X86InstrFoldTables.h

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//===-- X86InstrFoldTables.h - X86 Instruction Folding Tables ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the interface to query the X86 memory folding tables.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H
#define LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H

#include "llvm/Support/DataTypes.h"

namespace llvm {

enum {
  // Select which memory operand is being unfolded.
  // (stored in bits 0 - 3)
  TB_INDEX_0    = 0,
  TB_INDEX_1    = 1,
  TB_INDEX_2    = 2,
  TB_INDEX_3    = 3,
  TB_INDEX_4    = 4,
  TB_INDEX_MASK = 0xf,

  // Do not insert the reverse map (MemOp -> RegOp) into the table.
  // This may be needed because there is a many -> one mapping.
  TB_NO_REVERSE   = 1 << 4,

  // Do not insert the forward map (RegOp -> MemOp) into the table.
  // This is needed for Native Client, which prohibits branch
  // instructions from using a memory operand.
  TB_NO_FORWARD   = 1 << 5,

  TB_FOLDED_LOAD  = 1 << 6,
  TB_FOLDED_STORE = 1 << 7,

  // Minimum alignment required for load/store.
  // Used for RegOp->MemOp conversion.
  // (stored in bits 8 - 15)
  TB_ALIGN_SHIFT = 8,
  TB_ALIGN_NONE  =    0 << TB_ALIGN_SHIFT,
  TB_ALIGN_16    =   16 << TB_ALIGN_SHIFT,
  TB_ALIGN_32    =   32 << TB_ALIGN_SHIFT,
  TB_ALIGN_64    =   64 << TB_ALIGN_SHIFT,
  TB_ALIGN_MASK  = 0xff << TB_ALIGN_SHIFT
};

// This struct is used for both the folding and unfold tables. They KeyOp
// is used to determine the sorting order.
struct X86MemoryFoldTableEntry {
  uint16_t KeyOp;
  uint16_t DstOp;
  uint16_t Flags;

  bool operator<(const X86MemoryFoldTableEntry &RHS) const {
    return KeyOp < RHS.KeyOp;
  }
  bool operator==(const X86MemoryFoldTableEntry &RHS) const {
    return KeyOp == RHS.KeyOp;
  }
  friend bool operator<(const X86MemoryFoldTableEntry &TE, unsigned Opcode) {
    return TE.KeyOp < Opcode;
  }
};

// Look up the memory folding table entry for folding a load and a store into
// operand 0.
const X86MemoryFoldTableEntry *lookupTwoAddrFoldTable(unsigned RegOp);

// Look up the memory folding table entry for folding a load or store with
// operand OpNum.
const X86MemoryFoldTableEntry *lookupFoldTable(unsigned RegOp, unsigned OpNum);

// Look up the memory unfolding table entry for this instruction.
const X86MemoryFoldTableEntry *lookupUnfoldTable(unsigned MemOp);

} // namespace llvm

#endif