Operands and parameters
RegDst- Reg5 scalar destination or discard selector
SrcL- Reg5 scalar source
uimm12- unsigned 12-bit immediate
ADDI performs unsigned-immediate XLEN addition with Reg5 source and destination selection.
PTO-SCALAR-ADDIaddi SrcL, uimm, ->{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 | Encoded zero reads the architectural zero GPR. |
uimm12 | 12 | unsigned | unsigned 12-bit immediate | Encoded zero supplies numeric zero. |
Loading WaveDrom diagram… The encoding table and WaveJSON remain available below.
| Decoded item | Bit range | Value |
|---|---|---|
| uimm12 | 31:20 | variable |
| SrcL | 19:15 | variable |
| Constant | 14:12 | 3'b000 |
| RegDst | 11:7 | variable |
| Constant | 6:0 | 7'b0010101 |
{
"reg": [
{
"bits": 7,
"name": "7'b0010101"
},
{
"bits": 5,
"name": "RegDst"
},
{
"bits": 3,
"name": "3'b000"
},
{
"bits": 5,
"name": "SrcL"
},
{
"bits": 12,
"name": "uimm12"
}
],
"config": {
"bits": 32,
"fontsize": 13,
"hspace": 900,
"lanes": 1,
"offset": 0
}
}addi SrcL, uimm, ->{t, u, Rd}
RegDstSrcLuimm12This Operation comes directly from the instruction owner; the page does not rewrite its behavior.
readonly func InstructionContractOperation_ADDI() => ScalarOperationbegin return ScalarOperation_ADDI;end;readonly func InstructionContractHandler_ADDI() => ScalarSemanticHandlerbegin return ScalarHandler_ScalarBinary;end;
pure func InstructionContractImmediateWidth_ADDI() => integer {1..64}begin return 12;end;
pure func InstructionContractImmediateIsUnsigned_ADDI() => booleanbegin return TRUE;end;
pure func InstructionContractIsWordOperation_ADDI() => booleanbegin return FALSE;end;// PTO-INSTRUCTION: {"assembly":["addi SrcL, uimm, ->{t, u, Rd}"],"block":[],"catalog_indices":[3],"catalog_records":[{"asm":"addi SrcL, uimm, ->{t, u, Rd}","constraints":[],"encoding":[{"index":0,"mask":"0x0000707f","match":"0x00000015","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":"uimm12","pieces":[{"instruction_lsb":20,"value_lsb":0,"width":12}],"signedness":"unsigned","width":12}],"form_id":"addi_32_2decd0a93a0a","length_bits":32,"mnemonic":"ADDI","semantic_family":"ALU","semantic_group":"ALU","semantic_handler":"ScalarBinary","semantic_summary":"ADDI adds the zero-extended unsigned 12-bit immediate to the snapshotted XLEN source modulo 2^PTO_XLEN and publishes the result through the selected Reg5 destination.","status":"accepted"}],"classification":["alu"],"contract":{"block_composition":["none"],"canonical_assembly":["addi SrcL, uimm, ->{t, u, Rd}"],"defaults":["SrcL, uimm12, and RegDst are required encoded fields; no field can be omitted.","uimm12 is an unsigned 12-bit immediate from 0 through 4095. Encoded zero supplies numeric zero."],"encoding_class":"standalone-encoded","examples":["addi a0, 1, ->a0","addi t#1, 4095, ->u","addi zero, 0, ->zero"],"exceptions":["ADDI raises no arithmetic exception: addition wraps modulo 2^PTO_XLEN.","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.","uimm12":"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.","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 unsigned 12-bit immediate from 0 through 4095 is legal."],"memory_effects":["none"],"operands":[{"field":"RegDst","role":"Reg5 scalar destination or discard selector"},{"field":"SrcL","role":"Reg5 scalar source"},{"field":"uimm12","role":"unsigned 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 result and then advances TPC by four bytes."],"standalone_opcode":true,"state_effects":["Zero-extend uimm12, add it to the snapshotted SrcL value modulo 2^PTO_XLEN, and publish the XLEN result 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, 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-ADDI","mnemonic":"ADDI","summary":"ADDI performs unsigned-immediate XLEN addition with Reg5 source and destination selection.","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_ADDI() => ScalarOperationbegin return ScalarOperation_ADDI;end;// DOC-END: decode// DOC-BEGIN: operationreadonly func InstructionContractHandler_ADDI() => ScalarSemanticHandlerbegin return ScalarHandler_ScalarBinary;end;
pure func InstructionContractImmediateWidth_ADDI() => integer {1..64}begin return 12;end;
pure func InstructionContractImmediateIsUnsigned_ADDI() => booleanbegin return TRUE;end;
pure func InstructionContractIsWordOperation_ADDI() => booleanbegin return FALSE;end;// DOC-END: operation
ADDI is a 32-bit scalar ALU instruction. It performs addition under the complete XLEN value result rules; its current instruction contract defines the result publication path and any additional state effect.
Execution snapshots the encoded inputs, then performs addition under the complete XLEN value 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 scalar value through Reg5.uimm12 field carries the unsigned 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 ADDI example, SrcL=7 and uimm12=3 produce 10.
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-ADDI-ALIASES-001tests/asl/scalar/alu/ADDI/scalar-bound-addi-aliases-001.asl234dd391b9e306ad1649f17ea1fb19af435694a2ce4aa65feecde08a17d8403ePTO-AVS-SCALAR-ADDI-DECODE-001tests/asl/scalar/alu/ADDI/scalar-decode-addi-canonical-001.asldaea98e948768d451f23c84e927ba752698c67d047d58007e5b6e2ab9cf47eefPTO-AVS-SCALAR-ADDI-RESULT-001tests/asl/scalar/alu/ADDI/scalar-exec-addi-result-001.asl4b59ce693b326006faa874aed108f1738705bd5e42bca8f9b275f589fd4bd696PTO-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/ADDI.md",
"id": "PTO-SCALAR-ADDI",
"instruction_contract": {
"artifact": "spec/evidence/instruction-contract-closure.json",
"mnemonic": "ADDI",
"ndf_clause": "PTO-INST-SCALAR-ADDI"
},
"mnemonic": "ADDI",
"readiness_subjects": [
"ADR-0026",
"ADR-0059"
],
"semantic_tests": [
"PTO-AVS-SCALAR-ADDI-ALIASES-001",
"PTO-AVS-SCALAR-ADDI-RESULT-001"
],
"source": "asl/scalar/alu/ADDI.asl",
"surface": "scalar",
"tests": [
"PTO-AVS-SCALAR-ADDI-ALIASES-001",
"PTO-AVS-SCALAR-ADDI-DECODE-001",
"PTO-AVS-SCALAR-ADDI-RESULT-001"
]
}0.58.5 · Release candidate7dc8b7e5b121d2b2499a2273bebff29e2cd86812ac355d499920c9e5d39aa4c40283b540d6d61f88746ac1d0d88739fc33b71927cc5a4c1830ce32bb0d9da87ee7609f9d6c039986ebac560391ee42e7da7aa3cfasl/scalar/alu/ADDI.aslasl/scalar/alu/ADDI.asl