#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <algorithm>
using namespace llvm;
+namespace {
//===----------------------------------------------------------------------===//
// Implementation of various methods necessary for calculation of live ranges.
// The implementation of the methods abstracts from the concrete type of the
return I;
}
};
+} // namespace
//===----------------------------------------------------------------------===//
// LiveRange methods
verify();
}
+bool LiveRange::isLiveAtIndexes(ArrayRef<SlotIndex> Slots) const {
+ ArrayRef<SlotIndex>::iterator SlotI = Slots.begin();
+ ArrayRef<SlotIndex>::iterator SlotE = Slots.end();
+
+ // If there are no regmask slots, we have nothing to search.
+ if (SlotI == SlotE)
+ return false;
+
+ // Start our search at the first segment that ends after the first slot.
+ const_iterator SegmentI = find(*SlotI);
+ const_iterator SegmentE = end();
+
+ // If there are no segments that end after the first slot, we're done.
+ if (SegmentI == SegmentE)
+ return false;
+
+ // Look for each slot in the live range.
+ for ( ; SlotI != SlotE; ++SlotI) {
+ // Go to the next segment that ends after the current slot.
+ // The slot may be within a hole in the range.
+ SegmentI = advanceTo(SegmentI, *SlotI);
+ if (SegmentI == SegmentE)
+ return false;
+
+ // If this segment contains the slot, we're done.
+ if (SegmentI->contains(*SlotI))
+ return true;
+ // Otherwise, look for the next slot.
+ }
+
+ // We didn't find a segment containing any of the slots.
+ return false;
+}
+
void LiveInterval::freeSubRange(SubRange *S) {
S->~SubRange();
// Memory was allocated with BumpPtr allocator and is not freed here.
static void determineMissingVNIs(const SlotIndexes &Indexes, LiveInterval &LI) {
SmallPtrSet<const MachineBasicBlock*, 5> Visited;
- for (LiveRange::Segment &S : LI.segments) {
- if (S.valno != nullptr)
- continue;
- // This can only happen at the begin of a basic block.
- assert(S.start.isBlock() && "valno should only be missing at block begin");
-
- Visited.clear();
- const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(S.start);
- for (const MachineBasicBlock *Pred : MBB->predecessors()) {
- VNInfo *VNI = searchForVNI(Indexes, LI, Pred, Visited);
- if (VNI != nullptr) {
- S.valno = VNI;
- break;
+
+ LiveRange::iterator OutIt;
+ VNInfo *PrevValNo = nullptr;
+ for (LiveRange::iterator I = LI.begin(), E = LI.end(); I != E; ++I) {
+ LiveRange::Segment &S = *I;
+ // Determine final VNI if necessary.
+ if (S.valno == nullptr) {
+ // This can only happen at the begin of a basic block.
+ assert(S.start.isBlock() && "valno should only be missing at block begin");
+
+ Visited.clear();
+ const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(S.start);
+ for (const MachineBasicBlock *Pred : MBB->predecessors()) {
+ VNInfo *VNI = searchForVNI(Indexes, LI, Pred, Visited);
+ if (VNI != nullptr) {
+ S.valno = VNI;
+ break;
+ }
}
+ assert(S.valno != nullptr && "could not determine valno");
+ }
+ // Merge with previous segment if it has the same VNI.
+ if (PrevValNo == S.valno && OutIt->end == S.start) {
+ OutIt->end = S.end;
+ } else {
+ // Didn't merge. Move OutIt to next segment.
+ if (PrevValNo == nullptr)
+ OutIt = LI.begin();
+ else
+ ++OutIt;
+
+ if (OutIt != I)
+ *OutIt = *I;
+ PrevValNo = S.valno;
}
- assert(S.valno != nullptr && "could not determine valno");
}
+ // If we merged some segments chop off the end.
+ ++OutIt;
+ LI.segments.erase(OutIt, LI.end());
}
void LiveInterval::constructMainRangeFromSubranges(
// - If any of the subranges is live at a point the main liverange has to be
// live too, conversily if no subrange is live the main range mustn't be
// live either.
- // We do this by scannig through all the subranges simultaneously creating new
+ // We do this by scanning through all the subranges simultaneously creating new
// segments in the main range as segments start/ends come up in the subranges.
assert(hasSubRanges() && "expected subranges to be present");
assert(segments.empty() && valnos.empty() && "expected empty main range");
Segment CurrentSegment;
bool ConstructingSegment = false;
bool NeedVNIFixup = false;
- unsigned ActiveMask = 0;
+ LaneBitmask ActiveMask = 0;
SlotIndex Pos = First;
while (true) {
SlotIndex NextPos = Last;
END_SEGMENT,
} Event = NOTHING;
// Which subregister lanes are affected by the current event.
- unsigned EventMask = 0;
+ LaneBitmask EventMask = 0;
// Whether a BEGIN_SEGMENT is also a valno definition point.
bool IsDef = false;
// Find the next begin or end of a subrange segment. Combine masks if we
NeedVNIFixup = true;
}
+ // In rare cases we can produce adjacent segments with the same value
+ // number (if they come from different subranges, but happen to have
+ // the same defining instruction). VNIFixup will fix those cases.
+ if (!empty() && segments.back().end == Pos &&
+ segments.back().valno == VNI)
+ NeedVNIFixup = true;
CurrentSegment.start = Pos;
CurrentSegment.valno = VNI;
ConstructingSegment = true;
super::print(OS);
// Print subranges
for (const SubRange &SR : subranges()) {
- OS << format(" L%04X ", SR.LaneMask) << SR;
+ OS << " L" << PrintLaneMask(SR.LaneMask) << ' ' << SR;
}
}
super::verify();
// Make sure SubRanges are fine and LaneMasks are disjunct.
- unsigned Mask = 0;
- unsigned MaxMask = MRI != nullptr ? MRI->getMaxLaneMaskForVReg(reg) : ~0u;
+ LaneBitmask Mask = 0;
+ LaneBitmask MaxMask = MRI != nullptr ? MRI->getMaxLaneMaskForVReg(reg) : ~0u;
for (const SubRange &SR : subranges()) {
// Subrange lanemask should be disjunct to any previous subrange masks.
assert((Mask & SR.LaneMask) == 0);
// subrange mask should not contained in maximum lane mask for the vreg.
assert((Mask & ~MaxMask) == 0);
+ // empty subranges must be removed.
+ assert(!SR.empty());
SR.verify();
// Main liverange should cover subrange.
LR->verify();
}
-unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
+unsigned ConnectedVNInfoEqClasses::Classify(const LiveRange &LR) {
// Create initial equivalence classes.
EqClass.clear();
- EqClass.grow(LI->getNumValNums());
+ EqClass.grow(LR.getNumValNums());
const VNInfo *used = nullptr, *unused = nullptr;
// Determine connections.
- for (const VNInfo *VNI : LI->valnos) {
+ for (const VNInfo *VNI : LR.valnos) {
// Group all unused values into one class.
if (VNI->isUnused()) {
if (unused)
// Connect to values live out of predecessors.
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI)
- if (const VNInfo *PVNI = LI->getVNInfoBefore(LIS.getMBBEndIdx(*PI)))
+ if (const VNInfo *PVNI = LR.getVNInfoBefore(LIS.getMBBEndIdx(*PI)))
EqClass.join(VNI->id, PVNI->id);
} else {
// Normal value defined by an instruction. Check for two-addr redef.
// FIXME: This could be coincidental. Should we really check for a tied
// operand constraint?
// Note that VNI->def may be a use slot for an early clobber def.
- if (const VNInfo *UVNI = LI->getVNInfoBefore(VNI->def))
+ if (const VNInfo *UVNI = LR.getVNInfoBefore(VNI->def))
EqClass.join(VNI->id, UVNI->id);
}
}
return EqClass.getNumClasses();
}
-void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[],
- MachineRegisterInfo &MRI) {
- assert(LIV[0] && "LIV[0] must be set");
- LiveInterval &LI = *LIV[0];
+template<typename LiveRangeT, typename EqClassesT>
+static void DistributeRange(LiveRangeT &LR, LiveRangeT *SplitLRs[],
+ EqClassesT VNIClasses) {
+ // Move segments to new intervals.
+ LiveRange::iterator J = LR.begin(), E = LR.end();
+ while (J != E && VNIClasses[J->valno->id] == 0)
+ ++J;
+ for (LiveRange::iterator I = J; I != E; ++I) {
+ if (unsigned eq = VNIClasses[I->valno->id]) {
+ assert((SplitLRs[eq-1]->empty() || SplitLRs[eq-1]->expiredAt(I->start)) &&
+ "New intervals should be empty");
+ SplitLRs[eq-1]->segments.push_back(*I);
+ } else
+ *J++ = *I;
+ }
+ LR.segments.erase(J, E);
+ // Transfer VNInfos to their new owners and renumber them.
+ unsigned j = 0, e = LR.getNumValNums();
+ while (j != e && VNIClasses[j] == 0)
+ ++j;
+ for (unsigned i = j; i != e; ++i) {
+ VNInfo *VNI = LR.getValNumInfo(i);
+ if (unsigned eq = VNIClasses[i]) {
+ VNI->id = SplitLRs[eq-1]->getNumValNums();
+ SplitLRs[eq-1]->valnos.push_back(VNI);
+ } else {
+ VNI->id = j;
+ LR.valnos[j++] = VNI;
+ }
+ }
+ LR.valnos.resize(j);
+}
+
+void ConnectedVNInfoEqClasses::Distribute(LiveInterval &LI, LiveInterval *LIV[],
+ MachineRegisterInfo &MRI) {
// Rewrite instructions.
for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
RE = MRI.reg_end(); RI != RE;) {
// NULL. If the use is tied to a def, VNI will be the defined value.
if (!VNI)
continue;
- MO.setReg(LIV[getEqClass(VNI)]->reg);
- }
-
- // Move runs to new intervals.
- LiveInterval::iterator J = LI.begin(), E = LI.end();
- while (J != E && EqClass[J->valno->id] == 0)
- ++J;
- for (LiveInterval::iterator I = J; I != E; ++I) {
- if (unsigned eq = EqClass[I->valno->id]) {
- assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
- "New intervals should be empty");
- LIV[eq]->segments.push_back(*I);
- } else
- *J++ = *I;
+ if (unsigned EqClass = getEqClass(VNI))
+ MO.setReg(LIV[EqClass-1]->reg);
}
- // TODO: do not cheat anymore by simply cleaning all subranges
- LI.clearSubRanges();
- LI.segments.erase(J, E);
- // Transfer VNInfos to their new owners and renumber them.
- unsigned j = 0, e = LI.getNumValNums();
- while (j != e && EqClass[j] == 0)
- ++j;
- for (unsigned i = j; i != e; ++i) {
- VNInfo *VNI = LI.getValNumInfo(i);
- if (unsigned eq = EqClass[i]) {
- VNI->id = LIV[eq]->getNumValNums();
- LIV[eq]->valnos.push_back(VNI);
- } else {
- VNI->id = j;
- LI.valnos[j++] = VNI;
+ // Distribute subregister liveranges.
+ if (LI.hasSubRanges()) {
+ unsigned NumComponents = EqClass.getNumClasses();
+ SmallVector<unsigned, 8> VNIMapping;
+ SmallVector<LiveInterval::SubRange*, 8> SubRanges;
+ BumpPtrAllocator &Allocator = LIS.getVNInfoAllocator();
+ for (LiveInterval::SubRange &SR : LI.subranges()) {
+ // Create new subranges in the split intervals and construct a mapping
+ // for the VNInfos in the subrange.
+ unsigned NumValNos = SR.valnos.size();
+ VNIMapping.clear();
+ VNIMapping.reserve(NumValNos);
+ SubRanges.clear();
+ SubRanges.resize(NumComponents-1, nullptr);
+ for (unsigned I = 0; I < NumValNos; ++I) {
+ const VNInfo &VNI = *SR.valnos[I];
+ const VNInfo *MainRangeVNI = LI.getVNInfoAt(VNI.def);
+ assert(MainRangeVNI != nullptr
+ && "SubRange def must have corresponding main range def");
+ unsigned ComponentNum = getEqClass(MainRangeVNI);
+ VNIMapping.push_back(ComponentNum);
+ if (ComponentNum > 0 && SubRanges[ComponentNum-1] == nullptr) {
+ SubRanges[ComponentNum-1]
+ = LIV[ComponentNum-1]->createSubRange(Allocator, SR.LaneMask);
+ }
+ }
+ DistributeRange(SR, SubRanges.data(), VNIMapping);
}
+ LI.removeEmptySubRanges();
}
- LI.valnos.resize(j);
+
+ // Distribute main liverange.
+ DistributeRange(LI, LIV, EqClass);
}
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