState::clear() {
87 1269117 : Locations.clear();
88 1269116 : AllocatedStackSlots.clear();
89 : assert(PendingGCRelocateCalls.empty() &&
90 : "cleared before statepoint sequence completed");
91 1269116 : }
92 :
93 : SDValue
94 60 : StatepointLoweringState::allocateStackSlot(EVT ValueType,
95 : SelectionDAGBuilder &Builder) {
96 : NumSlotsAllocatedForStatepoints++;
97 60 : MachineFrameInfo &MFI = Builder.DAG.getMachineFunction().getFrameInfo();
98 :
99 : unsigned SpillSize = ValueType.getStoreSize();
100 : assert((SpillSize * 8) == ValueType.getSizeInBits() && "Size not in bytes?");
101 :
102 : // First look for a previously created stack slot which is not in
103 : // use (accounting for the fact arbitrary slots may already be
104 : // reserved), or to create a new stack slot and use it.
105 :
106 : const size_t NumSlots = AllocatedStackSlots.size();
107 : assert(NextSlotToAllocate <= NumSlots && "Broken invariant");
108 :
109 : assert(AllocatedStackSlots.size() ==
110 : Builder.FuncInfo.StatepointStackSlots.size() &&
111 : "Broken invariant");
112 :
113 85 : for (; NextSlotToAllocate < NumSlots; NextSlotToAllocate++) {
114 72 : if (!AllocatedStackSlots.test(NextSlotToAllocate)) {
115 26 : const int FI = Builder.FuncInfo.StatepointStackSlots[NextSlotToAllocate];
116 13 : if (MFI.getObjectSize(FI) == SpillSize) {
117 11 : AllocatedStackSlots.set(NextSlotToAllocate);
118 : // TODO: Is ValueType the right thing to use here?
119 11 : return Builder.DAG.getFrameIndex(FI, ValueType);
120 : }
121 : }
122 : }
123 :
124 : // Couldn't find a free slot, so create a new one:
125 :
126 49 : SDValue SpillSlot = Builder.DAG.CreateStackTemporary(ValueType);
127 49 : const unsigned FI = cast<FrameIndexSDNode>(SpillSlot)->getIndex();
128 : MFI.markAsStatepointSpillSlotObjectIndex(FI);
129 :
130 49 : Builder.FuncInfo.StatepointStackSlots.push_back(FI);
131 98 : AllocatedStackSlots.resize(AllocatedStackSlots.size()+1, true);
132 : assert(AllocatedStackSlots.size() ==
133 : Builder.FuncInfo.StatepointStackSlots.size() &&
134 : "Broken invariant");
135 :
136 : StatepointMaxSlotsRequired.updateMax(
137 : Builder.FuncInfo.StatepointStackSlots.size());
138 :
139 49 : return SpillSlot;
140 : }
141 :
142 : /// Utility function for reservePreviousStackSlotForValue. Tries to find
143 : /// stack slot index to which we have spilled value for previous statepoints.
144 : /// LookUpDepth specifies maximum DFS depth this function is allowed to look.
145 120 : static Optional<int> findPreviousSpillSlot(const Value *Val,
146 : SelectionDAGBuilder &Builder,
147 : int LookUpDepth) {
148 : // Can not look any further - give up now
149 120 : if (LookUpDepth <= 0)
150 : return None;
151 :
152 : // Spill location is known for gc relocates
153 : if (const auto *Relocate = dyn_cast<GCRelocateInst>(Val)) {
154 : const auto &SpillMap =
155 9 : Builder.FuncInfo.StatepointSpillMaps[Relocate->getStatepoint()];
156 :
157 9 : auto It = SpillMap.find(Relocate->getDerivedPtr());
158 9 : if (It == SpillMap.end())
159 : return None;
160 :
161 : return It->second;
162 : }
163 :
164 : // Look through bitcast instructions.
165 : if (const BitCastInst *Cast = dyn_cast<BitCastInst>(Val))
166 3 : return findPreviousSpillSlot(Cast->getOperand(0), Builder, LookUpDepth - 1);
167 :
168 : // Look through phi nodes
169 : // All incoming values should have same known stack slot, otherwise result
170 : // is unknown.
171 : if (const PHINode *Phi = dyn_cast<PHINode>(Val)) {
172 : Optional<int> MergedResult = None;
173 :
174 0 : for (auto &IncomingValue : Phi->incoming_values()) {
175 : Optional<int> SpillSlot =
176 0 : findPreviousSpillSlot(IncomingValue, Builder, LookUpDepth - 1);
177 0 : if (!SpillSlot.hasValue())
178 : return None;
179 :
180 0 : if (MergedResult.hasValue() && *MergedResult != *SpillSlot)
181 : return None;
182 :
183 : MergedResult = SpillSlot;
184 : }
185 : return MergedResult;
186 : }
187 :
188 : // TODO: We can do better for PHI nodes. In cases like this:
189 : // ptr = phi(relocated_pointer, not_relocated_pointer)
190 : // statepoint(ptr)
191 : // We will return that stack slot for ptr is unknown. And later we might
192 : // assign different stack slots for ptr and relocated_pointer. This limits
193 : // llvm's ability to remove redundant stores.
194 : // Unfortunately it's hard to accomplish in current infrastructure.
195 : // We use this function to eliminate spill store completely, while
196 : // in example we still need to emit store, but instead of any location
197 : // we need to use special "preferred" location.
198 :
199 : // TODO: handle simple updates. If a value is modified and the original
200 : // value is no longer live, it would be nice to put the modified value in the
201 : // same slot. This allows folding of the memory accesses for some
202 : // instructions types (like an increment).
203 : // statepoint (i)
204 : // i1 = i+1
205 : // statepoint (i1)
206 : // However we need to be careful for cases like this:
207 : // statepoint(i)
208 : // i1 = i+1
209 : // statepoint(i, i1)
210 : // Here we want to reserve spill slot for 'i', but not for 'i+1'. If we just
211 : // put handling of simple modifications in this function like it's done
212 : // for bitcasts we might end up reserving i's slot for 'i+1' because order in
213 : // which we visit values is unspecified.
214 :
215 : // Don't know any information about this instruction
216 : return None;
217 : }
218 :
219 : /// Try to find existing copies of the incoming values in stack slots used for
220 : /// statepoint spilling. If we can find a spill slot for the incoming value,
221 : /// mark that slot as allocated, and reuse the same slot for this safepoint.
222 : /// This helps to avoid series of loads and stores that only serve to reshuffle
223 : /// values on the stack between calls.
224 205 : static void reservePreviousStackSlotForValue(const Value *IncomingValue,
225 : SelectionDAGBuilder &Builder) {
226 205 : SDValue Incoming = Builder.getValue(IncomingValue);
227 :
228 : if (isa<ConstantSDNode>(Incoming) || isa<FrameIndexSDNode>(Incoming)) {
229 : // We won't need to spill this, so no need to check for previously
230 : // allocated stack slots
231 196 : return;
232 : }
233 :
234 128 : SDValue OldLocation = Builder.StatepointLowering.getLocation(Incoming);
235 128 : if (OldLocation.getNode())
236 : // Duplicates in input
237 : return;
238 :
239 : const int LookUpDepth = 6;
240 : Optional<int> Index =
241 117 : findPreviousSpillSlot(IncomingValue, Builder, LookUpDepth);
242 117 : if (!Index.hasValue())
243 : return;
244 :
245 9 : const auto &StatepointSlots = Builder.FuncInfo.StatepointStackSlots;
246 :
247 : auto SlotIt = find(StatepointSlots, *Index);
248 : assert(SlotIt != StatepointSlots.end() &&
249 : "Value spilled to the unknown stack slot");
250 :
251 : // This is one of our dedicated lowering slots
252 : const int Offset = std::distance(StatepointSlots.begin(), SlotIt);
253 9 : if (Builder.StatepointLowering.isStackSlotAllocated(Offset)) {
254 : // stack slot already assigned to someone else, can't use it!
255 : // TODO: currently we reserve space for gc arguments after doing
256 : // normal allocation for deopt arguments. We should reserve for
257 : // _all_ deopt and gc arguments, then start allocating. This
258 : // will prevent some moves being inserted when vm state changes,
259 : // but gc state doesn't between two calls.
260 : return;
261 : }
262 : // Reserve this stack slot
263 : Builder.StatepointLowering.reserveStackSlot(Offset);
264 :
265 : // Cache this slot so we find it when going through the normal
266 : // assignment loop.
267 : SDValue Loc =
268 18 : Builder.DAG.getTargetFrameIndex(*Index, Builder.getFrameIndexTy());
269 9 : Builder.StatepointLowering.setLocation(Incoming, Loc);
270 : }
271 :
272 : /// Remove any duplicate (as SDValues) from the derived pointer pairs. This
273 : /// is not required for correctness. It's purpose is to reduce the size of
274 : /// StackMap section. It has no effect on the number of spill slots required
275 : /// or the actual lowering.
276 : static void
277 70 : removeDuplicateGCPtrs(SmallVectorImpl<const Value *> &Bases,
278 : SmallVectorImpl<const Value *> &Ptrs,
279 : SmallVectorImpl<const GCRelocateInst *> &Relocs,
280 : SelectionDAGBuilder &Builder,
281 : FunctionLoweringInfo::StatepointSpillMap &SSM) {
282 : DenseMap<SDValue, const Value *> Seen;
283 :
284 : SmallVector<const Value *, 64> NewBases, NewPtrs;
285 : SmallVector<const GCRelocateInst *, 64> NewRelocs;
286 136 : for (size_t i = 0, e = Ptrs.size(); i < e; i++) {
287 66 : SDValue SD = Builder.getValue(Ptrs[i]);
288 66 : auto SeenIt = Seen.find(SD);
289 :
290 66 : if (SeenIt == Seen.end()) {
291 : // Only add non-duplicates
292 58 : NewBases.push_back(Bases[i]);
293 58 : NewPtrs.push_back(Ptrs[i]);
294 58 : NewRelocs.push_back(Relocs[i]);
295 58 : Seen[SD] = Ptrs[i];
296 : } else {
297 : // Duplicate pointer found, note in SSM and move on:
298 8 : SSM.DuplicateMap[Ptrs[i]] = SeenIt->second;
299 : }
300 : }
301 : assert(Bases.size() >= NewBases.size());
302 : assert(Ptrs.size() >= NewPtrs.size());
303 : assert(Relocs.size() >= NewRelocs.size());
304 70 : Bases = NewBases;
305 70 : Ptrs = NewPtrs;
306 70 : Relocs = NewRelocs;
307 : assert(Ptrs.size() == Bases.size());
308 : assert(Ptrs.size() == Relocs.size());
309 70 : }
310 :
311 : /// Extract call from statepoint, lower it and return pointer to the
312 : /// call node. Also update NodeMap so that getValue(statepoint) will
313 : /// reference lowered call result
314 0 : static std::pair<SDValue, SDNode *> lowerCallFromStatepointLoweringInfo(
315 : SelectionDAGBuilder::StatepointLoweringInfo &SI,
316 : SelectionDAGBuilder &Builder, SmallVectorImpl<SDValue> &PendingExports) {
317 : SDValue ReturnValue, CallEndVal;
318 0 : std::tie(ReturnValue, CallEndVal) =
319 0 : Builder.lowerInvokable(SI.CLI, SI.EHPadBB);
320 0 : SDNode *CallEnd = CallEndVal.getNode();
321 :
322 : // Get a call instruction from the call sequence chain. Tail calls are not
323 : // allowed. The following code is essentially reverse engineering X86's
324 : // LowerCallTo.
325 : //
326 : // We are expecting DAG to have the following form:
327 : //
328 : // ch = eh_label (only in case of invoke statepoint)
329 : // ch, glue = callseq_start ch
330 : // ch, glue = X86::Call ch, glue
331 : // ch, glue = callseq_end ch, glue
332 : // get_return_value ch, glue
333 : //
334 : // get_return_value can either be a sequence of CopyFromReg instructions
335 : // to grab the return value from the return register(s), or it can be a LOAD
336 : // to load a value returned by reference via a stack slot.
337 :
338 0 : bool HasDef = !SI.CLI.RetTy->isVoidTy();
339 0 : if (HasDef) {
340 0 : if (CallEnd->getOpcode() == ISD::LOAD)
341 0 : CallEnd = CallEnd->getOperand(0).getNode();
342 : else
343 0 : while (CallEnd->getOpcode() == ISD::CopyFromReg)
344 0 : CallEnd = CallEnd->getOperand(0).getNode();
345 : }
346 :
347 : assert(CallEnd->getOpcode() == ISD::CALLSEQ_END && "expected!");
348 0 : return std::make_pair(ReturnValue, CallEnd->getOperand(0).getNode());
349 : }
350 :
351 : /// Spill a value incoming to the statepoint. It might be either part of
352 : /// vmstate
353 : /// or gcstate. In both cases unconditionally spill it on the stack unless it
354 : /// is a null constant. Return pair with first element being frame index
355 : /// containing saved value and second element with outgoing chain from the
356 : /// emitted store
357 : static std::pair<SDValue, SDValue>
358 128 : spillIncomingStatepointValue(SDValue Incoming, SDValue Chain,
359 : SelectionDAGBuilder &Builder) {
360 128 : SDValue Loc = Builder.StatepointLowering.getLocation(Incoming);
361 :
362 : // Emit new store if we didn't do it for this ptr before
363 128 : if (!Loc.getNode()) {
364 60 : Loc = Builder.StatepointLowering.allocateStackSlot(Incoming.getValueType(),
365 120 : Builder);
366 60 : int Index = cast<FrameIndexSDNode>(Loc)->getIndex();
367 : // We use TargetFrameIndex so that isel will not select it into LEA
368 60 : Loc = Builder.DAG.getTargetFrameIndex(Index, Builder.getFrameIndexTy());
369 :
370 : // TODO: We can create TokenFactor node instead of
371 : // chaining stores one after another, this may allow
372 : // a bit more optimal scheduling for them
373 :
374 : #ifndef NDEBUG
375 : // Right now we always allocate spill slots that are of the same
376 : // size as the value we're about to spill (the size of spillee can
377 : // vary since we spill vectors of pointers too). At some point we
378 : // can consider allowing spills of smaller values to larger slots
379 : // (i.e. change the '==' in the assert below to a '>=').
380 : MachineFrameInfo &MFI = Builder.DAG.getMachineFunction().getFrameInfo();
381 : assert((MFI.getObjectSize(Index) * 8) == Incoming.getValueSizeInBits() &&
382 : "Bad spill: stack slot does not match!");
383 : #endif
384 :
385 120 : Chain = Builder.DAG.getStore(Chain, Builder.getCurSDLoc(), Incoming, Loc,
386 : MachinePointerInfo::getFixedStack(
387 180 : Builder.DAG.getMachineFunction(), Index));
388 :
389 60 : Builder.StatepointLowering.setLocation(Incoming, Loc);
390 : }
391 :
392 : assert(Loc.getNode());
393 128 : return std::make_pair(Loc, Chain);
394 : }
395 :
396 : /// Lower a single value incoming to a statepoint node. This value can be
397 : /// either a deopt value or a gc value, the handling is the same. We special
398 : /// case constants and allocas, then fall back to spilling if required.
399 247 : static void lowerIncomingStatepointValue(SDValue Incoming, bool LiveInOnly,
400 : SmallVectorImpl<SDValue> &Ops,
401 : SelectionDAGBuilder &Builder) {
402 247 : SDValue Chain = Builder.getRoot();
403 :
404 : if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Incoming)) {
405 : // If the original value was a constant, make sure it gets recorded as
406 : // such in the stackmap. This is required so that the consumer can
407 : // parse any internal format to the deopt state. It also handles null
408 : // pointers and other constant pointers in GC states. Note the constant
409 : // vectors do not appear to actually hit this path and that anything larger
410 : // than an i64 value (not type!) will fail asserts here.
411 148 : pushStackMapConstant(Ops, Builder, C->getSExtValue());
412 : } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Incoming)) {
413 : // This handles allocas as arguments to the statepoint (this is only
414 : // really meaningful for a deopt value. For GC, we'd be trying to
415 : // relocate the address of the alloca itself?)
416 : assert(Incoming.getValueType() == Builder.getFrameIndexTy() &&
417 : "Incoming value is a frame index!");
418 6 : Ops.push_back(Builder.DAG.getTargetFrameIndex(FI->getIndex(),
419 3 : Builder.getFrameIndexTy()));
420 170 : } else if (LiveInOnly) {
421 : // If this value is live in (not live-on-return, or live-through), we can
422 : // treat it the same way patchpoint treats it's "live in" values. We'll
423 : // end up folding some of these into stack references, but they'll be
424 : // handled by the register allocator. Note that we do not have the notion
425 : // of a late use so these values might be placed in registers which are
426 : // clobbered by the call. This is fine for live-in.
427 42 : Ops.push_back(Incoming);
428 : } else {
429 : // Otherwise, locate a spill slot and explicitly spill it so it
430 : // can be found by the runtime later. We currently do not support
431 : // tracking values through callee saved registers to their eventual
432 : // spill location. This would be a useful optimization, but would
433 : // need to be optional since it requires a lot of complexity on the
434 : // runtime side which not all would support.
435 128 : auto Res = spillIncomingStatepointValue(Incoming, Chain, Builder);
436 128 : Ops.push_back(Res.first);
437 128 : Chain = Res.second;
438 : }
439 :
440 247 : Builder.DAG.setRoot(Chain);
441 247 : }
442 :
443 : /// Lower deopt state and gc pointer arguments of the statepoint. The actual
444 : /// lowering is described in lowerIncomingStatepointValue. This function is
445 : /// responsible for lowering everything in the right position and playing some
446 : /// tricks to avoid redundant stack manipulation where possible. On
447 : /// completion, 'Ops' will contain ready to use operands for machine code
448 : /// statepoint. The chain nodes will have already been created and the DAG root
449 : /// will be set to the last value spilled (if any were).
450 : static void
451 70 : lowerStatepointMetaArgs(SmallVectorImpl<SDValue> &Ops,
452 : SelectionDAGBuilder::StatepointLoweringInfo &SI,
453 : SelectionDAGBuilder &Builder) {
454 : // Lower the deopt and gc arguments for this statepoint. Layout will be:
455 : // deopt argument length, deopt arguments.., gc arguments...
456 : #ifndef NDEBUG
457 : if (auto *GFI = Builder.GFI) {
458 : // Check that each of the gc pointer and bases we've gotten out of the
459 : // safepoint is something the strategy thinks might be a pointer (or vector
460 : // of pointers) into the GC heap. This is basically just here to help catch
461 : // errors during statepoint insertion. TODO: This should actually be in the
462 : // Verifier, but we can't get to the GCStrategy from there (yet).
463 : GCStrategy &S = GFI->getStrategy();
464 : for (const Value *V : SI.Bases) {
465 : auto Opt = S.isGCManagedPointer(V->getType()->getScalarType());
466 : if (Opt.hasValue()) {
467 : assert(Opt.getValue() &&
468 : "non gc managed base pointer found in statepoint");
469 : }
470 : }
471 : for (const Value *V : SI.Ptrs) {
472 : auto Opt = S.isGCManagedPointer(V->getType()->getScalarType());
473 : if (Opt.hasValue()) {
474 : assert(Opt.getValue() &&
475 : "non gc managed derived pointer found in statepoint");
476 : }
477 : }
478 : assert(SI.Bases.size() == SI.Ptrs.size() && "Pointer without base!");
479 : } else {
480 : assert(SI.Bases.empty() && "No gc specified, so cannot relocate pointers!");
481 : assert(SI.Ptrs.empty() && "No gc specified, so cannot relocate pointers!");
482 : }
483 : #endif
484 :
485 : // Figure out what lowering strategy we're going to use for each part
486 : // Note: Is is conservatively correct to lower both "live-in" and "live-out"
487 : // as "live-through". A "live-through" variable is one which is "live-in",
488 : // "live-out", and live throughout the lifetime of the call (i.e. we can find
489 : // it from any PC within the transitive callee of the statepoint). In
490 : // particular, if the callee spills callee preserved registers we may not
491 : // be able to find a value placed in that register during the call. This is
492 : // fine for live-out, but not for live-through. If we were willing to make
493 : // assumptions about the code generator producing the callee, we could
494 : // potentially allow live-through values in callee saved registers.
495 : const bool LiveInDeopt =
496 70 : SI.StatepointFlags & (uint64_t)StatepointFlags::DeoptLiveIn;
497 :
498 : auto isGCValue =[&](const Value *V) {
499 : return is_contained(SI.Ptrs, V) || is_contained(SI.Bases, V);
500 : };
501 :
502 : // Before we actually start lowering (and allocating spill slots for values),
503 : // reserve any stack slots which we judge to be profitable to reuse for a
504 : // particular value. This is purely an optimization over the code below and
505 : // doesn't change semantics at all. It is important for performance that we
506 : // reserve slots for both deopt and gc values before lowering either.
507 201 : for (const Value *V : SI.DeoptState) {
508 131 : if (!LiveInDeopt || isGCValue(V))
509 89 : reservePreviousStackSlotForValue(V, Builder);
510 : }
511 128 : for (unsigned i = 0; i < SI.Bases.size(); ++i) {
512 58 : reservePreviousStackSlotForValue(SI.Bases[i], Builder);
513 58 : reservePreviousStackSlotForValue(SI.Ptrs[i], Builder);
514 : }
515 :
516 : // First, prefix the list with the number of unique values to be
517 : // lowered. Note that this is the number of *Values* not the
518 : // number of SDValues required to lower them.
519 70 : const int NumVMSArgs = SI.DeoptState.size();
520 70 : pushStackMapConstant(Ops, Builder, NumVMSArgs);
521 :
522 : // The vm state arguments are lowered in an opaque manner. We do not know
523 : // what type of values are contained within.
524 201 : for (const Value *V : SI.DeoptState) {
525 131 : SDValue Incoming = Builder.getValue(V);
526 131 : const bool LiveInValue = LiveInDeopt && !isGCValue(V);
527 131 : lowerIncomingStatepointValue(Incoming, LiveInValue, Ops, Builder);
528 : }
529 :
530 : // Finally, go ahead and lower all the gc arguments. There's no prefixed
531 : // length for this one. After lowering, we'll have the base and pointer
532 : // arrays interwoven with each (lowered) base pointer immediately followed by
533 : // it's (lowered) derived pointer. i.e
534 : // (base[0], ptr[0], base[1], ptr[1], ...)
535 128 : for (unsigned i = 0; i < SI.Bases.size(); ++i) {
536 58 : const Value *Base = SI.Bases[i];
537 58 : lowerIncomingStatepointValue(Builder.getValue(Base), /*LiveInOnly*/ false,
538 : Ops, Builder);
539 :
540 58 : const Value *Ptr = SI.Ptrs[i];
541 58 : lowerIncomingStatepointValue(Builder.getValue(Ptr), /*LiveInOnly*/ false,
542 : Ops, Builder);
543 : }
544 :
545 : // If there are any explicit spill slots passed to the statepoint, record
546 : // them, but otherwise do not do anything special. These are user provided
547 : // allocas and give control over placement to the consumer. In this case,
548 : // it is the contents of the slot which may get updated, not the pointer to
549 : // the alloca
550 133 : for (Value *V : SI.GCArgs) {
551 63 : SDValue Incoming = Builder.getValue(V);
552 : if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Incoming)) {
553 : // This handles allocas as arguments to the statepoint
554 : assert(Incoming.getValueType() == Builder.getFrameIndexTy() &&
555 : "Incoming value is a frame index!");
556 4 : Ops.push_back(Builder.DAG.getTargetFrameIndex(FI->getIndex(),
557 2 : Builder.getFrameIndexTy()));
558 : }
559 : }
560 :
561 : // Record computed locations for all lowered values.
562 : // This can not be embedded in lowering loops as we need to record *all*
563 : // values, while previous loops account only values with unique SDValues.
564 70 : const Instruction *StatepointInstr = SI.StatepointInstr;
565 70 : auto &SpillMap = Builder.FuncInfo.StatepointSpillMaps[StatepointInstr];
566 :
567 128 : for (const GCRelocateInst *Relocate : SI.GCRelocates) {
568 58 : const Value *V = Relocate->getDerivedPtr();
569 58 : SDValue SDV = Builder.getValue(V);
570 58 : SDValue Loc = Builder.StatepointLowering.getLocation(SDV);
571 :
572 58 : if (Loc.getNode()) {
573 51 : SpillMap.SlotMap[V] = cast<FrameIndexSDNode>(Loc)->getIndex();
574 : } else {
575 : // Record value as visited, but not spilled. This is case for allocas
576 : // and constants. For this values we can avoid emitting spill load while
577 : // visiting corresponding gc_relocate.
578 : // Actually we do not need to record them in this map at all.
579 : // We do this only to check that we are not relocating any unvisited
580 : // value.
581 7 : SpillMap.SlotMap[V] = None;
582 :
583 : // Default llvm mechanisms for exporting values which are used in
584 : // different basic blocks does not work for gc relocates.
585 : // Note that it would be incorrect to teach llvm that all relocates are
586 : // uses of the corresponding values so that it would automatically
587 : // export them. Relocates of the spilled values does not use original
588 : // value.
589 7 : if (Relocate->getParent() != StatepointInstr->getParent())
590 3 : Builder.ExportFromCurrentBlock(V);
591 : }
592 : }
593 70 : }
594 :
595 70 : SDValue SelectionDAGBuilder::LowerAsSTATEPOINT(
596 : SelectionDAGBuilder::StatepointLoweringInfo &SI) {
597 : // The basic scheme here is that information about both the original call and
598 : // the safepoint is encoded in the CallInst. We create a temporary call and
599 : // lower it, then reverse engineer the calling sequence.
600 :
601 : NumOfStatepoints++;
602 : // Clear state
603 70 : StatepointLowering.startNewStatepoint(*this);
604 :
605 : #ifndef NDEBUG
606 : // We schedule gc relocates before removeDuplicateGCPtrs since we _will_
607 : // encounter the duplicate gc relocates we elide in removeDuplicateGCPtrs.
608 : for (auto *Reloc : SI.GCRelocates)
609 : if (Reloc->getParent() == SI.StatepointInstr->getParent())
610 : StatepointLowering.scheduleRelocCall(*Reloc);
611 : #endif
612 :
613 : // Remove any redundant llvm::Values which map to the same SDValue as another
614 : // input. Also has the effect of removing duplicates in the original
615 : // llvm::Value input list as well. This is a useful optimization for
616 : // reducing the size of the StackMap section. It has no other impact.
617 70 : removeDuplicateGCPtrs(SI.Bases, SI.Ptrs, SI.GCRelocates, *this,
618 70 : FuncInfo.StatepointSpillMaps[SI.StatepointInstr]);
619 : assert(SI.Bases.size() == SI.Ptrs.size() &&
620 : SI.Ptrs.size() == SI.GCRelocates.size());
621 :
622 : // Lower statepoint vmstate and gcstate arguments
623 : SmallVector<SDValue, 10> LoweredMetaArgs;
624 70 : lowerStatepointMetaArgs(LoweredMetaArgs, SI, *this);
625 :
626 : // Now that we've emitted the spills, we need to update the root so that the
627 : // call sequence is ordered correctly.
628 70 : SI.CLI.setChain(getRoot());
629 :
630 : // Get call node, we will replace it later with statepoint
631 : SDValue ReturnVal;
632 : SDNode *CallNode;
633 : std::tie(ReturnVal, CallNode) =
634 70 : lowerCallFromStatepointLoweringInfo(SI, *this, PendingExports);
635 :
636 : // Construct the actual GC_TRANSITION_START, STATEPOINT, and GC_TRANSITION_END
637 : // nodes with all the appropriate arguments and return values.
638 :
639 : // Call Node: Chain, Target, {Args}, RegMask, [Glue]
640 70 : SDValue Chain = CallNode->getOperand(0);
641 :
642 70 : SDValue Glue;
643 : bool CallHasIncomingGlue = CallNode->getGluedNode();
644 : if (CallHasIncomingGlue) {
645 : // Glue is always last operand
646 10 : Glue = CallNode->getOperand(CallNode->getNumOperands() - 1);
647 : }
648 :
649 : // Build the GC_TRANSITION_START node if necessary.
650 : //
651 : // The operands to the GC_TRANSITION_{START,END} nodes are laid out in the
652 : // order in which they appear in the call to the statepoint intrinsic. If
653 : // any of the operands is a pointer-typed, that operand is immediately
654 : // followed by a SRCVALUE for the pointer that may be used during lowering
655 : // (e.g. to form MachinePointerInfo values for loads/stores).
656 : const bool IsGCTransition =
657 70 : (SI.StatepointFlags & (uint64_t)StatepointFlags::GCTransition) ==
658 : (uint64_t)StatepointFlags::GCTransition;
659 70 : if (IsGCTransition) {
660 : SmallVector<SDValue, 8> TSOps;
661 :
662 : // Add chain
663 8 : TSOps.push_back(Chain);
664 :
665 : // Add GC transition arguments
666 9 : for (const Value *V : SI.GCTransitionArgs) {
667 1 : TSOps.push_back(getValue(V));
668 2 : if (V->getType()->isPointerTy())
669 1 : TSOps.push_back(DAG.getSrcValue(V));
670 : }
671 :
672 : // Add glue if necessary
673 8 : if (CallHasIncomingGlue)
674 2 : TSOps.push_back(Glue);
675 :
676 16 : SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
677 :
678 : SDValue GCTransitionStart =
679 24 : DAG.getNode(ISD::GC_TRANSITION_START, getCurSDLoc(), NodeTys, TSOps);
680 :
681 8 : Chain = GCTransitionStart.getValue(0);
682 8 : Glue = GCTransitionStart.getValue(1);
683 : }
684 :
685 : // TODO: Currently, all of these operands are being marked as read/write in
686 : // PrologEpilougeInserter.cpp, we should special case the VMState arguments
687 : // and flags to be read-only.
688 : SmallVector<SDValue, 40> Ops;
689 :
690 : // Add the <id> and <numBytes> constants.
691 140 : Ops.push_back(DAG.getTargetConstant(SI.ID, getCurSDLoc(), MVT::i64));
692 70 : Ops.push_back(
693 140 : DAG.getTargetConstant(SI.NumPatchBytes, getCurSDLoc(), MVT::i32));
694 :
695 : // Calculate and push starting position of vmstate arguments
696 : // Get number of arguments incoming directly into call node
697 : unsigned NumCallRegArgs =
698 140 : CallNode->getNumOperands() - (CallHasIncomingGlue ? 4 : 3);
699 140 : Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, getCurSDLoc(), MVT::i32));
700 :
701 : // Add call target
702 70 : SDValue CallTarget = SDValue(CallNode->getOperand(1).getNode(), 0);
703 70 : Ops.push_back(CallTarget);
704 :
705 : // Add call arguments
706 : // Get position of register mask in the call
707 : SDNode::op_iterator RegMaskIt;
708 70 : if (CallHasIncomingGlue)
709 20 : RegMaskIt = CallNode->op_end() - 2;
710 : else
711 120 : RegMaskIt = CallNode->op_end() - 1;
712 140 : Ops.insert(Ops.end(), CallNode->op_begin() + 2, RegMaskIt);
713 :
714 : // Add a constant argument for the calling convention
715 70 : pushStackMapConstant(Ops, *this, SI.CLI.CallConv);
716 :
717 : // Add a constant argument for the flags
718 70 : uint64_t Flags = SI.StatepointFlags;
719 : assert(((Flags & ~(uint64_t)StatepointFlags::MaskAll) == 0) &&
720 : "Unknown flag used");
721 70 : pushStackMapConstant(Ops, *this, Flags);
722 :
723 : // Insert all vmstate and gcstate arguments
724 70 : Ops.insert(Ops.end(), LoweredMetaArgs.begin(), LoweredMetaArgs.end());
725 :
726 : // Add register mask from call node
727 70 : Ops.push_back(*RegMaskIt);
728 :
729 : // Add chain
730 70 : Ops.push_back(Chain);
731 :
732 : // Same for the glue, but we add it only if original call had it
733 70 : if (Glue.getNode())
734 16 : Ops.push_back(Glue);
735 :
736 : // Compute return values. Provide a glue output since we consume one as
737 : // input. This allows someone else to chain off us as needed.
738 140 : SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
739 :
740 : SDNode *StatepointMCNode =
741 210 : DAG.getMachineNode(TargetOpcode::STATEPOINT, getCurSDLoc(), NodeTys, Ops);
742 :
743 : SDNode *SinkNode = StatepointMCNode;
744 :
745 : // Build the GC_TRANSITION_END node if necessary.
746 : //
747 : // See the comment above regarding GC_TRANSITION_START for the layout of
748 : // the operands to the GC_TRANSITION_END node.
749 70 : if (IsGCTransition) {
750 : SmallVector<SDValue, 8> TEOps;
751 :
752 : // Add chain
753 8 : TEOps.push_back(SDValue(StatepointMCNode, 0));
754 :
755 : // Add GC transition arguments
756 9 : for (const Value *V : SI.GCTransitionArgs) {
757 1 : TEOps.push_back(getValue(V));
758 2 : if (V->getType()->isPointerTy())
759 1 : TEOps.push_back(DAG.getSrcValue(V));
760 : }
761 :
762 : // Add glue
763 8 : TEOps.push_back(SDValue(StatepointMCNode, 1));
764 :
765 16 : SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
766 :
767 : SDValue GCTransitionStart =
768 24 : DAG.getNode(ISD::GC_TRANSITION_END, getCurSDLoc(), NodeTys, TEOps);
769 :
770 8 : SinkNode = GCTransitionStart.getNode();
771 : }
772 :
773 : // Replace original call
774 70 : DAG.ReplaceAllUsesWith(CallNode, SinkNode); // This may update Root
775 : // Remove original call node
776 70 : DAG.DeleteNode(CallNode);
777 :
778 : // DON'T set the root - under the assumption that it's already set past the
779 : // inserted node we created.
780 :
781 : // TODO: A better future implementation would be to emit a single variable
782 : // argument, variable return value STATEPOINT node here and then hookup the
783 : // return value of each gc.relocate to the respective output of the
784 : // previously emitted STATEPOINT value. Unfortunately, this doesn't appear
785 : // to actually be possible today.
786 :
787 70 : return ReturnVal;
788 : }
789 :
790 : void
791 67 : SelectionDAGBuilder::LowerStatepoint(ImmutableStatepoint ISP,
792 : const BasicBlock *EHPadBB /*= nullptr*/) {
793 : assert(ISP.getCallSite().getCallingConv() != CallingConv::AnyReg &&
794 : "anyregcc is not supported on statepoints!");
795 :
796 : #ifndef NDEBUG
797 : // If this is a malformed statepoint, report it early to simplify debugging.
798 : // This should catch any IR level mistake that's made when constructing or
799 : // transforming statepoints.
800 : ISP.verify();
801 :
802 : // Check that the associated GCStrategy expects to encounter statepoints.
803 : assert(GFI->getStrategy().useStatepoints() &&
804 : "GCStrategy does not expect to encounter statepoints");
805 : #endif
806 :
807 67 : SDValue ActualCallee;
808 :
809 67 : if (ISP.getNumPatchBytes() > 0) {
810 : // If we've been asked to emit a nop sequence instead of a call instruction
811 : // for this statepoint then don't lower the call target, but use a constant
812 : // `null` instead. Not lowering the call target lets statepoint clients get
813 : // away without providing a physical address for the symbolic call target at
814 : // link time.
815 :
816 1 : const auto &TLI = DAG.getTargetLoweringInfo();
817 1 : const auto &DL = DAG.getDataLayout();
818 :
819 1 : unsigned AS = ISP.getCalledValue()->getType()->getPointerAddressSpace();
820 3 : ActualCallee = DAG.getConstant(0, getCurSDLoc(), TLI.getPointerTy(DL, AS));
821 : } else {
822 66 : ActualCallee = getValue(ISP.getCalledValue());
823 : }
824 :
825 134 : StatepointLoweringInfo SI(DAG);
826 134 : populateCallLoweringInfo(SI.CLI, ISP.getCallSite(),
827 : ImmutableStatepoint::CallArgsBeginPos,
828 67 : ISP.getNumCallArgs(), ActualCallee,
829 : ISP.getActualReturnType(), false /* IsPatchPoint */);
830 :
831 200 : for (const GCRelocateInst *Relocate : ISP.getRelocates()) {
832 66 : SI.GCRelocates.push_back(Relocate);
833 66 : SI.Bases.push_back(Relocate->getBasePtr());
834 66 : SI.Ptrs.push_back(Relocate->getDerivedPtr());
835 : }
836 :
837 67 : SI.GCArgs = ArrayRef<const Use>(ISP.gc_args_begin(), ISP.gc_args_end());
838 67 : SI.StatepointInstr = ISP.getInstruction();
839 67 : SI.GCTransitionArgs =
840 : ArrayRef<const Use>(ISP.gc_args_begin(), ISP.gc_args_end());
841 67 : SI.ID = ISP.getID();
842 67 : SI.DeoptState = ArrayRef<const Use>(ISP.deopt_begin(), ISP.deopt_end());
843 67 : SI.StatepointFlags = ISP.getFlags();
844 67 : SI.NumPatchBytes = ISP.getNumPatchBytes();
845 67 : SI.EHPadBB = EHPadBB;
846 :
847 67 : SDValue ReturnValue = LowerAsSTATEPOINT(SI);
848 :
849 : // Export the result value if needed
850 67 : const GCResultInst *GCResult = ISP.getGCResult();
851 67 : Type *RetTy = ISP.getActualReturnType();
852 67 : if (!RetTy->isVoidTy() && GCResult) {
853 48 : if (GCResult->getParent() != ISP.getCallSite().getParent()) {
854 : // Result value will be used in a different basic block so we need to
855 : // export it now. Default exporting mechanism will not work here because
856 : // statepoint call has a different type than the actual call. It means
857 : // that by default llvm will create export register of the wrong type
858 : // (always i32 in our case). So instead we need to create export register
859 : // with correct type manually.
860 : // TODO: To eliminate this problem we can remove gc.result intrinsics
861 : // completely and make statepoint call to return a tuple.
862 2 : unsigned Reg = FuncInfo.CreateRegs(RetTy);
863 4 : RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(),
864 2 : DAG.getDataLayout(), Reg, RetTy,
865 2 : ISP.getCallSite().getCallingConv());
866 2 : SDValue Chain = DAG.getEntryNode();
867 :
868 4 : RFV.getCopyToRegs(ReturnValue, DAG, getCurSDLoc(), Chain, nullptr);
869 2 : PendingExports.push_back(Chain);
870 2 : FuncInfo.ValueMap[ISP.getInstruction()] = Reg;
871 : } else {
872 : // Result value will be used in a same basic block. Don't export it or
873 : // perform any explicit register copies.
874 : // We'll replace the actuall call node shortly. gc_result will grab
875 : // this value.
876 22 : setValue(ISP.getInstruction(), ReturnValue);
877 : }
878 : } else {
879 : // The token value is never used from here on, just generate a poison value
880 129 : setValue(ISP.getInstruction(), DAG.getIntPtrConstant(-1, getCurSDLoc()));
881 : }
882 67 : }
883 :
884 3 : void SelectionDAGBuilder::LowerCallSiteWithDeoptBundleImpl(
885 : ImmutableCallSite CS, SDValue Callee, const BasicBlock *EHPadBB,
886 : bool VarArgDisallowed, bool ForceVoidReturnTy) {
887 6 : StatepointLoweringInfo SI(DAG);
888 3 : unsigned ArgBeginIndex = CS.arg_begin() - CS.getInstruction()->op_begin();
889 6 : populateCallLoweringInfo(
890 : SI.CLI, CS, ArgBeginIndex, CS.getNumArgOperands(), Callee,
891 0 : ForceVoidReturnTy ? Type::getVoidTy(*DAG.getContext()) : CS.getType(),
892 : false);
893 3 : if (!VarArgDisallowed)
894 3 : SI.CLI.IsVarArg = CS.getFunctionType()->isVarArg();
895 :
896 3 : auto DeoptBundle = *CS.getOperandBundle(LLVMContext::OB_deopt);
897 :
898 : unsigned DefaultID = StatepointDirectives::DeoptBundleStatepointID;
899 :
900 3 : auto SD = parseStatepointDirectivesFromAttrs(CS.getAttributes());
901 3 : SI.ID = SD.StatepointID.getValueOr(DefaultID);
902 3 : SI.NumPatchBytes = SD.NumPatchBytes.getValueOr(0);
903 :
904 3 : SI.DeoptState =
905 : ArrayRef<const Use>(DeoptBundle.Inputs.begin(), DeoptBundle.Inputs.end());
906 3 : SI.StatepointFlags = static_cast<uint64_t>(StatepointFlags::None);
907 3 : SI.EHPadBB = EHPadBB;
908 :
909 : // NB! The GC arguments are deliberately left empty.
910 :
911 3 : if (SDValue ReturnVal = LowerAsSTATEPOINT(SI)) {
912 : const Instruction *Inst = CS.getInstruction();
913 0 : ReturnVal = lowerRangeToAssertZExt(DAG, *Inst, ReturnVal);
914 0 : setValue(Inst, ReturnVal);
915 : }
916 3 : }
917 :
918 3 : void SelectionDAGBuilder::LowerCallSiteWithDeoptBundle(
919 : ImmutableCallSite CS, SDValue Callee, const BasicBlock *EHPadBB) {
920 3 : LowerCallSiteWithDeoptBundleImpl(CS, Callee, EHPadBB,
921 : /* VarArgDisallowed = */ false,
922 : /* ForceVoidReturnTy = */ false);
923 3 : }
924 :
925 24 : void SelectionDAGBuilder::visitGCResult(const GCResultInst &CI) {
926 : // The result value of the gc_result is simply the result of the actual
927 : // call. We've already emitted this, so just grab the value.
928 24 : const Instruction *I = CI.getStatepoint();
929 :
930 24 : if (I->getParent() != CI.getParent()) {
931 : // Statepoint is in different basic block so we should have stored call
932 : // result in a virtual register.
933 : // We can not use default getValue() functionality to copy value from this
934 : // register because statepoint and actual call return types can be
935 : // different, and getValue() will use CopyFromReg of the wrong type,
936 : // which is always i32 in our case.
937 2 : PointerType *CalleeType = cast<PointerType>(
938 2 : ImmutableStatepoint(I).getCalledValue()->getType());
939 : Type *RetTy =
940 2 : cast<FunctionType>(CalleeType->getElementType())->getReturnType();
941 2 : SDValue CopyFromReg = getCopyFromRegs(I, RetTy);
942 :
943 : assert(CopyFromReg.getNode());
944 2 : setValue(&CI, CopyFromReg);
945 : } else {
946 22 : setValue(&CI, getValue(I));
947 : }
948 24 : }
949 :
950 66 : void SelectionDAGBuilder::visitGCRelocate(const GCRelocateInst &Relocate) {
951 : #ifndef NDEBUG
952 : // Consistency check
953 : // We skip this check for relocates not in the same basic block as their
954 : // statepoint. It would be too expensive to preserve validation info through
955 : // different basic blocks.
956 : if (Relocate.getStatepoint()->getParent() == Relocate.getParent())
957 : StatepointLowering.relocCallVisited(Relocate);
958 :
959 : auto *Ty = Relocate.getType()->getScalarType();
960 : if (auto IsManaged = GFI->getStrategy().isGCManagedPointer(Ty))
961 : assert(*IsManaged && "Non gc managed pointer relocated!");
962 : #endif
963 :
964 66 : const Value *DerivedPtr = Relocate.getDerivedPtr();
965 66 : SDValue SD = getValue(DerivedPtr);
966 :
967 66 : auto &SpillMap = FuncInfo.StatepointSpillMaps[Relocate.getStatepoint()];
968 66 : auto SlotIt = SpillMap.find(DerivedPtr);
969 : assert(SlotIt != SpillMap.end() && "Relocating not lowered gc value");
970 66 : Optional<int> DerivedPtrLocation = SlotIt->second;
971 :
972 : // We didn't need to spill these special cases (constants and allocas).
973 : // See the handling in spillIncomingValueForStatepoint for detail.
974 66 : if (!DerivedPtrLocation) {
975 8 : setValue(&Relocate, SD);
976 : return;
977 : }
978 :
979 : SDValue SpillSlot =
980 58 : DAG.getTargetFrameIndex(*DerivedPtrLocation, getFrameIndexTy());
981 :
982 : // Be conservative: flush all pending loads
983 : // TODO: Probably we can be less restrictive on this,
984 : // it may allow more scheduling opportunities.
985 58 : SDValue Chain = getRoot();
986 :
987 : SDValue SpillLoad =
988 58 : DAG.getLoad(DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
989 : Relocate.getType()),
990 58 : getCurSDLoc(), Chain, SpillSlot,
991 : MachinePointerInfo::getFixedStack(DAG.getMachineFunction(),
992 116 : *DerivedPtrLocation));
993 :
994 : // Again, be conservative, don't emit pending loads
995 58 : DAG.setRoot(SpillLoad.getValue(1));
996 :
997 : assert(SpillLoad.getNode());
998 58 : setValue(&Relocate, SpillLoad);
999 : }
1000 :
1001 0 : void SelectionDAGBuilder::LowerDeoptimizeCall(const CallInst *CI) {
1002 0 : const auto &TLI = DAG.getTargetLoweringInfo();
1003 : SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(RTLIB::DEOPTIMIZE),
1004 0 : TLI.getPointerTy(DAG.getDataLayout()));
1005 :
1006 : // We don't lower calls to __llvm_deoptimize as varargs, but as a regular
1007 : // call. We also do not lower the return value to any virtual register, and
1008 : // change the immediately following return to a trap instruction.
1009 0 : LowerCallSiteWithDeoptBundleImpl(CI, Callee, /* EHPadBB = */ nullptr,
1010 : /* VarArgDisallowed = */ true,
1011 : /* ForceVoidReturnTy = */ true);
1012 0 : }
1013 :
1014 0 : void SelectionDAGBuilder::LowerDeoptimizingReturn() {
1015 : // We do not lower the return value from llvm.deoptimize to any virtual
1016 : // register, and change the immediately following return to a trap
1017 : // instruction.
1018 0 : if (DAG.getTarget().Options.TrapUnreachable)
1019 : DAG.setRoot(
1020 0 : DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
1021 0 : }
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