aboutsummaryrefslogtreecommitdiff
path: root/lib/CodeGen/SplitKit.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/CodeGen/SplitKit.cpp')
-rw-r--r--lib/CodeGen/SplitKit.cpp143
1 files changed, 118 insertions, 25 deletions
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index bce606c3ef..da85b428b5 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -351,6 +351,11 @@ void LiveIntervalMap::reset(LiveInterval *li) {
valueMap_.clear();
}
+bool LiveIntervalMap::isComplexMapped(const VNInfo *ParentVNI) const {
+ ValueMap::const_iterator i = valueMap_.find(ParentVNI);
+ return i != valueMap_.end() && i->second == 0;
+}
+
// defValue - Introduce a li_ def for ParentVNI that could be later than
// ParentVNI->def.
VNInfo *LiveIntervalMap::defValue(const VNInfo *ParentVNI, SlotIndex Idx) {
@@ -359,22 +364,25 @@ VNInfo *LiveIntervalMap::defValue(const VNInfo *ParentVNI, SlotIndex Idx) {
assert(Idx.isValid() && "Invalid SlotIndex");
assert(parentli_.getVNInfoAt(Idx) == ParentVNI && "Bad ParentVNI");
- // Is this a simple 1-1 mapping? Not likely.
- if (Idx == ParentVNI->def)
- return mapValue(ParentVNI, Idx);
+ // Create a new value.
+ VNInfo *VNI = li_->getNextValue(Idx, 0, true, lis_.getVNInfoAllocator());
+
+ // Use insert for lookup, so we can add missing values with a second lookup.
+ std::pair<ValueMap::iterator,bool> InsP =
+ valueMap_.insert(makeVV(ParentVNI, Idx == ParentVNI->def ? VNI : 0));
// This is now a complex def. Mark with a NULL in valueMap.
- valueMap_[ParentVNI] = 0;
+ if (!InsP.second)
+ InsP.first->second = 0;
- // Should we insert a minimal snippet of VNI LiveRange, or can we count on
- // callers to do that? We need it for lookups of complex values.
- VNInfo *VNI = li_->getNextValue(Idx, 0, true, lis_.getVNInfoAllocator());
return VNI;
}
+
// mapValue - Find the mapped value for ParentVNI at Idx.
// Potentially create phi-def values.
-VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx) {
+VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx,
+ bool *simple) {
assert(li_ && "call reset first");
assert(ParentVNI && "Mapping NULL value");
assert(Idx.isValid() && "Invalid SlotIndex");
@@ -385,15 +393,21 @@ VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx) {
valueMap_.insert(makeVV(ParentVNI, 0));
// This was an unknown value. Create a simple mapping.
- if (InsP.second)
+ if (InsP.second) {
+ if (simple) *simple = true;
return InsP.first->second = li_->createValueCopy(ParentVNI,
lis_.getVNInfoAllocator());
+ }
+
// This was a simple mapped value.
- if (InsP.first->second)
+ if (InsP.first->second) {
+ if (simple) *simple = true;
return InsP.first->second;
+ }
// This is a complex mapped value. There may be multiple defs, and we may need
// to create phi-defs.
+ if (simple) *simple = false;
MachineBasicBlock *IdxMBB = lis_.getMBBFromIndex(Idx);
assert(IdxMBB && "No MBB at Idx");
@@ -519,9 +533,10 @@ VNInfo *LiveIntervalMap::extendTo(MachineBasicBlock *MBB, SlotIndex Idx) {
void LiveIntervalMap::addSimpleRange(SlotIndex Start, SlotIndex End,
const VNInfo *ParentVNI) {
assert(li_ && "call reset first");
- VNInfo *VNI = mapValue(ParentVNI, Start);
- // A simple mappoing is easy.
- if (VNI->def == ParentVNI->def) {
+ bool simple;
+ VNInfo *VNI = mapValue(ParentVNI, Start, &simple);
+ // A simple mapping is easy.
+ if (simple) {
li_->addRange(LiveRange(Start, End, VNI));
return;
}
@@ -619,15 +634,19 @@ LiveInterval *SplitEditor::createInterval() {
return &Intv;
}
+bool SplitEditor::intervalsLiveAt(SlotIndex Idx) const {
+ for (int i = firstInterval, e = intervals_.size(); i != e; ++i)
+ if (intervals_[i]->liveAt(Idx))
+ return true;
+ return false;
+}
+
/// Create a new virtual register and live interval.
void SplitEditor::openIntv() {
assert(!openli_.getLI() && "Previous LI not closed before openIntv");
- if (!dupli_.getLI()) {
- // Create an interval for dupli that is a copy of curli.
+ if (!dupli_.getLI())
dupli_.reset(createInterval());
- dupli_.getLI()->Copy(*curli_, &mri_, lis_.getVNInfoAllocator());
- }
openli_.reset(createInterval());
intervals_.push_back(openli_.getLI());
@@ -642,6 +661,7 @@ void SplitEditor::enterIntvBefore(SlotIndex Idx) {
DEBUG(dbgs() << " enterIntvBefore " << Idx << ": not live\n");
return;
}
+ truncatedValues.insert(ParentVNI);
MachineInstr *MI = lis_.getInstructionFromIndex(Idx);
assert(MI && "enterIntvBefore called with invalid index");
openli_.defByCopyFrom(curli_->reg, ParentVNI, *MI->getParent(), MI);
@@ -658,6 +678,7 @@ void SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) {
DEBUG(dbgs() << " enterIntvAtEnd " << End << ": not live\n");
return;
}
+ truncatedValues.insert(ParentVNI);
VNInfo *VNI = openli_.defByCopyFrom(curli_->reg, ParentVNI,
MBB, MBB.getFirstTerminator());
// Make sure openli is live out of MBB.
@@ -693,7 +714,7 @@ void SplitEditor::leaveIntvAfter(SlotIndex Idx) {
assert(MI && "leaveIntvAfter called with invalid index");
VNInfo *VNI = dupli_.defByCopyFrom(openli_.getLI()->reg, ParentVNI,
- *MI->getParent(), MI);
+ *MI->getParent(), MI);
// Finally we must make sure that openli is properly extended from Idx to the
// new copy.
@@ -736,21 +757,93 @@ void SplitEditor::closeIntv() {
DEBUG(dbgs() << " closeIntv cleaning up\n");
DEBUG(dbgs() << " open " << *openli_.getLI() << '\n');
+ openli_.reset(0);
+}
- for (LiveInterval::iterator I = openli_.getLI()->begin(),
- E = openli_.getLI()->end(); I != E; ++I) {
- dupli_.getLI()->removeRange(I->start, I->end);
+void
+SplitEditor::addTruncSimpleRange(SlotIndex Start, SlotIndex End, VNInfo *VNI) {
+ SlotIndex sidx = Start;
+
+ // Break [Start;End) into segments that don't overlap any intervals.
+ for (;;) {
+ SlotIndex next = sidx, eidx = End;
+ // Find overlapping intervals.
+ for (int i = firstInterval, e = intervals_.size(); i != e && sidx < eidx;
+ ++i) {
+ LiveInterval::const_iterator I = intervals_[i]->find(sidx);
+ LiveInterval::const_iterator E = intervals_[i]->end();
+ if (I == E)
+ continue;
+ // Interval I is overlapping [sidx;eidx). Trim sidx.
+ if (I->start <= sidx) {
+ sidx = I->end;
+ if (++I == E)
+ continue;
+ }
+ // Trim eidx too if needed.
+ if (I->start >= eidx)
+ continue;
+ eidx = I->start;
+ if (I->end > next)
+ next = I->end;
+ }
+ // Now, [sidx;eidx) doesn't overlap anything in intervals_.
+ if (sidx < eidx)
+ dupli_.addSimpleRange(sidx, eidx, VNI);
+ // If the interval end was truncated, we can try again from next.
+ if (next <= sidx)
+ break;
+ sidx = next;
}
- // FIXME: A block branching to the entry block may also branch elsewhere
- // curli is live. We need both openli and curli to be live in that case.
- DEBUG(dbgs() << " dup2 " << *dupli_.getLI() << '\n');
- openli_.reset(0);
}
/// rewrite - after all the new live ranges have been created, rewrite
/// instructions using curli to use the new intervals.
bool SplitEditor::rewrite() {
assert(!openli_.getLI() && "Previous LI not closed before rewrite");
+
+ // First we need to fill in the live ranges in dupli.
+ // If values were redefined, we need a full recoloring with SSA update.
+ // If values were truncated, we only need to truncate the ranges.
+ // If values were partially rematted, we should shrink to uses.
+ // If values were fully rematted, they should be omitted.
+ // FIXME: If a single value is redefined, just move the def and truncate.
+
+ // Values that are fully contained in the split intervals.
+ SmallPtrSet<const VNInfo*, 8> deadValues;
+
+ // Map all curli values that should have live defs in dupli.
+ for (LiveInterval::const_vni_iterator I = curli_->vni_begin(),
+ E = curli_->vni_end(); I != E; ++I) {
+ const VNInfo *VNI = *I;
+ // Original def is contained in the split intervals.
+ if (intervalsLiveAt(VNI->def)) {
+ // Did this value escape?
+ if (dupli_.isMapped(VNI))
+ truncatedValues.insert(VNI);
+ else
+ deadValues.insert(VNI);
+ continue;
+ }
+ // Add minimal live range at the definition.
+ VNInfo *DVNI = dupli_.defValue(VNI, VNI->def);
+ dupli_.getLI()->addRange(LiveRange(VNI->def, VNI->def.getNextSlot(), DVNI));
+ }
+
+ // Add all ranges to dupli.
+ for (LiveInterval::const_iterator I = curli_->begin(), E = curli_->end();
+ I != E; ++I) {
+ const LiveRange &LR = *I;
+ if (truncatedValues.count(LR.valno)) {
+ // recolor after removing intervals_.
+ addTruncSimpleRange(LR.start, LR.end, LR.valno);
+ } else if (!deadValues.count(LR.valno)) {
+ // recolor without truncation.
+ dupli_.addSimpleRange(LR.start, LR.end, LR.valno);
+ }
+ }
+
+
const LiveInterval *curli = sa_.getCurLI();
for (MachineRegisterInfo::reg_iterator RI = mri_.reg_begin(curli->reg),
RE = mri_.reg_end(); RI != RE;) {
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-07-21 03:52:20 +0000