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a1e554d253
Summary: NFC: no one uses AnalyzeBranchPredicate yet. Add TargetInstrInfo::AnalyzeBranchPredicate and implement for x86. A later change adding support for page-fault based implicit null checks depends on this. Reviewers: reames, ab, atrick Reviewed By: atrick Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10200 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239742 91177308-0d34-0410-b5e6-96231b3b80d8
518 lines
23 KiB
C++
518 lines
23 KiB
C++
//===-- X86InstrInfo.h - X86 Instruction Information ------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the X86 implementation of the TargetInstrInfo class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIB_TARGET_X86_X86INSTRINFO_H
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#define LLVM_LIB_TARGET_X86_X86INSTRINFO_H
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#include "MCTargetDesc/X86BaseInfo.h"
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#include "X86RegisterInfo.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/Target/TargetInstrInfo.h"
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#define GET_INSTRINFO_HEADER
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#include "X86GenInstrInfo.inc"
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namespace llvm {
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class X86RegisterInfo;
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class X86Subtarget;
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namespace MachineCombinerPattern {
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enum MC_PATTERN : int {
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// These are commutative variants for reassociating a computation chain
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// of the form:
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// B = A op X (Prev)
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// C = B op Y (Root)
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MC_REASSOC_AX_BY = 0,
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MC_REASSOC_AX_YB = 1,
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MC_REASSOC_XA_BY = 2,
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MC_REASSOC_XA_YB = 3,
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};
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} // end namespace MachineCombinerPattern
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namespace X86 {
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// X86 specific condition code. These correspond to X86_*_COND in
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// X86InstrInfo.td. They must be kept in synch.
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enum CondCode {
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COND_A = 0,
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COND_AE = 1,
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COND_B = 2,
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COND_BE = 3,
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COND_E = 4,
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COND_G = 5,
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COND_GE = 6,
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COND_L = 7,
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COND_LE = 8,
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COND_NE = 9,
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COND_NO = 10,
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COND_NP = 11,
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COND_NS = 12,
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COND_O = 13,
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COND_P = 14,
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COND_S = 15,
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LAST_VALID_COND = COND_S,
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// Artificial condition codes. These are used by AnalyzeBranch
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// to indicate a block terminated with two conditional branches to
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// the same location. This occurs in code using FCMP_OEQ or FCMP_UNE,
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// which can't be represented on x86 with a single condition. These
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// are never used in MachineInstrs.
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COND_NE_OR_P,
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COND_NP_OR_E,
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COND_INVALID
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};
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// Turn condition code into conditional branch opcode.
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unsigned GetCondBranchFromCond(CondCode CC);
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/// \brief Return a set opcode for the given condition and whether it has
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/// a memory operand.
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unsigned getSETFromCond(CondCode CC, bool HasMemoryOperand = false);
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/// \brief Return a cmov opcode for the given condition, register size in
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/// bytes, and operand type.
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unsigned getCMovFromCond(CondCode CC, unsigned RegBytes,
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bool HasMemoryOperand = false);
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// Turn CMov opcode into condition code.
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CondCode getCondFromCMovOpc(unsigned Opc);
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/// GetOppositeBranchCondition - Return the inverse of the specified cond,
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/// e.g. turning COND_E to COND_NE.
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CondCode GetOppositeBranchCondition(CondCode CC);
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} // end namespace X86;
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/// isGlobalStubReference - Return true if the specified TargetFlag operand is
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/// a reference to a stub for a global, not the global itself.
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inline static bool isGlobalStubReference(unsigned char TargetFlag) {
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switch (TargetFlag) {
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case X86II::MO_DLLIMPORT: // dllimport stub.
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case X86II::MO_GOTPCREL: // rip-relative GOT reference.
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case X86II::MO_GOT: // normal GOT reference.
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case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Normal $non_lazy_ptr ref.
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case X86II::MO_DARWIN_NONLAZY: // Normal $non_lazy_ptr ref.
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case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Hidden $non_lazy_ptr ref.
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return true;
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default:
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return false;
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}
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}
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/// isGlobalRelativeToPICBase - Return true if the specified global value
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/// reference is relative to a 32-bit PIC base (X86ISD::GlobalBaseReg). If this
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/// is true, the addressing mode has the PIC base register added in (e.g. EBX).
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inline static bool isGlobalRelativeToPICBase(unsigned char TargetFlag) {
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switch (TargetFlag) {
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case X86II::MO_GOTOFF: // isPICStyleGOT: local global.
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case X86II::MO_GOT: // isPICStyleGOT: other global.
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case X86II::MO_PIC_BASE_OFFSET: // Darwin local global.
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case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Darwin/32 external global.
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case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Darwin/32 hidden global.
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case X86II::MO_TLVP: // ??? Pretty sure..
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return true;
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default:
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return false;
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}
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}
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inline static bool isScale(const MachineOperand &MO) {
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return MO.isImm() &&
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(MO.getImm() == 1 || MO.getImm() == 2 ||
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MO.getImm() == 4 || MO.getImm() == 8);
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}
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inline static bool isLeaMem(const MachineInstr *MI, unsigned Op) {
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if (MI->getOperand(Op).isFI()) return true;
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return Op+X86::AddrSegmentReg <= MI->getNumOperands() &&
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MI->getOperand(Op+X86::AddrBaseReg).isReg() &&
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isScale(MI->getOperand(Op+X86::AddrScaleAmt)) &&
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MI->getOperand(Op+X86::AddrIndexReg).isReg() &&
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(MI->getOperand(Op+X86::AddrDisp).isImm() ||
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MI->getOperand(Op+X86::AddrDisp).isGlobal() ||
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MI->getOperand(Op+X86::AddrDisp).isCPI() ||
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MI->getOperand(Op+X86::AddrDisp).isJTI());
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}
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inline static bool isMem(const MachineInstr *MI, unsigned Op) {
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if (MI->getOperand(Op).isFI()) return true;
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return Op+X86::AddrNumOperands <= MI->getNumOperands() &&
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MI->getOperand(Op+X86::AddrSegmentReg).isReg() &&
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isLeaMem(MI, Op);
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}
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class X86InstrInfo final : public X86GenInstrInfo {
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X86Subtarget &Subtarget;
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const X86RegisterInfo RI;
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/// RegOp2MemOpTable3Addr, RegOp2MemOpTable0, RegOp2MemOpTable1,
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/// RegOp2MemOpTable2, RegOp2MemOpTable3 - Load / store folding opcode maps.
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///
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typedef DenseMap<unsigned,
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std::pair<unsigned, unsigned> > RegOp2MemOpTableType;
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RegOp2MemOpTableType RegOp2MemOpTable2Addr;
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RegOp2MemOpTableType RegOp2MemOpTable0;
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RegOp2MemOpTableType RegOp2MemOpTable1;
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RegOp2MemOpTableType RegOp2MemOpTable2;
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RegOp2MemOpTableType RegOp2MemOpTable3;
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RegOp2MemOpTableType RegOp2MemOpTable4;
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/// MemOp2RegOpTable - Load / store unfolding opcode map.
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///
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typedef DenseMap<unsigned,
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std::pair<unsigned, unsigned> > MemOp2RegOpTableType;
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MemOp2RegOpTableType MemOp2RegOpTable;
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static void AddTableEntry(RegOp2MemOpTableType &R2MTable,
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MemOp2RegOpTableType &M2RTable,
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unsigned RegOp, unsigned MemOp, unsigned Flags);
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virtual void anchor();
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bool AnalyzeBranchImpl(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
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MachineBasicBlock *&FBB,
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SmallVectorImpl<MachineOperand> &Cond,
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SmallVectorImpl<MachineInstr *> &CondBranches,
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bool AllowModify) const;
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public:
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explicit X86InstrInfo(X86Subtarget &STI);
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/// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
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/// such, whenever a client has an instance of instruction info, it should
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/// always be able to get register info as well (through this method).
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///
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const X86RegisterInfo &getRegisterInfo() const { return RI; }
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/// getSPAdjust - This returns the stack pointer adjustment made by
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/// this instruction. For x86, we need to handle more complex call
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/// sequences involving PUSHes.
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int getSPAdjust(const MachineInstr *MI) const override;
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/// isCoalescableExtInstr - Return true if the instruction is a "coalescable"
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/// extension instruction. That is, it's like a copy where it's legal for the
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/// source to overlap the destination. e.g. X86::MOVSX64rr32. If this returns
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/// true, then it's expected the pre-extension value is available as a subreg
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/// of the result register. This also returns the sub-register index in
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/// SubIdx.
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bool isCoalescableExtInstr(const MachineInstr &MI,
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unsigned &SrcReg, unsigned &DstReg,
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unsigned &SubIdx) const override;
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unsigned isLoadFromStackSlot(const MachineInstr *MI,
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int &FrameIndex) const override;
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/// isLoadFromStackSlotPostFE - Check for post-frame ptr elimination
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/// stack locations as well. This uses a heuristic so it isn't
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/// reliable for correctness.
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unsigned isLoadFromStackSlotPostFE(const MachineInstr *MI,
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int &FrameIndex) const override;
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unsigned isStoreToStackSlot(const MachineInstr *MI,
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int &FrameIndex) const override;
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/// isStoreToStackSlotPostFE - Check for post-frame ptr elimination
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/// stack locations as well. This uses a heuristic so it isn't
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/// reliable for correctness.
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unsigned isStoreToStackSlotPostFE(const MachineInstr *MI,
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int &FrameIndex) const override;
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bool isReallyTriviallyReMaterializable(const MachineInstr *MI,
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AliasAnalysis *AA) const override;
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void reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
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unsigned DestReg, unsigned SubIdx,
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const MachineInstr *Orig,
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const TargetRegisterInfo &TRI) const override;
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/// Given an operand within a MachineInstr, insert preceding code to put it
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/// into the right format for a particular kind of LEA instruction. This may
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/// involve using an appropriate super-register instead (with an implicit use
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/// of the original) or creating a new virtual register and inserting COPY
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/// instructions to get the data into the right class.
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///
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/// Reference parameters are set to indicate how caller should add this
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/// operand to the LEA instruction.
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bool classifyLEAReg(MachineInstr *MI, const MachineOperand &Src,
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unsigned LEAOpcode, bool AllowSP,
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unsigned &NewSrc, bool &isKill,
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bool &isUndef, MachineOperand &ImplicitOp) const;
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/// convertToThreeAddress - This method must be implemented by targets that
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/// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
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/// may be able to convert a two-address instruction into a true
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/// three-address instruction on demand. This allows the X86 target (for
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/// example) to convert ADD and SHL instructions into LEA instructions if they
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/// would require register copies due to two-addressness.
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///
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/// This method returns a null pointer if the transformation cannot be
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/// performed, otherwise it returns the new instruction.
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///
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MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
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MachineBasicBlock::iterator &MBBI,
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LiveVariables *LV) const override;
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/// commuteInstruction - We have a few instructions that must be hacked on to
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/// commute them.
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///
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MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const override;
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bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
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unsigned &SrcOpIdx2) const override;
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// Branch analysis.
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bool isUnpredicatedTerminator(const MachineInstr* MI) const override;
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bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
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MachineBasicBlock *&FBB,
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SmallVectorImpl<MachineOperand> &Cond,
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bool AllowModify) const override;
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bool getMemOpBaseRegImmOfs(MachineInstr *LdSt, unsigned &BaseReg,
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unsigned &Offset,
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const TargetRegisterInfo *TRI) const override;
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bool AnalyzeBranchPredicate(MachineBasicBlock &MBB,
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TargetInstrInfo::MachineBranchPredicate &MBP,
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bool AllowModify = false) const override;
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unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
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unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
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MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
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DebugLoc DL) const override;
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bool canInsertSelect(const MachineBasicBlock&, ArrayRef<MachineOperand> Cond,
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unsigned, unsigned, int&, int&, int&) const override;
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void insertSelect(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI, DebugLoc DL,
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unsigned DstReg, ArrayRef<MachineOperand> Cond,
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unsigned TrueReg, unsigned FalseReg) const override;
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void copyPhysReg(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI, DebugLoc DL,
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unsigned DestReg, unsigned SrcReg,
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bool KillSrc) const override;
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void storeRegToStackSlot(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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unsigned SrcReg, bool isKill, int FrameIndex,
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const TargetRegisterClass *RC,
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const TargetRegisterInfo *TRI) const override;
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void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
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SmallVectorImpl<MachineOperand> &Addr,
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const TargetRegisterClass *RC,
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MachineInstr::mmo_iterator MMOBegin,
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MachineInstr::mmo_iterator MMOEnd,
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SmallVectorImpl<MachineInstr*> &NewMIs) const;
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void loadRegFromStackSlot(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator MI,
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unsigned DestReg, int FrameIndex,
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const TargetRegisterClass *RC,
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const TargetRegisterInfo *TRI) const override;
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void loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
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SmallVectorImpl<MachineOperand> &Addr,
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const TargetRegisterClass *RC,
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MachineInstr::mmo_iterator MMOBegin,
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MachineInstr::mmo_iterator MMOEnd,
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SmallVectorImpl<MachineInstr*> &NewMIs) const;
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bool expandPostRAPseudo(MachineBasicBlock::iterator MI) const override;
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/// foldMemoryOperand - If this target supports it, fold a load or store of
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/// the specified stack slot into the specified machine instruction for the
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/// specified operand(s). If this is possible, the target should perform the
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/// folding and return true, otherwise it should return false. If it folds
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/// the instruction, it is likely that the MachineInstruction the iterator
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/// references has been changed.
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MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
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ArrayRef<unsigned> Ops,
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MachineBasicBlock::iterator InsertPt,
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int FrameIndex) const override;
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/// foldMemoryOperand - Same as the previous version except it allows folding
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/// of any load and store from / to any address, not just from a specific
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/// stack slot.
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MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
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ArrayRef<unsigned> Ops,
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MachineBasicBlock::iterator InsertPt,
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MachineInstr *LoadMI) const override;
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/// canFoldMemoryOperand - Returns true if the specified load / store is
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/// folding is possible.
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bool canFoldMemoryOperand(const MachineInstr *,
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ArrayRef<unsigned>) const override;
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/// unfoldMemoryOperand - Separate a single instruction which folded a load or
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/// a store or a load and a store into two or more instruction. If this is
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/// possible, returns true as well as the new instructions by reference.
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bool unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI,
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unsigned Reg, bool UnfoldLoad, bool UnfoldStore,
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SmallVectorImpl<MachineInstr*> &NewMIs) const override;
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bool unfoldMemoryOperand(SelectionDAG &DAG, SDNode *N,
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SmallVectorImpl<SDNode*> &NewNodes) const override;
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/// getOpcodeAfterMemoryUnfold - Returns the opcode of the would be new
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/// instruction after load / store are unfolded from an instruction of the
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/// specified opcode. It returns zero if the specified unfolding is not
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/// possible. If LoadRegIndex is non-null, it is filled in with the operand
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/// index of the operand which will hold the register holding the loaded
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/// value.
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unsigned getOpcodeAfterMemoryUnfold(unsigned Opc,
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bool UnfoldLoad, bool UnfoldStore,
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unsigned *LoadRegIndex = nullptr) const override;
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/// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler
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/// to determine if two loads are loading from the same base address. It
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/// should only return true if the base pointers are the same and the
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/// only differences between the two addresses are the offset. It also returns
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/// the offsets by reference.
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bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2, int64_t &Offset1,
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int64_t &Offset2) const override;
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/// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
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/// determine (in conjunction with areLoadsFromSameBasePtr) if two loads should
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/// be scheduled togther. On some targets if two loads are loading from
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/// addresses in the same cache line, it's better if they are scheduled
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/// together. This function takes two integers that represent the load offsets
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/// from the common base address. It returns true if it decides it's desirable
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/// to schedule the two loads together. "NumLoads" is the number of loads that
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/// have already been scheduled after Load1.
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bool shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
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int64_t Offset1, int64_t Offset2,
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unsigned NumLoads) const override;
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bool shouldScheduleAdjacent(MachineInstr* First,
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MachineInstr *Second) const override;
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void getNoopForMachoTarget(MCInst &NopInst) const override;
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bool
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ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
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/// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
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/// instruction that defines the specified register class.
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bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const override;
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/// isSafeToClobberEFLAGS - Return true if it's safe insert an instruction tha
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/// would clobber the EFLAGS condition register. Note the result may be
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/// conservative. If it cannot definitely determine the safety after visiting
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/// a few instructions in each direction it assumes it's not safe.
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bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB,
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MachineBasicBlock::iterator I) const;
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static bool isX86_64ExtendedReg(const MachineOperand &MO) {
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if (!MO.isReg()) return false;
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return X86II::isX86_64ExtendedReg(MO.getReg());
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}
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/// getGlobalBaseReg - Return a virtual register initialized with the
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/// the global base register value. Output instructions required to
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/// initialize the register in the function entry block, if necessary.
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///
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unsigned getGlobalBaseReg(MachineFunction *MF) const;
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std::pair<uint16_t, uint16_t>
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getExecutionDomain(const MachineInstr *MI) const override;
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void setExecutionDomain(MachineInstr *MI, unsigned Domain) const override;
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unsigned
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getPartialRegUpdateClearance(const MachineInstr *MI, unsigned OpNum,
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const TargetRegisterInfo *TRI) const override;
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unsigned getUndefRegClearance(const MachineInstr *MI, unsigned &OpNum,
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const TargetRegisterInfo *TRI) const override;
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void breakPartialRegDependency(MachineBasicBlock::iterator MI, unsigned OpNum,
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const TargetRegisterInfo *TRI) const override;
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MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
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unsigned OpNum,
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ArrayRef<MachineOperand> MOs,
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MachineBasicBlock::iterator InsertPt,
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unsigned Size, unsigned Alignment,
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bool AllowCommute) const;
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void
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getUnconditionalBranch(MCInst &Branch,
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const MCSymbolRefExpr *BranchTarget) const override;
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void getTrap(MCInst &MI) const override;
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unsigned getJumpInstrTableEntryBound() const override;
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bool isHighLatencyDef(int opc) const override;
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bool hasHighOperandLatency(const TargetSchedModel &SchedModel,
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const MachineRegisterInfo *MRI,
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const MachineInstr *DefMI, unsigned DefIdx,
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const MachineInstr *UseMI,
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unsigned UseIdx) const override;
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bool useMachineCombiner() const override {
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return true;
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}
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/// Return true when there is potentially a faster code sequence
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/// for an instruction chain ending in <Root>. All potential patterns are
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/// output in the <Pattern> array.
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bool hasPattern(
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MachineInstr &Root,
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SmallVectorImpl<MachineCombinerPattern::MC_PATTERN> &P) const override;
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/// When hasPattern() finds a pattern, this function generates the
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/// instructions that could replace the original code sequence.
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void genAlternativeCodeSequence(
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MachineInstr &Root, MachineCombinerPattern::MC_PATTERN P,
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SmallVectorImpl<MachineInstr *> &InsInstrs,
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|
SmallVectorImpl<MachineInstr *> &DelInstrs,
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DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
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/// analyzeCompare - For a comparison instruction, return the source registers
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/// in SrcReg and SrcReg2 if having two register operands, and the value it
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/// compares against in CmpValue. Return true if the comparison instruction
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/// can be analyzed.
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bool analyzeCompare(const MachineInstr *MI, unsigned &SrcReg,
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unsigned &SrcReg2, int &CmpMask,
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int &CmpValue) const override;
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/// optimizeCompareInstr - Check if there exists an earlier instruction that
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/// operates on the same source operands and sets flags in the same way as
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/// Compare; remove Compare if possible.
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bool optimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg,
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unsigned SrcReg2, int CmpMask, int CmpValue,
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const MachineRegisterInfo *MRI) const override;
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|
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|
/// optimizeLoadInstr - Try to remove the load by folding it to a register
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/// operand at the use. We fold the load instructions if and only if the
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/// def and use are in the same BB. We only look at one load and see
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/// whether it can be folded into MI. FoldAsLoadDefReg is the virtual register
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|
/// defined by the load we are trying to fold. DefMI returns the machine
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/// instruction that defines FoldAsLoadDefReg, and the function returns
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/// the machine instruction generated due to folding.
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MachineInstr* optimizeLoadInstr(MachineInstr *MI,
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const MachineRegisterInfo *MRI,
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|
unsigned &FoldAsLoadDefReg,
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MachineInstr *&DefMI) const override;
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private:
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MachineInstr * convertToThreeAddressWithLEA(unsigned MIOpc,
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MachineFunction::iterator &MFI,
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MachineBasicBlock::iterator &MBBI,
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|
LiveVariables *LV) const;
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|
|
/// isFrameOperand - Return true and the FrameIndex if the specified
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|
/// operand and follow operands form a reference to the stack frame.
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|
bool isFrameOperand(const MachineInstr *MI, unsigned int Op,
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|
int &FrameIndex) const;
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|
};
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} // End llvm namespace
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#endif
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