target/hexagon/gen_trans_funcs.py

   1 #!/usr/bin/env python3
   2
   3 ##
   4 ##  Copyright (c) 2024 Taylor Simpson <ltaylorsimpson@gmail.com>
   5 ##
   6 ##  This program is free software; you can redistribute it and/or modify
   7 ##  it under the terms of the GNU General Public License as published by
   8 ##  the Free Software Foundation; either version 2 of the License, or
   9 ##  (at your option) any later version.
  10 ##
  11 ##  This program is distributed in the hope that it will be useful,
  12 ##  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ##  GNU General Public License for more details.
  15 ##
  16 ##  You should have received a copy of the GNU General Public License
  17 ##  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 ##
  19
  20 import io
  21 import re
  22
  23 import sys
  24 import textwrap
  25 import iset
  26 import hex_common
  27
  28 encs = {
  29     tag: "".join(reversed(iset.iset[tag]["enc"].replace(" ", "")))
  30     for tag in iset.tags
  31     if iset.iset[tag]["enc"] != "MISSING ENCODING"
  32 }
  33
  34
  35 regre = re.compile(r"((?<!DUP)[MNORCPQXSGVZA])([stuvwxyzdefg]+)([.]?[LlHh]?)(\d+S?)")
  36 immre = re.compile(r"[#]([rRsSuUm])(\d+)(?:[:](\d+))?")
  37
  38
  39 def ordered_unique(l):
  40     return sorted(set(l), key=l.index)
  41
  42
  43 def code_fmt(txt):
  44     return textwrap.indent(textwrap.dedent(txt), "    ")
  45
  46 open_curly = "{"
  47 close_curly = "}"
  48
  49 def mark_which_imm_extended(f, tag):
  50     immre = re.compile(r"IMMEXT\([rRsSuUm]")
  51     imm = immre.findall(hex_common.semdict[tag])
  52     if len(imm) == 0:
  53         # No extended operand found
  54         return
  55     letter = re.split("\\(", imm[0])[1]
  56     f.write(code_fmt(f"""\
  57         insn->which_extended = {0 if letter.islower() else 1};
  58     """))
  59
  60 ##
  61 ## Generate the QEMU decodetree trans_<tag> function for each instruction
  62 ##     For A2_add: Rd32=add(Rs32,Rt32)
  63 ##     We produce:
  64 ##     static bool trans_A2_add(DisasContext *ctx, arg_A2_add *args)
  65 ##     {
  66 ##         Insn *insn = ctx->insn;
  67 ##         insn->opcode = A2_add;
  68 ##         insn->regno[0] = args->Rd;
  69 ##         insn->regno[1] = args->Rs;
  70 ##         insn->regno[2] = args->Rt;
  71 ##         insn->new_read_idx = -1;
  72 ##         insn->dest_idx = 0;
  73 ##         insn->has_pred_dest = false;
  74 ##         return true;
  75 ##     }
  76 ##
  77 def gen_trans_funcs(f):
  78     f.write(f"/* DO NOT MODIFY - This file is generated by {sys.argv[0]} */\n\n")
  79     for tag in sorted(encs.keys(), key=iset.tags.index):
  80         regs = ordered_unique(regre.findall(iset.iset[tag]["syntax"]))
  81         imms = ordered_unique(immre.findall(iset.iset[tag]["syntax"]))
  82
  83         f.write(textwrap.dedent(f"""\
  84             static bool trans_{tag}(DisasContext *ctx, arg_{tag} *args)
  85             {open_curly}
  86                 Insn *insn = ctx->insn;
  87                 insn->opcode = {tag};
  88         """))
  89
  90         new_read_idx = -1
  91         dest_idx = -1
  92         dest_idx_reg_id = None
  93         has_pred_dest = "false"
  94         for regno, (reg_type, reg_id, *_) in enumerate(regs):
  95             reg = hex_common.get_register(tag, reg_type, reg_id)
  96             f.write(code_fmt(f"""\
  97                 insn->regno[{regno}] = args->{reg_type}{reg_id};
  98             """))
  99             if reg.is_read() and reg.is_new():
 100                 new_read_idx = regno
 101             if reg.is_written():
 102                 # dest_idx should be the first destination alphabetically
 103                 if dest_idx_reg_id is None or reg_id < dest_idx_reg_id:
 104                     dest_idx = regno
 105                     dest_idx_reg_id = reg_id
 106             if reg_type == "P" and reg.is_written() and not reg.is_read():
 107                 has_pred_dest = "true"
 108
 109         if len(imms) != 0:
 110             mark_which_imm_extended(f, tag)
 111
 112         for imm in imms:
 113             imm_type = imm[0]
 114             imm_letter = "i" if imm_type.islower() else "I"
 115             immno = 0 if imm_type.islower() else 1
 116             imm_shift = int(imm[2]) if imm[2] else 0
 117             if imm_shift:
 118                 f.write(code_fmt(f"""\
 119                     insn->immed[{immno}] =
 120                         shift_left(ctx, args->{imm_type}{imm_letter},
 121                                    {imm_shift}, {immno});
 122                 """))
 123             else:
 124                 f.write(code_fmt(f"""\
 125                     insn->immed[{immno}] = args->{imm_type}{imm_letter};
 126                 """))
 127
 128         f.write(code_fmt(f"""\
 129             insn->new_read_idx = {new_read_idx};
 130             insn->dest_idx = {dest_idx};
 131             insn->has_pred_dest = {has_pred_dest};
 132         """))
 133         f.write(textwrap.dedent(f"""\
 134                 return true;
 135             {close_curly}
 136         """))
 137
 138
 139 if __name__ == "__main__":
 140     hex_common.read_semantics_file(sys.argv[1])
 141     hex_common.init_registers()
 142     with open(sys.argv[2], "w") as f:
 143         gen_trans_funcs(f)