insn代表什么？

Question

I need to come up with an x86(-64) disassembler so I started reading the source code for objdump. After searching around a bit I'm in a file, 'ia64-asmtab.h'. Inside is a struct 'ia64_main_table':

struct ia64_main_table
{
  /* The entry in the string table that corresponds to the name of this
     opcode. */
  unsigned short name_index;

  /* The type of opcode; corresponds to the TYPE field in 
     struct ia64_opcode. */
  unsigned char opcode_type;

  /* The number of outputs for this opcode. */
  unsigned char num_outputs;

  /* The base insn value for this opcode.  It may be modified by completers. */
  ia64_insn opcode;

  /* The mask of valid bits in OPCODE. Zeros indicate operand fields. */
  ia64_insn mask;

  /* The operands of this instruction.  Corresponds to the OPERANDS field
     in struct ia64_opcode. */
  unsigned char operands[5];

  /* The flags for this instruction.  Corresponds to the FLAGS field in
     struct ia64_opcode. */
  short flags;

  /* The tree of completers for this instruction; this is an offset into
     completer_table. */
  short completers;
};

A bit of Googling around hasn't shown any useful results and I'm stumped. Does anyone know what 'insn' stands for? I feel like it should stand for instruction, but it also seems to mean something else.

Answer 1

Answering my own question here. The only feasible meaning of insn seems to be instruction. Thanks for the link, Jeff.

Answer 2

Some insns are actual instructions; others represent dispatch tables for switch statements; others represent labels to jump to or various sorts of declarative information. A more detailed description of INSN is given in this link https://gcc.gnu.org/onlinedocs/gccint/Insns.html