xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AMDGPU/GCNRegPressure.cpp (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 //===- GCNRegPressure.cpp -------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file implements the GCNRegPressure class.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "GCNRegPressure.h"
15 #include "AMDGPU.h"
16 #include "llvm/CodeGen/RegisterPressure.h"
17 
18 using namespace llvm;
19 
20 #define DEBUG_TYPE "machine-scheduler"
21 
22 bool llvm::isEqual(const GCNRPTracker::LiveRegSet &S1,
23                    const GCNRPTracker::LiveRegSet &S2) {
24   if (S1.size() != S2.size())
25     return false;
26 
27   for (const auto &P : S1) {
28     auto I = S2.find(P.first);
29     if (I == S2.end() || I->second != P.second)
30       return false;
31   }
32   return true;
33 }
34 
35 ///////////////////////////////////////////////////////////////////////////////
36 // GCNRegPressure
37 
38 unsigned GCNRegPressure::getRegKind(Register Reg,
39                                     const MachineRegisterInfo &MRI) {
40   assert(Reg.isVirtual());
41   const auto RC = MRI.getRegClass(Reg);
42   auto STI = static_cast<const SIRegisterInfo*>(MRI.getTargetRegisterInfo());
43   return STI->isSGPRClass(RC)
44              ? (STI->getRegSizeInBits(*RC) == 32 ? SGPR32 : SGPR_TUPLE)
45          : STI->isAGPRClass(RC)
46              ? (STI->getRegSizeInBits(*RC) == 32 ? AGPR32 : AGPR_TUPLE)
47              : (STI->getRegSizeInBits(*RC) == 32 ? VGPR32 : VGPR_TUPLE);
48 }
49 
50 void GCNRegPressure::inc(unsigned Reg,
51                          LaneBitmask PrevMask,
52                          LaneBitmask NewMask,
53                          const MachineRegisterInfo &MRI) {
54   if (SIRegisterInfo::getNumCoveredRegs(NewMask) ==
55       SIRegisterInfo::getNumCoveredRegs(PrevMask))
56     return;
57 
58   int Sign = 1;
59   if (NewMask < PrevMask) {
60     std::swap(NewMask, PrevMask);
61     Sign = -1;
62   }
63 
64   switch (auto Kind = getRegKind(Reg, MRI)) {
65   case SGPR32:
66   case VGPR32:
67   case AGPR32:
68     Value[Kind] += Sign;
69     break;
70 
71   case SGPR_TUPLE:
72   case VGPR_TUPLE:
73   case AGPR_TUPLE:
74     assert(PrevMask < NewMask);
75 
76     Value[Kind == SGPR_TUPLE ? SGPR32 : Kind == AGPR_TUPLE ? AGPR32 : VGPR32] +=
77       Sign * SIRegisterInfo::getNumCoveredRegs(~PrevMask & NewMask);
78 
79     if (PrevMask.none()) {
80       assert(NewMask.any());
81       const TargetRegisterInfo *TRI = MRI.getTargetRegisterInfo();
82       Value[Kind] +=
83           Sign * TRI->getRegClassWeight(MRI.getRegClass(Reg)).RegWeight;
84     }
85     break;
86 
87   default: llvm_unreachable("Unknown register kind");
88   }
89 }
90 
91 bool GCNRegPressure::less(const GCNSubtarget &ST,
92                           const GCNRegPressure& O,
93                           unsigned MaxOccupancy) const {
94   const auto SGPROcc = std::min(MaxOccupancy,
95                                 ST.getOccupancyWithNumSGPRs(getSGPRNum()));
96   const auto VGPROcc =
97     std::min(MaxOccupancy,
98              ST.getOccupancyWithNumVGPRs(getVGPRNum(ST.hasGFX90AInsts())));
99   const auto OtherSGPROcc = std::min(MaxOccupancy,
100                                 ST.getOccupancyWithNumSGPRs(O.getSGPRNum()));
101   const auto OtherVGPROcc =
102     std::min(MaxOccupancy,
103              ST.getOccupancyWithNumVGPRs(O.getVGPRNum(ST.hasGFX90AInsts())));
104 
105   const auto Occ = std::min(SGPROcc, VGPROcc);
106   const auto OtherOcc = std::min(OtherSGPROcc, OtherVGPROcc);
107   if (Occ != OtherOcc)
108     return Occ > OtherOcc;
109 
110   bool SGPRImportant = SGPROcc < VGPROcc;
111   const bool OtherSGPRImportant = OtherSGPROcc < OtherVGPROcc;
112 
113   // if both pressures disagree on what is more important compare vgprs
114   if (SGPRImportant != OtherSGPRImportant) {
115     SGPRImportant = false;
116   }
117 
118   // compare large regs pressure
119   bool SGPRFirst = SGPRImportant;
120   for (int I = 2; I > 0; --I, SGPRFirst = !SGPRFirst) {
121     if (SGPRFirst) {
122       auto SW = getSGPRTuplesWeight();
123       auto OtherSW = O.getSGPRTuplesWeight();
124       if (SW != OtherSW)
125         return SW < OtherSW;
126     } else {
127       auto VW = getVGPRTuplesWeight();
128       auto OtherVW = O.getVGPRTuplesWeight();
129       if (VW != OtherVW)
130         return VW < OtherVW;
131     }
132   }
133   return SGPRImportant ? (getSGPRNum() < O.getSGPRNum()):
134                          (getVGPRNum(ST.hasGFX90AInsts()) <
135                           O.getVGPRNum(ST.hasGFX90AInsts()));
136 }
137 
138 Printable llvm::print(const GCNRegPressure &RP, const GCNSubtarget *ST) {
139   return Printable([&RP, ST](raw_ostream &OS) {
140     OS << "VGPRs: " << RP.Value[GCNRegPressure::VGPR32] << ' '
141        << "AGPRs: " << RP.getAGPRNum();
142     if (ST)
143       OS << "(O"
144          << ST->getOccupancyWithNumVGPRs(RP.getVGPRNum(ST->hasGFX90AInsts()))
145          << ')';
146     OS << ", SGPRs: " << RP.getSGPRNum();
147     if (ST)
148       OS << "(O" << ST->getOccupancyWithNumSGPRs(RP.getSGPRNum()) << ')';
149     OS << ", LVGPR WT: " << RP.getVGPRTuplesWeight()
150        << ", LSGPR WT: " << RP.getSGPRTuplesWeight();
151     if (ST)
152       OS << " -> Occ: " << RP.getOccupancy(*ST);
153     OS << '\n';
154   });
155 }
156 
157 static LaneBitmask getDefRegMask(const MachineOperand &MO,
158                                  const MachineRegisterInfo &MRI) {
159   assert(MO.isDef() && MO.isReg() && MO.getReg().isVirtual());
160 
161   // We don't rely on read-undef flag because in case of tentative schedule
162   // tracking it isn't set correctly yet. This works correctly however since
163   // use mask has been tracked before using LIS.
164   return MO.getSubReg() == 0 ?
165     MRI.getMaxLaneMaskForVReg(MO.getReg()) :
166     MRI.getTargetRegisterInfo()->getSubRegIndexLaneMask(MO.getSubReg());
167 }
168 
169 static void
170 collectVirtualRegUses(SmallVectorImpl<RegisterMaskPair> &RegMaskPairs,
171                       const MachineInstr &MI, const LiveIntervals &LIS,
172                       const MachineRegisterInfo &MRI) {
173   SlotIndex InstrSI;
174   for (const auto &MO : MI.operands()) {
175     if (!MO.isReg() || !MO.getReg().isVirtual())
176       continue;
177     if (!MO.isUse() || !MO.readsReg())
178       continue;
179 
180     Register Reg = MO.getReg();
181     if (llvm::any_of(RegMaskPairs, [Reg](const RegisterMaskPair &RM) {
182           return RM.RegUnit == Reg;
183         }))
184       continue;
185 
186     LaneBitmask UseMask;
187     auto &LI = LIS.getInterval(Reg);
188     if (!LI.hasSubRanges())
189       UseMask = MRI.getMaxLaneMaskForVReg(Reg);
190     else {
191       // For a tentative schedule LIS isn't updated yet but livemask should
192       // remain the same on any schedule. Subreg defs can be reordered but they
193       // all must dominate uses anyway.
194       if (!InstrSI)
195         InstrSI = LIS.getInstructionIndex(*MO.getParent()).getBaseIndex();
196       UseMask = getLiveLaneMask(LI, InstrSI, MRI);
197     }
198 
199     RegMaskPairs.emplace_back(Reg, UseMask);
200   }
201 }
202 
203 ///////////////////////////////////////////////////////////////////////////////
204 // GCNRPTracker
205 
206 LaneBitmask llvm::getLiveLaneMask(unsigned Reg, SlotIndex SI,
207                                   const LiveIntervals &LIS,
208                                   const MachineRegisterInfo &MRI) {
209   return getLiveLaneMask(LIS.getInterval(Reg), SI, MRI);
210 }
211 
212 LaneBitmask llvm::getLiveLaneMask(const LiveInterval &LI, SlotIndex SI,
213                                   const MachineRegisterInfo &MRI) {
214   LaneBitmask LiveMask;
215   if (LI.hasSubRanges()) {
216     for (const auto &S : LI.subranges())
217       if (S.liveAt(SI)) {
218         LiveMask |= S.LaneMask;
219         assert(LiveMask == (LiveMask & MRI.getMaxLaneMaskForVReg(LI.reg())));
220       }
221   } else if (LI.liveAt(SI)) {
222     LiveMask = MRI.getMaxLaneMaskForVReg(LI.reg());
223   }
224   return LiveMask;
225 }
226 
227 GCNRPTracker::LiveRegSet llvm::getLiveRegs(SlotIndex SI,
228                                            const LiveIntervals &LIS,
229                                            const MachineRegisterInfo &MRI) {
230   GCNRPTracker::LiveRegSet LiveRegs;
231   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
232     auto Reg = Register::index2VirtReg(I);
233     if (!LIS.hasInterval(Reg))
234       continue;
235     auto LiveMask = getLiveLaneMask(Reg, SI, LIS, MRI);
236     if (LiveMask.any())
237       LiveRegs[Reg] = LiveMask;
238   }
239   return LiveRegs;
240 }
241 
242 void GCNRPTracker::reset(const MachineInstr &MI,
243                          const LiveRegSet *LiveRegsCopy,
244                          bool After) {
245   const MachineFunction &MF = *MI.getMF();
246   MRI = &MF.getRegInfo();
247   if (LiveRegsCopy) {
248     if (&LiveRegs != LiveRegsCopy)
249       LiveRegs = *LiveRegsCopy;
250   } else {
251     LiveRegs = After ? getLiveRegsAfter(MI, LIS)
252                      : getLiveRegsBefore(MI, LIS);
253   }
254 
255   MaxPressure = CurPressure = getRegPressure(*MRI, LiveRegs);
256 }
257 
258 ////////////////////////////////////////////////////////////////////////////////
259 // GCNUpwardRPTracker
260 
261 void GCNUpwardRPTracker::reset(const MachineRegisterInfo &MRI_,
262                                const LiveRegSet &LiveRegs_) {
263   MRI = &MRI_;
264   LiveRegs = LiveRegs_;
265   LastTrackedMI = nullptr;
266   MaxPressure = CurPressure = getRegPressure(MRI_, LiveRegs_);
267 }
268 
269 void GCNUpwardRPTracker::recede(const MachineInstr &MI) {
270   assert(MRI && "call reset first");
271 
272   LastTrackedMI = &MI;
273 
274   if (MI.isDebugInstr())
275     return;
276 
277   // Kill all defs.
278   GCNRegPressure DefPressure, ECDefPressure;
279   bool HasECDefs = false;
280   for (const MachineOperand &MO : MI.all_defs()) {
281     if (!MO.getReg().isVirtual())
282       continue;
283 
284     Register Reg = MO.getReg();
285     LaneBitmask DefMask = getDefRegMask(MO, *MRI);
286 
287     // Treat a def as fully live at the moment of definition: keep a record.
288     if (MO.isEarlyClobber()) {
289       ECDefPressure.inc(Reg, LaneBitmask::getNone(), DefMask, *MRI);
290       HasECDefs = true;
291     } else
292       DefPressure.inc(Reg, LaneBitmask::getNone(), DefMask, *MRI);
293 
294     auto I = LiveRegs.find(Reg);
295     if (I == LiveRegs.end())
296       continue;
297 
298     LaneBitmask &LiveMask = I->second;
299     LaneBitmask PrevMask = LiveMask;
300     LiveMask &= ~DefMask;
301     CurPressure.inc(Reg, PrevMask, LiveMask, *MRI);
302     if (LiveMask.none())
303       LiveRegs.erase(I);
304   }
305 
306   // Update MaxPressure with defs pressure.
307   DefPressure += CurPressure;
308   if (HasECDefs)
309     DefPressure += ECDefPressure;
310   MaxPressure = max(DefPressure, MaxPressure);
311 
312   // Make uses alive.
313   SmallVector<RegisterMaskPair, 8> RegUses;
314   collectVirtualRegUses(RegUses, MI, LIS, *MRI);
315   for (const RegisterMaskPair &U : RegUses) {
316     LaneBitmask &LiveMask = LiveRegs[U.RegUnit];
317     LaneBitmask PrevMask = LiveMask;
318     LiveMask |= U.LaneMask;
319     CurPressure.inc(U.RegUnit, PrevMask, LiveMask, *MRI);
320   }
321 
322   // Update MaxPressure with uses plus early-clobber defs pressure.
323   MaxPressure = HasECDefs ? max(CurPressure + ECDefPressure, MaxPressure)
324                           : max(CurPressure, MaxPressure);
325 
326   assert(CurPressure == getRegPressure(*MRI, LiveRegs));
327 }
328 
329 ////////////////////////////////////////////////////////////////////////////////
330 // GCNDownwardRPTracker
331 
332 bool GCNDownwardRPTracker::reset(const MachineInstr &MI,
333                                  const LiveRegSet *LiveRegsCopy) {
334   MRI = &MI.getParent()->getParent()->getRegInfo();
335   LastTrackedMI = nullptr;
336   MBBEnd = MI.getParent()->end();
337   NextMI = &MI;
338   NextMI = skipDebugInstructionsForward(NextMI, MBBEnd);
339   if (NextMI == MBBEnd)
340     return false;
341   GCNRPTracker::reset(*NextMI, LiveRegsCopy, false);
342   return true;
343 }
344 
345 bool GCNDownwardRPTracker::advanceBeforeNext() {
346   assert(MRI && "call reset first");
347   if (!LastTrackedMI)
348     return NextMI == MBBEnd;
349 
350   assert(NextMI == MBBEnd || !NextMI->isDebugInstr());
351 
352   SlotIndex SI = NextMI == MBBEnd
353                      ? LIS.getInstructionIndex(*LastTrackedMI).getDeadSlot()
354                      : LIS.getInstructionIndex(*NextMI).getBaseIndex();
355   assert(SI.isValid());
356 
357   // Remove dead registers or mask bits.
358   SmallSet<Register, 8> SeenRegs;
359   for (auto &MO : LastTrackedMI->operands()) {
360     if (!MO.isReg() || !MO.getReg().isVirtual())
361       continue;
362     if (MO.isUse() && !MO.readsReg())
363       continue;
364     if (!SeenRegs.insert(MO.getReg()).second)
365       continue;
366     const LiveInterval &LI = LIS.getInterval(MO.getReg());
367     if (LI.hasSubRanges()) {
368       auto It = LiveRegs.end();
369       for (const auto &S : LI.subranges()) {
370         if (!S.liveAt(SI)) {
371           if (It == LiveRegs.end()) {
372             It = LiveRegs.find(MO.getReg());
373             if (It == LiveRegs.end())
374               llvm_unreachable("register isn't live");
375           }
376           auto PrevMask = It->second;
377           It->second &= ~S.LaneMask;
378           CurPressure.inc(MO.getReg(), PrevMask, It->second, *MRI);
379         }
380       }
381       if (It != LiveRegs.end() && It->second.none())
382         LiveRegs.erase(It);
383     } else if (!LI.liveAt(SI)) {
384       auto It = LiveRegs.find(MO.getReg());
385       if (It == LiveRegs.end())
386         llvm_unreachable("register isn't live");
387       CurPressure.inc(MO.getReg(), It->second, LaneBitmask::getNone(), *MRI);
388       LiveRegs.erase(It);
389     }
390   }
391 
392   MaxPressure = max(MaxPressure, CurPressure);
393 
394   LastTrackedMI = nullptr;
395 
396   return NextMI == MBBEnd;
397 }
398 
399 void GCNDownwardRPTracker::advanceToNext() {
400   LastTrackedMI = &*NextMI++;
401   NextMI = skipDebugInstructionsForward(NextMI, MBBEnd);
402 
403   // Add new registers or mask bits.
404   for (const auto &MO : LastTrackedMI->all_defs()) {
405     Register Reg = MO.getReg();
406     if (!Reg.isVirtual())
407       continue;
408     auto &LiveMask = LiveRegs[Reg];
409     auto PrevMask = LiveMask;
410     LiveMask |= getDefRegMask(MO, *MRI);
411     CurPressure.inc(Reg, PrevMask, LiveMask, *MRI);
412   }
413 
414   MaxPressure = max(MaxPressure, CurPressure);
415 }
416 
417 bool GCNDownwardRPTracker::advance() {
418   if (NextMI == MBBEnd)
419     return false;
420   advanceBeforeNext();
421   advanceToNext();
422   return true;
423 }
424 
425 bool GCNDownwardRPTracker::advance(MachineBasicBlock::const_iterator End) {
426   while (NextMI != End)
427     if (!advance()) return false;
428   return true;
429 }
430 
431 bool GCNDownwardRPTracker::advance(MachineBasicBlock::const_iterator Begin,
432                                    MachineBasicBlock::const_iterator End,
433                                    const LiveRegSet *LiveRegsCopy) {
434   reset(*Begin, LiveRegsCopy);
435   return advance(End);
436 }
437 
438 Printable llvm::reportMismatch(const GCNRPTracker::LiveRegSet &LISLR,
439                                const GCNRPTracker::LiveRegSet &TrackedLR,
440                                const TargetRegisterInfo *TRI, StringRef Pfx) {
441   return Printable([&LISLR, &TrackedLR, TRI, Pfx](raw_ostream &OS) {
442     for (auto const &P : TrackedLR) {
443       auto I = LISLR.find(P.first);
444       if (I == LISLR.end()) {
445         OS << Pfx << printReg(P.first, TRI) << ":L" << PrintLaneMask(P.second)
446            << " isn't found in LIS reported set\n";
447       } else if (I->second != P.second) {
448         OS << Pfx << printReg(P.first, TRI)
449            << " masks doesn't match: LIS reported " << PrintLaneMask(I->second)
450            << ", tracked " << PrintLaneMask(P.second) << '\n';
451       }
452     }
453     for (auto const &P : LISLR) {
454       auto I = TrackedLR.find(P.first);
455       if (I == TrackedLR.end()) {
456         OS << Pfx << printReg(P.first, TRI) << ":L" << PrintLaneMask(P.second)
457            << " isn't found in tracked set\n";
458       }
459     }
460   });
461 }
462 
463 bool GCNUpwardRPTracker::isValid() const {
464   const auto &SI = LIS.getInstructionIndex(*LastTrackedMI).getBaseIndex();
465   const auto LISLR = llvm::getLiveRegs(SI, LIS, *MRI);
466   const auto &TrackedLR = LiveRegs;
467 
468   if (!isEqual(LISLR, TrackedLR)) {
469     dbgs() << "\nGCNUpwardRPTracker error: Tracked and"
470               " LIS reported livesets mismatch:\n"
471            << print(LISLR, *MRI);
472     reportMismatch(LISLR, TrackedLR, MRI->getTargetRegisterInfo());
473     return false;
474   }
475 
476   auto LISPressure = getRegPressure(*MRI, LISLR);
477   if (LISPressure != CurPressure) {
478     dbgs() << "GCNUpwardRPTracker error: Pressure sets different\nTracked: "
479            << print(CurPressure) << "LIS rpt: " << print(LISPressure);
480     return false;
481   }
482   return true;
483 }
484 
485 Printable llvm::print(const GCNRPTracker::LiveRegSet &LiveRegs,
486                       const MachineRegisterInfo &MRI) {
487   return Printable([&LiveRegs, &MRI](raw_ostream &OS) {
488     const TargetRegisterInfo *TRI = MRI.getTargetRegisterInfo();
489     for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
490       Register Reg = Register::index2VirtReg(I);
491       auto It = LiveRegs.find(Reg);
492       if (It != LiveRegs.end() && It->second.any())
493         OS << ' ' << printVRegOrUnit(Reg, TRI) << ':'
494            << PrintLaneMask(It->second);
495     }
496     OS << '\n';
497   });
498 }
499 
500 void GCNRegPressure::dump() const { dbgs() << print(*this); }
501 
502 static cl::opt<bool> UseDownwardTracker(
503     "amdgpu-print-rp-downward",
504     cl::desc("Use GCNDownwardRPTracker for GCNRegPressurePrinter pass"),
505     cl::init(false), cl::Hidden);
506 
507 char llvm::GCNRegPressurePrinter::ID = 0;
508 char &llvm::GCNRegPressurePrinterID = GCNRegPressurePrinter::ID;
509 
510 INITIALIZE_PASS(GCNRegPressurePrinter, "amdgpu-print-rp", "", true, true)
511 
512 // Return lanemask of Reg's subregs that are live-through at [Begin, End] and
513 // are fully covered by Mask.
514 static LaneBitmask
515 getRegLiveThroughMask(const MachineRegisterInfo &MRI, const LiveIntervals &LIS,
516                       Register Reg, SlotIndex Begin, SlotIndex End,
517                       LaneBitmask Mask = LaneBitmask::getAll()) {
518 
519   auto IsInOneSegment = [Begin, End](const LiveRange &LR) -> bool {
520     auto *Segment = LR.getSegmentContaining(Begin);
521     return Segment && Segment->contains(End);
522   };
523 
524   LaneBitmask LiveThroughMask;
525   const LiveInterval &LI = LIS.getInterval(Reg);
526   if (LI.hasSubRanges()) {
527     for (auto &SR : LI.subranges()) {
528       if ((SR.LaneMask & Mask) == SR.LaneMask && IsInOneSegment(SR))
529         LiveThroughMask |= SR.LaneMask;
530     }
531   } else {
532     LaneBitmask RegMask = MRI.getMaxLaneMaskForVReg(Reg);
533     if ((RegMask & Mask) == RegMask && IsInOneSegment(LI))
534       LiveThroughMask = RegMask;
535   }
536 
537   return LiveThroughMask;
538 }
539 
540 bool GCNRegPressurePrinter::runOnMachineFunction(MachineFunction &MF) {
541   const MachineRegisterInfo &MRI = MF.getRegInfo();
542   const TargetRegisterInfo *TRI = MRI.getTargetRegisterInfo();
543   const LiveIntervals &LIS = getAnalysis<LiveIntervals>();
544 
545   auto &OS = dbgs();
546 
547 // Leading spaces are important for YAML syntax.
548 #define PFX "  "
549 
550   OS << "---\nname: " << MF.getName() << "\nbody:             |\n";
551 
552   auto printRP = [](const GCNRegPressure &RP) {
553     return Printable([&RP](raw_ostream &OS) {
554       OS << format(PFX "  %-5d", RP.getSGPRNum())
555          << format(" %-5d", RP.getVGPRNum(false));
556     });
557   };
558 
559   auto ReportLISMismatchIfAny = [&](const GCNRPTracker::LiveRegSet &TrackedLR,
560                                     const GCNRPTracker::LiveRegSet &LISLR) {
561     if (LISLR != TrackedLR) {
562       OS << PFX "  mis LIS: " << llvm::print(LISLR, MRI)
563          << reportMismatch(LISLR, TrackedLR, TRI, PFX "    ");
564     }
565   };
566 
567   // Register pressure before and at an instruction (in program order).
568   SmallVector<std::pair<GCNRegPressure, GCNRegPressure>, 16> RP;
569 
570   for (auto &MBB : MF) {
571     RP.clear();
572     RP.reserve(MBB.size());
573 
574     OS << PFX;
575     MBB.printName(OS);
576     OS << ":\n";
577 
578     SlotIndex MBBStartSlot = LIS.getSlotIndexes()->getMBBStartIdx(&MBB);
579     SlotIndex MBBEndSlot = LIS.getSlotIndexes()->getMBBEndIdx(&MBB);
580 
581     GCNRPTracker::LiveRegSet LiveIn, LiveOut;
582     GCNRegPressure RPAtMBBEnd;
583 
584     if (UseDownwardTracker) {
585       if (MBB.empty()) {
586         LiveIn = LiveOut = getLiveRegs(MBBStartSlot, LIS, MRI);
587         RPAtMBBEnd = getRegPressure(MRI, LiveIn);
588       } else {
589         GCNDownwardRPTracker RPT(LIS);
590         RPT.reset(MBB.front());
591 
592         LiveIn = RPT.getLiveRegs();
593 
594         while (!RPT.advanceBeforeNext()) {
595           GCNRegPressure RPBeforeMI = RPT.getPressure();
596           RPT.advanceToNext();
597           RP.emplace_back(RPBeforeMI, RPT.getPressure());
598         }
599 
600         LiveOut = RPT.getLiveRegs();
601         RPAtMBBEnd = RPT.getPressure();
602       }
603     } else {
604       GCNUpwardRPTracker RPT(LIS);
605       RPT.reset(MRI, MBBEndSlot);
606 
607       LiveOut = RPT.getLiveRegs();
608       RPAtMBBEnd = RPT.getPressure();
609 
610       for (auto &MI : reverse(MBB)) {
611         RPT.resetMaxPressure();
612         RPT.recede(MI);
613         if (!MI.isDebugInstr())
614           RP.emplace_back(RPT.getPressure(), RPT.getMaxPressure());
615       }
616 
617       LiveIn = RPT.getLiveRegs();
618     }
619 
620     OS << PFX "  Live-in: " << llvm::print(LiveIn, MRI);
621     if (!UseDownwardTracker)
622       ReportLISMismatchIfAny(LiveIn, getLiveRegs(MBBStartSlot, LIS, MRI));
623 
624     OS << PFX "  SGPR  VGPR\n";
625     int I = 0;
626     for (auto &MI : MBB) {
627       if (!MI.isDebugInstr()) {
628         auto &[RPBeforeInstr, RPAtInstr] =
629             RP[UseDownwardTracker ? I : (RP.size() - 1 - I)];
630         ++I;
631         OS << printRP(RPBeforeInstr) << '\n' << printRP(RPAtInstr) << "  ";
632       } else
633         OS << PFX "               ";
634       MI.print(OS);
635     }
636     OS << printRP(RPAtMBBEnd) << '\n';
637 
638     OS << PFX "  Live-out:" << llvm::print(LiveOut, MRI);
639     if (UseDownwardTracker)
640       ReportLISMismatchIfAny(LiveOut, getLiveRegs(MBBEndSlot, LIS, MRI));
641 
642     GCNRPTracker::LiveRegSet LiveThrough;
643     for (auto [Reg, Mask] : LiveIn) {
644       LaneBitmask MaskIntersection = Mask & LiveOut.lookup(Reg);
645       if (MaskIntersection.any()) {
646         LaneBitmask LTMask = getRegLiveThroughMask(
647             MRI, LIS, Reg, MBBStartSlot, MBBEndSlot, MaskIntersection);
648         if (LTMask.any())
649           LiveThrough[Reg] = LTMask;
650       }
651     }
652     OS << PFX "  Live-thr:" << llvm::print(LiveThrough, MRI);
653     OS << printRP(getRegPressure(MRI, LiveThrough)) << '\n';
654   }
655   OS << "...\n";
656   return false;
657 
658 #undef PFX
659 }