C.SETRET

assembly

[
  "c.setret uimm, ->ra"
]

block

[]

catalog_indices

[
  38
]

catalog_records

[
  {
    "asm": "c.setret uimm, ->ra",
    "constraints": [],
    "encoding": [
      {
        "index": 0,
        "mask": "0xf83f",
        "match": "0x5016",
        "width_bits": 16
      }
    ],
    "encoding_kind": "C16",
    "fields": [
      {
        "name": "uimm5",
        "pieces": [
          {
            "instruction_lsb": 6,
            "value_lsb": 0,
            "width": 5
          }
        ],
        "signedness": "unsigned",
        "width": 5
      }
    ],
    "form_id": "c_setret_16_335651ef6c27",
    "length_bits": 16,
    "mnemonic": "C.SETRET",
    "semantic_family": "ALU",
    "semantic_group": "ALU",
    "semantic_handler": "SetReturnAddress",
    "semantic_summary": "Materialize an unsigned halfword-scaled TPC-relative return address in ra and captured return state.",
    "status": "accepted"
  }
]

classification

[
  "alu"
]

contract

{
  "block_composition": [
    "Standalone scalar return-address materialization. Fused BSTART.CALL and BSTART.ICALL define call formation separately."
  ],
  "canonical_assembly": [
    "c.setret uimm, ->ra"
  ],
  "defaults": [
    "C.SETRET has no omitted field. Encoded uimm5 zero is the real zero displacement and materializes the address of C.SETRET itself."
  ],
  "encoding_class": "standalone-encoded",
  "examples": [
    "c.setret 0, ->ra",
    "c.setret 31, ->ra"
  ],
  "exceptions": [
    "All uimm5 values are legal. C.SETRET performs no target dereference and raises no alignment, memory, arithmetic, or block-control exception."
  ],
  "field_contracts": {},
  "field_zero_meanings": {
    "uimm5": "Encoded zero supplies numeric zero for the 5-bit unsigned immediate."
  },
  "legality": [
    "Every uimm5 value 0..31 is assigned. The fixed destination is architectural ra (GPR10).",
    "C.SETRET is legal as a standalone scalar operation and does not by itself form a call."
  ],
  "memory_effects": [
    "none"
  ],
  "operands": [
    {
      "field": "uimm5",
      "role": "unsigned five-bit halfword displacement from the pre-increment TPC"
    }
  ],
  "ordering": [
    "Snapshot the pre-increment TPC, compute the target, publish ra and captured return state together, then perform the ordinary two-byte sequential TPC advance."
  ],
  "standalone_opcode": true,
  "state_effects": [
    "Compute target = pre-increment TPC + (ZeroExtend(uimm5) << 1) with XLEN wrapping.",
    "Atomically write the same target to GPR10 ra and the captured return-address state; successful dispatch then advances TPC by two bytes.",
    "A later ordinary write to ra does not retroactively change the captured return-address state."
  ]
}

depends_on

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

id

PTO-SCALAR-C-SETRET

mnemonic

C.SETRET

summary

Materialize an unsigned halfword-scaled TPC-relative return address in ra and captured return state.

surface

scalar

{
  "classification": [
    "alu"
  ],
  "documentation": "docs/scalar/alu/C.SETRET.md",
  "id": "PTO-SCALAR-C-SETRET",
  "instruction_contract": {
    "artifact": "spec/evidence/instruction-contract-closure.json",
    "mnemonic": "C.SETRET",
    "ndf_clause": "PTO-INST-SCALAR-C-SETRET"
  },
  "mnemonic": "C.SETRET",
  "readiness_subjects": [
    "ADR-0021",
    "ADR-0026",
    "ADR-0059",
    "ADR-0084"
  ],
  "semantic_tests": [
    "PTO-AVS-SCALAR-C-SETRET-BOUND-001",
    "PTO-AVS-SCALAR-C-SETRET-WRAP-001",
    "PTO-AVS-SCALAR-C-SETRET-ZERO-001"
  ],
  "source": "asl/scalar/alu/C.SETRET.asl",
  "surface": "scalar",
  "tests": [
    "PTO-AVS-SCALAR-C-SETRET-BOUND-001",
    "PTO-AVS-SCALAR-C-SETRET-DECODE-001",
    "PTO-AVS-SCALAR-C-SETRET-WRAP-001",
    "PTO-AVS-SCALAR-C-SETRET-ZERO-001"
  ]
}