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from m5.params import *
from m5.proxy import *
from m5.objects.ClockedObject import ClockedObject
from m5.objects.IndexingPolicies import *


class BaseTags(ClockedObject):
    type = "BaseTags"
    abstract = True
    cxx_header = "mem/cache/tags/base.hh"
    cxx_class = "gem5::BaseTags"

    # Get system to which it belongs
    system = Param.System(Parent.any, "System we belong to")

    # Get the size from the parent (cache)
    size = Param.MemorySize(Parent.size, "capacity in bytes")

    # Get the block size from the parent (system)
    block_size = Param.Int(Parent.cache_line_size, "block size in bytes")

    # Get the tag lookup latency from the parent (cache)
    tag_latency = Param.Cycles(
        Parent.tag_latency, "The tag lookup latency for this cache"
    )

    # Get the warmup percentage from the parent (cache)
    warmup_percentage = Param.Percent(
        Parent.warmup_percentage,
        "Percentage of tags to be touched to warm up the cache",
    )

    sequential_access = Param.Bool(
        Parent.sequential_access,
        "Whether to access tags and data sequentially",
    )

    # Get indexing policy
    indexing_policy = Param.BaseIndexingPolicy(
        SetAssociative(), "Indexing policy"
    )

    # Set the indexing entry size as the block size
    entry_size = Param.Int(
        Parent.cache_line_size, "Indexing entry size in bytes"
    )


class BaseSetAssoc(BaseTags):
    type = "BaseSetAssoc"
    cxx_header = "mem/cache/tags/base_set_assoc.hh"
    cxx_class = "gem5::BaseSetAssoc"

    # Get the cache associativity
    assoc = Param.Int(Parent.assoc, "associativity")

    # Get replacement policy from the parent (cache)
    replacement_policy = Param.BaseReplacementPolicy(
        Parent.replacement_policy, "Replacement policy"
    )


class SectorTags(BaseTags):
    type = "SectorTags"
    cxx_header = "mem/cache/tags/sector_tags.hh"
    cxx_class = "gem5::SectorTags"

    # Get the cache associativity
    assoc = Param.Int(Parent.assoc, "associativity")

    # Number of sub-sectors (data blocks) per sector
    num_blocks_per_sector = Param.Int(1, "Number of sub-sectors per sector")

    # The indexing entry now is a sector block
    entry_size = Parent.cache_line_size * Self.num_blocks_per_sector

    # Get replacement policy from the parent (cache)
    replacement_policy = Param.BaseReplacementPolicy(
        Parent.replacement_policy, "Replacement policy"
    )


class CompressedTags(SectorTags):
    type = "CompressedTags"
    cxx_header = "mem/cache/tags/compressed_tags.hh"
    cxx_class = "gem5::CompressedTags"

    # Maximum number of compressed blocks per tag
    max_compression_ratio = Param.Int(
        2, "Maximum number of compressed blocks per tag."
    )

    # We simulate superblock as sector blocks
    num_blocks_per_sector = Self.max_compression_ratio

    # We virtually increase the number of data blocks per tag by multiplying
    # the cache size by the compression ratio
    size = Parent.size * Self.max_compression_ratio


class FALRU(BaseTags):
    type = "FALRU"
    cxx_header = "mem/cache/tags/fa_lru.hh"
    cxx_class = "gem5::FALRU"

    min_tracked_cache_size = Param.MemorySize(
        "128KiB", "Minimum cache size" " for which we track statistics"
    )

    # This tag uses its own embedded indexing
    indexing_policy = NULL