[llvm-commits] [llvm] r63536 - /llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
Evan Cheng
evan.cheng at apple.com
Mon Feb 2 10:33:18 PST 2009
Author: evancheng
Date: Mon Feb 2 12:33:18 2009
New Revision: 63536
URL: http://llvm.org/viewvc/llvm-project?rev=63536&view=rev
Log:
Refactor PerformPHIConstruction, no functionality changes.
Modified:
llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
Modified: llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp?rev=63536&r1=63535&r2=63536&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp (original)
+++ llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp Mon Feb 2 12:33:18 2009
@@ -164,16 +164,24 @@
bool removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split);
unsigned getNumberOfNonSpills(SmallPtrSet<MachineInstr*, 4>& MIs,
unsigned Reg, int FrameIndex, bool& TwoAddr);
- VNInfo* PerformPHIConstruction(MachineBasicBlock::iterator use,
- MachineBasicBlock* MBB,
- LiveInterval* LI,
+ VNInfo* PerformPHIConstruction(MachineBasicBlock::iterator Use,
+ MachineBasicBlock* MBB, LiveInterval* LI,
SmallPtrSet<MachineInstr*, 4>& Visited,
DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Defs,
DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Uses,
DenseMap<MachineInstr*, VNInfo*>& NewVNs,
DenseMap<MachineBasicBlock*, VNInfo*>& LiveOut,
DenseMap<MachineBasicBlock*, VNInfo*>& Phis,
- bool toplevel, bool intrablock);
+ bool IsTopLevel, bool IsIntraBlock);
+ VNInfo* PerformPHIConstructionFallBack(MachineBasicBlock::iterator Use,
+ MachineBasicBlock* MBB, LiveInterval* LI,
+ SmallPtrSet<MachineInstr*, 4>& Visited,
+ DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Defs,
+ DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Uses,
+ DenseMap<MachineInstr*, VNInfo*>& NewVNs,
+ DenseMap<MachineBasicBlock*, VNInfo*>& LiveOut,
+ DenseMap<MachineBasicBlock*, VNInfo*>& Phis,
+ bool IsTopLevel, bool IsIntraBlock);
};
} // end anonymous namespace
@@ -431,83 +439,35 @@
/// PerformPHIConstruction - From properly set up use and def lists, use a PHI
/// construction algorithm to compute the ranges and valnos for an interval.
-VNInfo* PreAllocSplitting::PerformPHIConstruction(
- MachineBasicBlock::iterator use,
- MachineBasicBlock* MBB,
- LiveInterval* LI,
+VNInfo*
+PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
+ MachineBasicBlock* MBB, LiveInterval* LI,
SmallPtrSet<MachineInstr*, 4>& Visited,
DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Defs,
DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Uses,
DenseMap<MachineInstr*, VNInfo*>& NewVNs,
DenseMap<MachineBasicBlock*, VNInfo*>& LiveOut,
DenseMap<MachineBasicBlock*, VNInfo*>& Phis,
- bool toplevel, bool intrablock) {
+ bool IsTopLevel, bool IsIntraBlock) {
// Return memoized result if it's available.
- if (toplevel && Visited.count(use) && NewVNs.count(use))
- return NewVNs[use];
- else if (!toplevel && intrablock && NewVNs.count(use))
- return NewVNs[use];
- else if (!intrablock && LiveOut.count(MBB))
+ if (IsTopLevel && Visited.count(UseI) && NewVNs.count(UseI))
+ return NewVNs[UseI];
+ else if (!IsTopLevel && IsIntraBlock && NewVNs.count(UseI))
+ return NewVNs[UseI];
+ else if (!IsIntraBlock && LiveOut.count(MBB))
return LiveOut[MBB];
- typedef DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> > RegMap;
-
// Check if our block contains any uses or defs.
bool ContainsDefs = Defs.count(MBB);
bool ContainsUses = Uses.count(MBB);
- VNInfo* ret = 0;
+ VNInfo* RetVNI = 0;
// Enumerate the cases of use/def contaning blocks.
if (!ContainsDefs && !ContainsUses) {
- Fallback:
- // NOTE: Because this is the fallback case from other cases, we do NOT
- // assume that we are not intrablock here.
- if (Phis.count(MBB)) return Phis[MBB];
-
- unsigned StartIndex = LIs->getMBBStartIdx(MBB);
-
- Phis[MBB] = ret = LI->getNextValue(~0U, /*FIXME*/ 0,
- LIs->getVNInfoAllocator());
- if (!intrablock) LiveOut[MBB] = ret;
-
- // If there are no uses or defs between our starting point and the
- // beginning of the block, then recursive perform phi construction
- // on our predecessors.
- DenseMap<MachineBasicBlock*, VNInfo*> IncomingVNs;
- for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
- PE = MBB->pred_end(); PI != PE; ++PI) {
- VNInfo* Incoming = PerformPHIConstruction((*PI)->end(), *PI, LI,
- Visited, Defs, Uses, NewVNs,
- LiveOut, Phis, false, false);
- if (Incoming != 0)
- IncomingVNs[*PI] = Incoming;
- }
-
- if (MBB->pred_size() == 1 && !ret->hasPHIKill) {
- LI->MergeValueNumberInto(ret, IncomingVNs.begin()->second);
- Phis[MBB] = ret = IncomingVNs.begin()->second;
- } else {
- // Otherwise, merge the incoming VNInfos with a phi join. Create a new
- // VNInfo to represent the joined value.
- for (DenseMap<MachineBasicBlock*, VNInfo*>::iterator I =
- IncomingVNs.begin(), E = IncomingVNs.end(); I != E; ++I) {
- I->second->hasPHIKill = true;
- unsigned KillIndex = LIs->getMBBEndIdx(I->first);
- if (!LiveInterval::isKill(I->second, KillIndex))
- LI->addKill(I->second, KillIndex);
- }
- }
-
- unsigned EndIndex = 0;
- if (intrablock) {
- EndIndex = LIs->getInstructionIndex(use);
- EndIndex = LiveIntervals::getUseIndex(EndIndex);
- } else
- EndIndex = LIs->getMBBEndIdx(MBB);
- LI->addRange(LiveRange(StartIndex, EndIndex+1, ret));
- if (intrablock)
- LI->addKill(ret, EndIndex);
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs, Uses,
+ NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
} else if (ContainsDefs && !ContainsUses) {
SmallPtrSet<MachineInstr*, 2>& BlockDefs = Defs[MBB];
@@ -515,71 +475,75 @@
// instruction we care about, go to the fallback case. Note that that
// should never happen: this cannot be intrablock, so use should
// always be an end() iterator.
- assert(use == MBB->end() && "No use marked in intrablock");
+ assert(UseI == MBB->end() && "No use marked in intrablock");
- MachineBasicBlock::iterator walker = use;
- --walker;
- while (walker != MBB->begin())
- if (BlockDefs.count(walker)) {
+ MachineBasicBlock::iterator Walker = UseI;
+ --Walker;
+ while (Walker != MBB->begin()) {
+ if (BlockDefs.count(Walker))
break;
- } else
- --walker;
+ --Walker;
+ }
// Once we've found it, extend its VNInfo to our instruction.
- unsigned DefIndex = LIs->getInstructionIndex(walker);
+ unsigned DefIndex = LIs->getInstructionIndex(Walker);
DefIndex = LiveIntervals::getDefIndex(DefIndex);
unsigned EndIndex = LIs->getMBBEndIdx(MBB);
- ret = NewVNs[walker];
- LI->addRange(LiveRange(DefIndex, EndIndex+1, ret));
+ RetVNI = NewVNs[Walker];
+ LI->addRange(LiveRange(DefIndex, EndIndex+1, RetVNI));
} else if (!ContainsDefs && ContainsUses) {
SmallPtrSet<MachineInstr*, 2>& BlockUses = Uses[MBB];
// Search for the use in this block that precedes the instruction we care
- // about, going to the fallback case if we don't find it.
+ // about, going to the fallback case if we don't find it.
+ if (UseI == MBB->begin())
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+ Uses, NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
- if (use == MBB->begin())
- goto Fallback;
-
- MachineBasicBlock::iterator walker = use;
- --walker;
+ MachineBasicBlock::iterator Walker = UseI;
+ --Walker;
bool found = false;
- while (walker != MBB->begin())
- if (BlockUses.count(walker)) {
+ while (Walker != MBB->begin()) {
+ if (BlockUses.count(Walker)) {
found = true;
break;
- } else
- --walker;
+ }
+ --Walker;
+ }
// Must check begin() too.
if (!found) {
- if (BlockUses.count(walker))
+ if (BlockUses.count(Walker))
found = true;
else
- goto Fallback;
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+ Uses, NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
}
- unsigned UseIndex = LIs->getInstructionIndex(walker);
+ unsigned UseIndex = LIs->getInstructionIndex(Walker);
UseIndex = LiveIntervals::getUseIndex(UseIndex);
unsigned EndIndex = 0;
- if (intrablock) {
- EndIndex = LIs->getInstructionIndex(use);
+ if (IsIntraBlock) {
+ EndIndex = LIs->getInstructionIndex(UseI);
EndIndex = LiveIntervals::getUseIndex(EndIndex);
} else
EndIndex = LIs->getMBBEndIdx(MBB);
// Now, recursively phi construct the VNInfo for the use we found,
// and then extend it to include the instruction we care about
- ret = PerformPHIConstruction(walker, MBB, LI, Visited, Defs, Uses,
- NewVNs, LiveOut, Phis, false, true);
+ RetVNI = PerformPHIConstruction(Walker, MBB, LI, Visited, Defs, Uses,
+ NewVNs, LiveOut, Phis, false, true);
- LI->addRange(LiveRange(UseIndex, EndIndex+1, ret));
+ LI->addRange(LiveRange(UseIndex, EndIndex+1, RetVNI));
// FIXME: Need to set kills properly for inter-block stuff.
- if (LI->isKill(ret, UseIndex)) LI->removeKill(ret, UseIndex);
- if (intrablock)
- LI->addKill(ret, EndIndex);
- } else if (ContainsDefs && ContainsUses){
+ if (LI->isKill(RetVNI, UseIndex)) LI->removeKill(RetVNI, UseIndex);
+ if (IsIntraBlock)
+ LI->addKill(RetVNI, EndIndex);
+ } else if (ContainsDefs && ContainsUses) {
SmallPtrSet<MachineInstr*, 2>& BlockDefs = Defs[MBB];
SmallPtrSet<MachineInstr*, 2>& BlockUses = Uses[MBB];
@@ -587,67 +551,143 @@
// special note that checking for defs must take precedence over checking
// for uses, because of two-address instructions.
- if (use == MBB->begin())
- goto Fallback;
+ if (UseI == MBB->begin())
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs, Uses,
+ NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
- MachineBasicBlock::iterator walker = use;
- --walker;
+ MachineBasicBlock::iterator Walker = UseI;
+ --Walker;
bool foundDef = false;
bool foundUse = false;
- while (walker != MBB->begin())
- if (BlockDefs.count(walker)) {
+ while (Walker != MBB->begin()) {
+ if (BlockDefs.count(Walker)) {
foundDef = true;
break;
- } else if (BlockUses.count(walker)) {
+ } else if (BlockUses.count(Walker)) {
foundUse = true;
break;
- } else
- --walker;
+ }
+ --Walker;
+ }
// Must check begin() too.
if (!foundDef && !foundUse) {
- if (BlockDefs.count(walker))
+ if (BlockDefs.count(Walker))
foundDef = true;
- else if (BlockUses.count(walker))
+ else if (BlockUses.count(Walker))
foundUse = true;
else
- goto Fallback;
+ return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+ Uses, NewVNs, LiveOut, Phis,
+ IsTopLevel, IsIntraBlock);
}
- unsigned StartIndex = LIs->getInstructionIndex(walker);
+ unsigned StartIndex = LIs->getInstructionIndex(Walker);
StartIndex = foundDef ? LiveIntervals::getDefIndex(StartIndex) :
LiveIntervals::getUseIndex(StartIndex);
unsigned EndIndex = 0;
- if (intrablock) {
- EndIndex = LIs->getInstructionIndex(use);
+ if (IsIntraBlock) {
+ EndIndex = LIs->getInstructionIndex(UseI);
EndIndex = LiveIntervals::getUseIndex(EndIndex);
} else
EndIndex = LIs->getMBBEndIdx(MBB);
if (foundDef)
- ret = NewVNs[walker];
+ RetVNI = NewVNs[Walker];
else
- ret = PerformPHIConstruction(walker, MBB, LI, Visited, Defs, Uses,
- NewVNs, LiveOut, Phis, false, true);
+ RetVNI = PerformPHIConstruction(Walker, MBB, LI, Visited, Defs, Uses,
+ NewVNs, LiveOut, Phis, false, true);
- LI->addRange(LiveRange(StartIndex, EndIndex+1, ret));
+ LI->addRange(LiveRange(StartIndex, EndIndex+1, RetVNI));
- if (foundUse && LI->isKill(ret, StartIndex))
- LI->removeKill(ret, StartIndex);
- if (intrablock) {
- LI->addKill(ret, EndIndex);
+ if (foundUse && LI->isKill(RetVNI, StartIndex))
+ LI->removeKill(RetVNI, StartIndex);
+ if (IsIntraBlock) {
+ LI->addKill(RetVNI, EndIndex);
}
}
// Memoize results so we don't have to recompute them.
- if (!intrablock) LiveOut[MBB] = ret;
+ if (!IsIntraBlock) LiveOut[MBB] = RetVNI;
+ else {
+ if (!NewVNs.count(UseI))
+ NewVNs[UseI] = RetVNI;
+ Visited.insert(UseI);
+ }
+
+ return RetVNI;
+}
+
+/// PerformPHIConstructionFallBack - PerformPHIConstruction fall back path.
+///
+VNInfo*
+PreAllocSplitting::PerformPHIConstructionFallBack(MachineBasicBlock::iterator UseI,
+ MachineBasicBlock* MBB, LiveInterval* LI,
+ SmallPtrSet<MachineInstr*, 4>& Visited,
+ DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Defs,
+ DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 2> >& Uses,
+ DenseMap<MachineInstr*, VNInfo*>& NewVNs,
+ DenseMap<MachineBasicBlock*, VNInfo*>& LiveOut,
+ DenseMap<MachineBasicBlock*, VNInfo*>& Phis,
+ bool IsTopLevel, bool IsIntraBlock) {
+ // NOTE: Because this is the fallback case from other cases, we do NOT
+ // assume that we are not intrablock here.
+ if (Phis.count(MBB)) return Phis[MBB];
+
+ unsigned StartIndex = LIs->getMBBStartIdx(MBB);
+ VNInfo *RetVNI = Phis[MBB] = LI->getNextValue(~0U, /*FIXME*/ 0,
+ LIs->getVNInfoAllocator());
+ if (!IsIntraBlock) LiveOut[MBB] = RetVNI;
+
+ // If there are no uses or defs between our starting point and the
+ // beginning of the block, then recursive perform phi construction
+ // on our predecessors.
+ DenseMap<MachineBasicBlock*, VNInfo*> IncomingVNs;
+ for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
+ PE = MBB->pred_end(); PI != PE; ++PI) {
+ VNInfo* Incoming = PerformPHIConstruction((*PI)->end(), *PI, LI,
+ Visited, Defs, Uses, NewVNs,
+ LiveOut, Phis, false, false);
+ if (Incoming != 0)
+ IncomingVNs[*PI] = Incoming;
+ }
+
+ if (MBB->pred_size() == 1 && !RetVNI->hasPHIKill) {
+ LI->MergeValueNumberInto(RetVNI, IncomingVNs.begin()->second);
+ Phis[MBB] = RetVNI = IncomingVNs.begin()->second;
+ } else {
+ // Otherwise, merge the incoming VNInfos with a phi join. Create a new
+ // VNInfo to represent the joined value.
+ for (DenseMap<MachineBasicBlock*, VNInfo*>::iterator I =
+ IncomingVNs.begin(), E = IncomingVNs.end(); I != E; ++I) {
+ I->second->hasPHIKill = true;
+ unsigned KillIndex = LIs->getMBBEndIdx(I->first);
+ if (!LiveInterval::isKill(I->second, KillIndex))
+ LI->addKill(I->second, KillIndex);
+ }
+ }
+
+ unsigned EndIndex = 0;
+ if (IsIntraBlock) {
+ EndIndex = LIs->getInstructionIndex(UseI);
+ EndIndex = LiveIntervals::getUseIndex(EndIndex);
+ } else
+ EndIndex = LIs->getMBBEndIdx(MBB);
+ LI->addRange(LiveRange(StartIndex, EndIndex+1, RetVNI));
+ if (IsIntraBlock)
+ LI->addKill(RetVNI, EndIndex);
+
+ // Memoize results so we don't have to recompute them.
+ if (!IsIntraBlock)
+ LiveOut[MBB] = RetVNI;
else {
- if (!NewVNs.count(use))
- NewVNs[use] = ret;
- Visited.insert(use);
+ if (!NewVNs.count(UseI))
+ NewVNs[UseI] = RetVNI;
+ Visited.insert(UseI);
}
- return ret;
+ return RetVNI;
}
/// ReconstructLiveInterval - Recompute a live interval from scratch.
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