--- /dev/null
+//===- SSEDomainFix.cpp - Use proper int/float domain for SSE ---*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the SSEDomainFix pass.
+//
+// Some SSE instructions like mov, and, or, xor are available in different
+// variants for different operand types. These variant instructions are
+// equivalent, but on Nehalem and newer cpus there is extra latency
+// transferring data between integer and floating point domains.
+//
+// This pass changes the variant instructions to minimize domain crossings.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "execution-fix"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+/// A DomainValue is a bit like LiveIntervals' ValNo, but it also keeps track
+/// of execution domains.
+///
+/// An open DomainValue represents a set of instructions that can still switch
+/// execution domain. Multiple registers may refer to the same open
+/// DomainValue - they will eventually be collapsed to the same execution
+/// domain.
+///
+/// A collapsed DomainValue represents a single register that has been forced
+/// into one of more execution domains. There is a separate collapsed
+/// DomainValue for each register, but it may contain multiple execution
+/// domains. A register value is initially created in a single execution
+/// domain, but if we were forced to pay the penalty of a domain crossing, we
+/// keep track of the fact the the register is now available in multiple
+/// domains.
+namespace {
+struct DomainValue {
+ // Basic reference counting.
+ unsigned Refs;
+
+ // Bitmask of available domains. For an open DomainValue, it is the still
+ // possible domains for collapsing. For a collapsed DomainValue it is the
+ // domains where the register is available for free.
+ unsigned AvailableDomains;
+
+ // Position of the last defining instruction.
+ unsigned Dist;
+
+ // Twiddleable instructions using or defining these registers.
+ SmallVector<MachineInstr*, 8> Instrs;
+
+ // A collapsed DomainValue has no instructions to twiddle - it simply keeps
+ // track of the domains where the registers are already available.
+ bool isCollapsed() const { return Instrs.empty(); }
+
+ // Is domain available?
+ bool hasDomain(unsigned domain) const {
+ return AvailableDomains & (1u << domain);
+ }
+
+ // Mark domain as available.
+ void addDomain(unsigned domain) {
+ AvailableDomains |= 1u << domain;
+ }
+
+ // Restrict to a single domain available.
+ void setSingleDomain(unsigned domain) {
+ AvailableDomains = 1u << domain;
+ }
+
+ // Return bitmask of domains that are available and in mask.
+ unsigned getCommonDomains(unsigned mask) const {
+ return AvailableDomains & mask;
+ }
+
+ // First domain available.
+ unsigned getFirstDomain() const {
+ return CountTrailingZeros_32(AvailableDomains);
+ }
+
+ DomainValue() { clear(); }
+
+ void clear() {
+ Refs = AvailableDomains = Dist = 0;
+ Instrs.clear();
+ }
+};
+}
+
+namespace {
+class SSEDomainFixPass : public MachineFunctionPass {
+ static char ID;
+ SpecificBumpPtrAllocator<DomainValue> Allocator;
+ SmallVector<DomainValue*,16> Avail;
+
+ const TargetRegisterClass *const RC;
+ MachineFunction *MF;
+ const TargetInstrInfo *TII;
+ const TargetRegisterInfo *TRI;
+ MachineBasicBlock *MBB;
+ std::vector<int> AliasMap;
+ const unsigned NumRegs;
+ DomainValue **LiveRegs;
+ typedef DenseMap<MachineBasicBlock*,DomainValue**> LiveOutMap;
+ LiveOutMap LiveOuts;
+ unsigned Distance;
+
+public:
+ SSEDomainFixPass(const TargetRegisterClass *rc)
+ : MachineFunctionPass(ID), RC(rc), NumRegs(RC->getNumRegs()) {}
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ virtual const char *getPassName() const {
+ return "SSE execution domain fixup";
+ }
+
+private:
+ // Register mapping.
+ int RegIndex(unsigned Reg);
+
+ // DomainValue allocation.
+ DomainValue *Alloc(int domain = -1);
+ void Recycle(DomainValue*);
+
+ // LiveRegs manipulations.
+ void SetLiveReg(int rx, DomainValue *DV);
+ void Kill(int rx);
+ void Force(int rx, unsigned domain);
+ void Collapse(DomainValue *dv, unsigned domain);
+ bool Merge(DomainValue *A, DomainValue *B);
+
+ void enterBasicBlock();
+ void visitGenericInstr(MachineInstr*);
+ void visitSoftInstr(MachineInstr*, unsigned mask);
+ void visitHardInstr(MachineInstr*, unsigned domain);
+};
+}
+
+char SSEDomainFixPass::ID = 0;
+
+/// Translate TRI register number to an index into our smaller tables of
+/// interesting registers. Return -1 for boring registers.
+int SSEDomainFixPass::RegIndex(unsigned Reg) {
+ assert(Reg < AliasMap.size() && "Invalid register");
+ return AliasMap[Reg];
+}
+
+DomainValue *SSEDomainFixPass::Alloc(int domain) {
+ DomainValue *dv = Avail.empty() ?
+ new(Allocator.Allocate()) DomainValue :
+ Avail.pop_back_val();
+ dv->Dist = Distance;
+ if (domain >= 0)
+ dv->addDomain(domain);
+ return dv;
+}
+
+void SSEDomainFixPass::Recycle(DomainValue *dv) {
+ assert(dv && "Cannot recycle NULL");
+ dv->clear();
+ Avail.push_back(dv);
+}
+
+/// Set LiveRegs[rx] = dv, updating reference counts.
+void SSEDomainFixPass::SetLiveReg(int rx, DomainValue *dv) {
+ assert(unsigned(rx) < NumRegs && "Invalid index");
+ if (!LiveRegs) {
+ LiveRegs = new DomainValue*[NumRegs];
+ std::fill(LiveRegs, LiveRegs+NumRegs, (DomainValue*)0);
+ }
+
+ if (LiveRegs[rx] == dv)
+ return;
+ if (LiveRegs[rx]) {
+ assert(LiveRegs[rx]->Refs && "Bad refcount");
+ if (--LiveRegs[rx]->Refs == 0) Recycle(LiveRegs[rx]);
+ }
+ LiveRegs[rx] = dv;
+ if (dv) ++dv->Refs;
+}
+
+// Kill register rx, recycle or collapse any DomainValue.
+void SSEDomainFixPass::Kill(int rx) {
+ assert(unsigned(rx) < NumRegs && "Invalid index");
+ if (!LiveRegs || !LiveRegs[rx]) return;
+
+ // Before killing the last reference to an open DomainValue, collapse it to
+ // the first available domain.
+ if (LiveRegs[rx]->Refs == 1 && !LiveRegs[rx]->isCollapsed())
+ Collapse(LiveRegs[rx], LiveRegs[rx]->getFirstDomain());
+ else
+ SetLiveReg(rx, 0);
+}
+
+/// Force register rx into domain.
+void SSEDomainFixPass::Force(int rx, unsigned domain) {
+ assert(unsigned(rx) < NumRegs && "Invalid index");
+ DomainValue *dv;
+ if (LiveRegs && (dv = LiveRegs[rx])) {
+ if (dv->isCollapsed())
+ dv->addDomain(domain);
+ else if (dv->hasDomain(domain))
+ Collapse(dv, domain);
+ else {
+ // This is an incompatible open DomainValue. Collapse it to whatever and force
+ // the new value into domain. This costs a domain crossing.
+ Collapse(dv, dv->getFirstDomain());
+ assert(LiveRegs[rx] && "Not live after collapse?");
+ LiveRegs[rx]->addDomain(domain);
+ }
+ } else {
+ // Set up basic collapsed DomainValue.
+ SetLiveReg(rx, Alloc(domain));
+ }
+}
+
+/// Collapse open DomainValue into given domain. If there are multiple
+/// registers using dv, they each get a unique collapsed DomainValue.
+void SSEDomainFixPass::Collapse(DomainValue *dv, unsigned domain) {
+ assert(dv->hasDomain(domain) && "Cannot collapse");
+
+ // Collapse all the instructions.
+ while (!dv->Instrs.empty())
+ TII->setExecutionDomain(dv->Instrs.pop_back_val(), domain);
+ dv->setSingleDomain(domain);
+
+ // If there are multiple users, give them new, unique DomainValues.
+ if (LiveRegs && dv->Refs > 1)
+ for (unsigned rx = 0; rx != NumRegs; ++rx)
+ if (LiveRegs[rx] == dv)
+ SetLiveReg(rx, Alloc(domain));
+}
+
+/// Merge - All instructions and registers in B are moved to A, and B is
+/// released.
+bool SSEDomainFixPass::Merge(DomainValue *A, DomainValue *B) {
+ assert(!A->isCollapsed() && "Cannot merge into collapsed");
+ assert(!B->isCollapsed() && "Cannot merge from collapsed");
+ if (A == B)
+ return true;
+ // Restrict to the domains that A and B have in common.
+ unsigned common = A->getCommonDomains(B->AvailableDomains);
+ if (!common)
+ return false;
+ A->AvailableDomains = common;
+ A->Dist = std::max(A->Dist, B->Dist);
+ A->Instrs.append(B->Instrs.begin(), B->Instrs.end());
+ for (unsigned rx = 0; rx != NumRegs; ++rx)
+ if (LiveRegs[rx] == B)
+ SetLiveReg(rx, A);
+ return true;
+}
+
+void SSEDomainFixPass::enterBasicBlock() {
+ // Try to coalesce live-out registers from predecessors.
+ for (MachineBasicBlock::livein_iterator i = MBB->livein_begin(),
+ e = MBB->livein_end(); i != e; ++i) {
+ int rx = RegIndex(*i);
+ if (rx < 0) continue;
+ for (MachineBasicBlock::const_pred_iterator pi = MBB->pred_begin(),
+ pe = MBB->pred_end(); pi != pe; ++pi) {
+ LiveOutMap::const_iterator fi = LiveOuts.find(*pi);
+ if (fi == LiveOuts.end()) continue;
+ DomainValue *pdv = fi->second[rx];
+ if (!pdv) continue;
+ if (!LiveRegs || !LiveRegs[rx]) {
+ SetLiveReg(rx, pdv);
+ continue;
+ }
+
+ // We have a live DomainValue from more than one predecessor.
+ if (LiveRegs[rx]->isCollapsed()) {
+ // We are already collapsed, but predecessor is not. Force him.
+ unsigned domain = LiveRegs[rx]->getFirstDomain();
+ if (!pdv->isCollapsed() && pdv->hasDomain(domain))
+ Collapse(pdv, domain);
+ continue;
+ }
+
+ // Currently open, merge in predecessor.
+ if (!pdv->isCollapsed())
+ Merge(LiveRegs[rx], pdv);
+ else
+ Force(rx, pdv->getFirstDomain());
+ }
+ }
+}
+
+// A hard instruction only works in one domain. All input registers will be
+// forced into that domain.
+void SSEDomainFixPass::visitHardInstr(MachineInstr *mi, unsigned domain) {
+ // Collapse all uses.
+ for (unsigned i = mi->getDesc().getNumDefs(),
+ e = mi->getDesc().getNumOperands(); i != e; ++i) {
+ MachineOperand &mo = mi->getOperand(i);
+ if (!mo.isReg()) continue;
+ int rx = RegIndex(mo.getReg());
+ if (rx < 0) continue;
+ Force(rx, domain);
+ }
+
+ // Kill all defs and force them.
+ for (unsigned i = 0, e = mi->getDesc().getNumDefs(); i != e; ++i) {
+ MachineOperand &mo = mi->getOperand(i);
+ if (!mo.isReg()) continue;
+ int rx = RegIndex(mo.getReg());
+ if (rx < 0) continue;
+ Kill(rx);
+ Force(rx, domain);
+ }
+}
+
+// A soft instruction can be changed to work in other domains given by mask.
+void SSEDomainFixPass::visitSoftInstr(MachineInstr *mi, unsigned mask) {
+ // Bitmask of available domains for this instruction after taking collapsed
+ // operands into account.
+ unsigned available = mask;
+
+ // Scan the explicit use operands for incoming domains.
+ SmallVector<int, 4> used;
+ if (LiveRegs)
+ for (unsigned i = mi->getDesc().getNumDefs(),
+ e = mi->getDesc().getNumOperands(); i != e; ++i) {
+ MachineOperand &mo = mi->getOperand(i);
+ if (!mo.isReg()) continue;
+ int rx = RegIndex(mo.getReg());
+ if (rx < 0) continue;
+ if (DomainValue *dv = LiveRegs[rx]) {
+ // Bitmask of domains that dv and available have in common.
+ unsigned common = dv->getCommonDomains(available);
+ // Is it possible to use this collapsed register for free?
+ if (dv->isCollapsed()) {
+ // Restrict available domains to the ones in common with the operand.
+ // If there are no common domains, we must pay the cross-domain
+ // penalty for this operand.
+ if (common) available = common;
+ } else if (common)
+ // Open DomainValue is compatible, save it for merging.
+ used.push_back(rx);
+ else
+ // Open DomainValue is not compatible with instruction. It is useless
+ // now.
+ Kill(rx);
+ }
+ }
+
+ // If the collapsed operands force a single domain, propagate the collapse.
+ if (isPowerOf2_32(available)) {
+ unsigned domain = CountTrailingZeros_32(available);
+ TII->setExecutionDomain(mi, domain);
+ visitHardInstr(mi, domain);
+ return;
+ }
+
+ // Kill off any remaining uses that don't match available, and build a list of
+ // incoming DomainValues that we want to merge.
+ SmallVector<DomainValue*,4> doms;
+ for (SmallVector<int, 4>::iterator i=used.begin(), e=used.end(); i!=e; ++i) {
+ int rx = *i;
+ DomainValue *dv = LiveRegs[rx];
+ // This useless DomainValue could have been missed above.
+ if (!dv->getCommonDomains(available)) {
+ Kill(*i);
+ continue;
+ }
+ // sorted, uniqued insert.
+ bool inserted = false;
+ for (SmallVector<DomainValue*,4>::iterator i = doms.begin(), e = doms.end();
+ i != e && !inserted; ++i) {
+ if (dv == *i)
+ inserted = true;
+ else if (dv->Dist < (*i)->Dist) {
+ inserted = true;
+ doms.insert(i, dv);
+ }
+ }
+ if (!inserted)
+ doms.push_back(dv);
+ }
+
+ // doms are now sorted in order of appearance. Try to merge them all, giving
+ // priority to the latest ones.
+ DomainValue *dv = 0;
+ while (!doms.empty()) {
+ if (!dv) {
+ dv = doms.pop_back_val();
+ continue;
+ }
+
+ DomainValue *latest = doms.pop_back_val();
+ if (Merge(dv, latest)) continue;
+
+ // If latest didn't merge, it is useless now. Kill all registers using it.
+ for (SmallVector<int,4>::iterator i=used.begin(), e=used.end(); i != e; ++i)
+ if (LiveRegs[*i] == latest)
+ Kill(*i);
+ }
+
+ // dv is the DomainValue we are going to use for this instruction.
+ if (!dv)
+ dv = Alloc();
+ dv->Dist = Distance;
+ dv->AvailableDomains = available;
+ dv->Instrs.push_back(mi);
+
+ // Finally set all defs and non-collapsed uses to dv.
+ for (unsigned i = 0, e = mi->getDesc().getNumOperands(); i != e; ++i) {
+ MachineOperand &mo = mi->getOperand(i);
+ if (!mo.isReg()) continue;
+ int rx = RegIndex(mo.getReg());
+ if (rx < 0) continue;
+ if (!LiveRegs || !LiveRegs[rx] || (mo.isDef() && LiveRegs[rx]!=dv)) {
+ Kill(rx);
+ SetLiveReg(rx, dv);
+ }
+ }
+}
+
+void SSEDomainFixPass::visitGenericInstr(MachineInstr *mi) {
+ // Process explicit defs, kill any XMM registers redefined.
+ for (unsigned i = 0, e = mi->getDesc().getNumDefs(); i != e; ++i) {
+ MachineOperand &mo = mi->getOperand(i);
+ if (!mo.isReg()) continue;
+ int rx = RegIndex(mo.getReg());
+ if (rx < 0) continue;
+ Kill(rx);
+ }
+}
+
+bool SSEDomainFixPass::runOnMachineFunction(MachineFunction &mf) {
+ MF = &mf;
+ TII = MF->getTarget().getInstrInfo();
+ TRI = MF->getTarget().getRegisterInfo();
+ MBB = 0;
+ LiveRegs = 0;
+ Distance = 0;
+ assert(NumRegs == RC->getNumRegs() && "Bad regclass");
+
+ // If no XMM registers are used in the function, we can skip it completely.
+ bool anyregs = false;
+ for (TargetRegisterClass::const_iterator I = RC->begin(), E = RC->end();
+ I != E; ++I)
+ if (MF->getRegInfo().isPhysRegUsed(*I)) {
+ anyregs = true;
+ break;
+ }
+ if (!anyregs) return false;
+
+ // Initialize the AliasMap on the first use.
+ if (AliasMap.empty()) {
+ // Given a PhysReg, AliasMap[PhysReg] is either the relevant index into RC,
+ // or -1.
+ AliasMap.resize(TRI->getNumRegs(), -1);
+ for (unsigned i = 0, e = RC->getNumRegs(); i != e; ++i)
+ for (const unsigned *AI = TRI->getOverlaps(RC->getRegister(i)); *AI; ++AI)
+ AliasMap[*AI] = i;
+ }
+
+ MachineBasicBlock *Entry = MF->begin();
+ SmallPtrSet<MachineBasicBlock*, 16> Visited;
+ for (df_ext_iterator<MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*, 16> >
+ DFI = df_ext_begin(Entry, Visited), DFE = df_ext_end(Entry, Visited);
+ DFI != DFE; ++DFI) {
+ MBB = *DFI;
+ enterBasicBlock();
+ for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
+ ++I) {
+ MachineInstr *mi = I;
+ if (mi->isDebugValue()) continue;
+ ++Distance;
+ std::pair<uint16_t, uint16_t> domp = TII->getExecutionDomain(mi);
+ if (domp.first)
+ if (domp.second)
+ visitSoftInstr(mi, domp.second);
+ else
+ visitHardInstr(mi, domp.first);
+ else if (LiveRegs)
+ visitGenericInstr(mi);
+ }
+
+ // Save live registers at end of MBB - used by enterBasicBlock().
+ if (LiveRegs)
+ LiveOuts.insert(std::make_pair(MBB, LiveRegs));
+ LiveRegs = 0;
+ }
+
+ // Clear the LiveOuts vectors. Should we also collapse any remaining
+ // DomainValues?
+ for (LiveOutMap::const_iterator i = LiveOuts.begin(), e = LiveOuts.end();
+ i != e; ++i)
+ delete[] i->second;
+ LiveOuts.clear();
+ Avail.clear();
+ Allocator.DestroyAll();
+
+ return false;
+}
+
+FunctionPass *
+llvm::createExecutionDependencyFixPass(const TargetRegisterClass *RC) {
+ return new SSEDomainFixPass(RC);
+}
+++ /dev/null
-//===- SSEDomainFix.cpp - Use proper int/float domain for SSE ---*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains the SSEDomainFix pass.
-//
-// Some SSE instructions like mov, and, or, xor are available in different
-// variants for different operand types. These variant instructions are
-// equivalent, but on Nehalem and newer cpus there is extra latency
-// transferring data between integer and floating point domains.
-//
-// This pass changes the variant instructions to minimize domain crossings.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "execution-fix"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/Support/Allocator.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-/// A DomainValue is a bit like LiveIntervals' ValNo, but it also keeps track
-/// of execution domains.
-///
-/// An open DomainValue represents a set of instructions that can still switch
-/// execution domain. Multiple registers may refer to the same open
-/// DomainValue - they will eventually be collapsed to the same execution
-/// domain.
-///
-/// A collapsed DomainValue represents a single register that has been forced
-/// into one of more execution domains. There is a separate collapsed
-/// DomainValue for each register, but it may contain multiple execution
-/// domains. A register value is initially created in a single execution
-/// domain, but if we were forced to pay the penalty of a domain crossing, we
-/// keep track of the fact the the register is now available in multiple
-/// domains.
-namespace {
-struct DomainValue {
- // Basic reference counting.
- unsigned Refs;
-
- // Bitmask of available domains. For an open DomainValue, it is the still
- // possible domains for collapsing. For a collapsed DomainValue it is the
- // domains where the register is available for free.
- unsigned AvailableDomains;
-
- // Position of the last defining instruction.
- unsigned Dist;
-
- // Twiddleable instructions using or defining these registers.
- SmallVector<MachineInstr*, 8> Instrs;
-
- // A collapsed DomainValue has no instructions to twiddle - it simply keeps
- // track of the domains where the registers are already available.
- bool isCollapsed() const { return Instrs.empty(); }
-
- // Is domain available?
- bool hasDomain(unsigned domain) const {
- return AvailableDomains & (1u << domain);
- }
-
- // Mark domain as available.
- void addDomain(unsigned domain) {
- AvailableDomains |= 1u << domain;
- }
-
- // Restrict to a single domain available.
- void setSingleDomain(unsigned domain) {
- AvailableDomains = 1u << domain;
- }
-
- // Return bitmask of domains that are available and in mask.
- unsigned getCommonDomains(unsigned mask) const {
- return AvailableDomains & mask;
- }
-
- // First domain available.
- unsigned getFirstDomain() const {
- return CountTrailingZeros_32(AvailableDomains);
- }
-
- DomainValue() { clear(); }
-
- void clear() {
- Refs = AvailableDomains = Dist = 0;
- Instrs.clear();
- }
-};
-}
-
-namespace {
-class SSEDomainFixPass : public MachineFunctionPass {
- static char ID;
- SpecificBumpPtrAllocator<DomainValue> Allocator;
- SmallVector<DomainValue*,16> Avail;
-
- const TargetRegisterClass *const RC;
- MachineFunction *MF;
- const TargetInstrInfo *TII;
- const TargetRegisterInfo *TRI;
- MachineBasicBlock *MBB;
- std::vector<int> AliasMap;
- const unsigned NumRegs;
- DomainValue **LiveRegs;
- typedef DenseMap<MachineBasicBlock*,DomainValue**> LiveOutMap;
- LiveOutMap LiveOuts;
- unsigned Distance;
-
-public:
- SSEDomainFixPass(const TargetRegisterClass *rc)
- : MachineFunctionPass(ID), RC(rc), NumRegs(RC->getNumRegs()) {}
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- virtual bool runOnMachineFunction(MachineFunction &MF);
-
- virtual const char *getPassName() const {
- return "SSE execution domain fixup";
- }
-
-private:
- // Register mapping.
- int RegIndex(unsigned Reg);
-
- // DomainValue allocation.
- DomainValue *Alloc(int domain = -1);
- void Recycle(DomainValue*);
-
- // LiveRegs manipulations.
- void SetLiveReg(int rx, DomainValue *DV);
- void Kill(int rx);
- void Force(int rx, unsigned domain);
- void Collapse(DomainValue *dv, unsigned domain);
- bool Merge(DomainValue *A, DomainValue *B);
-
- void enterBasicBlock();
- void visitGenericInstr(MachineInstr*);
- void visitSoftInstr(MachineInstr*, unsigned mask);
- void visitHardInstr(MachineInstr*, unsigned domain);
-};
-}
-
-char SSEDomainFixPass::ID = 0;
-
-/// Translate TRI register number to an index into our smaller tables of
-/// interesting registers. Return -1 for boring registers.
-int SSEDomainFixPass::RegIndex(unsigned Reg) {
- assert(Reg < AliasMap.size() && "Invalid register");
- return AliasMap[Reg];
-}
-
-DomainValue *SSEDomainFixPass::Alloc(int domain) {
- DomainValue *dv = Avail.empty() ?
- new(Allocator.Allocate()) DomainValue :
- Avail.pop_back_val();
- dv->Dist = Distance;
- if (domain >= 0)
- dv->addDomain(domain);
- return dv;
-}
-
-void SSEDomainFixPass::Recycle(DomainValue *dv) {
- assert(dv && "Cannot recycle NULL");
- dv->clear();
- Avail.push_back(dv);
-}
-
-/// Set LiveRegs[rx] = dv, updating reference counts.
-void SSEDomainFixPass::SetLiveReg(int rx, DomainValue *dv) {
- assert(unsigned(rx) < NumRegs && "Invalid index");
- if (!LiveRegs) {
- LiveRegs = new DomainValue*[NumRegs];
- std::fill(LiveRegs, LiveRegs+NumRegs, (DomainValue*)0);
- }
-
- if (LiveRegs[rx] == dv)
- return;
- if (LiveRegs[rx]) {
- assert(LiveRegs[rx]->Refs && "Bad refcount");
- if (--LiveRegs[rx]->Refs == 0) Recycle(LiveRegs[rx]);
- }
- LiveRegs[rx] = dv;
- if (dv) ++dv->Refs;
-}
-
-// Kill register rx, recycle or collapse any DomainValue.
-void SSEDomainFixPass::Kill(int rx) {
- assert(unsigned(rx) < NumRegs && "Invalid index");
- if (!LiveRegs || !LiveRegs[rx]) return;
-
- // Before killing the last reference to an open DomainValue, collapse it to
- // the first available domain.
- if (LiveRegs[rx]->Refs == 1 && !LiveRegs[rx]->isCollapsed())
- Collapse(LiveRegs[rx], LiveRegs[rx]->getFirstDomain());
- else
- SetLiveReg(rx, 0);
-}
-
-/// Force register rx into domain.
-void SSEDomainFixPass::Force(int rx, unsigned domain) {
- assert(unsigned(rx) < NumRegs && "Invalid index");
- DomainValue *dv;
- if (LiveRegs && (dv = LiveRegs[rx])) {
- if (dv->isCollapsed())
- dv->addDomain(domain);
- else if (dv->hasDomain(domain))
- Collapse(dv, domain);
- else {
- // This is an incompatible open DomainValue. Collapse it to whatever and force
- // the new value into domain. This costs a domain crossing.
- Collapse(dv, dv->getFirstDomain());
- assert(LiveRegs[rx] && "Not live after collapse?");
- LiveRegs[rx]->addDomain(domain);
- }
- } else {
- // Set up basic collapsed DomainValue.
- SetLiveReg(rx, Alloc(domain));
- }
-}
-
-/// Collapse open DomainValue into given domain. If there are multiple
-/// registers using dv, they each get a unique collapsed DomainValue.
-void SSEDomainFixPass::Collapse(DomainValue *dv, unsigned domain) {
- assert(dv->hasDomain(domain) && "Cannot collapse");
-
- // Collapse all the instructions.
- while (!dv->Instrs.empty())
- TII->setExecutionDomain(dv->Instrs.pop_back_val(), domain);
- dv->setSingleDomain(domain);
-
- // If there are multiple users, give them new, unique DomainValues.
- if (LiveRegs && dv->Refs > 1)
- for (unsigned rx = 0; rx != NumRegs; ++rx)
- if (LiveRegs[rx] == dv)
- SetLiveReg(rx, Alloc(domain));
-}
-
-/// Merge - All instructions and registers in B are moved to A, and B is
-/// released.
-bool SSEDomainFixPass::Merge(DomainValue *A, DomainValue *B) {
- assert(!A->isCollapsed() && "Cannot merge into collapsed");
- assert(!B->isCollapsed() && "Cannot merge from collapsed");
- if (A == B)
- return true;
- // Restrict to the domains that A and B have in common.
- unsigned common = A->getCommonDomains(B->AvailableDomains);
- if (!common)
- return false;
- A->AvailableDomains = common;
- A->Dist = std::max(A->Dist, B->Dist);
- A->Instrs.append(B->Instrs.begin(), B->Instrs.end());
- for (unsigned rx = 0; rx != NumRegs; ++rx)
- if (LiveRegs[rx] == B)
- SetLiveReg(rx, A);
- return true;
-}
-
-void SSEDomainFixPass::enterBasicBlock() {
- // Try to coalesce live-out registers from predecessors.
- for (MachineBasicBlock::livein_iterator i = MBB->livein_begin(),
- e = MBB->livein_end(); i != e; ++i) {
- int rx = RegIndex(*i);
- if (rx < 0) continue;
- for (MachineBasicBlock::const_pred_iterator pi = MBB->pred_begin(),
- pe = MBB->pred_end(); pi != pe; ++pi) {
- LiveOutMap::const_iterator fi = LiveOuts.find(*pi);
- if (fi == LiveOuts.end()) continue;
- DomainValue *pdv = fi->second[rx];
- if (!pdv) continue;
- if (!LiveRegs || !LiveRegs[rx]) {
- SetLiveReg(rx, pdv);
- continue;
- }
-
- // We have a live DomainValue from more than one predecessor.
- if (LiveRegs[rx]->isCollapsed()) {
- // We are already collapsed, but predecessor is not. Force him.
- unsigned domain = LiveRegs[rx]->getFirstDomain();
- if (!pdv->isCollapsed() && pdv->hasDomain(domain))
- Collapse(pdv, domain);
- continue;
- }
-
- // Currently open, merge in predecessor.
- if (!pdv->isCollapsed())
- Merge(LiveRegs[rx], pdv);
- else
- Force(rx, pdv->getFirstDomain());
- }
- }
-}
-
-// A hard instruction only works in one domain. All input registers will be
-// forced into that domain.
-void SSEDomainFixPass::visitHardInstr(MachineInstr *mi, unsigned domain) {
- // Collapse all uses.
- for (unsigned i = mi->getDesc().getNumDefs(),
- e = mi->getDesc().getNumOperands(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
- if (!mo.isReg()) continue;
- int rx = RegIndex(mo.getReg());
- if (rx < 0) continue;
- Force(rx, domain);
- }
-
- // Kill all defs and force them.
- for (unsigned i = 0, e = mi->getDesc().getNumDefs(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
- if (!mo.isReg()) continue;
- int rx = RegIndex(mo.getReg());
- if (rx < 0) continue;
- Kill(rx);
- Force(rx, domain);
- }
-}
-
-// A soft instruction can be changed to work in other domains given by mask.
-void SSEDomainFixPass::visitSoftInstr(MachineInstr *mi, unsigned mask) {
- // Bitmask of available domains for this instruction after taking collapsed
- // operands into account.
- unsigned available = mask;
-
- // Scan the explicit use operands for incoming domains.
- SmallVector<int, 4> used;
- if (LiveRegs)
- for (unsigned i = mi->getDesc().getNumDefs(),
- e = mi->getDesc().getNumOperands(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
- if (!mo.isReg()) continue;
- int rx = RegIndex(mo.getReg());
- if (rx < 0) continue;
- if (DomainValue *dv = LiveRegs[rx]) {
- // Bitmask of domains that dv and available have in common.
- unsigned common = dv->getCommonDomains(available);
- // Is it possible to use this collapsed register for free?
- if (dv->isCollapsed()) {
- // Restrict available domains to the ones in common with the operand.
- // If there are no common domains, we must pay the cross-domain
- // penalty for this operand.
- if (common) available = common;
- } else if (common)
- // Open DomainValue is compatible, save it for merging.
- used.push_back(rx);
- else
- // Open DomainValue is not compatible with instruction. It is useless
- // now.
- Kill(rx);
- }
- }
-
- // If the collapsed operands force a single domain, propagate the collapse.
- if (isPowerOf2_32(available)) {
- unsigned domain = CountTrailingZeros_32(available);
- TII->setExecutionDomain(mi, domain);
- visitHardInstr(mi, domain);
- return;
- }
-
- // Kill off any remaining uses that don't match available, and build a list of
- // incoming DomainValues that we want to merge.
- SmallVector<DomainValue*,4> doms;
- for (SmallVector<int, 4>::iterator i=used.begin(), e=used.end(); i!=e; ++i) {
- int rx = *i;
- DomainValue *dv = LiveRegs[rx];
- // This useless DomainValue could have been missed above.
- if (!dv->getCommonDomains(available)) {
- Kill(*i);
- continue;
- }
- // sorted, uniqued insert.
- bool inserted = false;
- for (SmallVector<DomainValue*,4>::iterator i = doms.begin(), e = doms.end();
- i != e && !inserted; ++i) {
- if (dv == *i)
- inserted = true;
- else if (dv->Dist < (*i)->Dist) {
- inserted = true;
- doms.insert(i, dv);
- }
- }
- if (!inserted)
- doms.push_back(dv);
- }
-
- // doms are now sorted in order of appearance. Try to merge them all, giving
- // priority to the latest ones.
- DomainValue *dv = 0;
- while (!doms.empty()) {
- if (!dv) {
- dv = doms.pop_back_val();
- continue;
- }
-
- DomainValue *latest = doms.pop_back_val();
- if (Merge(dv, latest)) continue;
-
- // If latest didn't merge, it is useless now. Kill all registers using it.
- for (SmallVector<int,4>::iterator i=used.begin(), e=used.end(); i != e; ++i)
- if (LiveRegs[*i] == latest)
- Kill(*i);
- }
-
- // dv is the DomainValue we are going to use for this instruction.
- if (!dv)
- dv = Alloc();
- dv->Dist = Distance;
- dv->AvailableDomains = available;
- dv->Instrs.push_back(mi);
-
- // Finally set all defs and non-collapsed uses to dv.
- for (unsigned i = 0, e = mi->getDesc().getNumOperands(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
- if (!mo.isReg()) continue;
- int rx = RegIndex(mo.getReg());
- if (rx < 0) continue;
- if (!LiveRegs || !LiveRegs[rx] || (mo.isDef() && LiveRegs[rx]!=dv)) {
- Kill(rx);
- SetLiveReg(rx, dv);
- }
- }
-}
-
-void SSEDomainFixPass::visitGenericInstr(MachineInstr *mi) {
- // Process explicit defs, kill any XMM registers redefined.
- for (unsigned i = 0, e = mi->getDesc().getNumDefs(); i != e; ++i) {
- MachineOperand &mo = mi->getOperand(i);
- if (!mo.isReg()) continue;
- int rx = RegIndex(mo.getReg());
- if (rx < 0) continue;
- Kill(rx);
- }
-}
-
-bool SSEDomainFixPass::runOnMachineFunction(MachineFunction &mf) {
- MF = &mf;
- TII = MF->getTarget().getInstrInfo();
- TRI = MF->getTarget().getRegisterInfo();
- MBB = 0;
- LiveRegs = 0;
- Distance = 0;
- assert(NumRegs == RC->getNumRegs() && "Bad regclass");
-
- // If no XMM registers are used in the function, we can skip it completely.
- bool anyregs = false;
- for (TargetRegisterClass::const_iterator I = RC->begin(), E = RC->end();
- I != E; ++I)
- if (MF->getRegInfo().isPhysRegUsed(*I)) {
- anyregs = true;
- break;
- }
- if (!anyregs) return false;
-
- // Initialize the AliasMap on the first use.
- if (AliasMap.empty()) {
- // Given a PhysReg, AliasMap[PhysReg] is either the relevant index into RC,
- // or -1.
- AliasMap.resize(TRI->getNumRegs(), -1);
- for (unsigned i = 0, e = RC->getNumRegs(); i != e; ++i)
- for (const unsigned *AI = TRI->getOverlaps(RC->getRegister(i)); *AI; ++AI)
- AliasMap[*AI] = i;
- }
-
- MachineBasicBlock *Entry = MF->begin();
- SmallPtrSet<MachineBasicBlock*, 16> Visited;
- for (df_ext_iterator<MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*, 16> >
- DFI = df_ext_begin(Entry, Visited), DFE = df_ext_end(Entry, Visited);
- DFI != DFE; ++DFI) {
- MBB = *DFI;
- enterBasicBlock();
- for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
- ++I) {
- MachineInstr *mi = I;
- if (mi->isDebugValue()) continue;
- ++Distance;
- std::pair<uint16_t, uint16_t> domp = TII->getExecutionDomain(mi);
- if (domp.first)
- if (domp.second)
- visitSoftInstr(mi, domp.second);
- else
- visitHardInstr(mi, domp.first);
- else if (LiveRegs)
- visitGenericInstr(mi);
- }
-
- // Save live registers at end of MBB - used by enterBasicBlock().
- if (LiveRegs)
- LiveOuts.insert(std::make_pair(MBB, LiveRegs));
- LiveRegs = 0;
- }
-
- // Clear the LiveOuts vectors. Should we also collapse any remaining
- // DomainValues?
- for (LiveOutMap::const_iterator i = LiveOuts.begin(), e = LiveOuts.end();
- i != e; ++i)
- delete[] i->second;
- LiveOuts.clear();
- Avail.clear();
- Allocator.DestroyAll();
-
- return false;
-}
-
-FunctionPass *
-llvm::createExecutionDependencyFixPass(const TargetRegisterClass *RC) {
- return new SSEDomainFixPass(RC);
-}
projects / oota-llvm.git / commitdiff