X86InstrFoldTables.h

//===-- X86InstrFoldTables.h - X86 Instruction Folding Tables ---*- 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 interface to query the X86 memory folding tables.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H
#define LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H

#include <cstdint>

namespace llvm {

enum {
  // Select which memory operand is being unfolded.
  // (stored in bits 0 - 2)
  TB_INDEX_0    = 0,
  TB_INDEX_1    = 1,
  TB_INDEX_2    = 2,
  TB_INDEX_3    = 3,
  TB_INDEX_4    = 4,
  TB_INDEX_MASK = 0x7,

  // 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 << 3,

  // 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 << 4,

  TB_FOLDED_LOAD  = 1 << 5,
  TB_FOLDED_STORE = 1 << 6,
  TB_FOLDED_BCAST = 1 << 7,

  // Minimum alignment required for load/store.
  // Used for RegOp->MemOp conversion. Encoded as Log2(Align) + 1 to allow 0
  // to mean align of 0.
  // (stored in bits 8 - 11)
  TB_ALIGN_SHIFT = 8,
  TB_ALIGN_NONE  =   0 << TB_ALIGN_SHIFT,
  TB_ALIGN_16    =   5 << TB_ALIGN_SHIFT,
  TB_ALIGN_32    =   6 << TB_ALIGN_SHIFT,
  TB_ALIGN_64    =   7 << TB_ALIGN_SHIFT,
  TB_ALIGN_MASK  = 0xf << TB_ALIGN_SHIFT,

  // Broadcast type.
  // (stored in bits 12 - 13)
  TB_BCAST_TYPE_SHIFT = 12,
  TB_BCAST_D    =   0 << TB_BCAST_TYPE_SHIFT,
  TB_BCAST_Q    =   1 << TB_BCAST_TYPE_SHIFT,
  TB_BCAST_SS   =   2 << TB_BCAST_TYPE_SHIFT,
  TB_BCAST_SD   =   3 << TB_BCAST_TYPE_SHIFT,
  TB_BCAST_MASK = 0x3 << TB_BCAST_TYPE_SHIFT,

  // Unused bits 14-15
};

// 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