config/uarch.schema.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id" : "uarch.schema.json",

  "title": "Microarchitecture Configuration",
  "description": "TBM configuration for a microarchitecture",

  "$ref" : "#/$defs/object",
  "properties" : {
    "config" : {
      "$ref" : "#/$defs/object",
      "properties" : {
        "branch_prediction" : { "enum" : ["none", "perfect"] },
        "fetch_rate" : { "$ref" : "#/$defs/positive_integer" },
        "fetch_queue_size" : {
          "description" : "Infinite queue if omitted",
          "$ref" : "#/$defs/positive_integer"
        },
        "decode_rate" : {
          "description" : "Unrestricted if omitted",
          "$ref" : "#/$defs/positive_integer"
        },
        "vector_slices" : {
          "description" : "The number of slices each vector register is composed of",
          "$ref" : "#/$defs/positive_integer"
        }
      },
      "unevaluatedProperties" : false,
      "required" : ["branch_prediction", "fetch_rate", "vector_slices"]
    },

    "register_files" : {
      "$ref" : "#/$defs/object",
      "unevaluatedProperties" : {
        "$ref" : "#/$defs/object",
        "properties" : {
          "type" : { "$ref" : "#/$defs/data_type" },
          "regs" : {
            "$comment" : "TODO(sflur): TBM currently ignores `regs`",
            "type" : "array",
            "items" : { "type": "string" },
            "minItems" : 1,
            "uniqueItems" : true
          },
          "read_ports" : { "$ref" : "#/$defs/positive_integer" },
          "write_ports" : { "$ref" : "#/$defs/positive_integer" }
        },
        "if" : {
          "properties" : { "type" : { "const" : "vector" } }
        }, "then" : {
          "properties" : {
            "dedicated_read_ports" : {
              "description" : "Reading from the listed registers doesn't use a read port.",
              "type" : "array",
              "items" : {
                "type" : "string",
                "$comment" : "items should be from `regs`"
              },
              "minItems" : 1,
              "uniqueItems" : true
            },
            "dedicated_write_ports" : {
              "description" : "Writing to the listed registers doesn't use a write port.",
              "type" : "array",
              "items" : {
                "type" : "string",
                "$comment" : "items should be from `regs`"
              },
              "minItems" : 1,
              "uniqueItems" : true
            }
          }
        },
        "unevaluatedProperties" : false,
        "required" : ["type"]
      }
    },

    "issue_queues" : {
      "$ref" : "#/$defs/object",
      "unevaluatedProperties" : {
        "$ref" : "#/$defs/object",
        "properties" : {
          "size" : { "$ref" : "#/$defs/positive_integer" }
        },
        "unevaluatedProperties" : false
      },
      "minProperties": 1
    },

    "functional_units" : {
      "$ref" : "#/$defs/object",
      "unevaluatedProperties" : {
        "$ref" : "#/$defs/object",
        "properties" : {
          "count" : { "$ref" : "#/$defs/positive_integer" },
          "type" : { "$ref" : "#/$defs/data_type" },
          "issue_queue" : {
            "type" : "string",
            "$comment" : "should be one of the `issue_queues`"
          },
          "eiq_size" : {
            "description" : "Unrestricted if omitted",
            "$ref" : "#/$defs/positive_integer"
          },
          "can_skip_eiq" : { "type" : "boolean" },
          "depth" : { "$ref" : "#/$defs/positive_integer" },
          "pipelined": { "type" : "boolean" },
          "load_stage": { "$ref" : "#/$defs/non_negative_integer" },
          "store_stage": { "$ref" : "#/$defs/non_negative_integer" },
          "writeback_buff_size": {
            "description" : "Unrestricted if omitted",
            "$ref" : "#/$defs/positive_integer"
          }
        },
        "dependentSchemas" : {
          "load_stage": {
            "properties" : {
              "fixed_load_latency": { "$ref" : "#/$defs/non_negative_integer" },
              "memory_interface" : {
                "type" : "string",
                "$comment" : "should be one of the cache levels, or `'main'`"
              }
            },
            "required" : ["fixed_load_latency", "memory_interface"]
          },
          "store_stage": {
            "properties" : {
              "fixed_store_latency": { "$ref" : "#/$defs/non_negative_integer" },
              "memory_interface" : {
                "type" : "string",
                "$comment" : "should be one of the cache levels, or `'main'`"
              }
            },
            "required" : ["fixed_store_latency", "memory_interface"]
          }
        },
        "unevaluatedProperties" : false,
        "required" : ["type", "issue_queue", "can_skip_eiq", "depth",
                      "pipelined"]
      }
    },

    "pipe_maps" : {
      "type" : "array",
      "items" : {
        "description" : "File (.json) path, that maps instructions to functional units",
        "type": "string"
      },
      "minItems" : 1,
      "uniqueItems" : true
    },

    "memory_system" : {
      "$ref" : "#/$defs/object",
      "properties" : {
        "latencies" : { "$ref" : "#/$defs/mem_latencies" },
        "levels" : { "$ref" : "#/$defs/cache_levels" }
      },
      "unevaluatedProperties" : false,
      "required" : ["latencies"]
    }
  },
  "unevaluatedProperties" : false,
  "required" : ["config", "register_files", "issue_queues", "functional_units",
                "pipe_maps", "memory_system"],

  "$defs" : {
    "object" : {
      "description" : "an object type that allows string `description` and `__comment__` prefix",
      "type" : "object",
      "properties" : {
        "description" : { "type" : "string" }
      },
      "patternProperties" : { "^__comment__" : true },
      "$comment" : "TBM also accepts the boolean 'replace' property in files passed with the '--extend' argument, but those are not validated separately, only the merged result is validated."
    },

    "positive_integer" : {
      "type" : "integer",
      "minimum" : 1
    },

    "non_negative_integer" : {
      "type" : "integer",
      "minimum" : 0
    },

    "data_type" : { "enum" : ["scalar", "vector"] },

    "bits" : {
      "type" : "integer"
    },

    "bytes" : {
      "type" : ["string", "integer"],
      "pattern" : "^\\d+(b|B|kb|KB|mb|MB|gb|GB|tb|TB)?$"
    },

    "mem_latencies" : {
      "$ref" : "#/$defs/object",
      "properties" : {
        "fetch_read" : { "$ref" : "#/$defs/positive_integer" },
        "fetch_write" : { "$ref" : "#/$defs/positive_integer" },
        "read" : { "$ref" : "#/$defs/positive_integer" },
        "write" : { "$ref" : "#/$defs/positive_integer" }
      },
      "unevaluatedProperties" : false
    },

    "cache_levels" : {
      "$ref" : "#/$defs/object",
      "unevaluatedProperties" : {
        "$ref" : "#/$defs/object",
        "properties" : {
          "type" : { "enum" : ["unified", "dcache", "icache"] },
          "placement" : {
            "$ref" : "#/$defs/object",
            "properties" : {
              "type" : { "enum" : ["direct_map", "set_assoc"] }
            },
            "if" : {
              "properties" : { "type" : { "constant" : "set_assoc" } }
            }, "then" : {
              "properties" : {
                "set_size" : {
                  "description" : "the number of lines in the set; must be a power of 2",
                  "$ref" : "#/$defs/positive_integer"
                },
                "replacement" : { "enum" : ["LRU"] }
              },
              "required" : ["set_size", "replacement"]
            },
            "unevaluatedProperties" : false,
            "required" : ["type"]
          },
          "write_policy" : { "enum" : ["write_back", "write_through"] },
          "line_size" : {
            "description" : "the number of bits in a cache line; must be equal to `2^(3*n)`, for some `n`",
            "$ref" : "#/$defs/bits",
            "$ref" : "#/$defs/positive_integer"
          },
          "size" : {
            "description" : "the total capacity of the cache in bytes; must be a power of 2",
            "$ref" : "#/$defs/bytes",
            "minimum" : 1,
            "pattern" : "^[1-9]"
          },
          "latencies" : { "$ref" : "#/$defs/mem_latencies" },
          "levels" : { "$ref" : "#/$defs/cache_levels" }
        },
        "dependentSchemas" : {
          "levels" : {
            "properties" : {
              "inclusion" : { "enum" : ["exclusive", "inclusive"] }
            },
            "required" : ["inclusion"]
          }
        },
        "unevaluatedProperties" : false,
        "required" : ["type", "placement", "write_policy", "line_size", "size",
                      "latencies"]
      }
    }
  }
}