xref: /gem5/src/arch/arm/isa/formats/fp.isa

// -*- mode:c++ -*-

// Copyright (c) 2007-2008 The Florida State University
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met: redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer;
// redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution;
// neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Authors: Stephen Hines

////////////////////////////////////////////////////////////////////
//
// Floating Point operate instructions
//

def template FPAExecute {{
        Fault %(class_name)s::execute(%(CPU_exec_context)s *xc, Trace::InstRecord *traceData) const
        {
                Fault fault = NoFault;

                %(fp_enable_check)s;

                %(op_decl)s;
                %(op_rd)s;

                if (%(predicate_test)s) {
                    %(code)s;
                    if (fault == NoFault) {
                        %(op_wb)s;
                    }
                }

                return fault;
        }
}};

def template FloatDoubleDecode {{
    {
        ArmStaticInst *i = NULL;
        switch (OPCODE_19 << 1 | OPCODE_7)
        {
            case 0:
                i = (ArmStaticInst *)new %(class_name)sS(machInst);
                break;
            case 1:
                i = (ArmStaticInst *)new %(class_name)sD(machInst);
                break;
            case 2:
            case 3:
            default:
                panic("Cannot decode float/double nature of the instruction");
        }
        return i;
    }
}};

// Primary format for float point operate instructions:
def format FloatOp(code, *flags) {{
        orig_code = code

        cblk = code
        iop = InstObjParams(name, Name, 'PredOp',
                            {"code": cblk,
                             "predicate_test": predicateTest},
                            flags)
        header_output = BasicDeclare.subst(iop)
        decoder_output = BasicConstructor.subst(iop)
        exec_output = FPAExecute.subst(iop)

        sng_cblk = code
        sng_iop = InstObjParams(name, Name+'S', 'PredOp',
                                {"code": sng_cblk,
                                 "predicate_test": predicateTest},
                                flags)
        header_output += BasicDeclare.subst(sng_iop)
        decoder_output += BasicConstructor.subst(sng_iop)
        exec_output += FPAExecute.subst(sng_iop)

        dbl_code = re.sub(r'\.sf', '.df', orig_code)

        dbl_cblk = dbl_code
        dbl_iop = InstObjParams(name, Name+'D', 'PredOp',
                                {"code": dbl_cblk,
                                 "predicate_test": predicateTest},
                                flags)
        header_output += BasicDeclare.subst(dbl_iop)
        decoder_output += BasicConstructor.subst(dbl_iop)
        exec_output += FPAExecute.subst(dbl_iop)

        decode_block = FloatDoubleDecode.subst(iop)
}};

let {{
        calcFPCcCode = '''
        uint16_t _in, _iz, _ic, _iv;

        _in = %(fReg1)s < %(fReg2)s;
        _iz = %(fReg1)s == %(fReg2)s;
        _ic = %(fReg1)s >= %(fReg2)s;
        _iv = (isnan(%(fReg1)s) || isnan(%(fReg2)s)) & 1;

        CondCodes = _in << 31 | _iz << 30 | _ic << 29 | _iv << 28 |
            (CondCodes & 0x0FFFFFFF);
        '''
}};

def format FloatCmp(fReg1, fReg2, *flags) {{
        code = calcFPCcCode % vars()
        iop = InstObjParams(name, Name, 'PredOp',
                            {"code": code,
                             "predicate_test": predicateTest},
                             flags)
        header_output = BasicDeclare.subst(iop)
        decoder_output = BasicConstructor.subst(iop)
        decode_block = BasicDecode.subst(iop)
        exec_output = FPAExecute.subst(iop)
}};