FLT

assembly

[
  "flt.{T} SrcL, SrcR, ->{t, u, Rd}"
]

block

[]

catalog_indices

[
  103
]

catalog_records

[
  {
    "asm": "flt.{T} SrcL, SrcR, ->{t, u, Rd}",
    "constraints": [
      {
        "field": "SrcType",
        "operator": "one-of",
        "values": [
          0,
          1
        ]
      }
    ],
    "encoding": [
      {
        "index": 0,
        "mask": "0xf800707f",
        "match": "0x0000205b",
        "width_bits": 32
      }
    ],
    "encoding_kind": "L32",
    "fields": [
      {
        "name": "RegDst",
        "pieces": [
          {
            "instruction_lsb": 7,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      },
      {
        "name": "SrcL",
        "pieces": [
          {
            "instruction_lsb": 15,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      },
      {
        "name": "SrcR",
        "pieces": [
          {
            "instruction_lsb": 20,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "encoding-defined",
        "width": 5
      },
      {
        "name": "SrcType",
        "pieces": [
          {
            "instruction_lsb": 25,
            "value_lsb": 0,
            "width": 2
          }
        ],
        "signedness": "encoding-defined",
        "width": 2
      }
    ],
    "form_id": "flt_32_1c09549d8d3f",
    "length_bits": 32,
    "mnemonic": "FLT",
    "semantic_family": "FSU",
    "semantic_group": "FSU",
    "semantic_handler": "FloatingCompare",
    "semantic_summary": "FLT performs ordered quiet less-than comparison and returns canonical XLEN zero or one.",
    "status": "accepted"
  }
]

classification

[
  "fsu"
]

contract

{
  "block_composition": [
    "none"
  ],
  "canonical_assembly": [
    "flt.{T} SrcL, SrcR, ->{t, u, Rd}"
  ],
  "defaults": [
    "Every displayed operand field is encoded explicitly; encoded zero is a value and never denotes omission.",
    "SrcType=0 selects an FP64 carrier and SrcType=1 selects the zero-extended low-word FP32 carrier. SrcType=2 and SrcType=3 are reserved."
  ],
  "encoding_class": "standalone-encoded",
  "examples": [
    "flt.fd a0, a1, ->a2",
    "flt.fs t#1, u#1, ->u"
  ],
  "exceptions": [
    "A fixed-bit mismatch, reserved SrcType, reserved DstType where present, or unavailable selected T/U source raises Fault_IllegalInstruction before source, profile, destination, flag, queue, or TPC effects.",
    "Numeric profile flags update sticky status and do not themselves raise a synchronous PTO trap."
  ],
  "field_contracts": {},
  "field_zero_meanings": {
    "RegDst": "Encoded zero discards the result.",
    "SrcL": "Encoded zero reads the architectural zero GPR.",
    "SrcR": "Encoded zero reads the architectural zero GPR.",
    "SrcType": "Encoded zero selects the 64-bit source carrier; it is not omission."
  },
  "legality": [
    "Every Reg5 source uses codes 0..23 for absolute GPRs, 24..27 for T#1..T#4, and 28..31 for U#1..U#4 without consumption.",
    "Every Reg5 destination is assigned: codes 1..23 write GPRs, 30 pushes U, 31 pushes T, and 0 plus 24..29 discard only the result.",
    "SrcType codes 0 and 1 are assigned; codes 2 and 3 are reserved."
  ],
  "memory_effects": [
    "none"
  ],
  "operands": [
    {
      "field": "RegDst",
      "role": "Reg5 destination or discard"
    },
    {
      "field": "SrcL",
      "role": "left or sole Reg5 source"
    },
    {
      "field": "SrcR",
      "role": "right Reg5 source"
    },
    {
      "field": "SrcType",
      "role": "source carrier selector"
    }
  ],
  "ordering": [
    "Validate every encoded type before the first architectural source read or profile call.",
    "Snapshot every explicit source before flag or destination effects; duplicate sources, destination aliases, and same-queue read-then-push observe pre-instruction values.",
    "Accumulate produced flags, publish or discard the destination, and then advance TPC."
  ],
  "standalone_opcode": true,
  "state_effects": [
    "FLT performs ordered quiet less-than comparison and returns canonical XLEN zero or one.",
    "Any NaN returns false. This quiet form records sticky NV only for a signaling NaN.",
    "Destination codes 1..23 write GPRs, 30 pushes U, 31 pushes T, and 0 plus 24..29 discard the result.",
    "Successful execution advances TPC by four bytes."
  ]
}

depends_on

[
  "PTO-SCALAR-MODEL-FSU-PROFILE"
]

id

PTO-SCALAR-FLT

mnemonic

FLT

summary

FLT performs ordered quiet less-than comparison and returns canonical XLEN zero or one.

surface

scalar

{
  "classification": [
    "fsu"
  ],
  "documentation": "docs/scalar/fsu/FLT.md",
  "id": "PTO-SCALAR-FLT",
  "instruction_contract": {
    "artifact": "spec/evidence/instruction-contract-closure.json",
    "mnemonic": "FLT",
    "ndf_clause": "PTO-INST-SCALAR-FLT"
  },
  "mnemonic": "FLT",
  "readiness_subjects": [
    "ADR-0028",
    "ADR-0038",
    "ADR-0059"
  ],
  "semantic_tests": [
    "PTO-AVS-FSU-FLT-BOUND-001",
    "PTO-AVS-FSU-FLT-DST-001",
    "PTO-AVS-FSU-FLT-EXEC-001",
    "PTO-AVS-FSU-FLT-FLAGS-001",
    "PTO-AVS-FSU-FLT-RSVD-001",
    "PTO-AVS-FSU-FLT-SNAP-001",
    "PTO-AVS-FSU-FLT-SRC-001",
    "PTO-AVS-FSU-FLT-TYPE-001"
  ],
  "source": "asl/scalar/fsu/FLT.asl",
  "surface": "scalar",
  "tests": [
    "PTO-AVS-FSU-FLT-BOUND-001",
    "PTO-AVS-FSU-FLT-DST-001",
    "PTO-AVS-FSU-FLT-EXEC-001",
    "PTO-AVS-FSU-FLT-FLAGS-001",
    "PTO-AVS-FSU-FLT-RSVD-001",
    "PTO-AVS-FSU-FLT-SNAP-001",
    "PTO-AVS-FSU-FLT-SRC-001",
    "PTO-AVS-FSU-FLT-TYPE-001",
    "PTO-AVS-SCALAR-FLT-DECODE-001"
  ]
}