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+//===-- StackMapLivenessAnalysis.cpp - StackMap live Out Analysis ----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the StackMap Liveness analysis pass. The pass calculates
+// the liveness for each basic block in a function and attaches the register
+// live-out information to a stackmap or patchpoint intrinsic if present.
+//
+//===----------------------------------------------------------------------===//
+
+#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"
+
+
+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)
+
+/// Default construct and initialize the pass.
+StackMapLiveness::StackMapLiveness() : MachineFunctionPass(ID) {
+ initializeStackMapLivenessPass(*PassRegistry::getPassRegistry());
+}
+
+/// Tell the pass manager which passes we depend on and what information we
+/// preserve.
+void StackMapLiveness::getAnalysisUsage(AnalysisUsage &AU) const {
+ // We preserve all information.
+ AU.setPreservesAll();
+ AU.setPreservesCFG();
+ // Default dependencie for all MachineFunction passes.
+ AU.addRequired<MachineFunctionAnalysis>();
+}
+
+/// Calculate the liveness information for the given machine function.
+bool StackMapLiveness::runOnMachineFunction(MachineFunction &_MF) {
+ if (!EnablePatchPointLiveness)
+ return false;
+
+ DEBUG(dbgs() << "********** COMPUTING STACKMAP LIVENESS: "
+ << _MF.getName() << " **********\n");
+ MF = &_MF;
+ TRI = MF->getTarget().getRegisterInfo();
+ ++NumStackMapFuncVisited;
+
+ // Skip this function if there are no patchpoints to process.
+ if (!MF->getFrameInfo()->hasPatchPoint()) {
+ ++NumStackMapFuncSkipped;
+ return false;
+ }
+ return calculateLiveness();
+}
+
+/// Performs the actual liveness calculation for the function.
+bool StackMapLiveness::calculateLiveness() {
+ bool HasChanged = false;
+ // For all basic blocks in the function.
+ 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;
+ // Reverse iterate over all instructions and add the current live register
+ // set to an instruction if we encounter a patchpoint instruction.
+ 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;
+}
+
+/// Add the current register live set to the instruction.
+void StackMapLiveness::addLiveOutSetToMI(MachineInstr &MI) {
+ uint32_t *Mask = createRegisterMask();
+ MachineOperand MO = MachineOperand::CreateRegLiveOut(Mask);
+ MI.addOperand(*MF, MO);
+}
+
+/// Create a register mask and initialize it with the registers from the
+/// register live set.
+uint32_t *StackMapLiveness::createRegisterMask() const {
+ // The mask is owned and cleaned up by the Machine Function.
+ 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);
+ return Mask;
+}
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