diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp b/contrib/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp new file mode 100644 index 0000000..d88be57 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp @@ -0,0 +1,169 @@ +//===-- 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/LivePhysRegs.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionAnalysis.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetSubtargetInfo.h" + +using namespace llvm; + +#define DEBUG_TYPE "stackmaps" + +static 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"); + +namespace { +/// \brief This pass calculates the liveness information for each basic block in +/// a function and attaches the register live-out information to a patchpoint +/// intrinsic if present. +/// +/// This pass can be disabled via the -enable-patchpoint-liveness=false flag. +/// The pass skips functions that don't have any patchpoint intrinsics. The +/// information provided by this pass is optional and not required by the +/// aformentioned intrinsic to function. +class StackMapLiveness : public MachineFunctionPass { + MachineFunction *MF; + const TargetRegisterInfo *TRI; + LivePhysRegs LiveRegs; + +public: + static char ID; + + /// \brief Default construct and initialize the pass. + StackMapLiveness(); + + /// \brief Tell the pass manager which passes we depend on and what + /// information we preserve. + void getAnalysisUsage(AnalysisUsage &AU) const override; + + /// \brief Calculate the liveness information for the given machine function. + bool runOnMachineFunction(MachineFunction &MF) override; + +private: + /// \brief Performs the actual liveness calculation for the function. + bool calculateLiveness(); + + /// \brief Add the current register live set to the instruction. + void addLiveOutSetToMI(MachineInstr &MI); + + /// \brief Create a register mask and initialize it with the registers from + /// the register live set. + uint32_t *createRegisterMask() const; +}; +} // namespace + +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"); + this->MF = &MF; + TRI = MF.getSubtarget().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); + + TRI->adjustStackMapLiveOutMask(Mask); + return Mask; +} |