Operands and parameters
RegDst- Reg5 scalar destination or discard selector
SrcL- Reg5 scalar source; only bits 31:0 participate
simm12- signed 12-bit immediate
ANDIW performs word conjunction with a signed 12-bit immediate and sign-extends the result.
PTO-SCALAR-ANDIWandiw SrcL, simm, ->{t, u, Rd}| Field | Bits | Signedness | Architectural role | Encoded zero |
|---|---|---|---|---|
RegDst | 5 | encoding-defined | Reg5 scalar destination or discard selector | Encoded zero discards the result and does not modify any GPR or queue. |
SrcL | 5 | encoding-defined | Reg5 scalar source; only bits 31:0 participate | Encoded zero reads the architectural zero GPR. |
simm12 | 12 | signed | signed 12-bit immediate | Encoded zero supplies numeric zero. |
Loading WaveDrom diagram… The encoding table and WaveJSON remain available below.
| Decoded item | Bit range | Value |
|---|---|---|
| simm12 | 31:20 | variable |
| SrcL | 19:15 | variable |
| Constant | 14:12 | 3'b010 |
| RegDst | 11:7 | variable |
| Constant | 6:0 | 7'b0110101 |
{
"reg": [
{
"bits": 7,
"name": "7'b0110101"
},
{
"bits": 5,
"name": "RegDst"
},
{
"bits": 3,
"name": "3'b010"
},
{
"bits": 5,
"name": "SrcL"
},
{
"bits": 12,
"name": "simm12"
}
],
"config": {
"bits": 32,
"fontsize": 13,
"hspace": 900,
"lanes": 1,
"offset": 0
}
}andiw SrcL, simm, ->{t, u, Rd}
RegDstSrcLsimm12This Operation comes directly from the instruction owner; the page does not rewrite its behavior.
readonly func InstructionContractOperation_ANDIW() => ScalarOperationbegin return ScalarOperation_ANDIW;end;readonly func InstructionContractHandler_ANDIW() => ScalarSemanticHandlerbegin return ScalarHandler_ScalarBinaryW;end;
pure func InstructionContractImmediateWidth_ANDIW() => integer {1..64}begin return 12;end;
pure func InstructionContractImmediateIsSigned_ANDIW() => booleanbegin return TRUE;end;
pure func InstructionContractIsWordOperation_ANDIW() => booleanbegin return TRUE;end;// PTO-INSTRUCTION: {"assembly":["andiw SrcL, simm, ->{t, u, Rd}"],"block":[],"catalog_indices":[9],"catalog_records":[{"asm":"andiw SrcL, simm, ->{t, u, Rd}","constraints":[],"encoding":[{"index":0,"mask":"0x0000707f","match":"0x00002035","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":"simm12","pieces":[{"instruction_lsb":20,"value_lsb":0,"width":12}],"signedness":"signed","width":12}],"form_id":"andiw_32_9ec1f7343dbd","length_bits":32,"mnemonic":"ANDIW","semantic_family":"ALU","semantic_group":"ALU","semantic_handler":"ScalarBinaryW","semantic_summary":"ANDIW ANDs SrcL[31:0] with the low 32 bits of sign-extended simm12, sign-extends the result to XLEN, and publishes it through RegDst.","status":"accepted"}],"classification":["alu"],"contract":{"block_composition":["none"],"canonical_assembly":["andiw SrcL, simm, ->{t, u, Rd}"],"defaults":["SrcL, simm12, and RegDst are required encoded fields; no field can be omitted.","simm12 is a signed 12-bit immediate from -2048 through 2047. Encoded zero supplies numeric zero."],"encoding_class":"standalone-encoded","examples":["andiw a0, -1, ->a0","andiw u#1, 2047, ->t","andiw zero, -2048, ->zero"],"exceptions":["ANDIW raises no arithmetic exception; word conjunction and final sign extension are defined for every source and simm12 bit pattern.","A fixed-bit mismatch or unavailable selected T/U source raises Fault_IllegalInstruction before the destination effect and before TPC advances."],"field_contracts":{},"field_zero_meanings":{"RegDst":"Encoded zero discards the result and does not modify any GPR or queue.","SrcL":"Encoded zero reads the architectural zero GPR.","simm12":"Encoded zero supplies numeric zero."},"legality":["All 32 SrcL encodings are assigned: 0..23 select absolute GPRs, 24..27 select T#1..T#4, and 28..31 select U#1..U#4 without consuming a queue entry.","All 32 RegDst encodings are assigned: codes 0 and 24..29 discard, code 30 pushes U, code 31 pushes T, and codes 1..23 write absolute GPRs.","Every signed 12-bit immediate from -2048 through 2047 is legal. Only the low 32 bits of SrcL and the sign-extended immediate participate."],"memory_effects":["none"],"operands":[{"field":"RegDst","role":"Reg5 scalar destination or discard selector"},{"field":"SrcL","role":"Reg5 scalar source; only bits 31:0 participate"},{"field":"simm12","role":"signed 12-bit immediate"}],"ordering":["Snapshot SrcL before the destination effect. Repeated source and destination selectors therefore read the pre-instruction value.","Successful execution publishes the sign-extended word result and then advances TPC by four bytes."],"standalone_opcode":true,"state_effects":["Sign-extend simm12, AND its low 32 bits with the low 32 bits of SrcL, then produce a 32-bit result sign-extended to XLEN and publish it through RegDst.","Codes 1..23 write a GPR; codes 0 and 24..29 discard; code 30 pushes U; code 31 pushes T. Source queue selections are non-consuming.","No memory, reservation, descriptor, block, privilege, numeric-flag, or control-flow state changes other than TPC advancing by four bytes after success."]},"depends_on":["PTO-BLOCK-MODEL-SCHEMA-PROFILE-ENCODING"],"id":"PTO-SCALAR-ANDIW","mnemonic":"ANDIW","summary":"ANDIW performs word conjunction with a signed 12-bit immediate and sign-extends the result.","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_ANDIW() => ScalarOperationbegin return ScalarOperation_ANDIW;end;// DOC-END: decode// DOC-BEGIN: operationreadonly func InstructionContractHandler_ANDIW() => ScalarSemanticHandlerbegin return ScalarHandler_ScalarBinaryW;end;
pure func InstructionContractImmediateWidth_ANDIW() => integer {1..64}begin return 12;end;
pure func InstructionContractImmediateIsSigned_ANDIW() => booleanbegin return TRUE;end;
pure func InstructionContractIsWordOperation_ANDIW() => booleanbegin return TRUE;end;// DOC-END: operation
ANDIW is a 32-bit scalar ALU instruction. It performs bitwise conjunction under the low 32-bit word, followed by sign-extension to XLEN result rules; its current instruction contract defines the result publication path and any additional state effect.
Execution snapshots the encoded inputs, then performs bitwise conjunction under the low 32-bit word, followed by sign-extension to XLEN result rules, and only afterward performs the destination effects.
RegDst field selects the Reg5 scalar result target or discards the result.SrcL field selects a Reg5 scalar value whose low 32 bits participate.simm12 field carries the signed 12-bit immediate.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.
Every scalar source is snapshotted before the destination effect. The completed value is then routed through RegDst using the current scalar destination map.
This ALU operation has no memory effect. After its successful architectural effects, TPC advances by 4 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.
Fixed-width arithmetic follows the operation’s wraparound rule without an arithmetic exception. A fixed-bit mismatch or unavailable selected T/U source raises Fault_IllegalInstruction before publication and before TPC advances.
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 ANDIW example, SrcL=0xc and simm12=0xa produce 0x8.
Bodies come from owning ASL. Dragging or buttons change only this page-session view order.
No NDF clause is attached to this unit.
10 matching entries
PTO-AVS-SCALAR-ANDIW-ALIASES-001tests/asl/scalar/alu/ANDIW/scalar-bound-andiw-aliases-001.aslcf2d5c71d55f550a82b3d57f965d85a88a1e056266913ffb908d06747304af44PTO-AVS-SCALAR-ANDIW-DECODE-001tests/asl/scalar/alu/ANDIW/scalar-decode-andiw-canonical-001.asl3a5d9b7fee203426b5c41a2946f6b848ac19741227eea5167b8c4556c5be069fPTO-AVS-SCALAR-ANDIW-RESULT-001tests/asl/scalar/alu/ANDIW/scalar-exec-andiw-result-001.aslc712edb7f17ace0e52a9abda95d82cbb8d70829e9ac462e6c07c467fac3ee0fePTO-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/ANDIW.md",
"id": "PTO-SCALAR-ANDIW",
"instruction_contract": {
"artifact": "spec/evidence/instruction-contract-closure.json",
"mnemonic": "ANDIW",
"ndf_clause": "PTO-INST-SCALAR-ANDIW"
},
"mnemonic": "ANDIW",
"readiness_subjects": [
"ADR-0026",
"ADR-0059"
],
"semantic_tests": [
"PTO-AVS-SCALAR-ANDIW-ALIASES-001",
"PTO-AVS-SCALAR-ANDIW-RESULT-001"
],
"source": "asl/scalar/alu/ANDIW.asl",
"surface": "scalar",
"tests": [
"PTO-AVS-SCALAR-ANDIW-ALIASES-001",
"PTO-AVS-SCALAR-ANDIW-DECODE-001",
"PTO-AVS-SCALAR-ANDIW-RESULT-001"
]
}0.58.5 · Release candidate7dc8b7e5b121d2b2499a2273bebff29e2cd868121fc36de98f5e5bc2c53ef8a3664eef8c30d691e03769cfd536cd36593a5d8ae8ea557ac70fee3a4dab1235488dd70e38ecde1beedbb6ac100721c1f30dc005a8asl/scalar/alu/ANDIW.aslasl/scalar/alu/ANDIW.asl