Analysis that tracks defined/used subregister lanes across COPY instructions and instructions that get lowered to a COPY (PHI, REG_SEQUENCE, INSERT_SUBREG, EXTRACT_SUBREG). More...
#include <deque>#include <vector>#include "llvm/ADT/BitVector.h"#include "llvm/ADT/SetVector.h"#include "llvm/CodeGen/MachineFunctionPass.h"#include "llvm/CodeGen/MachineRegisterInfo.h"#include "llvm/CodeGen/Passes.h"#include "llvm/CodeGen/TargetRegisterInfo.h"#include "llvm/CodeGen/TargetSubtargetInfo.h"#include "llvm/InitializePasses.h"#include "llvm/Pass.h"#include "llvm/PassRegistry.h"#include "llvm/Support/Debug.h"#include "llvm/Support/raw_ostream.h"
Go to the source code of this file.
Macros | |
| #define | DEBUG_TYPE "detect-dead-lanes" |
Functions | |
| static bool | lowersToCopies (const MachineInstr &MI) |
Returns true if MI will get lowered to a series of COPY instructions. More... | |
| static bool | isCrossCopy (const MachineRegisterInfo &MRI, const MachineInstr &MI, const TargetRegisterClass *DstRC, const MachineOperand &MO) |
Detailed Description
Analysis that tracks defined/used subregister lanes across COPY instructions and instructions that get lowered to a COPY (PHI, REG_SEQUENCE, INSERT_SUBREG, EXTRACT_SUBREG).
The information is used to detect dead definitions and the usage of (completely) undefined values and mark the operands as such. This pass is necessary because the dead/undef status is not obvious anymore when subregisters are involved.
Example: %0 = some definition %1 = IMPLICIT_DEF %2 = REG_SEQUENCE %0, sub0, %1, sub1 %3 = EXTRACT_SUBREG %2, sub1 = use %3 The %0 definition is dead and %3 contains an undefined value.
Definition in file DetectDeadLanes.cpp.
Macro Definition Documentation
◆ DEBUG_TYPE
| #define DEBUG_TYPE "detect-dead-lanes" |
Definition at line 47 of file DetectDeadLanes.cpp.
Function Documentation
◆ isCrossCopy()
|
static |
Definition at line 153 of file DetectDeadLanes.cpp.
References llvm::LaneBitmask::any(), assert(), llvm::TargetRegisterInfo::composeSubRegIndices(), llvm::TargetRegisterClass::CoveredBySubRegs, llvm::dbgs(), llvm::tgtok::Def, DefMI, llvm::MachineInstr::defs(), llvm::LaneBitmask::getAll(), llvm::TargetRegisterInfo::getCommonSubClass(), llvm::TargetRegisterInfo::getCommonSuperRegClass(), llvm::MachineInstr::getDesc(), llvm::MachineOperand::getImm(), llvm::TargetRegisterInfo::getMatchingSuperRegClass(), llvm::LaneBitmask::getNone(), llvm::MCInstrDesc::getNumDefs(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), llvm::MachineInstr::getOperandNo(), llvm::MachineOperand::getParent(), llvm::MachineOperand::getReg(), llvm::MachineRegisterInfo::getRegClass(), llvm::MachineFunction::getRegInfo(), llvm::MachineOperand::getSubReg(), llvm::MachineRegisterInfo::getTargetRegisterInfo(), llvm::TargetRegisterInfo::index2VirtReg(), Info, llvm::MachineOperand::isDead(), llvm::MachineOperand::isDef(), llvm::MachineInstr::isImplicitDef(), llvm::MachineInstr::isKill(), llvm::TargetRegisterInfo::isPhysicalRegister(), llvm::MachineOperand::isReg(), llvm::MachineOperand::isUse(), llvm::TargetRegisterInfo::isVirtualRegister(), llvm::TargetRegisterClass::LaneMask, LLVM_DEBUG, llvm_unreachable, lowersToCopies(), llvm::BitmaskEnumDetail::Mask(), MI, MRI, llvm::MachineInstr::operands(), llvm::PrintLaneMask(), llvm::printReg(), llvm::VRegInfo::RC, llvm::MachineOperand::readsReg(), Reg, llvm::MachineOperand::setIsDead(), llvm::MachineOperand::setIsUndef(), SubReg, TRI, UseMI, llvm::MachineInstr::uses(), and llvm::TargetRegisterInfo::virtReg2Index().
◆ lowersToCopies()
|
static |
Returns true if MI will get lowered to a series of COPY instructions.
We call this a COPY-like instruction.
Definition at line 138 of file DetectDeadLanes.cpp.
Referenced by isCrossCopy().
