From ccc9581e8b79b4216cb1143344bdae9342722d5d Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 11 Jan 2012 22:28:30 +0000 Subject: [PATCH] Move RegAllocBase into its own cpp file separate from RABasic. No functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147972 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CMakeLists.txt | 1 + lib/CodeGen/RegAllocBase.cpp | 334 ++++++++++++++++++++++++++++++++++ lib/CodeGen/RegAllocBasic.cpp | 313 +------------------------------ 3 files changed, 336 insertions(+), 312 deletions(-) create mode 100644 lib/CodeGen/RegAllocBase.cpp diff --git a/lib/CodeGen/CMakeLists.txt b/lib/CodeGen/CMakeLists.txt index 7fa5e47f9eb..65d4971ba3c 100644 --- a/lib/CodeGen/CMakeLists.txt +++ b/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/lib/CodeGen/RegAllocBase.cpp b/lib/CodeGen/RegAllocBase.cpp new file mode 100644 index 00000000000..3f77df3221d --- /dev/null +++ b/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 +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 + 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(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 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 &SplitVRegs) { + LiveIntervalUnion::Query &Q = query(VirtReg, PhysReg); + assert(Q.seenAllInterferences() && "need collectInterferences()"); + const SmallVectorImpl &PendingSpills = Q.interferingVRegs(); + + for (SmallVectorImpl::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 &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/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp index 8019cf227bd..a67a6169bee 100644 --- a/lib/CodeGen/RegAllocBasic.cpp +++ b/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 #include 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 -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 - 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(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 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 &SplitVRegs) { - LiveIntervalUnion::Query &Q = query(VirtReg, PhysReg); - assert(Q.seenAllInterferences() && "need collectInterferences()"); - const SmallVectorImpl &PendingSpills = Q.interferingVRegs(); - - for (SmallVectorImpl::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 &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. // -- 2.34.1