#define DEBUG_TYPE "sse-domain-fix"
#include "X86InstrInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineRegisterInfo.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;
namespace {
struct DomainValue {
unsigned Refs;
unsigned AvailableDomains;
unsigned Dist;
SmallVector<MachineInstr*, 8> Instrs;
bool isCollapsed() const { return Instrs.empty(); }
bool hasDomain(unsigned domain) const {
return AvailableDomains & (1u << domain);
}
void addDomain(unsigned domain) {
AvailableDomains |= 1u << domain;
}
void setSingleDomain(unsigned domain) {
AvailableDomains = 1u << domain;
}
unsigned getCommonDomains(unsigned mask) const {
return AvailableDomains & mask;
}
unsigned getFirstDomain() const {
return CountTrailingZeros_32(AvailableDomains);
}
DomainValue() { clear(); }
void clear() {
Refs = AvailableDomains = Dist = 0;
Instrs.clear();
}
};
}
static const unsigned NumRegs = 16;
namespace {
class SSEDomainFixPass : public MachineFunctionPass {
static char ID;
SpecificBumpPtrAllocator<DomainValue> Allocator;
SmallVector<DomainValue*,16> Avail;
MachineFunction *MF;
const X86InstrInfo *TII;
const TargetRegisterInfo *TRI;
MachineBasicBlock *MBB;
DomainValue **LiveRegs;
typedef DenseMap<MachineBasicBlock*,DomainValue**> LiveOutMap;
LiveOutMap LiveOuts;
unsigned Distance;
public:
SSEDomainFixPass() : MachineFunctionPass(ID) {}
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:
int RegIndex(unsigned Reg);
DomainValue *Alloc(int domain = -1);
void Recycle(DomainValue*);
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;
int SSEDomainFixPass::RegIndex(unsigned reg) {
assert(X86::XMM15 == X86::XMM0+NumRegs-1 && "Unexpected sort");
reg -= X86::XMM0;
return reg < NumRegs ? (int) reg : -1;
}
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);
}
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;
}
void SSEDomainFixPass::Kill(int rx) {
assert(unsigned(rx) < NumRegs && "Invalid index");
if (!LiveRegs || !LiveRegs[rx]) return;
if (LiveRegs[rx]->Refs == 1 && !LiveRegs[rx]->isCollapsed())
Collapse(LiveRegs[rx], LiveRegs[rx]->getFirstDomain());
else
SetLiveReg(rx, 0);
}
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 {
Collapse(dv, dv->getFirstDomain());
assert(LiveRegs[rx] && "Not live after collapse?");
LiveRegs[rx]->addDomain(domain);
}
} else {
SetLiveReg(rx, Alloc(domain));
}
}
void SSEDomainFixPass::Collapse(DomainValue *dv, unsigned domain) {
assert(dv->hasDomain(domain) && "Cannot collapse");
while (!dv->Instrs.empty())
TII->SetSSEDomain(dv->Instrs.pop_back_val(), domain);
dv->setSingleDomain(domain);
if (LiveRegs && dv->Refs > 1)
for (unsigned rx = 0; rx != NumRegs; ++rx)
if (LiveRegs[rx] == dv)
SetLiveReg(rx, Alloc(domain));
}
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;
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() {
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;
}
if (LiveRegs[rx]->isCollapsed()) {
unsigned domain = LiveRegs[rx]->getFirstDomain();
if (!pdv->isCollapsed() && pdv->hasDomain(domain))
Collapse(pdv, domain);
continue;
}
if (!pdv->isCollapsed())
Merge(LiveRegs[rx], pdv);
else
Force(rx, pdv->getFirstDomain());
}
}
}
void SSEDomainFixPass::visitHardInstr(MachineInstr *mi, unsigned domain) {
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);
}
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);
}
}
void SSEDomainFixPass::visitSoftInstr(MachineInstr *mi, unsigned mask) {
unsigned available = mask;
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]) {
unsigned common = dv->getCommonDomains(available);
if (dv->isCollapsed()) {
if (common) available = common;
} else if (common)
used.push_back(rx);
else
Kill(rx);
}
}
if (isPowerOf2_32(available)) {
unsigned domain = CountTrailingZeros_32(available);
TII->SetSSEDomain(mi, domain);
visitHardInstr(mi, domain);
return;
}
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];
if (!dv->getCommonDomains(available)) {
Kill(*i);
continue;
}
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);
}
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;
for (SmallVector<int,4>::iterator i=used.begin(), e=used.end(); i != e; ++i)
if (LiveRegs[*i] == latest)
Kill(*i);
}
if (!dv)
dv = Alloc();
dv->Dist = Distance;
dv->AvailableDomains = available;
dv->Instrs.push_back(mi);
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) {
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 = static_cast<const X86InstrInfo*>(MF->getTarget().getInstrInfo());
TRI = MF->getTarget().getRegisterInfo();
MBB = 0;
LiveRegs = 0;
Distance = 0;
assert(NumRegs == X86::VR128RegClass.getNumRegs() && "Bad regclass");
bool anyregs = false;
for (TargetRegisterClass::const_iterator I = X86::VR128RegClass.begin(),
E = X86::VR128RegClass.end(); I != E; ++I)
if (MF->getRegInfo().isPhysRegUsed(*I)) {
anyregs = true;
break;
}
if (!anyregs) return false;
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->GetSSEDomain(mi);
if (domp.first)
if (domp.second)
visitSoftInstr(mi, domp.second);
else
visitHardInstr(mi, domp.first);
else if (LiveRegs)
visitGenericInstr(mi);
}
if (LiveRegs)
LiveOuts.insert(std::make_pair(MBB, LiveRegs));
LiveRegs = 0;
}
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::createSSEDomainFixPass() {
return new SSEDomainFixPass();
}