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llvm-mirror/lib/Target/SystemZ/SystemZInstrInfo.h
Jonas Paulsson 27037aea90 [SystemZ] Implement -fstack-clash-protection
Probing of allocated stack space is now done when this option is passed. The
purpose is to protect against the stack clash attack (see
https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt).

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D78717
2020-06-06 18:38:36 +02:00

363 lines
15 KiB
C++

//===-- SystemZInstrInfo.h - SystemZ instruction information ----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the SystemZ implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
#define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
#include "SystemZ.h"
#include "SystemZRegisterInfo.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include <cstdint>
#define GET_INSTRINFO_HEADER
#include "SystemZGenInstrInfo.inc"
namespace llvm {
class SystemZSubtarget;
namespace SystemZII {
enum {
// See comments in SystemZInstrFormats.td.
SimpleBDXLoad = (1 << 0),
SimpleBDXStore = (1 << 1),
Has20BitOffset = (1 << 2),
HasIndex = (1 << 3),
Is128Bit = (1 << 4),
AccessSizeMask = (31 << 5),
AccessSizeShift = 5,
CCValuesMask = (15 << 10),
CCValuesShift = 10,
CompareZeroCCMaskMask = (15 << 14),
CompareZeroCCMaskShift = 14,
CCMaskFirst = (1 << 18),
CCMaskLast = (1 << 19),
IsLogical = (1 << 20),
CCIfNoSignedWrap = (1 << 21)
};
static inline unsigned getAccessSize(unsigned int Flags) {
return (Flags & AccessSizeMask) >> AccessSizeShift;
}
static inline unsigned getCCValues(unsigned int Flags) {
return (Flags & CCValuesMask) >> CCValuesShift;
}
static inline unsigned getCompareZeroCCMask(unsigned int Flags) {
return (Flags & CompareZeroCCMaskMask) >> CompareZeroCCMaskShift;
}
// SystemZ MachineOperand target flags.
enum {
// Masks out the bits for the access model.
MO_SYMBOL_MODIFIER = (3 << 0),
// @GOT (aka @GOTENT)
MO_GOT = (1 << 0),
// @INDNTPOFF
MO_INDNTPOFF = (2 << 0)
};
// Classifies a branch.
enum BranchType {
// An instruction that branches on the current value of CC.
BranchNormal,
// An instruction that peforms a 32-bit signed comparison and branches
// on the result.
BranchC,
// An instruction that peforms a 32-bit unsigned comparison and branches
// on the result.
BranchCL,
// An instruction that peforms a 64-bit signed comparison and branches
// on the result.
BranchCG,
// An instruction that peforms a 64-bit unsigned comparison and branches
// on the result.
BranchCLG,
// An instruction that decrements a 32-bit register and branches if
// the result is nonzero.
BranchCT,
// An instruction that decrements a 64-bit register and branches if
// the result is nonzero.
BranchCTG,
// An instruction representing an asm goto statement.
AsmGoto
};
// Information about a branch instruction.
class Branch {
// The target of the branch. In case of INLINEASM_BR, this is nullptr.
const MachineOperand *Target;
public:
// The type of the branch.
BranchType Type;
// CCMASK_<N> is set if CC might be equal to N.
unsigned CCValid;
// CCMASK_<N> is set if the branch should be taken when CC == N.
unsigned CCMask;
Branch(BranchType type, unsigned ccValid, unsigned ccMask,
const MachineOperand *target)
: Target(target), Type(type), CCValid(ccValid), CCMask(ccMask) {}
bool isIndirect() { return Target != nullptr && Target->isReg(); }
bool hasMBBTarget() { return Target != nullptr && Target->isMBB(); }
MachineBasicBlock *getMBBTarget() {
return hasMBBTarget() ? Target->getMBB() : nullptr;
}
};
// Kinds of fused compares in compare-and-* instructions. Together with type
// of the converted compare, this identifies the compare-and-*
// instruction.
enum FusedCompareType {
// Relative branch - CRJ etc.
CompareAndBranch,
// Indirect branch, used for return - CRBReturn etc.
CompareAndReturn,
// Indirect branch, used for sibcall - CRBCall etc.
CompareAndSibcall,
// Trap
CompareAndTrap
};
} // end namespace SystemZII
namespace SystemZ {
int getTwoOperandOpcode(uint16_t Opcode);
int getTargetMemOpcode(uint16_t Opcode);
// Return a version of comparison CC mask CCMask in which the LT and GT
// actions are swapped.
unsigned reverseCCMask(unsigned CCMask);
// Create a new basic block after MBB.
MachineBasicBlock *emitBlockAfter(MachineBasicBlock *MBB);
// Split MBB after MI and return the new block (the one that contains
// instructions after MI).
MachineBasicBlock *splitBlockAfter(MachineBasicBlock::iterator MI,
MachineBasicBlock *MBB);
// Split MBB before MI and return the new block (the one that contains MI).
MachineBasicBlock *splitBlockBefore(MachineBasicBlock::iterator MI,
MachineBasicBlock *MBB);
}
class SystemZInstrInfo : public SystemZGenInstrInfo {
const SystemZRegisterInfo RI;
SystemZSubtarget &STI;
void splitMove(MachineBasicBlock::iterator MI, unsigned NewOpcode) const;
void splitAdjDynAlloc(MachineBasicBlock::iterator MI) const;
void expandRIPseudo(MachineInstr &MI, unsigned LowOpcode, unsigned HighOpcode,
bool ConvertHigh) const;
void expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
unsigned LowOpcodeK, unsigned HighOpcode) const;
void expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
unsigned HighOpcode) const;
void expandLOCPseudo(MachineInstr &MI, unsigned LowOpcode,
unsigned HighOpcode) const;
void expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
unsigned Size) const;
void expandLoadStackGuard(MachineInstr *MI) const;
MachineInstrBuilder
emitGRX32Move(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
unsigned LowLowOpcode, unsigned Size, bool KillSrc,
bool UndefSrc) const;
virtual void anchor();
protected:
/// Commutes the operands in the given instruction by changing the operands
/// order and/or changing the instruction's opcode and/or the immediate value
/// operand.
///
/// The arguments 'CommuteOpIdx1' and 'CommuteOpIdx2' specify the operands
/// to be commuted.
///
/// Do not call this method for a non-commutable instruction or
/// non-commutable operands.
/// Even though the instruction is commutable, the method may still
/// fail to commute the operands, null pointer is returned in such cases.
MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
unsigned CommuteOpIdx1,
unsigned CommuteOpIdx2) const override;
public:
explicit SystemZInstrInfo(SystemZSubtarget &STI);
// Override TargetInstrInfo.
unsigned isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
unsigned isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
bool isStackSlotCopy(const MachineInstr &MI, int &DestFrameIndex,
int &SrcFrameIndex) const override;
bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const override;
unsigned removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved = nullptr) const override;
unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
const DebugLoc &DL,
int *BytesAdded = nullptr) const override;
bool analyzeCompare(const MachineInstr &MI, Register &SrcReg,
Register &SrcReg2, int &Mask, int &Value) const override;
bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
Register, Register, Register, int &, int &,
int &) const override;
void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const DebugLoc &DL, Register DstReg,
ArrayRef<MachineOperand> Cond, Register TrueReg,
Register FalseReg) const override;
bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, Register Reg,
MachineRegisterInfo *MRI) const override;
bool isPredicable(const MachineInstr &MI) const override;
bool isProfitableToIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
unsigned ExtraPredCycles,
BranchProbability Probability) const override;
bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
unsigned NumCyclesT, unsigned ExtraPredCyclesT,
MachineBasicBlock &FMBB,
unsigned NumCyclesF, unsigned ExtraPredCyclesF,
BranchProbability Probability) const override;
bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
BranchProbability Probability) const override;
bool PredicateInstruction(MachineInstr &MI,
ArrayRef<MachineOperand> Pred) const override;
void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
bool KillSrc) const override;
void storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
Register SrcReg, bool isKill, int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
void loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
Register DestReg, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
MachineInstr &MI,
LiveVariables *LV) const override;
MachineInstr *
foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
ArrayRef<unsigned> Ops,
MachineBasicBlock::iterator InsertPt, int FrameIndex,
LiveIntervals *LIS = nullptr,
VirtRegMap *VRM = nullptr) const override;
MachineInstr *foldMemoryOperandImpl(
MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
LiveIntervals *LIS = nullptr) const override;
bool expandPostRAPseudo(MachineInstr &MBBI) const override;
bool reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
override;
// Return the SystemZRegisterInfo, which this class owns.
const SystemZRegisterInfo &getRegisterInfo() const { return RI; }
// Return the size in bytes of MI.
unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
// Return true if MI is a conditional or unconditional branch.
// When returning true, set Cond to the mask of condition-code
// values on which the instruction will branch, and set Target
// to the operand that contains the branch target. This target
// can be a register or a basic block.
SystemZII::Branch getBranchInfo(const MachineInstr &MI) const;
// Get the load and store opcodes for a given register class.
void getLoadStoreOpcodes(const TargetRegisterClass *RC,
unsigned &LoadOpcode, unsigned &StoreOpcode) const;
// Opcode is the opcode of an instruction that has an address operand,
// and the caller wants to perform that instruction's operation on an
// address that has displacement Offset. Return the opcode of a suitable
// instruction (which might be Opcode itself) or 0 if no such instruction
// exists.
unsigned getOpcodeForOffset(unsigned Opcode, int64_t Offset) const;
// If Opcode is a load instruction that has a LOAD AND TEST form,
// return the opcode for the testing form, otherwise return 0.
unsigned getLoadAndTest(unsigned Opcode) const;
// Return true if ROTATE AND ... SELECTED BITS can be used to select bits
// Mask of the R2 operand, given that only the low BitSize bits of Mask are
// significant. Set Start and End to the I3 and I4 operands if so.
bool isRxSBGMask(uint64_t Mask, unsigned BitSize,
unsigned &Start, unsigned &End) const;
// If Opcode is a COMPARE opcode for which an associated fused COMPARE AND *
// operation exists, return the opcode for the latter, otherwise return 0.
// MI, if nonnull, is the compare instruction.
unsigned getFusedCompare(unsigned Opcode,
SystemZII::FusedCompareType Type,
const MachineInstr *MI = nullptr) const;
// Try to find all CC users of the compare instruction (MBBI) and update
// all of them to maintain equivalent behavior after swapping the compare
// operands. Return false if not all users can be conclusively found and
// handled. The compare instruction is *not* changed.
bool prepareCompareSwapOperands(MachineBasicBlock::iterator MBBI) const;
// If Opcode is a LOAD opcode for with an associated LOAD AND TRAP
// operation exists, returh the opcode for the latter, otherwise return 0.
unsigned getLoadAndTrap(unsigned Opcode) const;
// Emit code before MBBI in MI to move immediate value Value into
// physical register Reg.
void loadImmediate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
unsigned Reg, uint64_t Value) const;
// Perform target specific instruction verification.
bool verifyInstruction(const MachineInstr &MI,
StringRef &ErrInfo) const override;
// Sometimes, it is possible for the target to tell, even without
// aliasing information, that two MIs access different memory
// addresses. This function returns true if two MIs access different
// memory addresses and false otherwise.
bool
areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
const MachineInstr &MIb) const override;
};
} // end namespace llvm
#endif // LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H