# Copyright (c) 2014, 2016, 2018-2019 ARM Limited
# All rights reserved
#
# The license below extends only to copyright in the software and shall
# not be construed as granting a license to any other intellectual
# property including but not limited to intellectual property relating
# to a hardware implementation of the functionality of the software
# licensed hereunder.  You may use the software subject to the license
# terms below provided that you ensure that this notice is replicated
# unmodified and in its entirety in all distributions of the software,
# modified or unmodified, in source code or in binary form.
#
# Copyright (c) 2003-2005 The Regents of The University of Michigan
# Copyright (c) 2013,2015 Advanced Micro Devices, Inc.
# 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.

def overrideInOperand(func):
    func.override_in_operand = True
    return func

overrideInOperand.overrides = dict()

class OperandDesc(object):
    def __init__(self, base_cls, dflt_ext, reg_spec, flags=None,
            sort_pri=None, read_predicate=None, write_predicate=None):

        from .isa_parser import makeList

        # Canonical flag structure is a triple of lists, where each list
        # indicates the set of flags implied by this operand always, when
        # used as a source, and when used as a dest, respectively.
        # For simplicity this can be initialized using a variety of fairly
        # obvious shortcuts; we convert these to canonical form here.
        if not flags:
            # no flags specified (e.g., 'None')
            flags = ( [], [], [] )
        elif isinstance(flags, str):
            # a single flag: assumed to be unconditional
            flags = ( [ flags ], [], [] )
        elif isinstance(flags, list):
            # a list of flags: also assumed to be unconditional
            flags = ( flags, [], [] )
        elif isinstance(flags, tuple):
            # it's a tuple: it should be a triple,
            # but each item could be a single string or a list
            (uncond_flags, src_flags, dest_flags) = flags
            flags = (makeList(uncond_flags),
                     makeList(src_flags), makeList(dest_flags))

        attrs = {}
        # reg_spec is either just a string or a dictionary
        # (for elems of vector)
        if isinstance(reg_spec, tuple):
            (reg_spec, elem_spec) = reg_spec
            if isinstance(elem_spec, str):
                attrs['elem_spec'] = elem_spec
            else:
                assert(isinstance(elem_spec, dict))
                attrs['elems'] = elem_spec

        for key in dir(self):
            val = getattr(self, key)
            # If this is a method, extract the function that implements it.
            if hasattr(val, '__func__'):
                val = val.__func__
            # If this should override something in the operand
            if getattr(val, 'override_in_operand', False):
                attrs[key] = val

        attrs.update({
            'base_cls': base_cls,
            'dflt_ext': dflt_ext,
            'reg_spec': reg_spec,
            'flags': flags,
            'sort_pri': sort_pri,
            'read_predicate': read_predicate,
            'write_predicate': write_predicate,
        })
        self.attrs = attrs

    def setName(self, name):
        self.attrs['base_name'] = name


class Operand(object):
    '''Base class for operand descriptors.  An instance of this class
    (or actually a class derived from this one) represents a specific
    operand for a code block (e.g, "Rc.sq" as a dest). Intermediate
    derived classes encapsulates the traits of a particular operand
    type (e.g., "32-bit integer register").'''

    src_reg_constructor = '\n\tsetSrcRegIdx(_numSrcRegs++, %s);'
    dst_reg_constructor = '\n\tsetDestRegIdx(_numDestRegs++, %s);'

    def regId(self):
        return f'RegId({self.reg_class}, {self.reg_spec})'

    def srcRegId(self):
        return self.regId()

    def destRegId(self):
        return self.regId()

    def __init__(self, parser, full_name, ext, is_src, is_dest):
        self.parser = parser
        self.full_name = full_name
        self.ext = ext
        self.is_src = is_src
        self.is_dest = is_dest
        # The 'effective extension' (eff_ext) is either the actual
        # extension, if one was explicitly provided, or the default.
        if ext:
            self.eff_ext = ext
        elif hasattr(self, 'dflt_ext'):
            self.eff_ext = self.dflt_ext

        if hasattr(self, 'eff_ext'):
            self.ctype = parser.operandTypeMap[self.eff_ext]

    # Finalize additional fields (primarily code fields).  This step
    # is done separately since some of these fields may depend on the
    # register index enumeration that hasn't been performed yet at the
    # time of __init__(). The register index enumeration is affected
    # by predicated register reads/writes. Hence, we forward the flags
    # that indicate whether or not predication is in use.
    def finalize(self, pred_read, pred_write):
        self.flags = self.getFlags()
        self.constructor = self.makeConstructor(pred_read, pred_write)
        self.op_decl = self.makeDecl()

        if self.is_src:
            if pred_read:
                op_idx = '_sourceIndex++'
            elif hasattr(self, 'src_reg_idx'):
                op_idx = str(self.src_reg_idx)
            else:
                op_idx = None
            self.op_rd = self.makeRead(pred_read, op_idx)
            self.op_src_decl = self.makeDecl()
        else:
            self.op_rd = ''
            self.op_src_decl = ''

        if self.is_dest:
            if pred_read:
                op_idx = '_destIndex++'
            elif hasattr(self, 'dest_reg_idx'):
                op_idx = str(self.dest_reg_idx)
            else:
                op_idx = None
            self.op_wb = self.makeWrite(pred_write, op_idx)
            self.op_dest_decl = self.makeDecl()
        else:
            self.op_wb = ''
            self.op_dest_decl = ''

    def isMem(self):
        return 0

    def isReg(self):
        return 0

    def isPCState(self):
        return 0

    def isPCPart(self):
        return self.isPCState() and self.reg_spec

    def hasReadPred(self):
        return self.read_predicate != None

    def hasWritePred(self):
        return self.write_predicate != None

    def getFlags(self):
        # note the empty slice '[:]' gives us a copy of self.flags[0]
        # instead of a reference to it
        my_flags = self.flags[0][:]
        if self.is_src:
            my_flags += self.flags[1]
        if self.is_dest:
            my_flags += self.flags[2]
        return my_flags

    def makeDecl(self):
        # Note that initializations in the declarations are solely
        # to avoid 'uninitialized variable' errors from the compiler.
        return self.ctype + ' ' + self.base_name + ' = 0;\n';

class RegOperand(Operand):
    def isReg(self):
        return 1

    def makeConstructor(self, pred_read, pred_write):
        c_src = ''
        c_dest = ''

        if self.is_src:
            c_src = self.src_reg_constructor % self.srcRegId()
            if self.hasReadPred():
                c_src = '\n\tif (%s) {%s\n\t}' % \
                        (self.read_predicate, c_src)

        if self.is_dest:
            c_dest = self.dst_reg_constructor % self.destRegId()
            c_dest += f'\n\t_numTypedDestRegs[{self.reg_class}]++;'
            if self.hasWritePred():
                c_dest = '\n\tif (%s) {%s\n\t}' % \
                         (self.write_predicate, c_dest)

        return c_src + c_dest

class RegValOperand(RegOperand):
    def makeRead(self, pred_read, op_idx):
        reg_val = f'xc->getRegOperand(this, {op_idx})'

        if self.ctype == 'float':
            reg_val = f'bitsToFloat32({reg_val})'
        elif self.ctype == 'double':
            reg_val = f'bitsToFloat64({reg_val})'

        if pred_read and self.hasReadPred():
            reg_val = f'({self.read_predicate}) ? {reg_val} : 0'

        return f'{self.base_name} = {reg_val};\n'

    def makeWrite(self, pred_write, op_idx):
        reg_val = self.base_name

        if self.ctype == 'float':
            reg_val = f'floatToBits32({reg_val})'
        elif self.ctype == 'double':
            reg_val = f'floatToBits64({reg_val})'

        if pred_write and self.hasWritePred():
            wcond = f'if ({self.write_predicate})'
        else:
            wcond = ''

        return f'''
        {wcond}
        {{
            RegVal final_val = {reg_val};
            xc->setRegOperand(this, {op_idx}, final_val);
            if (traceData)
                traceData->setData(final_val);
        }}'''

class RegOperandDesc(OperandDesc):
    def __init__(self, reg_class, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.attrs['reg_class'] = reg_class

class IntRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('IntRegClass', RegValOperand, *args, **kwargs)

class FloatRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('FloatRegClass', RegValOperand, *args, **kwargs)

class CCRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('CCRegClass', RegValOperand, *args, **kwargs)

class VecElemOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('VecElemClass', RegValOperand, *args, **kwargs)

class VecRegOperand(RegOperand):
    reg_class = 'VecRegClass'

    def __init__(self, parser, full_name, ext, is_src, is_dest):
        super().__init__(parser, full_name, ext, is_src, is_dest)
        self.elemExt = None

    def makeDeclElem(self, elem_op):
        (elem_name, elem_ext) = elem_op
        (elem_spec, dflt_elem_ext) = self.elems[elem_name]
        if elem_ext:
            ext = elem_ext
        else:
            ext = dflt_elem_ext
        ctype = self.parser.operandTypeMap[ext]
        return '\n\t%s %s = 0;' % (ctype, elem_name)

    def makeDecl(self):
        if not self.is_dest and self.is_src:
            c_decl = '\t/* Vars for %s*/' % (self.base_name)
            if hasattr(self, 'active_elems'):
                if self.active_elems:
                    for elem in self.active_elems:
                        c_decl += self.makeDeclElem(elem)
            return c_decl + '\t/* End vars for %s */\n' % (self.base_name)
        else:
            return ''

    # Read destination register to write
    def makeReadWElem(self, elem_op):
        (elem_name, elem_ext) = elem_op
        (elem_spec, dflt_elem_ext) = self.elems[elem_name]
        if elem_ext:
            ext = elem_ext
        else:
            ext = dflt_elem_ext
        ctype = self.parser.operandTypeMap[ext]
        c_read = '\t\t%s& %s = %s[%s];\n' % \
                  (ctype, elem_name, self.base_name, elem_spec)
        return c_read

    def makeReadW(self, pred_write, op_idx):
        c_readw = f'\t\tauto &tmp_d{op_idx} = \n' \
                  f'\t\t    *({self.parser.namespace}::VecRegContainer *)\n' \
                  f'\t\t    xc->getWritableRegOperand(this, {op_idx});\n'
        if self.elemExt:
            c_readw += '\t\tauto %s = tmp_d%s.as<%s>();\n' % (self.base_name,
                        op_idx, self.parser.operandTypeMap[self.elemExt])
        if self.ext:
            c_readw += '\t\tauto %s = tmp_d%s.as<%s>();\n' % (self.base_name,
                        op_idx, self.parser.operandTypeMap[self.ext])
        if hasattr(self, 'active_elems'):
            if self.active_elems:
                for elem in self.active_elems:
                    c_readw += self.makeReadWElem(elem)
        return c_readw

    # Normal source operand read
    def makeReadElem(self, elem_op, name):
        (elem_name, elem_ext) = elem_op
        (elem_spec, dflt_elem_ext) = self.elems[elem_name]

        if elem_ext:
            ext = elem_ext
        else:
            ext = dflt_elem_ext
        ctype = self.parser.operandTypeMap[ext]
        c_read = '\t\t%s = %s[%s];\n' % \
                  (elem_name, name, elem_spec)
        return c_read

    def makeRead(self, pred_read, op_idx):
        name = self.base_name
        if self.is_dest and self.is_src:
            name += '_merger'

        c_read = f'\t\t{self.parser.namespace}::VecRegContainer ' \
                 f'\t\t        tmp_s{op_idx};\n' \
                 f'\t\txc->getRegOperand(this, {op_idx}, &tmp_s{op_idx});\n'
        # If the parser has detected that elements are being access, create
        # the appropriate view
        if self.elemExt:
            c_read += '\t\tauto %s = tmp_s%s.as<%s>();\n' % \
                 (name, op_idx, self.parser.operandTypeMap[self.elemExt])
        if self.ext:
            c_read += '\t\tauto %s = tmp_s%s.as<%s>();\n' % \
                 (name, op_idx, self.parser.operandTypeMap[self.ext])
        if hasattr(self, 'active_elems'):
            if self.active_elems:
                for elem in self.active_elems:
                    c_read += self.makeReadElem(elem, name)
        return c_read

    def makeWrite(self, pred_write, op_idx):
        return f'''
        if (traceData) {{
            traceData->setData(tmp_d{op_idx});
        }}
        '''

    def finalize(self, pred_read, pred_write):
        super().finalize(pred_read, pred_write)
        if self.is_dest:
            op_idx = str(self.dest_reg_idx)
            self.op_rd = self.makeReadW(pred_write, op_idx) + self.op_rd

class VecRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('VecRegClass', VecRegOperand, *args, **kwargs)

class VecPredRegOperand(RegOperand):
    reg_class = 'VecPredRegClass'

    def makeDecl(self):
        return ''

    def makeRead(self, pred_read, op_idx):
        c_read =  f'\t\t{self.parser.namespace}::VecPredRegContainer ' \
                  f'\t\t        tmp_s{op_idx}; ' \
                  f'xc->getRegOperand(this, {op_idx}, &tmp_s{op_idx});\n'
        if self.ext:
            c_read += f'\t\tauto {self.base_name} = ' \
                      f'tmp_s{op_idx}.as<' \
                      f'{self.parser.operandTypeMap[self.ext]}>();\n'
        return c_read

    def makeReadW(self, pred_write, op_idx):
        c_readw = f'\t\tauto &tmp_d{op_idx} = \n' \
                  f'\t\t    *({self.parser.namespace}::' \
                  f'VecPredRegContainer *)xc->getWritableRegOperand(' \
                  f'this, {op_idx});\n'
        if self.ext:
            c_readw += '\t\tauto %s = tmp_d%s.as<%s>();\n' % (
                    self.base_name, op_idx,
                    self.parser.operandTypeMap[self.ext])
        return c_readw

    def makeWrite(self, pred_write, op_idx):
        return f'''
        if (traceData) {{
            traceData->setData(tmp_d{op_idx});
        }}
        '''

    def finalize(self, pred_read, pred_write):
        super().finalize(pred_read, pred_write)
        if self.is_dest:
            op_idx = str(self.dest_reg_idx)
            self.op_rd = self.makeReadW(pred_write, op_idx) + self.op_rd

class VecPredRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('VecPredRegClass', VecPredRegOperand, *args, **kwargs)

class ControlRegOperand(Operand):
    reg_class = 'MiscRegClass'

    def isReg(self):
        return 1

    def isControlReg(self):
        return 1

    def makeConstructor(self, pred_read, pred_write):
        c_src = ''
        c_dest = ''

        if self.is_src:
            c_src = self.src_reg_constructor % self.srcRegId()

        if self.is_dest:
            c_dest = self.dst_reg_constructor % self.destRegId()

        return c_src + c_dest

    def makeRead(self, pred_read, op_idx):
        bit_select = 0
        if (self.ctype == 'float' or self.ctype == 'double'):
            error('Attempt to read control register as FP')

        return '%s = xc->readMiscRegOperand(this, %s);\n' % \
            (self.base_name, op_idx)

    def makeWrite(self, pred_write, op_idx):
        if (self.ctype == 'float' or self.ctype == 'double'):
            error('Attempt to write control register as FP')
        wb = 'xc->setMiscRegOperand(this, %s, %s);\n' % \
             (op_idx, self.base_name)
        wb += 'if (traceData) { traceData->setData(%s); }' % \
              self.base_name

        return wb

class ControlRegOperandDesc(RegOperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__('MiscRegClass', ControlRegOperand, *args, **kwargs)

class MemOperand(Operand):
    def isMem(self):
        return 1

    def makeConstructor(self, pred_read, pred_write):
        return ''

    def makeDecl(self):
        # Declare memory data variable.
        return '%s %s = {};\n' % (self.ctype, self.base_name)

    def makeRead(self, pred_read, op_idx):
        return ''

    def makeWrite(self, pred_write, op_idx):
        return ''

class MemOperandDesc(OperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__(MemOperand, *args, **kwargs)

class PCStateOperand(Operand):
    def __init__(self, parser, *args, **kwargs):
        super().__init__(parser, *args, **kwargs)
        self.parser = parser

    def makeConstructor(self, pred_read, pred_write):
        return ''

    def makeRead(self, pred_read, op_idx):
        if self.reg_spec:
            # A component of the PC state.
            return '%s = __parserAutoPCState.%s();\n' % \
                (self.base_name, self.reg_spec)
        else:
            # The whole PC state itself.
            return f'{self.base_name} = ' \
                    f'xc->pcState().as<{self.parser.namespace}::PCState>();\n'

    def makeWrite(self, pred_write, op_idx):
        if self.reg_spec:
            # A component of the PC state.
            return '__parserAutoPCState.%s(%s);\n' % \
                (self.reg_spec, self.base_name)
        else:
            # The whole PC state itself.
            return f'xc->pcState({self.base_name});\n'

    def makeDecl(self):
        ctype = f'{self.parser.namespace}::PCState'
        if self.isPCPart():
            ctype = self.ctype
        # Note that initializations in the declarations are solely
        # to avoid 'uninitialized variable' errors from the compiler.
        return '%s %s = 0;\n' % (ctype, self.base_name)

    def isPCState(self):
        return 1

class PCStateOperandDesc(OperandDesc):
    def __init__(self, *args, **kwargs):
        super().__init__(PCStateOperand, *args, **kwargs)