Operands and parameters
SrcL- Reg5 source
C.SEXT.W sign-extends SrcL[31:0] to XLEN and pushes the result to T.
PTO-SCALAR-C-SEXT-Wc.sext.w srcL, ->t| Field | Bits | Signedness | Architectural role | Encoded zero |
|---|---|---|---|---|
SrcL | 5 | encoding-defined | Reg5 source | Encoded zero reads the architectural zero GPR. |
Loading WaveDrom diagram… The encoding table and WaveJSON remain available below.
| Decoded item | Bit range | Value |
|---|---|---|
| Constant | 15:11 | 5'b01010 |
| SrcL | 10:6 | variable |
| Constant | 5:0 | 6'b011100 |
{
"reg": [
{
"bits": 6,
"name": "6'b011100"
},
{
"bits": 5,
"name": "SrcL"
},
{
"bits": 5,
"name": "5'b01010"
}
],
"config": {
"bits": 16,
"fontsize": 13,
"hspace": 640,
"lanes": 1,
"offset": 0
}
}c.sext.w srcL, ->t
SrcLThis Operation comes directly from the instruction owner; the page does not rewrite its behavior.
readonly func InstructionContractOperation_C_SEXT_W() => ScalarOperationbegin return ScalarOperation_C_SEXT_W;end;readonly func InstructionContractHandler_C_SEXT_W() => ScalarSemanticHandlerbegin return ScalarHandler_ExtendScalarValue;end;
pure func InstructionContractResult_C_SEXT_W(value: Word) => Wordbegin return ExtendScalarValue( value, 32, TRUE);end;// PTO-INSTRUCTION: {"assembly":["c.sext.w srcL, ->t"],"block":[],"catalog_indices":[41],"catalog_records":[{"asm":"c.sext.w srcL, ->t","constraints":[],"encoding":[{"index":0,"mask":"0xf83f","match":"0x501c","width_bits":16}],"encoding_kind":"C16","fields":[{"name":"SrcL","pieces":[{"instruction_lsb":6,"value_lsb":0,"width":5}],"signedness":"encoding-defined","width":5}],"form_id":"c_sext_w_16_f2bb13f0797b","length_bits":16,"mnemonic":"C.SEXT.W","semantic_family":"ALU","semantic_group":"ALU","semantic_handler":"ExtendScalarValue","semantic_summary":"C.SEXT.W sign-extends SrcL[31:0] to XLEN and pushes the result to T.","status":"accepted"}],"classification":["alu"],"contract":{"block_composition":["none"],"canonical_assembly":["c.sext.w srcL, ->t"],"defaults":["Every encoded source, immediate, and explicit destination field is required; no field can be omitted.","The mnemonic fixes immediate signedness, selected source width, and implicit-versus-explicit destination behavior."],"encoding_class":"standalone-encoded","examples":["c.sext.w srcl, ->t"],"exceptions":["Materialization, movement, and extension are total fixed-width operations and raise no arithmetic exception.","An unavailable selected T/U source raises Fault_IllegalInstruction before the destination effect and before TPC advances."],"field_contracts":{},"field_zero_meanings":{"SrcL":"Encoded zero reads the architectural zero GPR."},"legality":["SrcL codes 0..23 select absolute GPRs, 24..27 select T#1..T#4, and 28..31 select U#1..U#4 without consumption.","The compressed form has no destination field and always pushes exactly one result to T.","Every encoded operand value is assigned; fixed encoding bits must match the canonical form."],"memory_effects":["none"],"operands":[{"field":"SrcL","role":"Reg5 source"}],"ordering":["Snapshot any Reg5 source before the destination effect.","Publish the result, then advance TPC by the encoded instruction length."],"standalone_opcode":true,"state_effects":["Sign-extend source bit 31 through the XLEN result.","Push the complete XLEN result to T. The source queue is non-consuming, and no explicit destination encoding exists.","No memory, reservation, descriptor, numeric-status, block, privilege, branch-target, or other control state changes. Successful execution advances TPC by two bytes."]},"depends_on":["PTO-BLOCK-MODEL-SCHEMA-PROFILE-ENCODING"],"id":"PTO-SCALAR-C-SEXT-W","mnemonic":"C.SEXT.W","summary":"C.SEXT.W sign-extends SrcL[31:0] to XLEN and pushes the result to T.","surface":"scalar"}// PTO-REVIEW: {"review_method":"formal-definition-read","outcome":"FORMAL-COMPLETE","reviewed_fields":["assembly","encoding","defaults","operation","state","memory","ordering","faults","reserved"]}// DOC-BEGIN: decodereadonly func InstructionContractOperation_C_SEXT_W() => ScalarOperationbegin return ScalarOperation_C_SEXT_W;end;// DOC-END: decode// DOC-BEGIN: operationreadonly func InstructionContractHandler_C_SEXT_W() => ScalarSemanticHandlerbegin return ScalarHandler_ExtendScalarValue;end;
pure func InstructionContractResult_C_SEXT_W(value: Word) => Wordbegin return ExtendScalarValue( value, 32, TRUE);end;// DOC-END: operation
C.SEXT.W is a 16-bit scalar ALU instruction. It sign-extends the low 32 source bits to XLEN; its current instruction contract defines the result publication path and any additional state effect.
Execution snapshots the encoded inputs, then sign-extends the low 32 source bits to XLEN, and only afterward performs the destination effects.
SrcL field selects a scalar input through Reg5.These roles come from the current instruction contract. T/U sources are read and snapshotted without being removed from their queues; exact encoded-zero meanings appear in the generated defaults below.
Any scalar source is snapshotted before publication, and the completed instruction pushes exactly one result to T.
This ALU operation has no memory effect. After its successful architectural effects, TPC advances by 2 bytes.
The operation does not introduce a hidden scalar publication target or an implicit memory access. Architectural changes remain limited to the state effects enumerated by the current contract.
Materialization, movement, and extension are total at their fixed widths and do not raise arithmetic exceptions. A fixed-bit mismatch or unavailable selected T/U source faults before state effects.
The generated legality table is authoritative for assigned field values, reserved encodings, and destination discard codes. Decode and source availability are checked before architectural effects.
This example illustrates the current ASL owner and does not replace the normative operation.
For a small C.SEXT.W example, source low 32 bits 0x80000000 become XLEN value -2147483648 after sign extension.
Bodies come from owning ASL. Dragging or buttons change only this page-session view order.
No NDF clause is attached to this unit.
9 matching entries
PTO-AVS-SCALAR-C-SEXT-W-DECODE-001tests/asl/scalar/alu/C.SEXT.W/scalar-decode-c-sext-w-canonical-001.aslbfddd2900c17e99843a6140b8a1729c08d9533df57e425fb3ebaeeba86c5597fPTO-AVS-SCALAR-C-SEXT-W-MATERIALIZE-001tests/asl/scalar/alu/C.SEXT.W/scalar-exec-c-sext-w-materialize-001.asl35e8b57e79221450899f305b85a51b71089a905e3ace320c457c31d8be0a51a6PTO-EVIDENCE-RELEASE-TRACEABILITYPTO-EVIDENCE-RELEASE-TRACEABILITYspec/evidence/release-traceability-readiness.jsonc7327021d39dc67ac5564bc55073b3870a397d79ac8d9648284d56e33bc14a3ePTO-EVIDENCE-INSTRUCTION-CONTRACT-CLOSUREPTO-EVIDENCE-INSTRUCTION-CONTRACT-CLOSUREspec/evidence/instruction-contract-closure.json3ef2bb62421c79dff8fa77a1c7983923b523244b8090812883ef81286ca8106aPTO-EVIDENCE-ARCHITECTURE-READINESSPTO-EVIDENCE-ARCHITECTURE-READINESSspec/evidence/architecture-readiness.json4b0b85199101251bea744e0f3591cc31906909dc80d5ab651c417a936036a004PTO-EVIDENCE-RELEASE-GATE-READINESSPTO-EVIDENCE-RELEASE-GATE-READINESSspec/evidence/release-gate-readiness.jsona0f4d2b6920c08981ea55fd8ef820708a40d4feb5402c5150e8e9ab532d84ce0PTO-EVIDENCE-RELEASE-MANIFESTPTO-EVIDENCE-RELEASE-MANIFESTspec/release-manifest.json1a64c109ed7a90351c41e2a418b3c0ebaf8ad975838986d2101385186b85c0d8Loading ADR-0026…
ADR-0026docs/status/decisions/0026-scalar-alu-totality-and-alias-order.md41d126f224dddc371832120f1b02eab64e426872fdcbea452bad77c90bdec349Loading ADR-0059…
ADR-0059docs/status/decisions/0059-mnemonic-field-encoding-closure.mdf18d13f735cfaf9f2803c754c5818f4af33d1cc42c489f0d9ce060b07bb3a196{
"classification": [
"alu"
],
"documentation": "docs/scalar/alu/C.SEXT.W.md",
"id": "PTO-SCALAR-C-SEXT-W",
"instruction_contract": {
"artifact": "spec/evidence/instruction-contract-closure.json",
"mnemonic": "C.SEXT.W",
"ndf_clause": "PTO-INST-SCALAR-C-SEXT-W"
},
"mnemonic": "C.SEXT.W",
"readiness_subjects": [
"ADR-0026",
"ADR-0059"
],
"semantic_tests": [
"PTO-AVS-SCALAR-C-SEXT-W-MATERIALIZE-001"
],
"source": "asl/scalar/alu/C.SEXT.W.asl",
"surface": "scalar",
"tests": [
"PTO-AVS-SCALAR-C-SEXT-W-DECODE-001",
"PTO-AVS-SCALAR-C-SEXT-W-MATERIALIZE-001"
]
}0.58.5 · Release candidate7dc8b7e5b121d2b2499a2273bebff29e2cd8681230407203240b1ca0117ba6440476083f2e92057cb38517e0249e6d7d0e43b33c4c47acfec40dcbecdbdbaae3f58250d5fbe1b8c2bfb3ee2e53bd1aaad413cc01asl/scalar/alu/C.SEXT.W.aslasl/scalar/alu/C.SEXT.W.asl