# ISA Support Matrix

## Target ISA String

```
RV64GCZicsr_Zifencei
```

Equivalent to `RV64IMAFDCZicsr_Zifencei`

---

## Extension Implementation Status

| Extension | Full Name | Status | Description |
|---|---|---|---|
| **I** | Base Integer (RV64I) | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64i`) |
| **M** | Multiply/Divide | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64im`) |
| **A** | Atomic | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64ia`) |
| **F** | Single-Precision Float | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64if`) |
| **D** | Double-Precision Float | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64id`) |
| **C** | Compressed | 🟢 Implemented | Strict ACT4 compliance suite passes (`rv64ic`) |
| **Zicsr** | CSR Instructions | 🟢 Implemented | Full CSR unit with delegation, FCSR, and dedicated testbench ([rtl/core/csr_unit.sv](rtl/core/csr_unit.sv), [tb/unit/tb_csr.cc](tb/unit/tb_csr.cc)) |
| **Zifencei** | Instruction Fence | 🟢 Implemented | Included in strict ACT4 passing suites |

Privilege-related tests (`S`, `Sm`) also pass through `rv64priv` strict suite.

---

## Recent Progress Highlights (2026-04)

- `riscv-arch-test` ACT4 flow integrated in `scripts/run_compliance.py`.
- Dedicated `tb/compliance/compliance_runner.cc` executes ELF tests and dumps signatures.
- Strict suite passes with reference comparison enabled (`--require-reference`):
	- `rv64i` (51/51)
	- `rv64im` (64/64)
	- `rv64ia` (51/51)
	- `rv64ic` (51/51)
	- `rv64if` (133/133)
	- `rv64id` (165/165)
	- `rv64priv` (2/2)
	- `rv64full` aggregate (262/262)

## Detailed Instruction Tables

The detailed per-instruction checklist sections below are retained as reference,
but are not the primary source of truth for completion status at this stage.
Current completion is determined by strict ACT4 suite pass results listed above.

---

## RV64I Instruction List

### R-type Arithmetic/Logic
| Instruction | Operation | Status |
|---|---|---|
| ADD | rd = rs1 + rs2 | ⬜ |
| SUB | rd = rs1 - rs2 | ⬜ |
| AND | rd = rs1 & rs2 | ⬜ |
| OR | rd = rs1 \| rs2 | ⬜ |
| XOR | rd = rs1 ^ rs2 | ⬜ |
| SLL | rd = rs1 << rs2[5:0] | ⬜ |
| SRL | rd = rs1 >> rs2[5:0] (logical) | ⬜ |
| SRA | rd = rs1 >> rs2[5:0] (arith) | ⬜ |
| SLT | rd = (rs1 < rs2) ? 1 : 0 (signed) | ⬜ |
| SLTU | rd = (rs1 < rs2) ? 1 : 0 (unsigned) | ⬜ |

### R-type RV64 Word Operations
| Instruction | Operation | Status |
|---|---|---|
| ADDW | rd = sext((rs1+rs2)[31:0]) | ⬜ |
| SUBW | rd = sext((rs1-rs2)[31:0]) | ⬜ |
| SLLW | rd = sext((rs1 << rs2[4:0])[31:0]) | ⬜ |
| SRLW | rd = sext((rs1[31:0] >> rs2[4:0])) | ⬜ |
| SRAW | rd = sext((rs1[31:0] >>> rs2[4:0])) | ⬜ |

### I-type Immediate Arithmetic
| Instruction | Operation | Status |
|---|---|---|
| ADDI | rd = rs1 + imm | ⬜ |
| ANDI | rd = rs1 & imm | ⬜ |
| ORI | rd = rs1 \| imm | ⬜ |
| XORI | rd = rs1 ^ imm | ⬜ |
| SLLI | rd = rs1 << shamt[5:0] | ⬜ |
| SRLI | rd = rs1 >> shamt[5:0] (logical) | ⬜ |
| SRAI | rd = rs1 >> shamt[5:0] (arith) | ⬜ |
| SLTI | rd = (rs1 < imm) ? 1 : 0 (signed) | ⬜ |
| SLTIU | rd = (rs1 < imm) ? 1 : 0 (unsigned) | ⬜ |
| ADDIW | rd = sext((rs1+imm)[31:0]) | ⬜ |
| SLLIW | rd = sext((rs1 << shamt[4:0])[31:0]) | ⬜ |
| SRLIW | rd = sext((rs1[31:0] >> shamt[4:0])) | ⬜ |
| SRAIW | rd = sext((rs1[31:0] >>> shamt[4:0])) | ⬜ |

### Load
| Instruction | Width | Sign Extension | Status |
|---|---|---|---|
| LB | 8-bit | Signed | ⬜ |
| LBU | 8-bit | Zero-extended | ⬜ |
| LH | 16-bit | Signed | ⬜ |
| LHU | 16-bit | Zero-extended | ⬜ |
| LW | 32-bit | Signed | ⬜ |
| LWU | 32-bit | Zero-extended | ⬜ |
| LD | 64-bit | — | ⬜ |

### Store
| Instruction | Width | Status |
|---|---|---|
| SB | 8-bit | ⬜ |
| SH | 16-bit | ⬜ |
| SW | 32-bit | ⬜ |
| SD | 64-bit | ⬜ |

### Branch
| Instruction | Condition | Status |
|---|---|---|
| BEQ | rs1 == rs2 | ⬜ |
| BNE | rs1 != rs2 | ⬜ |
| BLT | rs1 < rs2 (signed) | ⬜ |
| BGE | rs1 >= rs2 (signed) | ⬜ |
| BLTU | rs1 < rs2 (unsigned) | ⬜ |
| BGEU | rs1 >= rs2 (unsigned) | ⬜ |

### Upper Immediate / Jump
| Instruction | Operation | Status |
|---|---|---|
| LUI | rd = imm << 12 | ⬜ |
| AUIPC | rd = pc + (imm << 12) | ⬜ |
| JAL | rd = pc+4; pc = pc + imm | ⬜ |
| JALR | rd = pc+4; pc = (rs1 + imm) & ~1 | ⬜ |

### System
| Instruction | Status |
|---|---|
| ECALL | ⬜ |
| EBREAK | ⬜ |
| MRET | ⬜ |
| SRET | ⬜ |
| WFI | ⬜ |
| FENCE | ⬜ |
| FENCE.I | ⬜ |
| SFENCE.VMA | ⬜ |

---

## M Extension (Multiply/Divide)

| Instruction | Operation | Status |
|---|---|---|
| MUL | rd = (rs1 × rs2)[63:0] | ⬜ |
| MULH | rd = (rs1 × rs2)[127:64] signed | ⬜ |
| MULHSU | rd = (rs1 × rs2)[127:64] signed×unsigned | ⬜ |
| MULHU | rd = (rs1 × rs2)[127:64] unsigned | ⬜ |
| DIV | rd = rs1 / rs2 signed | ⬜ |
| DIVU | rd = rs1 / rs2 unsigned | ⬜ |
| REM | rd = rs1 % rs2 signed | ⬜ |
| REMU | rd = rs1 % rs2 unsigned | ⬜ |
| MULW | rd = sext((rs1×rs2)[31:0]) | ⬜ |
| DIVW / DIVUW | 32-bit division | ⬜ |
| REMW / REMUW | 32-bit remainder | ⬜ |

---

## A Extension (Atomic Instructions)

| Instruction | Status |
|---|---|
| LR.W / LR.D | ⬜ |
| SC.W / SC.D | ⬜ |
| AMOSWAP.W/D | ⬜ |
| AMOADD.W/D | ⬜ |
| AMOAND.W/D | ⬜ |
| AMOOR.W/D | ⬜ |
| AMOXOR.W/D | ⬜ |
| AMOMAX[U].W/D | ⬜ |
| AMOMIN[U].W/D | ⬜ |

---

## F/D Extension (Floating-Point)

| Category | F (32-bit) Instructions | D (64-bit) Instructions | Status |
|---|---|---|---|
| Load/Store | FLW, FSW | FLD, FSD | ⬜ |
| Arithmetic | FADD.S, FSUB.S, FMUL.S, FDIV.S, FSQRT.S | FADD.D, ... | ⬜ |
| Fused Multiply-Add | FMADD.S, FMSUB.S, FNMADD.S, FNMSUB.S | FMADD.D, ... | ⬜ |
| Sign Manipulation | FSGNJ[N/X].S | FSGNJ[N/X].D | ⬜ |
| Compare | FEQ.S, FLT.S, FLE.S | FEQ.D, FLT.D, FLE.D | ⬜ |
| Classify | FCLASS.S | FCLASS.D | ⬜ |
| Conversion | FCVT.W/WU/L/LU.S, FCVT.S.W/WU/L/LU | FCVT.*.D | ⬜ |
| F↔D Conversion | — | FCVT.S.D, FCVT.D.S | ⬜ |
| Move | FMV.X.W, FMV.W.X | FMV.X.D, FMV.D.X | ⬜ |
| MIN/MAX | FMIN.S, FMAX.S | FMIN.D, FMAX.D | ⬜ |

### Floating-Point CSRs
| CSR | Address | Description |
|---|---|---|
| `fflags` | 0x001 | Floating-point exception flags (NV, DZ, OF, UF, NX) |
| `frm` | 0x002 | Floating-point rounding mode |
| `fcsr` | 0x003 | fflags + frm combined |

---

## C Extension (Compressed Instructions)

16-bit encoded subset of common instructions, improving code density. Requires handling 16/32-bit mixed instruction stream alignment at the IF stage.

| Quadrant | Selected Instructions | Status |
|---|---|---|
| C0 | C.LW, C.LD, C.SW, C.SD, C.ADDI4SPN | ⬜ |
| C1 | C.ADDI, C.LI, C.LUI, C.SRLI, C.SRAI, C.ANDI, C.SUB, C.XOR, C.OR, C.AND, C.J, C.BEQZ, C.BNEZ | ⬜ |
| C2 | C.SLLI, C.LDSP, C.LWSP, C.JR, C.MV, C.JALR, C.ADD, C.SDSP, C.SWSP | ⬜ |

---

## Zicsr Instructions

| Instruction | Operation | Status |
|---|---|---|
| CSRRW | t=CSR; CSR=rs1; rd=t | ⬜ |
| CSRRS | t=CSR; CSR=t\|rs1; rd=t | ⬜ |
| CSRRC | t=CSR; CSR=t&~rs1; rd=t | ⬜ |
| CSRRWI | t=CSR; CSR=zimm; rd=t | ⬜ |
| CSRRSI | t=CSR; CSR=t\|zimm; rd=t | ⬜ |
| CSRRCI | t=CSR; CSR=t&~zimm; rd=t | ⬜ |