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      1 //===-- X86InstrFoldTables.h - X86 Instruction Folding Tables ---*- C++ -*-===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8 //
      9 // This file contains the interface to query the X86 memory folding tables.
     10 //
     11 //===----------------------------------------------------------------------===//
     12 
     13 #ifndef LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H
     14 #define LLVM_LIB_TARGET_X86_X86INSTRFOLDTABLES_H
     15 
     16 #include <cstdint>
     17 
     18 namespace llvm {
     19 
     20 enum {
     21   // Select which memory operand is being unfolded.
     22   // (stored in bits 0 - 2)
     23   TB_INDEX_0    = 0,
     24   TB_INDEX_1    = 1,
     25   TB_INDEX_2    = 2,
     26   TB_INDEX_3    = 3,
     27   TB_INDEX_4    = 4,
     28   TB_INDEX_MASK = 0x7,
     29 
     30   // Do not insert the reverse map (MemOp -> RegOp) into the table.
     31   // This may be needed because there is a many -> one mapping.
     32   TB_NO_REVERSE   = 1 << 3,
     33 
     34   // Do not insert the forward map (RegOp -> MemOp) into the table.
     35   // This is needed for Native Client, which prohibits branch
     36   // instructions from using a memory operand.
     37   TB_NO_FORWARD   = 1 << 4,
     38 
     39   TB_FOLDED_LOAD  = 1 << 5,
     40   TB_FOLDED_STORE = 1 << 6,
     41   TB_FOLDED_BCAST = 1 << 7,
     42 
     43   // Minimum alignment required for load/store.
     44   // Used for RegOp->MemOp conversion. Encoded as Log2(Align) + 1 to allow 0
     45   // to mean align of 0.
     46   // (stored in bits 8 - 11)
     47   TB_ALIGN_SHIFT = 8,
     48   TB_ALIGN_NONE  =   0 << TB_ALIGN_SHIFT,
     49   TB_ALIGN_16    =   5 << TB_ALIGN_SHIFT,
     50   TB_ALIGN_32    =   6 << TB_ALIGN_SHIFT,
     51   TB_ALIGN_64    =   7 << TB_ALIGN_SHIFT,
     52   TB_ALIGN_MASK  = 0xf << TB_ALIGN_SHIFT,
     53 
     54   // Broadcast type.
     55   // (stored in bits 12 - 13)
     56   TB_BCAST_TYPE_SHIFT = 12,
     57   TB_BCAST_D    =   0 << TB_BCAST_TYPE_SHIFT,
     58   TB_BCAST_Q    =   1 << TB_BCAST_TYPE_SHIFT,
     59   TB_BCAST_SS   =   2 << TB_BCAST_TYPE_SHIFT,
     60   TB_BCAST_SD   =   3 << TB_BCAST_TYPE_SHIFT,
     61   TB_BCAST_MASK = 0x3 << TB_BCAST_TYPE_SHIFT,
     62 
     63   // Unused bits 14-15
     64 };
     65 
     66 // This struct is used for both the folding and unfold tables. They KeyOp
     67 // is used to determine the sorting order.
     68 struct X86MemoryFoldTableEntry {
     69   uint16_t KeyOp;
     70   uint16_t DstOp;
     71   uint16_t Flags;
     72 
     73   bool operator<(const X86MemoryFoldTableEntry &RHS) const {
     74     return KeyOp < RHS.KeyOp;
     75   }
     76   bool operator==(const X86MemoryFoldTableEntry &RHS) const {
     77     return KeyOp == RHS.KeyOp;
     78   }
     79   friend bool operator<(const X86MemoryFoldTableEntry &TE, unsigned Opcode) {
     80     return TE.KeyOp < Opcode;
     81   }
     82 };
     83 
     84 // Look up the memory folding table entry for folding a load and a store into
     85 // operand 0.
     86 const X86MemoryFoldTableEntry *lookupTwoAddrFoldTable(unsigned RegOp);
     87 
     88 // Look up the memory folding table entry for folding a load or store with
     89 // operand OpNum.
     90 const X86MemoryFoldTableEntry *lookupFoldTable(unsigned RegOp, unsigned OpNum);
     91 
     92 // Look up the memory unfolding table entry for this instruction.
     93 const X86MemoryFoldTableEntry *lookupUnfoldTable(unsigned MemOp);
     94 
     95 } // namespace llvm
     96 
     97 #endif
     98