#!/usr/bin/env python3

##
##  Copyright(c) 2019-2024 Qualcomm Innovation Center, Inc. All Rights Reserved.
##
##  This program is free software; you can redistribute it and/or modify
##  it under the terms of the GNU General Public License as published by
##  the Free Software Foundation; either version 2 of the License, or
##  (at your option) any later version.
##
##  This program is distributed in the hope that it will be useful,
##  but WITHOUT ANY WARRANTY; without even the implied warranty of
##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##  GNU General Public License for more details.
##
##  You should have received a copy of the GNU General Public License
##  along with this program; if not, see <http://www.gnu.org/licenses/>.
##

import sys
import re
import string
import hex_common
from textwrap import dedent

##
## Generate the TCG code to call the helper
##     For A2_add: Rd32=add(Rs32,Rt32), { RdV=RsV+RtV;}
##     We produce:
##    static void generate_A2_add(DisasContext *ctx)
##    {
##        Insn *insn G_GNUC_UNUSED = ctx->insn;
##        const int RdN = insn->regno[0];
##        TCGv RdV = get_result_gpr(ctx, RdN);
##        TCGv RsV = hex_gpr[insn->regno[1]];
##        TCGv RtV = hex_gpr[insn->regno[2]];
##        <GEN>
##    }
##
##       where <GEN> depends on hex_common.skip_qemu_helper(tag)
##       if hex_common.skip_qemu_helper(tag) is True
##       <GEN>  is fGEN_TCG_A2_add({ RdV=RsV+RtV;});
##       if hex_common.skip_qemu_helper(tag) is False
##       <GEN>  is gen_helper_A2_add(RdV, tcg_env, RsV, RtV);
##
def gen_tcg_func(f, tag, regs, imms):
    f.write(f"static void generate_{tag}(DisasContext *ctx)\n")
    f.write("{\n")

    f.write("    Insn *insn G_GNUC_UNUSED = ctx->insn;\n")

    if "A_PRIV" in hex_common.attribdict[tag]:
        f.write(dedent("""\
#ifdef CONFIG_USER_ONLY
    hex_gen_exception_end_tb(ctx, HEX_CAUSE_PRIV_USER_NO_SINSN);
#else
"""))
    if "A_GUEST" in hex_common.attribdict[tag]:
        f.write(dedent("""\
#ifdef CONFIG_USER_ONLY
    hex_gen_exception_end_tb(ctx, HEX_CAUSE_PRIV_USER_NO_GINSN);
#else
"""))
    if hex_common.need_ea(tag):
        f.write("    TCGv EA G_GNUC_UNUSED = tcg_temp_new();\n")

    ## Declare all the operands (regs and immediates)
    i = 0
    for regtype, regid in regs:
        reg = hex_common.get_register(tag, regtype, regid)
        reg.decl_tcg(f, tag, i)
        i += 1
    for immlett, bits, immshift in imms:
        i = 1 if immlett.isupper() else 0
        f.write(f"    int {hex_common.imm_name(immlett)} = insn->immed[{i}];\n")

    if hex_common.is_idef_parser_enabled(tag):
        declared = []
        ## Handle registers
        for regtype, regid in regs:
            reg = hex_common.get_register(tag, regtype, regid)
            reg.idef_arg(declared)
        ## Handle immediates
        for immlett, bits, immshift in imms:
            declared.append(hex_common.imm_name(immlett))

        arguments = ", ".join(["ctx", "ctx->insn", "&ctx->pkt"] + declared)
        f.write(f"    emit_{tag}({arguments});\n")

    elif hex_common.skip_qemu_helper(tag):
        if "A_FPOP" in hex_common.attribdict[tag]:
            f.write("    TCGv pkt_need_commit = ")
            f.write("tcg_constant_tl(ctx->need_commit);\n")

        f.write(f"    fGEN_TCG_{tag}({hex_common.semdict[tag]});\n")
    else:
        ## Generate the call to the helper
        declared = []
        ret_type = hex_common.helper_ret_type(tag, regs).call_arg
        if ret_type != "void":
            declared.append(ret_type)

        for arg in hex_common.helper_args(tag, regs, imms):
            declared.append(arg.call_arg)

        arguments = ", ".join(declared)
        f.write(f"    gen_helper_{tag}({arguments});\n")

    ## Write all the outputs
    for regtype, regid in regs:
        reg = hex_common.get_register(tag, regtype, regid)
        if reg.is_written():
            reg.gen_write(f, tag)

    if (
        "A_PRIV" in hex_common.attribdict[tag]
        or "A_GUEST" in hex_common.attribdict[tag]
    ):
        f.write("#endif   /* CONFIG_USER_ONLY */\n")
    f.write("}\n\n")


def gen_def_tcg_func(f, tag, tagregs, tagimms):
    regs = tagregs[tag]
    imms = tagimms[tag]

    gen_tcg_func(f, tag, regs, imms)


def main():
    args = hex_common.parse_common_args(
        "Emit functions calling generated code implementing instruction semantics (helpers, idef-parser)"
    )
    tagregs = hex_common.get_tagregs()
    tagimms = hex_common.get_tagimms()

    with open(args.out, "w") as f:
        f.write("#ifndef HEXAGON_TCG_FUNCS_H\n")
        f.write("#define HEXAGON_TCG_FUNCS_H\n\n")
        if args.idef_parser:
            f.write('#include "idef-generated-emitter.h.inc"\n\n')

        for tag in hex_common.tags:
            if hex_common.tag_ignore(tag):
                f.write(f"static void generate_{tag}"
                        f"(DisasContext *ctx)\n")
                f.write("{\n}\n\n")
                continue

            gen_def_tcg_func(f, tag, tagregs, tagimms)

        f.write("#endif    /* HEXAGON_TCG_FUNCS_H */\n")


if __name__ == "__main__":
    main()
