StackMapLivenessAnalysis.cpp [plain text]
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/StackMapLivenessAnalysis.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "stackmaps"
namespace llvm {
cl::opt<bool> EnablePatchPointLiveness("enable-patchpoint-liveness",
cl::Hidden, cl::init(true),
cl::desc("Enable PatchPoint Liveness Analysis Pass"));
}
STATISTIC(NumStackMapFuncVisited, "Number of functions visited");
STATISTIC(NumStackMapFuncSkipped, "Number of functions skipped");
STATISTIC(NumBBsVisited, "Number of basic blocks visited");
STATISTIC(NumBBsHaveNoStackmap, "Number of basic blocks with no stackmap");
STATISTIC(NumStackMaps, "Number of StackMaps visited");
char StackMapLiveness::ID = 0;
char &llvm::StackMapLivenessID = StackMapLiveness::ID;
INITIALIZE_PASS(StackMapLiveness, "stackmap-liveness",
"StackMap Liveness Analysis", false, false)
StackMapLiveness::StackMapLiveness() : MachineFunctionPass(ID) {
initializeStackMapLivenessPass(*PassRegistry::getPassRegistry());
}
void StackMapLiveness::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.setPreservesCFG();
AU.addRequired<MachineFunctionAnalysis>();
}
bool StackMapLiveness::runOnMachineFunction(MachineFunction &_MF) {
if (!EnablePatchPointLiveness)
return false;
DEBUG(dbgs() << "********** COMPUTING STACKMAP LIVENESS: "
<< _MF.getName() << " **********\n");
MF = &_MF;
TRI = MF->getSubtarget().getRegisterInfo();
++NumStackMapFuncVisited;
if (!MF->getFrameInfo()->hasPatchPoint()) {
++NumStackMapFuncSkipped;
return false;
}
return calculateLiveness();
}
bool StackMapLiveness::calculateLiveness() {
bool HasChanged = false;
for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
MBBI != MBBE; ++MBBI) {
DEBUG(dbgs() << "****** BB " << MBBI->getName() << " ******\n");
LiveRegs.init(TRI);
LiveRegs.addLiveOuts(MBBI);
bool HasStackMap = false;
for (MachineBasicBlock::reverse_iterator I = MBBI->rbegin(),
E = MBBI->rend(); I != E; ++I) {
if (I->getOpcode() == TargetOpcode::PATCHPOINT) {
addLiveOutSetToMI(*I);
HasChanged = true;
HasStackMap = true;
++NumStackMaps;
}
DEBUG(dbgs() << " " << LiveRegs << " " << *I);
LiveRegs.stepBackward(*I);
}
++NumBBsVisited;
if (!HasStackMap)
++NumBBsHaveNoStackmap;
}
return HasChanged;
}
void StackMapLiveness::addLiveOutSetToMI(MachineInstr &MI) {
uint32_t *Mask = createRegisterMask();
MachineOperand MO = MachineOperand::CreateRegLiveOut(Mask);
MI.addOperand(*MF, MO);
}
uint32_t *StackMapLiveness::createRegisterMask() const {
uint32_t *Mask = MF->allocateRegisterMask(TRI->getNumRegs());
for (LivePhysRegs::const_iterator RI = LiveRegs.begin(), RE = LiveRegs.end();
RI != RE; ++RI)
Mask[*RI / 32] |= 1U << (*RI % 32);
TRI->adjustStackMapLiveOutMask(Mask);
return Mask;
}