MSET

assembly

[
  "MSET [RegSrc0=Destination, RegSrc1=FillByte, RegSrc2=LengthBytes]"
]

block

[]

catalog_indices

[
  70
]

catalog_records

[
  {
    "asm": "MSET [RegSrc0=Destination, RegSrc1=FillByte, RegSrc2=LengthBytes]",
    "constraints": [
      {
        "field": "RegSrc0",
        "operator": "one-of",
        "values": [
          0,
          1,
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9,
          10,
          11,
          12,
          13,
          14,
          15,
          16,
          17,
          18,
          19,
          20,
          21,
          22,
          23
        ]
      },
      {
        "field": "RegSrc1",
        "operator": "one-of",
        "values": [
          0,
          1,
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9,
          10,
          11,
          12,
          13,
          14,
          15,
          16,
          17,
          18,
          19,
          20,
          21,
          22,
          23
        ]
      },
      {
        "field": "RegSrc2",
        "operator": "one-of",
        "values": [
          0,
          1,
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9,
          10,
          11,
          12,
          13,
          14,
          15,
          16,
          17,
          18,
          19,
          20,
          21,
          22,
          23
        ]
      }
    ],
    "encoding": [
      {
        "index": 0,
        "mask": "0x06007fff",
        "match": "0x00001031",
        "width_bits": 32
      }
    ],
    "encoding_kind": "L32",
    "fields": [
      {
        "name": "RegSrc0",
        "pieces": [
          {
            "instruction_lsb": 15,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      },
      {
        "name": "RegSrc1",
        "pieces": [
          {
            "instruction_lsb": 20,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      },
      {
        "name": "RegSrc2",
        "pieces": [
          {
            "instruction_lsb": 27,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      }
    ],
    "form_id": "mset_32_0b932f291932",
    "length_bits": 32,
    "mnemonic": "MSET",
    "semantic_family": "CMD",
    "semantic_group": "Bundle Split",
    "semantic_handler": "ExecuteMemorySet",
    "semantic_summary": "Fills zero through 63 bytes with the low byte of an absolute GPR after complete access preflight.",
    "status": "accepted"
  }
]

classification

[
  "lifecycle"
]

contract

{
  "block_composition": [
    "MSET is a standalone template instruction and does not consume a BSTART/BSTOP body."
  ],
  "canonical_assembly": [
    "MSET [Destination, FillByte, LengthBytes]"
  ],
  "defaults": [
    "All three absolute GPR fields are encoded and required; encoded zero reads the architectural zero GPR.",
    "LengthBytes is the complete unsigned XLEN value. Zero is a successful zero-length command; values 1 through 63 fill that many bytes."
  ],
  "encoding_class": "standalone-encoded",
  "examples": [
    "MSET [a0, a1, a2]",
    "MSET [zero, zero, zero]"
  ],
  "exceptions": [
    "Selectors 24 through 31 in any source field raise Fault_IllegalInstruction before register, memory, reservation, last-command, or TPC effects.",
    "LengthBytes greater than 63 raises Fault_IllegalInstruction before memory or last-command effects.",
    "A destination access fault is reported before the first store and leaves the complete range unchanged."
  ],
  "field_contracts": {},
  "field_zero_meanings": {
    "RegSrc0": "Encoded zero supplies destination address zero.",
    "RegSrc1": "Encoded zero supplies fill byte zero.",
    "RegSrc2": "Encoded zero supplies zero length."
  },
  "legality": [
    "RegSrc0, RegSrc1, and RegSrc2 each accept only absolute GPR codes 0 through 23; 24 through 31 are reserved.",
    "The complete unsigned LengthBytes value must be at most 63; it is never truncated to a smaller surrogate.",
    "Every byte address is naturally aligned and the full destination range must pass write access preflight before effects."
  ],
  "memory_effects": [
    "For nonzero length, probe the complete destination byte range before the first store, then write FillByte[7:0] to every byte in increasing address order.",
    "A successful nonzero fill invalidates an overlapping local load-reservation granule; zero length performs no memory or reservation access."
  ],
  "operands": [
    {
      "field": "RegSrc0",
      "role": "absolute GPR containing destination byte address"
    },
    {
      "field": "RegSrc1",
      "role": "absolute GPR whose low eight bits are replicated"
    },
    {
      "field": "RegSrc2",
      "role": "absolute GPR containing complete unsigned byte length"
    }
  ],
  "ordering": [
    "Snapshot all three GPR values before access validation and memory effects.",
    "Successful completion records the command state and then advances TPC by four bytes."
  ],
  "standalone_opcode": true,
  "state_effects": [
    "After successful zero or nonzero completion, set _LastMemoryCommandAddress to Destination and _LastMemoryCommandSize to LengthBytes.",
    "On every fault, preserve memory, reservation state, last-command state, and TPC."
  ]
}

depends_on

[
  "PTO-BLOCK-MODEL-SCHEMA-PROFILE-ENCODING"
]

id

PTO-BLOCK-MSET

mnemonic

MSET

summary

Fills a bounded byte range from three absolute GPR operands after complete access preflight.

surface

block

{
  "classification": [
    "lifecycle"
  ],
  "documentation": "docs/block/lifecycle/MSET.md",
  "id": "PTO-BLOCK-MSET",
  "instruction_contract": {
    "artifact": "spec/evidence/instruction-contract-closure.json",
    "mnemonic": "MSET",
    "ndf_clause": "PTO-INST-BLOCK-MSET"
  },
  "mnemonic": "MSET",
  "readiness_subjects": [
    "ADR-0032",
    "ADR-0052",
    "ADR-0059",
    "ADR-0084"
  ],
  "semantic_tests": [
    "PTO-AVS-BLOCK-MSET-DATAPAGE-002",
    "PTO-AVS-BLOCK-MSET-FILL-001",
    "PTO-AVS-BLOCK-MSET-GPR-001",
    "PTO-AVS-BLOCK-MSET-RESERVATION-003"
  ],
  "source": "asl/block/lifecycle/MSET.asl",
  "surface": "block",
  "tests": [
    "PTO-AVS-BLOCK-MSET-DATAPAGE-002",
    "PTO-AVS-BLOCK-MSET-DECODE-001",
    "PTO-AVS-BLOCK-MSET-FILL-001",
    "PTO-AVS-BLOCK-MSET-GPR-001",
    "PTO-AVS-BLOCK-MSET-RESERVATION-003"
  ]
}