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Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +00001//===---------- SplitKit.cpp - Toolkit for splitting live ranges ----------===//
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 contains the SplitAnalysis class as well as mutator functions for
11// live range splitting.
12//
13//===----------------------------------------------------------------------===//
14
Jakob Stoklund Olesen376dcbd2010-11-03 20:39:23 +000015#define DEBUG_TYPE "regalloc"
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000016#include "SplitKit.h"
Jakob Stoklund Olesena17768f2010-10-14 23:49:52 +000017#include "LiveRangeEdit.h"
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +000018#include "VirtRegMap.h"
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +000019#include "llvm/ADT/Statistic.h"
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000020#include "llvm/CodeGen/LiveIntervalAnalysis.h"
Jakob Stoklund Olesend68f4582010-10-28 20:34:50 +000021#include "llvm/CodeGen/MachineDominators.h"
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +000022#include "llvm/CodeGen/MachineInstrBuilder.h"
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000023#include "llvm/CodeGen/MachineRegisterInfo.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/raw_ostream.h"
Jakob Stoklund Olesen6a0dc072010-07-20 21:46:58 +000026#include "llvm/Target/TargetInstrInfo.h"
27#include "llvm/Target/TargetMachine.h"
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000028
29using namespace llvm;
30
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +000031STATISTIC(NumFinished, "Number of splits finished");
32STATISTIC(NumSimple, "Number of splits that were simple");
Jakob Stoklund Olesene9bd4ea2011-05-05 17:22:53 +000033STATISTIC(NumCopies, "Number of copies inserted for splitting");
34STATISTIC(NumRemats, "Number of rematerialized defs for splitting");
Jakob Stoklund Olesenbdda37d2011-05-10 17:37:41 +000035STATISTIC(NumRepairs, "Number of invalid live ranges repaired");
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +000036
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000037//===----------------------------------------------------------------------===//
38// Split Analysis
39//===----------------------------------------------------------------------===//
40
Jakob Stoklund Olesen1b847de2011-02-19 00:53:42 +000041SplitAnalysis::SplitAnalysis(const VirtRegMap &vrm,
Jakob Stoklund Olesenf2c6e362010-07-20 23:50:15 +000042 const LiveIntervals &lis,
43 const MachineLoopInfo &mli)
Jakob Stoklund Olesen1b847de2011-02-19 00:53:42 +000044 : MF(vrm.getMachineFunction()),
45 VRM(vrm),
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +000046 LIS(lis),
47 Loops(mli),
Jakob Stoklund Olesen1b847de2011-02-19 00:53:42 +000048 TII(*MF.getTarget().getInstrInfo()),
Jakob Stoklund Olesen1a774452011-04-05 04:20:27 +000049 CurLI(0),
50 LastSplitPoint(MF.getNumBlockIDs()) {}
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000051
52void SplitAnalysis::clear() {
Jakob Stoklund Olesenb5fa9332011-01-18 21:13:27 +000053 UseSlots.clear();
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +000054 UseBlocks.clear();
55 ThroughBlocks.clear();
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +000056 CurLI = 0;
Jakob Stoklund Olesen7d6b6a02011-05-03 20:42:13 +000057 DidRepairRange = false;
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +000058}
59
Jakob Stoklund Olesen1a774452011-04-05 04:20:27 +000060SlotIndex SplitAnalysis::computeLastSplitPoint(unsigned Num) {
61 const MachineBasicBlock *MBB = MF.getBlockNumbered(Num);
62 const MachineBasicBlock *LPad = MBB->getLandingPadSuccessor();
63 std::pair<SlotIndex, SlotIndex> &LSP = LastSplitPoint[Num];
64
65 // Compute split points on the first call. The pair is independent of the
66 // current live interval.
67 if (!LSP.first.isValid()) {
68 MachineBasicBlock::const_iterator FirstTerm = MBB->getFirstTerminator();
69 if (FirstTerm == MBB->end())
70 LSP.first = LIS.getMBBEndIdx(MBB);
71 else
72 LSP.first = LIS.getInstructionIndex(FirstTerm);
73
74 // If there is a landing pad successor, also find the call instruction.
75 if (!LPad)
76 return LSP.first;
77 // There may not be a call instruction (?) in which case we ignore LPad.
78 LSP.second = LSP.first;
Jakob Stoklund Olesen1e0bd632011-06-28 01:18:58 +000079 for (MachineBasicBlock::const_iterator I = MBB->end(), E = MBB->begin();
80 I != E;) {
81 --I;
Jakob Stoklund Olesen1a774452011-04-05 04:20:27 +000082 if (I->getDesc().isCall()) {
83 LSP.second = LIS.getInstructionIndex(I);
84 break;
85 }
Jakob Stoklund Olesen1e0bd632011-06-28 01:18:58 +000086 }
Jakob Stoklund Olesen1a774452011-04-05 04:20:27 +000087 }
88
89 // If CurLI is live into a landing pad successor, move the last split point
90 // back to the call that may throw.
Jakob Stoklund Olesen71d9e652011-04-05 23:43:16 +000091 if (LPad && LSP.second.isValid() && LIS.isLiveInToMBB(*CurLI, LPad))
Jakob Stoklund Olesen1a774452011-04-05 04:20:27 +000092 return LSP.second;
93 else
94 return LSP.first;
Jakob Stoklund Olesen6a0dc072010-07-20 21:46:58 +000095}
96
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +000097/// analyzeUses - Count instructions, basic blocks, and loops using CurLI.
Jakob Stoklund Olesenabff2802010-07-20 16:12:37 +000098void SplitAnalysis::analyzeUses() {
Jakob Stoklund Olesena2948ef2011-04-05 15:18:18 +000099 assert(UseSlots.empty() && "Call clear first");
100
101 // First get all the defs from the interval values. This provides the correct
102 // slots for early clobbers.
103 for (LiveInterval::const_vni_iterator I = CurLI->vni_begin(),
104 E = CurLI->vni_end(); I != E; ++I)
105 if (!(*I)->isPHIDef() && !(*I)->isUnused())
106 UseSlots.push_back((*I)->def);
107
108 // Get use slots form the use-def chain.
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000109 const MachineRegisterInfo &MRI = MF.getRegInfo();
Jakob Stoklund Olesena2948ef2011-04-05 15:18:18 +0000110 for (MachineRegisterInfo::use_nodbg_iterator
111 I = MRI.use_nodbg_begin(CurLI->reg), E = MRI.use_nodbg_end(); I != E;
112 ++I)
113 if (!I.getOperand().isUndef())
114 UseSlots.push_back(LIS.getInstructionIndex(&*I).getDefIndex());
115
Jakob Stoklund Olesenb5fa9332011-01-18 21:13:27 +0000116 array_pod_sort(UseSlots.begin(), UseSlots.end());
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000117
Jakob Stoklund Olesena2948ef2011-04-05 15:18:18 +0000118 // Remove duplicates, keeping the smaller slot for each instruction.
119 // That is what we want for early clobbers.
120 UseSlots.erase(std::unique(UseSlots.begin(), UseSlots.end(),
121 SlotIndex::isSameInstr),
122 UseSlots.end());
123
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000124 // Compute per-live block info.
125 if (!calcLiveBlockInfo()) {
126 // FIXME: calcLiveBlockInfo found inconsistencies in the live range.
Rafael Espindola5b220212011-06-26 22:34:10 +0000127 // I am looking at you, RegisterCoalescer!
Jakob Stoklund Olesen7d6b6a02011-05-03 20:42:13 +0000128 DidRepairRange = true;
Jakob Stoklund Olesenbdda37d2011-05-10 17:37:41 +0000129 ++NumRepairs;
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000130 DEBUG(dbgs() << "*** Fixing inconsistent live interval! ***\n");
131 const_cast<LiveIntervals&>(LIS)
132 .shrinkToUses(const_cast<LiveInterval*>(CurLI));
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +0000133 UseBlocks.clear();
134 ThroughBlocks.clear();
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000135 bool fixed = calcLiveBlockInfo();
136 (void)fixed;
137 assert(fixed && "Couldn't fix broken live interval");
138 }
139
Jakob Stoklund Olesenef1f5cc2011-03-27 22:49:23 +0000140 DEBUG(dbgs() << "Analyze counted "
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +0000141 << UseSlots.size() << " instrs in "
142 << UseBlocks.size() << " blocks, through "
Jakob Stoklund Olesenf4afdfc2011-04-09 02:59:09 +0000143 << NumThroughBlocks << " blocks.\n");
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +0000144}
145
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000146/// calcLiveBlockInfo - Fill the LiveBlocks array with information about blocks
147/// where CurLI is live.
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000148bool SplitAnalysis::calcLiveBlockInfo() {
Jakob Stoklund Olesenf4afdfc2011-04-09 02:59:09 +0000149 ThroughBlocks.resize(MF.getNumBlockIDs());
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000150 NumThroughBlocks = NumGapBlocks = 0;
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000151 if (CurLI->empty())
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000152 return true;
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000153
154 LiveInterval::const_iterator LVI = CurLI->begin();
155 LiveInterval::const_iterator LVE = CurLI->end();
156
157 SmallVectorImpl<SlotIndex>::const_iterator UseI, UseE;
158 UseI = UseSlots.begin();
159 UseE = UseSlots.end();
160
161 // Loop over basic blocks where CurLI is live.
162 MachineFunction::iterator MFI = LIS.getMBBFromIndex(LVI->start);
163 for (;;) {
164 BlockInfo BI;
165 BI.MBB = MFI;
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000166 SlotIndex Start, Stop;
167 tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB);
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000168
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000169 // If the block contains no uses, the range must be live through. At one
Rafael Espindola5b220212011-06-26 22:34:10 +0000170 // point, RegisterCoalescer could create dangling ranges that ended
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000171 // mid-block.
172 if (UseI == UseE || *UseI >= Stop) {
173 ++NumThroughBlocks;
174 ThroughBlocks.set(BI.MBB->getNumber());
175 // The range shouldn't end mid-block if there are no uses. This shouldn't
176 // happen.
177 if (LVI->end < Stop)
178 return false;
179 } else {
180 // This block has uses. Find the first and last uses in the block.
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000181 BI.FirstUse = *UseI;
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000182 assert(BI.FirstUse >= Start);
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000183 do ++UseI;
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000184 while (UseI != UseE && *UseI < Stop);
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000185 BI.LastUse = UseI[-1];
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000186 assert(BI.LastUse < Stop);
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000187
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000188 // LVI is the first live segment overlapping MBB.
189 BI.LiveIn = LVI->start <= Start;
Jakob Stoklund Olesen626d6fb2011-05-29 21:24:39 +0000190
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000191 // Look for gaps in the live range.
192 BI.LiveOut = true;
193 while (LVI->end < Stop) {
194 SlotIndex LastStop = LVI->end;
195 if (++LVI == LVE || LVI->start >= Stop) {
196 BI.LiveOut = false;
197 BI.LastUse = LastStop;
198 break;
199 }
200 if (LastStop < LVI->start) {
201 // There is a gap in the live range. Create duplicate entries for the
202 // live-in snippet and the live-out snippet.
203 ++NumGapBlocks;
204
205 // Push the Live-in part.
206 BI.LiveThrough = false;
207 BI.LiveOut = false;
208 UseBlocks.push_back(BI);
209 UseBlocks.back().LastUse = LastStop;
210
211 // Set up BI for the live-out part.
212 BI.LiveIn = false;
213 BI.LiveOut = true;
214 BI.FirstUse = LVI->start;
215 }
216 }
217
218 // Don't set LiveThrough when the block has a gap.
219 BI.LiveThrough = BI.LiveIn && BI.LiveOut;
Jakob Stoklund Olesen626d6fb2011-05-29 21:24:39 +0000220 UseBlocks.push_back(BI);
Jakob Stoklund Olesen626d6fb2011-05-29 21:24:39 +0000221
Jakob Stoklund Olesena2e79ef2011-05-30 01:33:26 +0000222 // LVI is now at LVE or LVI->end >= Stop.
223 if (LVI == LVE)
224 break;
225 }
Jakob Stoklund Olesen626d6fb2011-05-29 21:24:39 +0000226
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000227 // Live segment ends exactly at Stop. Move to the next segment.
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000228 if (LVI->end == Stop && ++LVI == LVE)
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000229 break;
230
231 // Pick the next basic block.
Jakob Stoklund Olesen6c8afd72011-04-04 15:32:15 +0000232 if (LVI->start < Stop)
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000233 ++MFI;
234 else
235 MFI = LIS.getMBBFromIndex(LVI->start);
236 }
Jakob Stoklund Olesenb2abfa02011-05-28 02:32:57 +0000237
238 assert(getNumLiveBlocks() == countLiveBlocks(CurLI) && "Bad block count");
Jakob Stoklund Olesen2b0f9e72011-03-05 18:33:49 +0000239 return true;
Jakob Stoklund Olesenf0ac26c2011-02-09 22:50:26 +0000240}
241
Jakob Stoklund Olesen9f4b8932011-04-26 22:33:12 +0000242unsigned SplitAnalysis::countLiveBlocks(const LiveInterval *cli) const {
243 if (cli->empty())
244 return 0;
245 LiveInterval *li = const_cast<LiveInterval*>(cli);
246 LiveInterval::iterator LVI = li->begin();
247 LiveInterval::iterator LVE = li->end();
248 unsigned Count = 0;
249
250 // Loop over basic blocks where li is live.
251 MachineFunction::const_iterator MFI = LIS.getMBBFromIndex(LVI->start);
252 SlotIndex Stop = LIS.getMBBEndIdx(MFI);
253 for (;;) {
254 ++Count;
255 LVI = li->advanceTo(LVI, Stop);
256 if (LVI == LVE)
257 return Count;
258 do {
259 ++MFI;
260 Stop = LIS.getMBBEndIdx(MFI);
261 } while (Stop <= LVI->start);
262 }
263}
264
Jakob Stoklund Olesen06c0f252011-02-21 23:09:46 +0000265bool SplitAnalysis::isOriginalEndpoint(SlotIndex Idx) const {
266 unsigned OrigReg = VRM.getOriginal(CurLI->reg);
267 const LiveInterval &Orig = LIS.getInterval(OrigReg);
268 assert(!Orig.empty() && "Splitting empty interval?");
269 LiveInterval::const_iterator I = Orig.find(Idx);
270
271 // Range containing Idx should begin at Idx.
272 if (I != Orig.end() && I->start <= Idx)
273 return I->start == Idx;
274
275 // Range does not contain Idx, previous must end at Idx.
276 return I != Orig.begin() && (--I)->end == Idx;
277}
278
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +0000279void SplitAnalysis::analyze(const LiveInterval *li) {
280 clear();
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000281 CurLI = li;
Jakob Stoklund Olesenabff2802010-07-20 16:12:37 +0000282 analyzeUses();
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +0000283}
284
Jakob Stoklund Olesen697483a2010-12-15 17:49:52 +0000285
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000286//===----------------------------------------------------------------------===//
287// Split Editor
288//===----------------------------------------------------------------------===//
289
290/// Create a new SplitEditor for editing the LiveInterval analyzed by SA.
Jakob Stoklund Olesend68f4582010-10-28 20:34:50 +0000291SplitEditor::SplitEditor(SplitAnalysis &sa,
292 LiveIntervals &lis,
293 VirtRegMap &vrm,
Jakob Stoklund Olesenbece06f2011-03-03 01:29:13 +0000294 MachineDominatorTree &mdt)
Jakob Stoklund Olesen0eeca442011-02-19 00:42:33 +0000295 : SA(sa), LIS(lis), VRM(vrm),
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000296 MRI(vrm.getMachineFunction().getRegInfo()),
Eric Christopher0f438112011-02-03 06:18:29 +0000297 MDT(mdt),
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000298 TII(*vrm.getMachineFunction().getTarget().getInstrInfo()),
299 TRI(*vrm.getMachineFunction().getTarget().getRegisterInfo()),
Jakob Stoklund Olesenbece06f2011-03-03 01:29:13 +0000300 Edit(0),
Eric Christopher0f438112011-02-03 06:18:29 +0000301 OpenIdx(0),
302 RegAssign(Allocator)
Jakob Stoklund Olesenbece06f2011-03-03 01:29:13 +0000303{}
304
305void SplitEditor::reset(LiveRangeEdit &lre) {
306 Edit = &lre;
307 OpenIdx = 0;
308 RegAssign.clear();
309 Values.clear();
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000310
311 // We don't need to clear LiveOutCache, only LiveOutSeen entries are read.
312 LiveOutSeen.clear();
Jakob Stoklund Olesenbece06f2011-03-03 01:29:13 +0000313
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000314 // We don't need an AliasAnalysis since we will only be performing
315 // cheap-as-a-copy remats anyway.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000316 Edit->anyRematerializable(LIS, TII, 0);
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000317}
318
Eric Christopher0f438112011-02-03 06:18:29 +0000319void SplitEditor::dump() const {
320 if (RegAssign.empty()) {
321 dbgs() << " empty\n";
322 return;
323 }
324
325 for (RegAssignMap::const_iterator I = RegAssign.begin(); I.valid(); ++I)
326 dbgs() << " [" << I.start() << ';' << I.stop() << "):" << I.value();
327 dbgs() << '\n';
Jakob Stoklund Olesen5fa42a42010-09-21 22:32:21 +0000328}
329
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +0000330VNInfo *SplitEditor::defValue(unsigned RegIdx,
331 const VNInfo *ParentVNI,
332 SlotIndex Idx) {
333 assert(ParentVNI && "Mapping NULL value");
334 assert(Idx.isValid() && "Invalid SlotIndex");
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000335 assert(Edit->getParent().getVNInfoAt(Idx) == ParentVNI && "Bad Parent VNI");
336 LiveInterval *LI = Edit->get(RegIdx);
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +0000337
338 // Create a new value.
339 VNInfo *VNI = LI->getNextValue(Idx, 0, LIS.getVNInfoAllocator());
340
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +0000341 // Use insert for lookup, so we can add missing values with a second lookup.
342 std::pair<ValueMap::iterator, bool> InsP =
343 Values.insert(std::make_pair(std::make_pair(RegIdx, ParentVNI->id), VNI));
344
345 // This was the first time (RegIdx, ParentVNI) was mapped.
346 // Keep it as a simple def without any liveness.
347 if (InsP.second)
348 return VNI;
349
350 // If the previous value was a simple mapping, add liveness for it now.
351 if (VNInfo *OldVNI = InsP.first->second) {
352 SlotIndex Def = OldVNI->def;
353 LI->addRange(LiveRange(Def, Def.getNextSlot(), OldVNI));
354 // No longer a simple mapping.
355 InsP.first->second = 0;
356 }
357
358 // This is a complex mapping, add liveness for VNI
359 SlotIndex Def = VNI->def;
360 LI->addRange(LiveRange(Def, Def.getNextSlot(), VNI));
361
362 return VNI;
363}
364
365void SplitEditor::markComplexMapped(unsigned RegIdx, const VNInfo *ParentVNI) {
366 assert(ParentVNI && "Mapping NULL value");
367 VNInfo *&VNI = Values[std::make_pair(RegIdx, ParentVNI->id)];
368
369 // ParentVNI was either unmapped or already complex mapped. Either way.
370 if (!VNI)
371 return;
372
373 // This was previously a single mapping. Make sure the old def is represented
374 // by a trivial live range.
375 SlotIndex Def = VNI->def;
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000376 Edit->get(RegIdx)->addRange(LiveRange(Def, Def.getNextSlot(), VNI));
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +0000377 VNI = 0;
378}
379
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000380// extendRange - Extend the live range to reach Idx.
381// Potentially create phi-def values.
382void SplitEditor::extendRange(unsigned RegIdx, SlotIndex Idx) {
383 assert(Idx.isValid() && "Invalid SlotIndex");
384 MachineBasicBlock *IdxMBB = LIS.getMBBFromIndex(Idx);
385 assert(IdxMBB && "No MBB at Idx");
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000386 LiveInterval *LI = Edit->get(RegIdx);
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000387
388 // Is there a def in the same MBB we can extend?
389 if (LI->extendInBlock(LIS.getMBBStartIdx(IdxMBB), Idx))
390 return;
391
392 // Now for the fun part. We know that ParentVNI potentially has multiple defs,
393 // and we may need to create even more phi-defs to preserve VNInfo SSA form.
394 // Perform a search for all predecessor blocks where we know the dominating
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000395 // VNInfo.
396 VNInfo *VNI = findReachingDefs(LI, IdxMBB, Idx.getNextSlot());
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000397
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000398 // When there were multiple different values, we may need new PHIs.
399 if (!VNI)
400 return updateSSA();
401
402 // Poor man's SSA update for the single-value case.
403 LiveOutPair LOP(VNI, MDT[LIS.getMBBFromIndex(VNI->def)]);
404 for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
405 E = LiveInBlocks.end(); I != E; ++I) {
406 MachineBasicBlock *MBB = I->DomNode->getBlock();
407 SlotIndex Start = LIS.getMBBStartIdx(MBB);
408 if (I->Kill.isValid())
409 LI->addRange(LiveRange(Start, I->Kill, VNI));
410 else {
411 LiveOutCache[MBB] = LOP;
412 LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI));
413 }
414 }
415}
416
417/// findReachingDefs - Search the CFG for known live-out values.
418/// Add required live-in blocks to LiveInBlocks.
419VNInfo *SplitEditor::findReachingDefs(LiveInterval *LI,
420 MachineBasicBlock *KillMBB,
421 SlotIndex Kill) {
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000422 // Initialize the live-out cache the first time it is needed.
423 if (LiveOutSeen.empty()) {
424 unsigned N = VRM.getMachineFunction().getNumBlockIDs();
425 LiveOutSeen.resize(N);
426 LiveOutCache.resize(N);
427 }
428
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000429 // Blocks where LI should be live-in.
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000430 SmallVector<MachineBasicBlock*, 16> WorkList(1, KillMBB);
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000431
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000432 // Remember if we have seen more than one value.
433 bool UniqueVNI = true;
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000434 VNInfo *TheVNI = 0;
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000435
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000436 // Using LiveOutCache as a visited set, perform a BFS for all reaching defs.
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000437 for (unsigned i = 0; i != WorkList.size(); ++i) {
438 MachineBasicBlock *MBB = WorkList[i];
Jakob Stoklund Olesen7cec1792011-03-18 03:06:02 +0000439 assert(!MBB->pred_empty() && "Value live-in to entry block?");
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000440 for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
441 PE = MBB->pred_end(); PI != PE; ++PI) {
442 MachineBasicBlock *Pred = *PI;
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000443 LiveOutPair &LOP = LiveOutCache[Pred];
444
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000445 // Is this a known live-out block?
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000446 if (LiveOutSeen.test(Pred->getNumber())) {
447 if (VNInfo *VNI = LOP.first) {
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000448 if (TheVNI && TheVNI != VNI)
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000449 UniqueVNI = false;
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000450 TheVNI = VNI;
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000451 }
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000452 continue;
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000453 }
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000454
455 // First time. LOP is garbage and must be cleared below.
456 LiveOutSeen.set(Pred->getNumber());
457
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000458 // Does Pred provide a live-out value?
459 SlotIndex Start, Last;
460 tie(Start, Last) = LIS.getSlotIndexes()->getMBBRange(Pred);
461 Last = Last.getPrevSlot();
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000462 VNInfo *VNI = LI->extendInBlock(Start, Last);
463 LOP.first = VNI;
464 if (VNI) {
465 LOP.second = MDT[LIS.getMBBFromIndex(VNI->def)];
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000466 if (TheVNI && TheVNI != VNI)
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000467 UniqueVNI = false;
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000468 TheVNI = VNI;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000469 continue;
470 }
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000471 LOP.second = 0;
472
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000473 // No, we need a live-in value for Pred as well
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000474 if (Pred != KillMBB)
475 WorkList.push_back(Pred);
Jakob Stoklund Olesen87017682011-03-03 01:29:10 +0000476 else
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000477 // Loopback to KillMBB, so value is really live through.
478 Kill = SlotIndex();
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000479 }
480 }
481
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000482 // Transfer WorkList to LiveInBlocks in reverse order.
483 // This ordering works best with updateSSA().
484 LiveInBlocks.clear();
485 LiveInBlocks.reserve(WorkList.size());
486 while(!WorkList.empty())
487 LiveInBlocks.push_back(MDT[WorkList.pop_back_val()]);
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000488
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000489 // The kill block may not be live-through.
490 assert(LiveInBlocks.back().DomNode->getBlock() == KillMBB);
491 LiveInBlocks.back().Kill = Kill;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000492
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000493 return UniqueVNI ? TheVNI : 0;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000494}
495
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000496void SplitEditor::updateSSA() {
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000497 // This is essentially the same iterative algorithm that SSAUpdater uses,
498 // except we already have a dominator tree, so we don't have to recompute it.
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000499 unsigned Changes;
500 do {
501 Changes = 0;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000502 // Propagate live-out values down the dominator tree, inserting phi-defs
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000503 // when necessary.
504 for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
505 E = LiveInBlocks.end(); I != E; ++I) {
506 MachineDomTreeNode *Node = I->DomNode;
507 // Skip block if the live-in value has already been determined.
508 if (!Node)
509 continue;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000510 MachineBasicBlock *MBB = Node->getBlock();
511 MachineDomTreeNode *IDom = Node->getIDom();
512 LiveOutPair IDomValue;
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000513
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000514 // We need a live-in value to a block with no immediate dominator?
515 // This is probably an unreachable block that has survived somehow.
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000516 bool needPHI = !IDom || !LiveOutSeen.test(IDom->getBlock()->getNumber());
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000517
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000518 // IDom dominates all of our predecessors, but it may not be their
519 // immediate dominator. Check if any of them have live-out values that are
520 // properly dominated by IDom. If so, we need a phi-def here.
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000521 if (!needPHI) {
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000522 IDomValue = LiveOutCache[IDom->getBlock()];
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000523 for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
524 PE = MBB->pred_end(); PI != PE; ++PI) {
525 LiveOutPair Value = LiveOutCache[*PI];
526 if (!Value.first || Value.first == IDomValue.first)
527 continue;
528 // This predecessor is carrying something other than IDomValue.
529 // It could be because IDomValue hasn't propagated yet, or it could be
530 // because MBB is in the dominance frontier of that value.
531 if (MDT.dominates(IDom, Value.second)) {
532 needPHI = true;
533 break;
534 }
535 }
536 }
537
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000538 // The value may be live-through even if Kill is set, as can happen when
539 // we are called from extendRange. In that case LiveOutSeen is true, and
540 // LiveOutCache indicates a foreign or missing value.
541 LiveOutPair &LOP = LiveOutCache[MBB];
542
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000543 // Create a phi-def if required.
544 if (needPHI) {
545 ++Changes;
546 SlotIndex Start = LIS.getMBBStartIdx(MBB);
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000547 unsigned RegIdx = RegAssign.lookup(Start);
548 LiveInterval *LI = Edit->get(RegIdx);
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000549 VNInfo *VNI = LI->getNextValue(Start, 0, LIS.getVNInfoAllocator());
550 VNI->setIsPHIDef(true);
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000551 I->Value = VNI;
552 // This block is done, we know the final value.
553 I->DomNode = 0;
554 if (I->Kill.isValid())
555 LI->addRange(LiveRange(Start, I->Kill, VNI));
556 else {
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000557 LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI));
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000558 LOP = LiveOutPair(VNI, Node);
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000559 }
560 } else if (IDomValue.first) {
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000561 // No phi-def here. Remember incoming value.
562 I->Value = IDomValue.first;
563 if (I->Kill.isValid())
564 continue;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000565 // Propagate IDomValue if needed:
566 // MBB is live-out and doesn't define its own value.
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000567 if (LOP.second != Node && LOP.first != IDomValue.first) {
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000568 ++Changes;
Jakob Stoklund Olesen13ba2da2011-03-04 00:15:36 +0000569 LOP = IDomValue;
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000570 }
571 }
572 }
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000573 } while (Changes);
574
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000575 // The values in LiveInBlocks are now accurate. No more phi-defs are needed
576 // for these blocks, so we can color the live ranges.
577 for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
578 E = LiveInBlocks.end(); I != E; ++I) {
579 if (!I->DomNode)
580 continue;
581 assert(I->Value && "No live-in value found");
582 MachineBasicBlock *MBB = I->DomNode->getBlock();
583 SlotIndex Start = LIS.getMBBStartIdx(MBB);
584 unsigned RegIdx = RegAssign.lookup(Start);
585 LiveInterval *LI = Edit->get(RegIdx);
586 LI->addRange(LiveRange(Start, I->Kill.isValid() ?
587 I->Kill : LIS.getMBBEndIdx(MBB), I->Value));
588 }
Jakob Stoklund Olesen1c38ba62011-03-02 01:59:34 +0000589}
590
Eric Christopher0f438112011-02-03 06:18:29 +0000591VNInfo *SplitEditor::defFromParent(unsigned RegIdx,
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000592 VNInfo *ParentVNI,
593 SlotIndex UseIdx,
594 MachineBasicBlock &MBB,
595 MachineBasicBlock::iterator I) {
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000596 MachineInstr *CopyMI = 0;
597 SlotIndex Def;
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000598 LiveInterval *LI = Edit->get(RegIdx);
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000599
Jakob Stoklund Olesenbb30dd42011-05-02 05:29:58 +0000600 // We may be trying to avoid interference that ends at a deleted instruction,
601 // so always begin RegIdx 0 early and all others late.
602 bool Late = RegIdx != 0;
603
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000604 // Attempt cheap-as-a-copy rematerialization.
605 LiveRangeEdit::Remat RM(ParentVNI);
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000606 if (Edit->canRematerializeAt(RM, UseIdx, true, LIS)) {
Jakob Stoklund Olesenbb30dd42011-05-02 05:29:58 +0000607 Def = Edit->rematerializeAt(MBB, I, LI->reg, RM, LIS, TII, TRI, Late);
Jakob Stoklund Olesene9bd4ea2011-05-05 17:22:53 +0000608 ++NumRemats;
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000609 } else {
610 // Can't remat, just insert a copy from parent.
Eric Christopher0f438112011-02-03 06:18:29 +0000611 CopyMI = BuildMI(MBB, I, DebugLoc(), TII.get(TargetOpcode::COPY), LI->reg)
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000612 .addReg(Edit->getReg());
Jakob Stoklund Olesenbb30dd42011-05-02 05:29:58 +0000613 Def = LIS.getSlotIndexes()->insertMachineInstrInMaps(CopyMI, Late)
614 .getDefIndex();
Jakob Stoklund Olesene9bd4ea2011-05-05 17:22:53 +0000615 ++NumCopies;
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000616 }
617
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +0000618 // Define the value in Reg.
619 VNInfo *VNI = defValue(RegIdx, ParentVNI, Def);
620 VNI->setCopy(CopyMI);
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000621 return VNI;
622}
623
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000624/// Create a new virtual register and live interval.
Jakob Stoklund Olesene1b43c32011-04-12 18:11:31 +0000625unsigned SplitEditor::openIntv() {
Eric Christopher0f438112011-02-03 06:18:29 +0000626 // Create the complement as index 0.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000627 if (Edit->empty())
Jakob Stoklund Olesen6a3dbd32011-03-17 20:37:07 +0000628 Edit->create(LIS, VRM);
Eric Christopher0f438112011-02-03 06:18:29 +0000629
630 // Create the open interval.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000631 OpenIdx = Edit->size();
Jakob Stoklund Olesen6a3dbd32011-03-17 20:37:07 +0000632 Edit->create(LIS, VRM);
Jakob Stoklund Olesene1b43c32011-04-12 18:11:31 +0000633 return OpenIdx;
634}
635
636void SplitEditor::selectIntv(unsigned Idx) {
637 assert(Idx != 0 && "Cannot select the complement interval");
638 assert(Idx < Edit->size() && "Can only select previously opened interval");
Jakob Stoklund Olesen4d517e32011-06-29 00:24:24 +0000639 DEBUG(dbgs() << " selectIntv " << OpenIdx << " -> " << Idx << '\n');
Jakob Stoklund Olesene1b43c32011-04-12 18:11:31 +0000640 OpenIdx = Idx;
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000641}
642
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000643SlotIndex SplitEditor::enterIntvBefore(SlotIndex Idx) {
Eric Christopher0f438112011-02-03 06:18:29 +0000644 assert(OpenIdx && "openIntv not called before enterIntvBefore");
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000645 DEBUG(dbgs() << " enterIntvBefore " << Idx);
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000646 Idx = Idx.getBaseIndex();
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000647 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000648 if (!ParentVNI) {
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000649 DEBUG(dbgs() << ": not live\n");
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000650 return Idx;
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000651 }
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000652 DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n');
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000653 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000654 assert(MI && "enterIntvBefore called with invalid index");
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000655
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000656 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(), MI);
657 return VNI->def;
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000658}
659
Jakob Stoklund Olesen4d517e32011-06-29 00:24:24 +0000660SlotIndex SplitEditor::enterIntvAfter(SlotIndex Idx) {
661 assert(OpenIdx && "openIntv not called before enterIntvAfter");
662 DEBUG(dbgs() << " enterIntvAfter " << Idx);
663 Idx = Idx.getBoundaryIndex();
664 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
665 if (!ParentVNI) {
666 DEBUG(dbgs() << ": not live\n");
667 return Idx;
668 }
669 DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n');
670 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
671 assert(MI && "enterIntvAfter called with invalid index");
672
673 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(),
674 llvm::next(MachineBasicBlock::iterator(MI)));
675 return VNI->def;
676}
677
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000678SlotIndex SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) {
Eric Christopher0f438112011-02-03 06:18:29 +0000679 assert(OpenIdx && "openIntv not called before enterIntvAtEnd");
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000680 SlotIndex End = LIS.getMBBEndIdx(&MBB);
681 SlotIndex Last = End.getPrevSlot();
682 DEBUG(dbgs() << " enterIntvAtEnd BB#" << MBB.getNumber() << ", " << Last);
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000683 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Last);
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000684 if (!ParentVNI) {
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000685 DEBUG(dbgs() << ": not live\n");
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000686 return End;
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000687 }
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000688 DEBUG(dbgs() << ": valno " << ParentVNI->id);
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000689 VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Last, MBB,
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000690 LIS.getLastSplitPoint(Edit->getParent(), &MBB));
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000691 RegAssign.insert(VNI->def, End, OpenIdx);
Eric Christopher0f438112011-02-03 06:18:29 +0000692 DEBUG(dump());
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000693 return VNI->def;
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000694}
695
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000696/// useIntv - indicate that all instructions in MBB should use OpenLI.
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000697void SplitEditor::useIntv(const MachineBasicBlock &MBB) {
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000698 useIntv(LIS.getMBBStartIdx(&MBB), LIS.getMBBEndIdx(&MBB));
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000699}
700
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000701void SplitEditor::useIntv(SlotIndex Start, SlotIndex End) {
Eric Christopher0f438112011-02-03 06:18:29 +0000702 assert(OpenIdx && "openIntv not called before useIntv");
703 DEBUG(dbgs() << " useIntv [" << Start << ';' << End << "):");
704 RegAssign.insert(Start, End, OpenIdx);
705 DEBUG(dump());
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000706}
707
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000708SlotIndex SplitEditor::leaveIntvAfter(SlotIndex Idx) {
Eric Christopher0f438112011-02-03 06:18:29 +0000709 assert(OpenIdx && "openIntv not called before leaveIntvAfter");
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000710 DEBUG(dbgs() << " leaveIntvAfter " << Idx);
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000711
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000712 // The interval must be live beyond the instruction at Idx.
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000713 Idx = Idx.getBoundaryIndex();
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000714 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000715 if (!ParentVNI) {
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000716 DEBUG(dbgs() << ": not live\n");
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000717 return Idx.getNextSlot();
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000718 }
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000719 DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n');
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000720
Jakob Stoklund Olesen01cb34b2011-02-08 18:50:18 +0000721 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
722 assert(MI && "No instruction at index");
723 VNInfo *VNI = defFromParent(0, ParentVNI, Idx, *MI->getParent(),
724 llvm::next(MachineBasicBlock::iterator(MI)));
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000725 return VNI->def;
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +0000726}
727
Jakob Stoklund Olesen9b057772011-02-09 23:30:25 +0000728SlotIndex SplitEditor::leaveIntvBefore(SlotIndex Idx) {
729 assert(OpenIdx && "openIntv not called before leaveIntvBefore");
730 DEBUG(dbgs() << " leaveIntvBefore " << Idx);
731
732 // The interval must be live into the instruction at Idx.
733 Idx = Idx.getBoundaryIndex();
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000734 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
Jakob Stoklund Olesen9b057772011-02-09 23:30:25 +0000735 if (!ParentVNI) {
736 DEBUG(dbgs() << ": not live\n");
737 return Idx.getNextSlot();
738 }
739 DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n');
740
741 MachineInstr *MI = LIS.getInstructionFromIndex(Idx);
742 assert(MI && "No instruction at index");
743 VNInfo *VNI = defFromParent(0, ParentVNI, Idx, *MI->getParent(), MI);
744 return VNI->def;
745}
746
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000747SlotIndex SplitEditor::leaveIntvAtTop(MachineBasicBlock &MBB) {
Eric Christopher0f438112011-02-03 06:18:29 +0000748 assert(OpenIdx && "openIntv not called before leaveIntvAtTop");
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000749 SlotIndex Start = LIS.getMBBStartIdx(&MBB);
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000750 DEBUG(dbgs() << " leaveIntvAtTop BB#" << MBB.getNumber() << ", " << Start);
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000751
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000752 VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
Jakob Stoklund Olesenf6a129a2010-09-16 00:01:36 +0000753 if (!ParentVNI) {
Jakob Stoklund Olesen9b24afe2010-10-07 17:56:35 +0000754 DEBUG(dbgs() << ": not live\n");
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000755 return Start;
Jakob Stoklund Olesen7536f722010-08-04 22:08:39 +0000756 }
757
Eric Christopher0f438112011-02-03 06:18:29 +0000758 VNInfo *VNI = defFromParent(0, ParentVNI, Start, MBB,
Jakob Stoklund Olesencfa71342010-11-10 19:31:50 +0000759 MBB.SkipPHIsAndLabels(MBB.begin()));
Eric Christopher0f438112011-02-03 06:18:29 +0000760 RegAssign.insert(Start, VNI->def, OpenIdx);
761 DEBUG(dump());
Jakob Stoklund Olesen207c8682011-02-03 17:04:16 +0000762 return VNI->def;
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +0000763}
764
Jakob Stoklund Olesen5c716bd2011-02-08 18:50:21 +0000765void SplitEditor::overlapIntv(SlotIndex Start, SlotIndex End) {
766 assert(OpenIdx && "openIntv not called before overlapIntv");
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000767 const VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
768 assert(ParentVNI == Edit->getParent().getVNInfoAt(End.getPrevSlot()) &&
Jakob Stoklund Olesen5c716bd2011-02-08 18:50:21 +0000769 "Parent changes value in extended range");
Jakob Stoklund Olesen5c716bd2011-02-08 18:50:21 +0000770 assert(LIS.getMBBFromIndex(Start) == LIS.getMBBFromIndex(End) &&
771 "Range cannot span basic blocks");
772
Jakob Stoklund Olesend3fdaeb2011-03-02 00:49:28 +0000773 // The complement interval will be extended as needed by extendRange().
Jakob Stoklund Olesenb3dd8262011-04-05 23:43:14 +0000774 if (ParentVNI)
775 markComplexMapped(0, ParentVNI);
Jakob Stoklund Olesen5c716bd2011-02-08 18:50:21 +0000776 DEBUG(dbgs() << " overlapIntv [" << Start << ';' << End << "):");
777 RegAssign.insert(Start, End, OpenIdx);
778 DEBUG(dump());
779}
780
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000781/// transferValues - Transfer all possible values to the new live ranges.
782/// Values that were rematerialized are left alone, they need extendRange().
783bool SplitEditor::transferValues() {
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000784 bool Skipped = false;
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000785 LiveInBlocks.clear();
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000786 RegAssignMap::const_iterator AssignI = RegAssign.begin();
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000787 for (LiveInterval::const_iterator ParentI = Edit->getParent().begin(),
788 ParentE = Edit->getParent().end(); ParentI != ParentE; ++ParentI) {
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000789 DEBUG(dbgs() << " blit " << *ParentI << ':');
790 VNInfo *ParentVNI = ParentI->valno;
791 // RegAssign has holes where RegIdx 0 should be used.
792 SlotIndex Start = ParentI->start;
793 AssignI.advanceTo(Start);
794 do {
795 unsigned RegIdx;
796 SlotIndex End = ParentI->end;
797 if (!AssignI.valid()) {
798 RegIdx = 0;
799 } else if (AssignI.start() <= Start) {
800 RegIdx = AssignI.value();
801 if (AssignI.stop() < End) {
802 End = AssignI.stop();
803 ++AssignI;
804 }
805 } else {
806 RegIdx = 0;
807 End = std::min(End, AssignI.start());
808 }
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000809
810 // The interval [Start;End) is continuously mapped to RegIdx, ParentVNI.
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000811 DEBUG(dbgs() << " [" << Start << ';' << End << ")=" << RegIdx);
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000812 LiveInterval *LI = Edit->get(RegIdx);
813
814 // Check for a simply defined value that can be blitted directly.
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000815 if (VNInfo *VNI = Values.lookup(std::make_pair(RegIdx, ParentVNI->id))) {
816 DEBUG(dbgs() << ':' << VNI->id);
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000817 LI->addRange(LiveRange(Start, End, VNI));
818 Start = End;
819 continue;
820 }
821
822 // Skip rematerialized values, we need to use extendRange() and
823 // extendPHIKillRanges() to completely recompute the live ranges.
824 if (Edit->didRematerialize(ParentVNI)) {
825 DEBUG(dbgs() << "(remat)");
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000826 Skipped = true;
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000827 Start = End;
828 continue;
829 }
830
831 // Initialize the live-out cache the first time it is needed.
832 if (LiveOutSeen.empty()) {
833 unsigned N = VRM.getMachineFunction().getNumBlockIDs();
834 LiveOutSeen.resize(N);
835 LiveOutCache.resize(N);
836 }
837
838 // This value has multiple defs in RegIdx, but it wasn't rematerialized,
839 // so the live range is accurate. Add live-in blocks in [Start;End) to the
840 // LiveInBlocks.
841 MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
842 SlotIndex BlockStart, BlockEnd;
843 tie(BlockStart, BlockEnd) = LIS.getSlotIndexes()->getMBBRange(MBB);
844
845 // The first block may be live-in, or it may have its own def.
846 if (Start != BlockStart) {
847 VNInfo *VNI = LI->extendInBlock(BlockStart,
848 std::min(BlockEnd, End).getPrevSlot());
849 assert(VNI && "Missing def for complex mapped value");
850 DEBUG(dbgs() << ':' << VNI->id << "*BB#" << MBB->getNumber());
851 // MBB has its own def. Is it also live-out?
852 if (BlockEnd <= End) {
853 LiveOutSeen.set(MBB->getNumber());
854 LiveOutCache[MBB] = LiveOutPair(VNI, MDT[MBB]);
855 }
856 // Skip to the next block for live-in.
857 ++MBB;
858 BlockStart = BlockEnd;
859 }
860
861 // Handle the live-in blocks covered by [Start;End).
862 assert(Start <= BlockStart && "Expected live-in block");
863 while (BlockStart < End) {
864 DEBUG(dbgs() << ">BB#" << MBB->getNumber());
865 BlockEnd = LIS.getMBBEndIdx(MBB);
866 if (BlockStart == ParentVNI->def) {
867 // This block has the def of a parent PHI, so it isn't live-in.
868 assert(ParentVNI->isPHIDef() && "Non-phi defined at block start?");
869 VNInfo *VNI = LI->extendInBlock(BlockStart,
870 std::min(BlockEnd, End).getPrevSlot());
871 assert(VNI && "Missing def for complex mapped parent PHI");
872 if (End >= BlockEnd) {
873 // Live-out as well.
874 LiveOutSeen.set(MBB->getNumber());
875 LiveOutCache[MBB] = LiveOutPair(VNI, MDT[MBB]);
876 }
877 } else {
878 // This block needs a live-in value.
879 LiveInBlocks.push_back(MDT[MBB]);
880 // The last block covered may not be live-out.
881 if (End < BlockEnd)
882 LiveInBlocks.back().Kill = End;
883 else {
884 // Live-out, but we need updateSSA to tell us the value.
885 LiveOutSeen.set(MBB->getNumber());
Francois Pichetcbc5f402011-04-16 14:20:39 +0000886 LiveOutCache[MBB] = LiveOutPair((VNInfo*)0,
887 (MachineDomTreeNode*)0);
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000888 }
889 }
890 BlockStart = BlockEnd;
891 ++MBB;
892 }
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000893 Start = End;
894 } while (Start != ParentI->end);
895 DEBUG(dbgs() << '\n');
896 }
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +0000897
898 if (!LiveInBlocks.empty())
899 updateSSA();
900
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000901 return Skipped;
902}
903
Jakob Stoklund Olesene2dc0c92011-03-02 23:05:16 +0000904void SplitEditor::extendPHIKillRanges() {
905 // Extend live ranges to be live-out for successor PHI values.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000906 for (LiveInterval::const_vni_iterator I = Edit->getParent().vni_begin(),
907 E = Edit->getParent().vni_end(); I != E; ++I) {
Jakob Stoklund Olesene2dc0c92011-03-02 23:05:16 +0000908 const VNInfo *PHIVNI = *I;
909 if (PHIVNI->isUnused() || !PHIVNI->isPHIDef())
910 continue;
911 unsigned RegIdx = RegAssign.lookup(PHIVNI->def);
912 MachineBasicBlock *MBB = LIS.getMBBFromIndex(PHIVNI->def);
913 for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
914 PE = MBB->pred_end(); PI != PE; ++PI) {
915 SlotIndex End = LIS.getMBBEndIdx(*PI).getPrevSlot();
916 // The predecessor may not have a live-out value. That is OK, like an
917 // undef PHI operand.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000918 if (Edit->getParent().liveAt(End)) {
Jakob Stoklund Olesene2dc0c92011-03-02 23:05:16 +0000919 assert(RegAssign.lookup(End) == RegIdx &&
920 "Different register assignment in phi predecessor");
921 extendRange(RegIdx, End);
922 }
923 }
924 }
925}
926
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000927/// rewriteAssigned - Rewrite all uses of Edit->getReg().
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +0000928void SplitEditor::rewriteAssigned(bool ExtendRanges) {
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000929 for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(Edit->getReg()),
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000930 RE = MRI.reg_end(); RI != RE;) {
Jakob Stoklund Olesen74669272010-10-08 23:42:21 +0000931 MachineOperand &MO = RI.getOperand();
932 MachineInstr *MI = MO.getParent();
933 ++RI;
Eric Christopher0f438112011-02-03 06:18:29 +0000934 // LiveDebugVariables should have handled all DBG_VALUE instructions.
Jakob Stoklund Olesen74669272010-10-08 23:42:21 +0000935 if (MI->isDebugValue()) {
936 DEBUG(dbgs() << "Zapping " << *MI);
Jakob Stoklund Olesen74669272010-10-08 23:42:21 +0000937 MO.setReg(0);
938 continue;
939 }
Jakob Stoklund Olesena372d162011-02-09 21:52:09 +0000940
941 // <undef> operands don't really read the register, so just assign them to
942 // the complement.
943 if (MO.isUse() && MO.isUndef()) {
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000944 MO.setReg(Edit->get(0)->reg);
Jakob Stoklund Olesena372d162011-02-09 21:52:09 +0000945 continue;
946 }
947
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +0000948 SlotIndex Idx = LIS.getInstructionIndex(MI);
Jakob Stoklund Olesen7cec1792011-03-18 03:06:02 +0000949 if (MO.isDef())
950 Idx = MO.isEarlyClobber() ? Idx.getUseIndex() : Idx.getDefIndex();
Eric Christopher0f438112011-02-03 06:18:29 +0000951
952 // Rewrite to the mapped register at Idx.
953 unsigned RegIdx = RegAssign.lookup(Idx);
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +0000954 MO.setReg(Edit->get(RegIdx)->reg);
Eric Christopher0f438112011-02-03 06:18:29 +0000955 DEBUG(dbgs() << " rewr BB#" << MI->getParent()->getNumber() << '\t'
956 << Idx << ':' << RegIdx << '\t' << *MI);
957
Jakob Stoklund Olesen7cec1792011-03-18 03:06:02 +0000958 // Extend liveness to Idx if the instruction reads reg.
959 if (!ExtendRanges)
960 continue;
961
962 // Skip instructions that don't read Reg.
963 if (MO.isDef()) {
964 if (!MO.getSubReg() && !MO.isEarlyClobber())
965 continue;
966 // We may wan't to extend a live range for a partial redef, or for a use
967 // tied to an early clobber.
968 Idx = Idx.getPrevSlot();
969 if (!Edit->getParent().liveAt(Idx))
970 continue;
971 } else
972 Idx = Idx.getUseIndex();
973
974 extendRange(RegIdx, Idx);
Jakob Stoklund Olesen74669272010-10-08 23:42:21 +0000975 }
976}
977
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +0000978void SplitEditor::deleteRematVictims() {
979 SmallVector<MachineInstr*, 8> Dead;
Jakob Stoklund Olesen2dc455a2011-03-20 19:46:23 +0000980 for (LiveRangeEdit::iterator I = Edit->begin(), E = Edit->end(); I != E; ++I){
981 LiveInterval *LI = *I;
982 for (LiveInterval::const_iterator LII = LI->begin(), LIE = LI->end();
983 LII != LIE; ++LII) {
984 // Dead defs end at the store slot.
985 if (LII->end != LII->valno->def.getNextSlot())
986 continue;
987 MachineInstr *MI = LIS.getInstructionFromIndex(LII->valno->def);
988 assert(MI && "Missing instruction for dead def");
989 MI->addRegisterDead(LI->reg, &TRI);
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +0000990
Jakob Stoklund Olesen2dc455a2011-03-20 19:46:23 +0000991 if (!MI->allDefsAreDead())
992 continue;
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +0000993
Jakob Stoklund Olesen2dc455a2011-03-20 19:46:23 +0000994 DEBUG(dbgs() << "All defs dead: " << *MI);
995 Dead.push_back(MI);
996 }
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +0000997 }
998
999 if (Dead.empty())
1000 return;
1001
Jakob Stoklund Olesen6a3dbd32011-03-17 20:37:07 +00001002 Edit->eliminateDeadDefs(Dead, LIS, VRM, TII);
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +00001003}
1004
Jakob Stoklund Olesen59280462011-04-21 18:38:15 +00001005void SplitEditor::finish(SmallVectorImpl<unsigned> *LRMap) {
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +00001006 ++NumFinished;
Eric Christopher463a2972011-02-03 05:40:54 +00001007
Eric Christopher0f438112011-02-03 06:18:29 +00001008 // At this point, the live intervals in Edit contain VNInfos corresponding to
1009 // the inserted copies.
1010
1011 // Add the original defs from the parent interval.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +00001012 for (LiveInterval::const_vni_iterator I = Edit->getParent().vni_begin(),
1013 E = Edit->getParent().vni_end(); I != E; ++I) {
Eric Christopher0f438112011-02-03 06:18:29 +00001014 const VNInfo *ParentVNI = *I;
Jakob Stoklund Olesen9ecd1e72011-02-04 00:59:23 +00001015 if (ParentVNI->isUnused())
1016 continue;
Jakob Stoklund Olesen670ccd12011-03-01 23:14:53 +00001017 unsigned RegIdx = RegAssign.lookup(ParentVNI->def);
Jakob Stoklund Olesen29ef8752011-03-15 21:13:22 +00001018 VNInfo *VNI = defValue(RegIdx, ParentVNI, ParentVNI->def);
1019 VNI->setIsPHIDef(ParentVNI->isPHIDef());
1020 VNI->setCopy(ParentVNI->getCopy());
1021
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +00001022 // Mark rematted values as complex everywhere to force liveness computation.
1023 // The new live ranges may be truncated.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +00001024 if (Edit->didRematerialize(ParentVNI))
1025 for (unsigned i = 0, e = Edit->size(); i != e; ++i)
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +00001026 markComplexMapped(i, ParentVNI);
Eric Christopher0f438112011-02-03 06:18:29 +00001027 }
1028
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +00001029 // Transfer the simply mapped values, check if any are skipped.
1030 bool Skipped = transferValues();
1031 if (Skipped)
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +00001032 extendPHIKillRanges();
1033 else
1034 ++NumSimple;
Eric Christopher0f438112011-02-03 06:18:29 +00001035
Jakob Stoklund Olesen46703532011-03-02 23:05:19 +00001036 // Rewrite virtual registers, possibly extending ranges.
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +00001037 rewriteAssigned(Skipped);
Eric Christopher0f438112011-02-03 06:18:29 +00001038
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +00001039 // Delete defs that were rematted everywhere.
Jakob Stoklund Olesen44b7ae22011-04-15 17:24:49 +00001040 if (Skipped)
Jakob Stoklund Olesen58817992011-03-08 22:46:11 +00001041 deleteRematVictims();
Jakob Stoklund Olesen5fa42a42010-09-21 22:32:21 +00001042
Jakob Stoklund Olesen0253df92010-10-07 23:34:34 +00001043 // Get rid of unused values and set phi-kill flags.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +00001044 for (LiveRangeEdit::iterator I = Edit->begin(), E = Edit->end(); I != E; ++I)
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +00001045 (*I)->RenumberValues(LIS);
Jakob Stoklund Olesen5fa42a42010-09-21 22:32:21 +00001046
Jakob Stoklund Olesen59280462011-04-21 18:38:15 +00001047 // Provide a reverse mapping from original indices to Edit ranges.
1048 if (LRMap) {
1049 LRMap->clear();
1050 for (unsigned i = 0, e = Edit->size(); i != e; ++i)
1051 LRMap->push_back(i);
1052 }
1053
Jakob Stoklund Olesen3a0e0712010-10-26 22:36:09 +00001054 // Now check if any registers were separated into multiple components.
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +00001055 ConnectedVNInfoEqClasses ConEQ(LIS);
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +00001056 for (unsigned i = 0, e = Edit->size(); i != e; ++i) {
Jakob Stoklund Olesen3a0e0712010-10-26 22:36:09 +00001057 // Don't use iterators, they are invalidated by create() below.
Jakob Stoklund Olesena2cae582011-03-02 23:31:50 +00001058 LiveInterval *li = Edit->get(i);
Jakob Stoklund Olesen3a0e0712010-10-26 22:36:09 +00001059 unsigned NumComp = ConEQ.Classify(li);
1060 if (NumComp <= 1)
1061 continue;
1062 DEBUG(dbgs() << " " << NumComp << " components: " << *li << '\n');
1063 SmallVector<LiveInterval*, 8> dups;
1064 dups.push_back(li);
Matt Beaumont-Gayae5fbee2011-04-21 19:46:23 +00001065 for (unsigned j = 1; j != NumComp; ++j)
Jakob Stoklund Olesen6a3dbd32011-03-17 20:37:07 +00001066 dups.push_back(&Edit->create(LIS, VRM));
Jakob Stoklund Olesen22542272011-03-17 00:23:45 +00001067 ConEQ.Distribute(&dups[0], MRI);
Jakob Stoklund Olesen59280462011-04-21 18:38:15 +00001068 // The new intervals all map back to i.
1069 if (LRMap)
1070 LRMap->resize(Edit->size(), i);
Jakob Stoklund Olesen3a0e0712010-10-26 22:36:09 +00001071 }
1072
Jakob Stoklund Olesen08e93b12010-08-10 17:07:22 +00001073 // Calculate spill weight and allocation hints for new intervals.
Jakob Stoklund Olesen6094bd82011-03-29 21:20:19 +00001074 Edit->calculateRegClassAndHint(VRM.getMachineFunction(), LIS, SA.Loops);
Jakob Stoklund Olesen59280462011-04-21 18:38:15 +00001075
1076 assert(!LRMap || LRMap->size() == Edit->size());
Jakob Stoklund Olesenf0179002010-07-26 23:44:11 +00001077}
1078
1079
Jakob Stoklund Olesen8ae02632010-07-20 15:41:07 +00001080//===----------------------------------------------------------------------===//
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +00001081// Single Block Splitting
1082//===----------------------------------------------------------------------===//
1083
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +00001084/// getMultiUseBlocks - if CurLI has more than one use in a basic block, it
1085/// may be an advantage to split CurLI for the duration of the block.
Jakob Stoklund Olesen2bfb3242010-10-22 22:48:56 +00001086bool SplitAnalysis::getMultiUseBlocks(BlockPtrSet &Blocks) {
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +00001087 // If CurLI is local to one block, there is no point to splitting it.
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +00001088 if (UseBlocks.size() <= 1)
Jakob Stoklund Olesen2bfb3242010-10-22 22:48:56 +00001089 return false;
1090 // Add blocks with multiple uses.
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +00001091 for (unsigned i = 0, e = UseBlocks.size(); i != e; ++i) {
1092 const BlockInfo &BI = UseBlocks[i];
1093 if (BI.FirstUse == BI.LastUse)
Jakob Stoklund Olesen9b057772011-02-09 23:30:25 +00001094 continue;
1095 Blocks.insert(BI.MBB);
1096 }
Jakob Stoklund Olesen2bfb3242010-10-22 22:48:56 +00001097 return !Blocks.empty();
1098}
1099
Jakob Stoklund Olesenfd5c5132011-04-12 19:32:53 +00001100void SplitEditor::splitSingleBlock(const SplitAnalysis::BlockInfo &BI) {
1101 openIntv();
1102 SlotIndex LastSplitPoint = SA.getLastSplitPoint(BI.MBB->getNumber());
1103 SlotIndex SegStart = enterIntvBefore(std::min(BI.FirstUse,
1104 LastSplitPoint));
1105 if (!BI.LiveOut || BI.LastUse < LastSplitPoint) {
1106 useIntv(SegStart, leaveIntvAfter(BI.LastUse));
1107 } else {
1108 // The last use is after the last valid split point.
1109 SlotIndex SegStop = leaveIntvBefore(LastSplitPoint);
1110 useIntv(SegStart, SegStop);
1111 overlapIntv(SegStop, BI.LastUse);
1112 }
Jakob Stoklund Olesenfd5c5132011-04-12 19:32:53 +00001113}
1114
Jakob Stoklund Olesen07862842011-01-26 00:50:53 +00001115/// splitSingleBlocks - Split CurLI into a separate live interval inside each
Jakob Stoklund Olesen57d0f2d2010-10-05 22:19:33 +00001116/// basic block in Blocks.
1117void SplitEditor::splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks) {
Jakob Stoklund Olesene1f543f2010-08-12 18:50:55 +00001118 DEBUG(dbgs() << " splitSingleBlocks for " << Blocks.size() << " blocks.\n");
Jakob Stoklund Olesendb529a82011-04-06 03:57:00 +00001119 ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA.getUseBlocks();
1120 for (unsigned i = 0; i != UseBlocks.size(); ++i) {
1121 const SplitAnalysis::BlockInfo &BI = UseBlocks[i];
Jakob Stoklund Olesenfd5c5132011-04-12 19:32:53 +00001122 if (Blocks.count(BI.MBB))
1123 splitSingleBlock(BI);
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +00001124 }
Jakob Stoklund Olesen74669272010-10-08 23:42:21 +00001125 finish();
Jakob Stoklund Olesenf1b05f22010-08-12 17:07:14 +00001126}