[llvm-commits] [llvm] r91273 - in /llvm/trunk: include/llvm/CodeGen/CalcSpillWeights.h lib/CodeGen/CalcSpillWeights.cpp lib/CodeGen/PreAllocSplitting.cpp lib/CodeGen/RegAllocLinearScan.cpp lib/CodeGen/RegAllocPBQP.cpp lib/CodeGen/SimpleRegisterCoalescing.cpp lib/CodeGen/SimpleRegisterCoalescing.h
Lang Hames
lhames at gmail.com
Sun Dec 13 22:49:42 PST 2009
Author: lhames
Date: Mon Dec 14 00:49:42 2009
New Revision: 91273
URL: http://llvm.org/viewvc/llvm-project?rev=91273&view=rev
Log:
Moved spill weight calculation out of SimpleRegisterCoalescing and into its own pass: CalculateSpillWeights.
Added:
llvm/trunk/include/llvm/CodeGen/CalcSpillWeights.h
llvm/trunk/lib/CodeGen/CalcSpillWeights.cpp
Modified:
llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp
llvm/trunk/lib/CodeGen/RegAllocPBQP.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
Added: llvm/trunk/include/llvm/CodeGen/CalcSpillWeights.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/CalcSpillWeights.h?rev=91273&view=auto
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/CalcSpillWeights.h (added)
+++ llvm/trunk/include/llvm/CodeGen/CalcSpillWeights.h Mon Dec 14 00:49:42 2009
@@ -0,0 +1,39 @@
+//===---------------- lib/CodeGen/CalcSpillWeights.h ------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+
+#ifndef LLVM_CODEGEN_CALCSPILLWEIGHTS_H
+#define LLVM_CODEGEN_CALCSPILLWEIGHTS_H
+
+#include "llvm/CodeGen/MachineFunctionPass.h"
+
+namespace llvm {
+
+ class LiveInterval;
+
+ /// CalculateSpillWeights - Compute spill weights for all virtual register
+ /// live intervals.
+ class CalculateSpillWeights : public MachineFunctionPass {
+ public:
+ static char ID;
+
+ CalculateSpillWeights() : MachineFunctionPass(&ID) {}
+
+ virtual void getAnalysisUsage(AnalysisUsage &au) const;
+
+ virtual bool runOnMachineFunction(MachineFunction &fn);
+
+ private:
+ /// Returns true if the given live interval is zero length.
+ bool isZeroLengthInterval(LiveInterval *li) const;
+ };
+
+}
+
+#endif // LLVM_CODEGEN_CALCSPILLWEIGHTS_H
Added: llvm/trunk/lib/CodeGen/CalcSpillWeights.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CalcSpillWeights.cpp?rev=91273&view=auto
==============================================================================
--- llvm/trunk/lib/CodeGen/CalcSpillWeights.cpp (added)
+++ llvm/trunk/lib/CodeGen/CalcSpillWeights.cpp Mon Dec 14 00:49:42 2009
@@ -0,0 +1,154 @@
+//===------------------------ CalcSpillWeights.cpp ------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "calcspillweights"
+
+#include "llvm/Function.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/CodeGen/CalcSpillWeights.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+
+using namespace llvm;
+
+char CalculateSpillWeights::ID = 0;
+static RegisterPass<CalculateSpillWeights> X("calcspillweights",
+ "Calculate spill weights");
+
+void CalculateSpillWeights::getAnalysisUsage(AnalysisUsage &au) const {
+ au.addRequired<LiveIntervals>();
+ au.addRequired<MachineLoopInfo>();
+ au.setPreservesAll();
+ MachineFunctionPass::getAnalysisUsage(au);
+}
+
+bool CalculateSpillWeights::runOnMachineFunction(MachineFunction &fn) {
+
+ DEBUG(errs() << "********** Compute Spill Weights **********\n"
+ << "********** Function: "
+ << fn.getFunction()->getName() << '\n');
+
+ LiveIntervals *lis = &getAnalysis<LiveIntervals>();
+ MachineLoopInfo *loopInfo = &getAnalysis<MachineLoopInfo>();
+ const TargetInstrInfo *tii = fn.getTarget().getInstrInfo();
+ MachineRegisterInfo *mri = &fn.getRegInfo();
+
+ SmallSet<unsigned, 4> processed;
+ for (MachineFunction::iterator mbbi = fn.begin(), mbbe = fn.end();
+ mbbi != mbbe; ++mbbi) {
+ MachineBasicBlock* mbb = mbbi;
+ SlotIndex mbbEnd = lis->getMBBEndIdx(mbb);
+ MachineLoop* loop = loopInfo->getLoopFor(mbb);
+ unsigned loopDepth = loop ? loop->getLoopDepth() : 0;
+ bool isExiting = loop ? loop->isLoopExiting(mbb) : false;
+
+ for (MachineBasicBlock::const_iterator mii = mbb->begin(), mie = mbb->end();
+ mii != mie; ++mii) {
+ const MachineInstr *mi = mii;
+ if (tii->isIdentityCopy(*mi))
+ continue;
+
+ if (mi->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
+ continue;
+
+ for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) {
+ const MachineOperand &mopi = mi->getOperand(i);
+ if (!mopi.isReg() || mopi.getReg() == 0)
+ continue;
+ unsigned reg = mopi.getReg();
+ if (!TargetRegisterInfo::isVirtualRegister(mopi.getReg()))
+ continue;
+ // Multiple uses of reg by the same instruction. It should not
+ // contribute to spill weight again.
+ if (!processed.insert(reg))
+ continue;
+
+ bool hasDef = mopi.isDef();
+ bool hasUse = !hasDef;
+ for (unsigned j = i+1; j != e; ++j) {
+ const MachineOperand &mopj = mi->getOperand(j);
+ if (!mopj.isReg() || mopj.getReg() != reg)
+ continue;
+ hasDef |= mopj.isDef();
+ hasUse |= mopj.isUse();
+ if (hasDef && hasUse)
+ break;
+ }
+
+ LiveInterval ®Int = lis->getInterval(reg);
+ float weight = lis->getSpillWeight(hasDef, hasUse, loopDepth);
+ if (hasDef && isExiting) {
+ // Looks like this is a loop count variable update.
+ SlotIndex defIdx = lis->getInstructionIndex(mi).getDefIndex();
+ const LiveRange *dlr =
+ lis->getInterval(reg).getLiveRangeContaining(defIdx);
+ if (dlr->end > mbbEnd)
+ weight *= 3.0F;
+ }
+ regInt.weight += weight;
+ }
+ processed.clear();
+ }
+ }
+
+ for (LiveIntervals::iterator I = lis->begin(), E = lis->end(); I != E; ++I) {
+ LiveInterval &li = *I->second;
+ if (TargetRegisterInfo::isVirtualRegister(li.reg)) {
+ // If the live interval length is essentially zero, i.e. in every live
+ // range the use follows def immediately, it doesn't make sense to spill
+ // it and hope it will be easier to allocate for this li.
+ if (isZeroLengthInterval(&li)) {
+ li.weight = HUGE_VALF;
+ continue;
+ }
+
+ bool isLoad = false;
+ SmallVector<LiveInterval*, 4> spillIs;
+ if (lis->isReMaterializable(li, spillIs, isLoad)) {
+ // If all of the definitions of the interval are re-materializable,
+ // it is a preferred candidate for spilling. If non of the defs are
+ // loads, then it's potentially very cheap to re-materialize.
+ // FIXME: this gets much more complicated once we support non-trivial
+ // re-materialization.
+ if (isLoad)
+ li.weight *= 0.9F;
+ else
+ li.weight *= 0.5F;
+ }
+
+ // Slightly prefer live interval that has been assigned a preferred reg.
+ std::pair<unsigned, unsigned> Hint = mri->getRegAllocationHint(li.reg);
+ if (Hint.first || Hint.second)
+ li.weight *= 1.01F;
+
+ // Divide the weight of the interval by its size. This encourages
+ // spilling of intervals that are large and have few uses, and
+ // discourages spilling of small intervals with many uses.
+ li.weight /= lis->getApproximateInstructionCount(li) * SlotIndex::NUM;
+ }
+ }
+
+ return false;
+}
+
+/// Returns true if the given live interval is zero length.
+bool CalculateSpillWeights::isZeroLengthInterval(LiveInterval *li) const {
+ for (LiveInterval::Ranges::const_iterator
+ i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
+ if (i->end.getPrevIndex() > i->start)
+ return false;
+ return true;
+}
Modified: llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp?rev=91273&r1=91272&r2=91273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp (original)
+++ llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp Mon Dec 14 00:49:42 2009
@@ -16,6 +16,7 @@
#define DEBUG_TYPE "pre-alloc-split"
#include "VirtRegMap.h"
+#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
@@ -104,6 +105,7 @@
AU.addRequired<LiveStacks>();
AU.addPreserved<LiveStacks>();
AU.addPreserved<RegisterCoalescer>();
+ AU.addPreserved<CalculateSpillWeights>();
if (StrongPHIElim)
AU.addPreservedID(StrongPHIEliminationID);
else
Modified: llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp?rev=91273&r1=91272&r2=91273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp Mon Dec 14 00:49:42 2009
@@ -16,6 +16,7 @@
#include "VirtRegRewriter.h"
#include "Spiller.h"
#include "llvm/Function.h"
+#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
@@ -187,6 +188,7 @@
// Make sure PassManager knows which analyses to make available
// to coalescing and which analyses coalescing invalidates.
AU.addRequiredTransitive<RegisterCoalescer>();
+ AU.addRequired<CalculateSpillWeights>();
if (PreSplitIntervals)
AU.addRequiredID(PreAllocSplittingID);
AU.addRequired<LiveStacks>();
Modified: llvm/trunk/lib/CodeGen/RegAllocPBQP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocPBQP.cpp?rev=91273&r1=91272&r2=91273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocPBQP.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocPBQP.cpp Mon Dec 14 00:49:42 2009
@@ -36,6 +36,7 @@
#include "PBQP/Heuristics/Briggs.h"
#include "VirtRegMap.h"
#include "VirtRegRewriter.h"
+#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
@@ -90,6 +91,7 @@
au.addRequired<LiveIntervals>();
//au.addRequiredID(SplitCriticalEdgesID);
au.addRequired<RegisterCoalescer>();
+ au.addRequired<CalculateSpillWeights>();
au.addRequired<LiveStacks>();
au.addPreserved<LiveStacks>();
au.addRequired<MachineLoopInfo>();
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=91273&r1=91272&r2=91273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Mon Dec 14 00:49:42 2009
@@ -2622,114 +2622,6 @@
ReMatDefs.clear();
}
-/// Returns true if the given live interval is zero length.
-static bool isZeroLengthInterval(LiveInterval *li, LiveIntervals *li_) {
- for (LiveInterval::Ranges::const_iterator
- i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
- if (i->end.getPrevIndex() > i->start)
- return false;
- return true;
-}
-
-
-void SimpleRegisterCoalescing::CalculateSpillWeights() {
- SmallSet<unsigned, 4> Processed;
- for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
- mbbi != mbbe; ++mbbi) {
- MachineBasicBlock* MBB = mbbi;
- SlotIndex MBBEnd = li_->getMBBEndIdx(MBB);
- MachineLoop* loop = loopInfo->getLoopFor(MBB);
- unsigned loopDepth = loop ? loop->getLoopDepth() : 0;
- bool isExiting = loop ? loop->isLoopExiting(MBB) : false;
-
- for (MachineBasicBlock::const_iterator mii = MBB->begin(), mie = MBB->end();
- mii != mie; ++mii) {
- const MachineInstr *MI = mii;
- if (tii_->isIdentityCopy(*MI))
- continue;
-
- if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
- continue;
-
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- const MachineOperand &mopi = MI->getOperand(i);
- if (!mopi.isReg() || mopi.getReg() == 0)
- continue;
- unsigned Reg = mopi.getReg();
- if (!TargetRegisterInfo::isVirtualRegister(mopi.getReg()))
- continue;
- // Multiple uses of reg by the same instruction. It should not
- // contribute to spill weight again.
- if (!Processed.insert(Reg))
- continue;
-
- bool HasDef = mopi.isDef();
- bool HasUse = !HasDef;
- for (unsigned j = i+1; j != e; ++j) {
- const MachineOperand &mopj = MI->getOperand(j);
- if (!mopj.isReg() || mopj.getReg() != Reg)
- continue;
- HasDef |= mopj.isDef();
- HasUse |= mopj.isUse();
- if (HasDef && HasUse)
- break;
- }
-
- LiveInterval &RegInt = li_->getInterval(Reg);
- float Weight = li_->getSpillWeight(HasDef, HasUse, loopDepth);
- if (HasDef && isExiting) {
- // Looks like this is a loop count variable update.
- SlotIndex DefIdx = li_->getInstructionIndex(MI).getDefIndex();
- const LiveRange *DLR =
- li_->getInterval(Reg).getLiveRangeContaining(DefIdx);
- if (DLR->end > MBBEnd)
- Weight *= 3.0F;
- }
- RegInt.weight += Weight;
- }
- Processed.clear();
- }
- }
-
- for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I) {
- LiveInterval &LI = *I->second;
- if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
- // If the live interval length is essentially zero, i.e. in every live
- // range the use follows def immediately, it doesn't make sense to spill
- // it and hope it will be easier to allocate for this li.
- if (isZeroLengthInterval(&LI, li_)) {
- LI.weight = HUGE_VALF;
- continue;
- }
-
- bool isLoad = false;
- SmallVector<LiveInterval*, 4> SpillIs;
- if (li_->isReMaterializable(LI, SpillIs, isLoad)) {
- // If all of the definitions of the interval are re-materializable,
- // it is a preferred candidate for spilling. If non of the defs are
- // loads, then it's potentially very cheap to re-materialize.
- // FIXME: this gets much more complicated once we support non-trivial
- // re-materialization.
- if (isLoad)
- LI.weight *= 0.9F;
- else
- LI.weight *= 0.5F;
- }
-
- // Slightly prefer live interval that has been assigned a preferred reg.
- std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(LI.reg);
- if (Hint.first || Hint.second)
- LI.weight *= 1.01F;
-
- // Divide the weight of the interval by its size. This encourages
- // spilling of intervals that are large and have few uses, and
- // discourages spilling of small intervals with many uses.
- LI.weight /= li_->getApproximateInstructionCount(LI) * InstrSlots::NUM;
- }
- }
-}
-
-
bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
mf_ = &fn;
mri_ = &fn.getRegInfo();
@@ -2860,8 +2752,6 @@
}
}
- CalculateSpillWeights();
-
DEBUG(dump());
return true;
}
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h?rev=91273&r1=91272&r2=91273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h Mon Dec 14 00:49:42 2009
@@ -244,10 +244,6 @@
MachineOperand *lastRegisterUse(SlotIndex Start, SlotIndex End,
unsigned Reg, SlotIndex &LastUseIdx) const;
- /// CalculateSpillWeights - Compute spill weights for all virtual register
- /// live intervals.
- void CalculateSpillWeights();
-
void printRegName(unsigned reg) const;
};
More information about the llvm-commits
mailing list