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-rw-r--r--llvm/lib/CodeGen/CMakeLists.txt1
-rw-r--r--llvm/lib/CodeGen/RegAllocBase.cpp334
-rw-r--r--llvm/lib/CodeGen/RegAllocBasic.cpp313
3 files changed, 336 insertions, 312 deletions
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index 7fa5e47f9eb..65d4971ba3c 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/llvm/lib/CodeGen/CMakeLists.txt
@@ -69,6 +69,7 @@ add_llvm_library(LLVMCodeGen
ProcessImplicitDefs.cpp
PrologEpilogInserter.cpp
PseudoSourceValue.cpp
+ RegAllocBase.cpp
RegAllocBasic.cpp
RegAllocFast.cpp
RegAllocGreedy.cpp
diff --git a/llvm/lib/CodeGen/RegAllocBase.cpp b/llvm/lib/CodeGen/RegAllocBase.cpp
new file mode 100644
index 00000000000..3f77df3221d
--- /dev/null
+++ b/llvm/lib/CodeGen/RegAllocBase.cpp
@@ -0,0 +1,334 @@
+//===-- RegAllocBase.cpp - Register Allocator Base Class ------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the RegAllocBase class which provides comon functionality
+// for LiveIntervalUnion-based register allocators.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "regalloc"
+#include "RegAllocBase.h"
+#include "LiveRangeEdit.h"
+#include "Spiller.h"
+#include "VirtRegMap.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#ifndef NDEBUG
+#include "llvm/ADT/SparseBitVector.h"
+#endif
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Timer.h"
+
+using namespace llvm;
+
+STATISTIC(NumAssigned , "Number of registers assigned");
+STATISTIC(NumUnassigned , "Number of registers unassigned");
+STATISTIC(NumNewQueued , "Number of new live ranges queued");
+
+// Temporary verification option until we can put verification inside
+// MachineVerifier.
+static cl::opt<bool, true>
+VerifyRegAlloc("verify-regalloc", cl::location(RegAllocBase::VerifyEnabled),
+ cl::desc("Verify during register allocation"));
+
+const char *RegAllocBase::TimerGroupName = "Register Allocation";
+bool RegAllocBase::VerifyEnabled = false;
+
+#ifndef NDEBUG
+// Verify each LiveIntervalUnion.
+void RegAllocBase::verify() {
+ LiveVirtRegBitSet VisitedVRegs;
+ OwningArrayPtr<LiveVirtRegBitSet>
+ unionVRegs(new LiveVirtRegBitSet[PhysReg2LiveUnion.numRegs()]);
+
+ // Verify disjoint unions.
+ for (unsigned PhysReg = 0; PhysReg < PhysReg2LiveUnion.numRegs(); ++PhysReg) {
+ DEBUG(PhysReg2LiveUnion[PhysReg].print(dbgs(), TRI));
+ LiveVirtRegBitSet &VRegs = unionVRegs[PhysReg];
+ PhysReg2LiveUnion[PhysReg].verify(VRegs);
+ // Union + intersection test could be done efficiently in one pass, but
+ // don't add a method to SparseBitVector unless we really need it.
+ assert(!VisitedVRegs.intersects(VRegs) && "vreg in multiple unions");
+ VisitedVRegs |= VRegs;
+ }
+
+ // Verify vreg coverage.
+ for (LiveIntervals::iterator liItr = LIS->begin(), liEnd = LIS->end();
+ liItr != liEnd; ++liItr) {
+ unsigned reg = liItr->first;
+ if (TargetRegisterInfo::isPhysicalRegister(reg)) continue;
+ if (!VRM->hasPhys(reg)) continue; // spilled?
+ unsigned PhysReg = VRM->getPhys(reg);
+ if (!unionVRegs[PhysReg].test(reg)) {
+ dbgs() << "LiveVirtReg " << reg << " not in union " <<
+ TRI->getName(PhysReg) << "\n";
+ llvm_unreachable("unallocated live vreg");
+ }
+ }
+ // FIXME: I'm not sure how to verify spilled intervals.
+}
+#endif //!NDEBUG
+
+//===----------------------------------------------------------------------===//
+// RegAllocBase Implementation
+//===----------------------------------------------------------------------===//
+
+// Instantiate a LiveIntervalUnion for each physical register.
+void RegAllocBase::LiveUnionArray::init(LiveIntervalUnion::Allocator &allocator,
+ unsigned NRegs) {
+ NumRegs = NRegs;
+ Array =
+ static_cast<LiveIntervalUnion*>(malloc(sizeof(LiveIntervalUnion)*NRegs));
+ for (unsigned r = 0; r != NRegs; ++r)
+ new(Array + r) LiveIntervalUnion(r, allocator);
+}
+
+void RegAllocBase::init(VirtRegMap &vrm, LiveIntervals &lis) {
+ NamedRegionTimer T("Initialize", TimerGroupName, TimePassesIsEnabled);
+ TRI = &vrm.getTargetRegInfo();
+ MRI = &vrm.getRegInfo();
+ VRM = &vrm;
+ LIS = &lis;
+ MRI->freezeReservedRegs(vrm.getMachineFunction());
+ RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
+
+ const unsigned NumRegs = TRI->getNumRegs();
+ if (NumRegs != PhysReg2LiveUnion.numRegs()) {
+ PhysReg2LiveUnion.init(UnionAllocator, NumRegs);
+ // Cache an interferece query for each physical reg
+ Queries.reset(new LiveIntervalUnion::Query[PhysReg2LiveUnion.numRegs()]);
+ }
+}
+
+void RegAllocBase::LiveUnionArray::clear() {
+ if (!Array)
+ return;
+ for (unsigned r = 0; r != NumRegs; ++r)
+ Array[r].~LiveIntervalUnion();
+ free(Array);
+ NumRegs = 0;
+ Array = 0;
+}
+
+void RegAllocBase::releaseMemory() {
+ for (unsigned r = 0, e = PhysReg2LiveUnion.numRegs(); r != e; ++r)
+ PhysReg2LiveUnion[r].clear();
+}
+
+// Visit all the live registers. If they are already assigned to a physical
+// register, unify them with the corresponding LiveIntervalUnion, otherwise push
+// them on the priority queue for later assignment.
+void RegAllocBase::seedLiveRegs() {
+ NamedRegionTimer T("Seed Live Regs", TimerGroupName, TimePassesIsEnabled);
+ for (LiveIntervals::iterator I = LIS->begin(), E = LIS->end(); I != E; ++I) {
+ unsigned RegNum = I->first;
+ LiveInterval &VirtReg = *I->second;
+ if (TargetRegisterInfo::isPhysicalRegister(RegNum))
+ PhysReg2LiveUnion[RegNum].unify(VirtReg);
+ else
+ enqueue(&VirtReg);
+ }
+}
+
+void RegAllocBase::assign(LiveInterval &VirtReg, unsigned PhysReg) {
+ DEBUG(dbgs() << "assigning " << PrintReg(VirtReg.reg, TRI)
+ << " to " << PrintReg(PhysReg, TRI) << '\n');
+ assert(!VRM->hasPhys(VirtReg.reg) && "Duplicate VirtReg assignment");
+ VRM->assignVirt2Phys(VirtReg.reg, PhysReg);
+ MRI->setPhysRegUsed(PhysReg);
+ PhysReg2LiveUnion[PhysReg].unify(VirtReg);
+ ++NumAssigned;
+}
+
+void RegAllocBase::unassign(LiveInterval &VirtReg, unsigned PhysReg) {
+ DEBUG(dbgs() << "unassigning " << PrintReg(VirtReg.reg, TRI)
+ << " from " << PrintReg(PhysReg, TRI) << '\n');
+ assert(VRM->getPhys(VirtReg.reg) == PhysReg && "Inconsistent unassign");
+ PhysReg2LiveUnion[PhysReg].extract(VirtReg);
+ VRM->clearVirt(VirtReg.reg);
+ ++NumUnassigned;
+}
+
+// Top-level driver to manage the queue of unassigned VirtRegs and call the
+// selectOrSplit implementation.
+void RegAllocBase::allocatePhysRegs() {
+ seedLiveRegs();
+
+ // Continue assigning vregs one at a time to available physical registers.
+ while (LiveInterval *VirtReg = dequeue()) {
+ assert(!VRM->hasPhys(VirtReg->reg) && "Register already assigned");
+
+ // Unused registers can appear when the spiller coalesces snippets.
+ if (MRI->reg_nodbg_empty(VirtReg->reg)) {
+ DEBUG(dbgs() << "Dropping unused " << *VirtReg << '\n');
+ LIS->removeInterval(VirtReg->reg);
+ continue;
+ }
+
+ // Invalidate all interference queries, live ranges could have changed.
+ invalidateVirtRegs();
+
+ // selectOrSplit requests the allocator to return an available physical
+ // register if possible and populate a list of new live intervals that
+ // result from splitting.
+ DEBUG(dbgs() << "\nselectOrSplit "
+ << MRI->getRegClass(VirtReg->reg)->getName()
+ << ':' << *VirtReg << '\n');
+ typedef SmallVector<LiveInterval*, 4> VirtRegVec;
+ VirtRegVec SplitVRegs;
+ unsigned AvailablePhysReg = selectOrSplit(*VirtReg, SplitVRegs);
+
+ if (AvailablePhysReg == ~0u) {
+ // selectOrSplit failed to find a register!
+ const char *Msg = "ran out of registers during register allocation";
+ // Probably caused by an inline asm.
+ MachineInstr *MI;
+ for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(VirtReg->reg);
+ (MI = I.skipInstruction());)
+ if (MI->isInlineAsm())
+ break;
+ if (MI)
+ MI->emitError(Msg);
+ else
+ report_fatal_error(Msg);
+ // Keep going after reporting the error.
+ VRM->assignVirt2Phys(VirtReg->reg,
+ RegClassInfo.getOrder(MRI->getRegClass(VirtReg->reg)).front());
+ continue;
+ }
+
+ if (AvailablePhysReg)
+ assign(*VirtReg, AvailablePhysReg);
+
+ for (VirtRegVec::iterator I = SplitVRegs.begin(), E = SplitVRegs.end();
+ I != E; ++I) {
+ LiveInterval *SplitVirtReg = *I;
+ assert(!VRM->hasPhys(SplitVirtReg->reg) && "Register already assigned");
+ if (MRI->reg_nodbg_empty(SplitVirtReg->reg)) {
+ DEBUG(dbgs() << "not queueing unused " << *SplitVirtReg << '\n');
+ LIS->removeInterval(SplitVirtReg->reg);
+ continue;
+ }
+ DEBUG(dbgs() << "queuing new interval: " << *SplitVirtReg << "\n");
+ assert(TargetRegisterInfo::isVirtualRegister(SplitVirtReg->reg) &&
+ "expect split value in virtual register");
+ enqueue(SplitVirtReg);
+ ++NumNewQueued;
+ }
+ }
+}
+
+// Check if this live virtual register interferes with a physical register. If
+// not, then check for interference on each register that aliases with the
+// physical register. Return the interfering register.
+unsigned RegAllocBase::checkPhysRegInterference(LiveInterval &VirtReg,
+ unsigned PhysReg) {
+ for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
+ if (query(VirtReg, *AliasI).checkInterference())
+ return *AliasI;
+ return 0;
+}
+
+// Helper for spillInteferences() that spills all interfering vregs currently
+// assigned to this physical register.
+void RegAllocBase::spillReg(LiveInterval& VirtReg, unsigned PhysReg,
+ SmallVectorImpl<LiveInterval*> &SplitVRegs) {
+ LiveIntervalUnion::Query &Q = query(VirtReg, PhysReg);
+ assert(Q.seenAllInterferences() && "need collectInterferences()");
+ const SmallVectorImpl<LiveInterval*> &PendingSpills = Q.interferingVRegs();
+
+ for (SmallVectorImpl<LiveInterval*>::const_iterator I = PendingSpills.begin(),
+ E = PendingSpills.end(); I != E; ++I) {
+ LiveInterval &SpilledVReg = **I;
+ DEBUG(dbgs() << "extracting from " <<
+ TRI->getName(PhysReg) << " " << SpilledVReg << '\n');
+
+ // Deallocate the interfering vreg by removing it from the union.
+ // A LiveInterval instance may not be in a union during modification!
+ unassign(SpilledVReg, PhysReg);
+
+ // Spill the extracted interval.
+ LiveRangeEdit LRE(SpilledVReg, SplitVRegs, 0, &PendingSpills);
+ spiller().spill(LRE);
+ }
+ // After extracting segments, the query's results are invalid. But keep the
+ // contents valid until we're done accessing pendingSpills.
+ Q.clear();
+}
+
+// Spill or split all live virtual registers currently unified under PhysReg
+// that interfere with VirtReg. The newly spilled or split live intervals are
+// returned by appending them to SplitVRegs.
+bool
+RegAllocBase::spillInterferences(LiveInterval &VirtReg, unsigned PhysReg,
+ SmallVectorImpl<LiveInterval*> &SplitVRegs) {
+ // Record each interference and determine if all are spillable before mutating
+ // either the union or live intervals.
+ unsigned NumInterferences = 0;
+ // Collect interferences assigned to any alias of the physical register.
+ for (const unsigned *asI = TRI->getOverlaps(PhysReg); *asI; ++asI) {
+ LiveIntervalUnion::Query &QAlias = query(VirtReg, *asI);
+ NumInterferences += QAlias.collectInterferingVRegs();
+ if (QAlias.seenUnspillableVReg()) {
+ return false;
+ }
+ }
+ DEBUG(dbgs() << "spilling " << TRI->getName(PhysReg) <<
+ " interferences with " << VirtReg << "\n");
+ assert(NumInterferences > 0 && "expect interference");
+
+ // Spill each interfering vreg allocated to PhysReg or an alias.
+ for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
+ spillReg(VirtReg, *AliasI, SplitVRegs);
+ return true;
+}
+
+// Add newly allocated physical registers to the MBB live in sets.
+void RegAllocBase::addMBBLiveIns(MachineFunction *MF) {
+ NamedRegionTimer T("MBB Live Ins", TimerGroupName, TimePassesIsEnabled);
+ SlotIndexes *Indexes = LIS->getSlotIndexes();
+ if (MF->size() <= 1)
+ return;
+
+ LiveIntervalUnion::SegmentIter SI;
+ for (unsigned PhysReg = 0; PhysReg < PhysReg2LiveUnion.numRegs(); ++PhysReg) {
+ LiveIntervalUnion &LiveUnion = PhysReg2LiveUnion[PhysReg];
+ if (LiveUnion.empty())
+ continue;
+ DEBUG(dbgs() << PrintReg(PhysReg, TRI) << " live-in:");
+ MachineFunction::iterator MBB = llvm::next(MF->begin());
+ MachineFunction::iterator MFE = MF->end();
+ SlotIndex Start, Stop;
+ tie(Start, Stop) = Indexes->getMBBRange(MBB);
+ SI.setMap(LiveUnion.getMap());
+ SI.find(Start);
+ while (SI.valid()) {
+ if (SI.start() <= Start) {
+ if (!MBB->isLiveIn(PhysReg))
+ MBB->addLiveIn(PhysReg);
+ DEBUG(dbgs() << "\tBB#" << MBB->getNumber() << ':'
+ << PrintReg(SI.value()->reg, TRI));
+ } else if (SI.start() > Stop)
+ MBB = Indexes->getMBBFromIndex(SI.start().getPrevIndex());
+ if (++MBB == MFE)
+ break;
+ tie(Start, Stop) = Indexes->getMBBRange(MBB);
+ SI.advanceTo(Start);
+ }
+ DEBUG(dbgs() << '\n');
+ }
+}
+
diff --git a/llvm/lib/CodeGen/RegAllocBasic.cpp b/llvm/lib/CodeGen/RegAllocBasic.cpp
index 8019cf227bd..a67a6169bee 100644
--- a/llvm/lib/CodeGen/RegAllocBasic.cpp
+++ b/llvm/lib/CodeGen/RegAllocBasic.cpp
@@ -1,4 +1,4 @@
-//===-- RegAllocBasic.cpp - basic register allocator ----------------------===//
+//===-- RegAllocBasic.cpp - Basic Register Allocator ----------------------===//
//
// The LLVM Compiler Infrastructure
//
@@ -15,13 +15,10 @@
#define DEBUG_TYPE "regalloc"
#include "RegAllocBase.h"
#include "LiveDebugVariables.h"
-#include "LiveIntervalUnion.h"
#include "LiveRangeEdit.h"
#include "RenderMachineFunction.h"
#include "Spiller.h"
#include "VirtRegMap.h"
-#include "llvm/ADT/OwningPtr.h"
-#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Function.h"
#include "llvm/PassAnalysisSupport.h"
@@ -37,35 +34,17 @@
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#ifndef NDEBUG
-#include "llvm/ADT/SparseBitVector.h"
-#endif
#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/Timer.h"
#include <cstdlib>
#include <queue>
using namespace llvm;
-STATISTIC(NumAssigned , "Number of registers assigned");
-STATISTIC(NumUnassigned , "Number of registers unassigned");
-STATISTIC(NumNewQueued , "Number of new live ranges queued");
-
static RegisterRegAlloc basicRegAlloc("basic", "basic register allocator",
createBasicRegisterAllocator);
-// Temporary verification option until we can put verification inside
-// MachineVerifier.
-static cl::opt<bool, true>
-VerifyRegAlloc("verify-regalloc", cl::location(RegAllocBase::VerifyEnabled),
- cl::desc("Verify during register allocation"));
-
-const char *RegAllocBase::TimerGroupName = "Register Allocation";
-bool RegAllocBase::VerifyEnabled = false;
-
namespace {
struct CompSpillWeight {
bool operator()(LiveInterval *A, LiveInterval *B) const {
@@ -178,296 +157,6 @@ void RABasic::releaseMemory() {
RegAllocBase::releaseMemory();
}
-#ifndef NDEBUG
-// Verify each LiveIntervalUnion.
-void RegAllocBase::verify() {
- LiveVirtRegBitSet VisitedVRegs;
- OwningArrayPtr<LiveVirtRegBitSet>
- unionVRegs(new LiveVirtRegBitSet[PhysReg2LiveUnion.numRegs()]);
-
- // Verify disjoint unions.
- for (unsigned PhysReg = 0; PhysReg < PhysReg2LiveUnion.numRegs(); ++PhysReg) {
- DEBUG(PhysReg2LiveUnion[PhysReg].print(dbgs(), TRI));
- LiveVirtRegBitSet &VRegs = unionVRegs[PhysReg];
- PhysReg2LiveUnion[PhysReg].verify(VRegs);
- // Union + intersection test could be done efficiently in one pass, but
- // don't add a method to SparseBitVector unless we really need it.
- assert(!VisitedVRegs.intersects(VRegs) && "vreg in multiple unions");
- VisitedVRegs |= VRegs;
- }
-
- // Verify vreg coverage.
- for (LiveIntervals::iterator liItr = LIS->begin(), liEnd = LIS->end();
- liItr != liEnd; ++liItr) {
- unsigned reg = liItr->first;
- if (TargetRegisterInfo::isPhysicalRegister(reg)) continue;
- if (!VRM->hasPhys(reg)) continue; // spilled?
- unsigned PhysReg = VRM->getPhys(reg);
- if (!unionVRegs[PhysReg].test(reg)) {
- dbgs() << "LiveVirtReg " << reg << " not in union " <<
- TRI->getName(PhysReg) << "\n";
- llvm_unreachable("unallocated live vreg");
- }
- }
- // FIXME: I'm not sure how to verify spilled intervals.
-}
-#endif //!NDEBUG
-
-//===----------------------------------------------------------------------===//
-// RegAllocBase Implementation
-//===----------------------------------------------------------------------===//
-
-// Instantiate a LiveIntervalUnion for each physical register.
-void RegAllocBase::LiveUnionArray::init(LiveIntervalUnion::Allocator &allocator,
- unsigned NRegs) {
- NumRegs = NRegs;
- Array =
- static_cast<LiveIntervalUnion*>(malloc(sizeof(LiveIntervalUnion)*NRegs));
- for (unsigned r = 0; r != NRegs; ++r)
- new(Array + r) LiveIntervalUnion(r, allocator);
-}
-
-void RegAllocBase::init(VirtRegMap &vrm, LiveIntervals &lis) {
- NamedRegionTimer T("Initialize", TimerGroupName, TimePassesIsEnabled);
- TRI = &vrm.getTargetRegInfo();
- MRI = &vrm.getRegInfo();
- VRM = &vrm;
- LIS = &lis;
- MRI->freezeReservedRegs(vrm.getMachineFunction());
- RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
-
- const unsigned NumRegs = TRI->getNumRegs();
- if (NumRegs != PhysReg2LiveUnion.numRegs()) {
- PhysReg2LiveUnion.init(UnionAllocator, NumRegs);
- // Cache an interferece query for each physical reg
- Queries.reset(new LiveIntervalUnion::Query[PhysReg2LiveUnion.numRegs()]);
- }
-}
-
-void RegAllocBase::LiveUnionArray::clear() {
- if (!Array)
- return;
- for (unsigned r = 0; r != NumRegs; ++r)
- Array[r].~LiveIntervalUnion();
- free(Array);
- NumRegs = 0;
- Array = 0;
-}
-
-void RegAllocBase::releaseMemory() {
- for (unsigned r = 0, e = PhysReg2LiveUnion.numRegs(); r != e; ++r)
- PhysReg2LiveUnion[r].clear();
-}
-
-// Visit all the live registers. If they are already assigned to a physical
-// register, unify them with the corresponding LiveIntervalUnion, otherwise push
-// them on the priority queue for later assignment.
-void RegAllocBase::seedLiveRegs() {
- NamedRegionTimer T("Seed Live Regs", TimerGroupName, TimePassesIsEnabled);
- for (LiveIntervals::iterator I = LIS->begin(), E = LIS->end(); I != E; ++I) {
- unsigned RegNum = I->first;
- LiveInterval &VirtReg = *I->second;
- if (TargetRegisterInfo::isPhysicalRegister(RegNum))
- PhysReg2LiveUnion[RegNum].unify(VirtReg);
- else
- enqueue(&VirtReg);
- }
-}
-
-void RegAllocBase::assign(LiveInterval &VirtReg, unsigned PhysReg) {
- DEBUG(dbgs() << "assigning " << PrintReg(VirtReg.reg, TRI)
- << " to " << PrintReg(PhysReg, TRI) << '\n');
- assert(!VRM->hasPhys(VirtReg.reg) && "Duplicate VirtReg assignment");
- VRM->assignVirt2Phys(VirtReg.reg, PhysReg);
- MRI->setPhysRegUsed(PhysReg);
- PhysReg2LiveUnion[PhysReg].unify(VirtReg);
- ++NumAssigned;
-}
-
-void RegAllocBase::unassign(LiveInterval &VirtReg, unsigned PhysReg) {
- DEBUG(dbgs() << "unassigning " << PrintReg(VirtReg.reg, TRI)
- << " from " << PrintReg(PhysReg, TRI) << '\n');
- assert(VRM->getPhys(VirtReg.reg) == PhysReg && "Inconsistent unassign");
- PhysReg2LiveUnion[PhysReg].extract(VirtReg);
- VRM->clearVirt(VirtReg.reg);
- ++NumUnassigned;
-}
-
-// Top-level driver to manage the queue of unassigned VirtRegs and call the
-// selectOrSplit implementation.
-void RegAllocBase::allocatePhysRegs() {
- seedLiveRegs();
-
- // Continue assigning vregs one at a time to available physical registers.
- while (LiveInterval *VirtReg = dequeue()) {
- assert(!VRM->hasPhys(VirtReg->reg) && "Register already assigned");
-
- // Unused registers can appear when the spiller coalesces snippets.
- if (MRI->reg_nodbg_empty(VirtReg->reg)) {
- DEBUG(dbgs() << "Dropping unused " << *VirtReg << '\n');
- LIS->removeInterval(VirtReg->reg);
- continue;
- }
-
- // Invalidate all interference queries, live ranges could have changed.
- invalidateVirtRegs();
-
- // selectOrSplit requests the allocator to return an available physical
- // register if possible and populate a list of new live intervals that
- // result from splitting.
- DEBUG(dbgs() << "\nselectOrSplit "
- << MRI->getRegClass(VirtReg->reg)->getName()
- << ':' << *VirtReg << '\n');
- typedef SmallVector<LiveInterval*, 4> VirtRegVec;
- VirtRegVec SplitVRegs;
- unsigned AvailablePhysReg = selectOrSplit(*VirtReg, SplitVRegs);
-
- if (AvailablePhysReg == ~0u) {
- // selectOrSplit failed to find a register!
- const char *Msg = "ran out of registers during register allocation";
- // Probably caused by an inline asm.
- MachineInstr *MI;
- for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(VirtReg->reg);
- (MI = I.skipInstruction());)
- if (MI->isInlineAsm())
- break;
- if (MI)
- MI->emitError(Msg);
- else
- report_fatal_error(Msg);
- // Keep going after reporting the error.
- VRM->assignVirt2Phys(VirtReg->reg,
- RegClassInfo.getOrder(MRI->getRegClass(VirtReg->reg)).front());
- continue;
- }
-
- if (AvailablePhysReg)
- assign(*VirtReg, AvailablePhysReg);
-
- for (VirtRegVec::iterator I = SplitVRegs.begin(), E = SplitVRegs.end();
- I != E; ++I) {
- LiveInterval *SplitVirtReg = *I;
- assert(!VRM->hasPhys(SplitVirtReg->reg) && "Register already assigned");
- if (MRI->reg_nodbg_empty(SplitVirtReg->reg)) {
- DEBUG(dbgs() << "not queueing unused " << *SplitVirtReg << '\n');
- LIS->removeInterval(SplitVirtReg->reg);
- continue;
- }
- DEBUG(dbgs() << "queuing new interval: " << *SplitVirtReg << "\n");
- assert(TargetRegisterInfo::isVirtualRegister(SplitVirtReg->reg) &&
- "expect split value in virtual register");
- enqueue(SplitVirtReg);
- ++NumNewQueued;
- }
- }
-}
-
-// Check if this live virtual register interferes with a physical register. If
-// not, then check for interference on each register that aliases with the
-// physical register. Return the interfering register.
-unsigned RegAllocBase::checkPhysRegInterference(LiveInterval &VirtReg,
- unsigned PhysReg) {
- for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
- if (query(VirtReg, *AliasI).checkInterference())
- return *AliasI;
- return 0;
-}
-
-// Helper for spillInteferences() that spills all interfering vregs currently
-// assigned to this physical register.
-void RegAllocBase::spillReg(LiveInterval& VirtReg, unsigned PhysReg,
- SmallVectorImpl<LiveInterval*> &SplitVRegs) {
- LiveIntervalUnion::Query &Q = query(VirtReg, PhysReg);
- assert(Q.seenAllInterferences() && "need collectInterferences()");
- const SmallVectorImpl<LiveInterval*> &PendingSpills = Q.interferingVRegs();
-
- for (SmallVectorImpl<LiveInterval*>::const_iterator I = PendingSpills.begin(),
- E = PendingSpills.end(); I != E; ++I) {
- LiveInterval &SpilledVReg = **I;
- DEBUG(dbgs() << "extracting from " <<
- TRI->getName(PhysReg) << " " << SpilledVReg << '\n');
-
- // Deallocate the interfering vreg by removing it from the union.
- // A LiveInterval instance may not be in a union during modification!
- unassign(SpilledVReg, PhysReg);
-
- // Spill the extracted interval.
- LiveRangeEdit LRE(SpilledVReg, SplitVRegs, 0, &PendingSpills);
- spiller().spill(LRE);
- }
- // After extracting segments, the query's results are invalid. But keep the
- // contents valid until we're done accessing pendingSpills.
- Q.clear();
-}
-
-// Spill or split all live virtual registers currently unified under PhysReg
-// that interfere with VirtReg. The newly spilled or split live intervals are
-// returned by appending them to SplitVRegs.
-bool
-RegAllocBase::spillInterferences(LiveInterval &VirtReg, unsigned PhysReg,
- SmallVectorImpl<LiveInterval*> &SplitVRegs) {
- // Record each interference and determine if all are spillable before mutating
- // either the union or live intervals.
- unsigned NumInterferences = 0;
- // Collect interferences assigned to any alias of the physical register.
- for (const unsigned *asI = TRI->getOverlaps(PhysReg); *asI; ++asI) {
- LiveIntervalUnion::Query &QAlias = query(VirtReg, *asI);
- NumInterferences += QAlias.collectInterferingVRegs();
- if (QAlias.seenUnspillableVReg()) {
- return false;
- }
- }
- DEBUG(dbgs() << "spilling " << TRI->getName(PhysReg) <<
- " interferences with " << VirtReg << "\n");
- assert(NumInterferences > 0 && "expect interference");
-
- // Spill each interfering vreg allocated to PhysReg or an alias.
- for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI)
- spillReg(VirtReg, *AliasI, SplitVRegs);
- return true;
-}
-
-// Add newly allocated physical registers to the MBB live in sets.
-void RegAllocBase::addMBBLiveIns(MachineFunction *MF) {
- NamedRegionTimer T("MBB Live Ins", TimerGroupName, TimePassesIsEnabled);
- SlotIndexes *Indexes = LIS->getSlotIndexes();
- if (MF->size() <= 1)
- return;
-
- LiveIntervalUnion::SegmentIter SI;
- for (unsigned PhysReg = 0; PhysReg < PhysReg2LiveUnion.numRegs(); ++PhysReg) {
- LiveIntervalUnion &LiveUnion = PhysReg2LiveUnion[PhysReg];
- if (LiveUnion.empty())
- continue;
- DEBUG(dbgs() << PrintReg(PhysReg, TRI) << " live-in:");
- MachineFunction::iterator MBB = llvm::next(MF->begin());
- MachineFunction::iterator MFE = MF->end();
- SlotIndex Start, Stop;
- tie(Start, Stop) = Indexes->getMBBRange(MBB);
- SI.setMap(LiveUnion.getMap());
- SI.find(Start);
- while (SI.valid()) {
- if (SI.start() <= Start) {
- if (!MBB->isLiveIn(PhysReg))
- MBB->addLiveIn(PhysReg);
- DEBUG(dbgs() << "\tBB#" << MBB->getNumber() << ':'
- << PrintReg(SI.value()->reg, TRI));
- } else if (SI.start() > Stop)
- MBB = Indexes->getMBBFromIndex(SI.start().getPrevIndex());
- if (++MBB == MFE)
- break;
- tie(Start, Stop) = Indexes->getMBBRange(MBB);
- SI.advanceTo(Start);
- }
- DEBUG(dbgs() << '\n');
- }
-}
-
-
-//===----------------------------------------------------------------------===//
-// RABasic Implementation
-//===----------------------------------------------------------------------===//
-
// Driver for the register assignment and splitting heuristics.
// Manages iteration over the LiveIntervalUnions.
//
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