操作数与参数
RegDst- Reg5 destination or discard
SrcL- Reg5 source
imml- selected field width N minus one
imms- selected field starting bit M
BIC clears every bit in an independently selected wrapping scalar field and publishes the modified XLEN value.
PTO-SCALAR-BICbic SrcL, M, N, ->{t, u, Rd}| 字段 | 位宽 | 有符号性 | 架构角色 | 编码零 |
|---|---|---|---|---|
RegDst | 5 | encoding-defined | Reg5 destination or discard | Encoded zero discards the result. |
SrcL | 5 | encoding-defined | Reg5 source | Encoded zero reads the architectural zero GPR. |
imml | 6 | encoding-defined | selected field width N minus one | Encoded zero selects a one-bit field. |
imms | 6 | encoding-defined | selected field starting bit M | Encoded zero starts the selected field at source bit zero. |
Loading WaveDrom diagram… The encoding table and WaveJSON remain available below.
| Decoded item | Bit range | Value |
|---|---|---|
| imms | 31:26 | variable |
| imml | 25:20 | variable |
| SrcL | 19:15 | variable |
| Constant | 14:12 | 3'b010 |
| RegDst | 11:7 | variable |
| Constant | 6:0 | 7'b1100111 |
{
"reg": [
{
"bits": 7,
"name": "7'b1100111"
},
{
"bits": 5,
"name": "RegDst"
},
{
"bits": 3,
"name": "3'b010"
},
{
"bits": 5,
"name": "SrcL"
},
{
"bits": 6,
"name": "imml"
},
{
"bits": 6,
"name": "imms"
}
],
"config": {
"bits": 32,
"fontsize": 13,
"hspace": 900,
"lanes": 1,
"offset": 0
}
}bic SrcL, M, N, ->{t, u, Rd}
RegDstSrcLimmlimms下面是该指令所有者中的 Operation;页面没有重写这段行为。
readonly func InstructionContractOperation_BIC() => ScalarOperationbegin return ScalarOperation_BIC;end;
pure func InstructionContractWidth_BIC(encoded_imml: bits(6)) => integer {1..64}begin return UInt(encoded_imml) + 1;end;
pure func InstructionContractOffset_BIC(encoded_imms: bits(6)) => integer {0..63}begin return UInt(encoded_imms);end;readonly func InstructionContractHandler_BIC() => ScalarSemanticHandlerbegin return ScalarHandler_ModifyBitfield;end;
pure func InstructionContractResult_BIC( value: Word, width: integer {1..64}, offset: integer {0..63}) => Wordbegin return ModifyBitfield( value, width, offset, FALSE);end;// PTO-INSTRUCTION: {"assembly":["bic SrcL, M, N, ->{t, u, Rd}"],"block":[],"catalog_indices":[15],"catalog_records":[{"asm":"bic SrcL, M, N, ->{t, u, Rd}","constraints":[],"encoding":[{"index":0,"mask":"0x0000707f","match":"0x00002067","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":"imml","pieces":[{"instruction_lsb":20,"value_lsb":0,"width":6}],"signedness":"encoding-defined","width":6},{"name":"imms","pieces":[{"instruction_lsb":26,"value_lsb":0,"width":6}],"signedness":"encoding-defined","width":6}],"form_id":"bic_32_3a10830a3a93","length_bits":32,"mnemonic":"BIC","semantic_family":"ALU","semantic_group":"ALU","semantic_handler":"ModifyBitfield","semantic_summary":"BIC clears every bit in an independently selected wrapping scalar field and publishes the modified XLEN value.","status":"accepted"}],"classification":["alu"],"contract":{"block_composition":["none"],"canonical_assembly":["bic SrcL, M, N, ->{t, u, Rd}"],"defaults":["SrcL, imml, imms, and RegDst are required encoded fields; no field can be omitted.","imml encodes N minus one, so raw values 0 through 63 select widths 1 through 64; encoded zero selects N=1.","imms directly encodes M from 0 through 63; encoded zero selects source bit zero."],"encoding_class":"standalone-encoded","examples":["bic a0, 60, 8, ->a1","bic t#1, 0, 64, ->u"],"exceptions":["An unavailable selected T/U source raises Fault_IllegalInstruction before the destination effect and before TPC advances.","BIC raises no arithmetic, memory, alignment, permission, or control-flow exception."],"field_contracts":{},"field_zero_meanings":{"RegDst":"Encoded zero discards the result.","SrcL":"Encoded zero reads the architectural zero GPR.","imml":"Encoded zero selects a one-bit field.","imms":"Encoded zero starts the selected field at source bit zero."},"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.","RegDst codes 0 and 24..29 discard, codes 1..23 write GPRs, code 30 pushes U, and code 31 pushes T.","Every imml and imms value is assigned. The selected N-bit field begins at bit M and wraps through bit 63 to bit 0."],"memory_effects":["none"],"operands":[{"field":"RegDst","role":"Reg5 destination or discard"},{"field":"SrcL","role":"Reg5 source"},{"field":"imml","role":"selected field width N minus one"},{"field":"imms","role":"selected field starting bit M"}],"ordering":["Snapshot SrcL before any destination effect so a GPR alias or T/U destination push observes the pre-instruction value.","Publish the result, then advance TPC by four bytes."],"standalone_opcode":true,"state_effects":["Extract the N-bit field beginning at bit M, wrapping from bit 63 to bit 0. Clear the N selected source bits and preserve every unselected source bit.","Publish the complete XLEN result through the common Reg5 destination map. Relative sources are non-consuming; only a T or U destination push changes a temporary queue.","No memory, reservation, descriptor, numeric-status, block, privilege, branch-target, or other control state changes. Successful execution advances TPC by four bytes."]},"depends_on":["PTO-BLOCK-MODEL-SCHEMA-PROFILE-ENCODING"],"id":"PTO-SCALAR-BIC","mnemonic":"BIC","summary":"BIC clears every bit in an independently selected wrapping scalar field and publishes the modified XLEN value.","surface":"scalar"}// PTO-REVIEW: {"review_method":"formal-definition-read","outcome":"FORMAL-COMPLETE","reviewed_fields":["assembly","encoding","defaults","operation","state","memory","ordering","faults","reserved"]}// NDF-BEGIN: PTO-BIC-DECISION-BINDING-001// ndf: kind=contract level=L1 layer=scalar status=accepted// BIC MUST implement the mnemonic-local canonical assembly, encoded// legality, defaults, state and memory effects, ordering, and fault boundaries// declared in this owner. The operation region below is the executable binding// for every accepted decision that names this mnemonic.// NDF-END: PTO-BIC-DECISION-BINDING-001// DOC-BEGIN: decodereadonly func InstructionContractOperation_BIC() => ScalarOperationbegin return ScalarOperation_BIC;end;
pure func InstructionContractWidth_BIC(encoded_imml: bits(6)) => integer {1..64}begin return UInt(encoded_imml) + 1;end;
pure func InstructionContractOffset_BIC(encoded_imms: bits(6)) => integer {0..63}begin return UInt(encoded_imms);end;// DOC-END: decode// DOC-BEGIN: operationreadonly func InstructionContractHandler_BIC() => ScalarSemanticHandlerbegin return ScalarHandler_ModifyBitfield;end;
pure func InstructionContractResult_BIC( value: Word, width: integer {1..64}, offset: integer {0..63}) => Wordbegin return ModifyBitfield( value, width, offset, FALSE);end;// DOC-END: operation
BIC 是一条 32 位标量 ALU 指令。它清除独立选择且可回绕目标位域中的每一位;当前指令契约定义结果发布路径以及任何额外状态效果。
执行时先对编码输入做快照,然后清除独立选择且可回绕目标位域中的每一位,最后才产生目标效果。
imml 与 imms 分别选择位域宽度和起始位;回绕属于所选位域机制的一部分。RegDst 是 5 位字段,选择 Reg5 结果目标,或丢弃结果。SrcL 是 5 位字段,通过 Reg5 选择标量输入。imml 是 6 位字段,以 N-1 编码所选位域宽度。imms 是 6 位字段,编码所选位域起始位 M。这些角色来自当前指令契约;T/U 源只被读取和快照,不会因源选择而出队。编码零的精确含义列在下方生成的默认值章节中。
所有标量源都在目标效果前完成快照。完成后的值随后通过 RegDst 按当前标量目标映射发布。
该 ALU 操作不产生内存效果。成功完成架构效果后,TPC 前进 4 字节。
该操作不会产生隐藏的标量发布目标或隐式内存访问。架构变化仅限于当前契约列出的状态效果。
位域选择可从位 63 回绕到位 0;宽度与起点的精确编码含义由下方生成的默认值和合法性表给出。
下方生成的合法性表是已分配字段值、保留编码和目标丢弃编码的权威说明。解码与源可用性检查先于架构效果完成。
本示例只用于演示当前 ASL 所有者,不替代规范操作。
以一个小型 BIC 示例说明:清除基值 0xf 的所选位 1..2 后得到 0x9。
正文来自 owning ASL。拖拽或按钮只临时改变当前页面显示顺序。
BIC MUST implement the mnemonic-local canonical assembly, encoded legality, defaults, state and memory effects, ordering, and fault boundaries declared in this owner. The operation region below is the executable binding for every accepted decision that names this mnemonic.
PTO-BIC-DECISION-BINDING-001asl/scalar/alu/BIC.asl06d35a2843a86fed4b03d5cd2c261c00e72e28b14f1eec30a2484666f7c4e7b07c8ddbd5d4d6e8de2a9aa95abfe9faf98aceea2afaafcf216d6e496753124a0113 matching entries
PTO-AVS-SCALAR-BIC-DECODE-001tests/asl/scalar/alu/BIC/scalar-decode-bic-canonical-001.asl5829904580fc30eb399302f20b9cb126f43c3f737b389a1f71e254400f33c2b9PTO-AVS-SCALAR-BIC-READINESS-001tests/asl/scalar/alu/BIC/scalar-fault-bic-readiness-001.asle28a086f095fd3f0ca43e8e47dade4e9f046c14f9e7d0dd2ea4e2986e1f7474dPTO-AVS-SCALAR-BIC-SELECTORS-001tests/asl/scalar/alu/BIC/scalar-bound-bic-selectors-001.asl6b7fed0a9b23e33ee0f11329e37068cfafe0b13492db535e4bdb658eef331c2fPTO-AVS-SCALAR-BIC-WRAP-001tests/asl/scalar/alu/BIC/scalar-exec-bic-wrap-001.asld507e4fb481404c1115b0f9dd98bfb5bc9e9b18938fbc6361fea4ec9e33db18dPTO-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-0025…
ADR-0025docs/status/decisions/0025-scalar-bitfield-and-reverse-bounds.md1c9dcf2e2f9c8ea16659db372545ac8dd76c4a88af9140fbd95c4473f2fef5dcLoading 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.mdf18d13f735cfaf9f2803c754c5818f4af33d1cc42c489f0d9ce060b07bb3a196Loading ADR-0084…
ADR-0084docs/status/decisions/0084-scalar-system-and-queue-operations.mde068992fa81e2c4ac46e492391a2f784141d68e041bf0b9e0586c37217d1e08c{
"classification": [
"alu"
],
"documentation": "docs/scalar/alu/BIC.md",
"id": "PTO-SCALAR-BIC",
"instruction_contract": {
"artifact": "spec/evidence/instruction-contract-closure.json",
"mnemonic": "BIC",
"ndf_clause": "PTO-INST-SCALAR-BIC"
},
"mnemonic": "BIC",
"readiness_subjects": [
"ADR-0025",
"ADR-0026",
"ADR-0059",
"ADR-0084"
],
"semantic_tests": [
"PTO-AVS-SCALAR-BIC-READINESS-001",
"PTO-AVS-SCALAR-BIC-SELECTORS-001",
"PTO-AVS-SCALAR-BIC-WRAP-001"
],
"source": "asl/scalar/alu/BIC.asl",
"surface": "scalar",
"tests": [
"PTO-AVS-SCALAR-BIC-DECODE-001",
"PTO-AVS-SCALAR-BIC-READINESS-001",
"PTO-AVS-SCALAR-BIC-SELECTORS-001",
"PTO-AVS-SCALAR-BIC-WRAP-001"
]
}0.58.5 · 候选发布7dc8b7e5b121d2b2499a2273bebff29e2cd8681206d35a2843a86fed4b03d5cd2c261c00e72e28b14f1eec30a2484666f7c4e7b0346077f9020a65f9963a4fcc3ec6c7d1ff85485b58648c09a864b45e0e611543asl/scalar/alu/BIC.aslasl/scalar/alu/BIC.aslasl/scalar/alu/BIC.asl