xref: /qemu/target/hexagon/gen_trans_funcs.py (revision 4614b8f3) 
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
20import io
21import re
22
23import sys
24import textwrap
25import iset
26import hex_common
27
28encs = {
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
35regre = re.compile(r"((?<!DUP)[MNORCPQXSGVZA])([stuvwxyzdefg]+)([.]?[LlHh]?)(\d+S?)")
36immre = re.compile(r"[#]([rRsSuUm])(\d+)(?:[:](\d+))?")
37
38
39def ordered_unique(l):
40    return sorted(set(l), key=l.index)
41
42
43def code_fmt(txt):
44    return textwrap.indent(textwrap.dedent(txt), "    ")
45
46open_curly = "{"
47close_curly = "}"
48
49def 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##
77def 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        has_pred_dest = "false"
93        for regno, (reg_type, reg_id, *_) in enumerate(regs):
94            reg = hex_common.get_register(tag, reg_type, reg_id)
95            f.write(code_fmt(f"""\
96                insn->regno[{regno}] = args->{reg_type}{reg_id};
97            """))
98            if reg.is_read() and reg.is_new():
99                new_read_idx = regno
100            # dest_idx should be the first destination, so check for -1
101            if reg.is_written() and dest_idx == -1:
102                dest_idx = regno
103            if reg_type == "P" and reg.is_written() and not reg.is_read():
104                has_pred_dest = "true"
105
106        if len(imms) != 0:
107            mark_which_imm_extended(f, tag)
108
109        for imm in imms:
110            imm_type = imm[0]
111            imm_letter = "i" if imm_type.islower() else "I"
112            immno = 0 if imm_type.islower() else 1
113            imm_shift = int(imm[2]) if imm[2] else 0
114            if imm_shift:
115                f.write(code_fmt(f"""\
116                    insn->immed[{immno}] =
117                        shift_left(ctx, args->{imm_type}{imm_letter},
118                                   {imm_shift}, {immno});
119                """))
120            else:
121                f.write(code_fmt(f"""\
122                    insn->immed[{immno}] = args->{imm_type}{imm_letter};
123                """))
124
125        f.write(code_fmt(f"""\
126            insn->new_read_idx = {new_read_idx};
127            insn->dest_idx = {dest_idx};
128            insn->has_pred_dest = {has_pred_dest};
129        """))
130        f.write(textwrap.dedent(f"""\
131                return true;
132            {close_curly}
133        """))
134
135
136if __name__ == "__main__":
137    hex_common.read_semantics_file(sys.argv[1])
138    hex_common.init_registers()
139    with open(sys.argv[2], "w") as f:
140        gen_trans_funcs(f)
141