Program 18: Dependent ALU chain¶
Program catalogue · Instruction reference · Executable reference
Purpose¶
Provide an adjacent read-after-write dependency chain for later forwarding and throughput comparisons.
This is one of the six workload fixtures. This page specifies its instructions and architectural result; pipeline cycles, stalls, and throughput are implementation-specific and are not established by this reference run.
Setup¶
| Property | Value |
|---|---|
| Benchmark workload ID | program-18 |
| Headless selection | --program 18 |
| Visualizer scenario | rv32i-program18 |
| Registered test | RV32ISingleCycleSystemTest/program-18 |
| Instruction image | 66 words, starting at 0x00000000; last word at 0x00000104 |
| Initial state | PC = 0x00000000; all registers zero; neither halted nor trapped |
| Memories | Separate instruction and data memories, 256 KiB each; unlisted data bytes zero |
| Start address | Bytes, in increasing address order |
|---|---|
| None | — |
The table lists the complete preloaded data image, not instruction bytes. No data image is required.
| Register | Role established by the program |
|---|---|
x1 |
Single accumulator, starting at 1 |
The shared setup describes reset, loading, and the behavioral-core selection. These hand-written programs do not use the standard ABI stack.
Assembly¶
Every instruction word is shown, including words that a trap or branch may prevent from executing. Address and word comments identify the exact fixture image. The repeated blocks are fully expanded; there are no omitted instructions or runtime loop directives.
addi x1, x0, 1 # 0x00000000 | 0x00100093
addi x1, x1, 1 # 0x00000004 | 0x00108093
addi x1, x1, 1 # 0x00000008 | 0x00108093
addi x1, x1, 1 # 0x0000000C | 0x00108093
addi x1, x1, 1 # 0x00000010 | 0x00108093
addi x1, x1, 1 # 0x00000014 | 0x00108093
addi x1, x1, 1 # 0x00000018 | 0x00108093
addi x1, x1, 1 # 0x0000001C | 0x00108093
addi x1, x1, 1 # 0x00000020 | 0x00108093
addi x1, x1, 1 # 0x00000024 | 0x00108093
addi x1, x1, 1 # 0x00000028 | 0x00108093
addi x1, x1, 1 # 0x0000002C | 0x00108093
addi x1, x1, 1 # 0x00000030 | 0x00108093
addi x1, x1, 1 # 0x00000034 | 0x00108093
addi x1, x1, 1 # 0x00000038 | 0x00108093
addi x1, x1, 1 # 0x0000003C | 0x00108093
addi x1, x1, 1 # 0x00000040 | 0x00108093
addi x1, x1, 1 # 0x00000044 | 0x00108093
addi x1, x1, 1 # 0x00000048 | 0x00108093
addi x1, x1, 1 # 0x0000004C | 0x00108093
addi x1, x1, 1 # 0x00000050 | 0x00108093
addi x1, x1, 1 # 0x00000054 | 0x00108093
addi x1, x1, 1 # 0x00000058 | 0x00108093
addi x1, x1, 1 # 0x0000005C | 0x00108093
addi x1, x1, 1 # 0x00000060 | 0x00108093
addi x1, x1, 1 # 0x00000064 | 0x00108093
addi x1, x1, 1 # 0x00000068 | 0x00108093
addi x1, x1, 1 # 0x0000006C | 0x00108093
addi x1, x1, 1 # 0x00000070 | 0x00108093
addi x1, x1, 1 # 0x00000074 | 0x00108093
addi x1, x1, 1 # 0x00000078 | 0x00108093
addi x1, x1, 1 # 0x0000007C | 0x00108093
addi x1, x1, 1 # 0x00000080 | 0x00108093
addi x1, x1, 1 # 0x00000084 | 0x00108093
addi x1, x1, 1 # 0x00000088 | 0x00108093
addi x1, x1, 1 # 0x0000008C | 0x00108093
addi x1, x1, 1 # 0x00000090 | 0x00108093
addi x1, x1, 1 # 0x00000094 | 0x00108093
addi x1, x1, 1 # 0x00000098 | 0x00108093
addi x1, x1, 1 # 0x0000009C | 0x00108093
addi x1, x1, 1 # 0x000000A0 | 0x00108093
addi x1, x1, 1 # 0x000000A4 | 0x00108093
addi x1, x1, 1 # 0x000000A8 | 0x00108093
addi x1, x1, 1 # 0x000000AC | 0x00108093
addi x1, x1, 1 # 0x000000B0 | 0x00108093
addi x1, x1, 1 # 0x000000B4 | 0x00108093
addi x1, x1, 1 # 0x000000B8 | 0x00108093
addi x1, x1, 1 # 0x000000BC | 0x00108093
addi x1, x1, 1 # 0x000000C0 | 0x00108093
addi x1, x1, 1 # 0x000000C4 | 0x00108093
addi x1, x1, 1 # 0x000000C8 | 0x00108093
addi x1, x1, 1 # 0x000000CC | 0x00108093
addi x1, x1, 1 # 0x000000D0 | 0x00108093
addi x1, x1, 1 # 0x000000D4 | 0x00108093
addi x1, x1, 1 # 0x000000D8 | 0x00108093
addi x1, x1, 1 # 0x000000DC | 0x00108093
addi x1, x1, 1 # 0x000000E0 | 0x00108093
addi x1, x1, 1 # 0x000000E4 | 0x00108093
addi x1, x1, 1 # 0x000000E8 | 0x00108093
addi x1, x1, 1 # 0x000000EC | 0x00108093
addi x1, x1, 1 # 0x000000F0 | 0x00108093
addi x1, x1, 1 # 0x000000F4 | 0x00108093
addi x1, x1, 1 # 0x000000F8 | 0x00108093
addi x1, x1, 1 # 0x000000FC | 0x00108093
addi x1, x1, 1 # 0x00000100 | 0x00108093
ebreak # 0x00000104 | 0x00100073
Execution¶
- Initialize
x1=1. - Execute 64 unrolled copies of
addi x1, x1, 1. Every instruction consumes the result of its immediate predecessor. - The final value is 65. EBREAK makes the total
1 + 64 + 1 = 66attempts.
Unlike Program 17, all updates share one register. There is still no branch loop and no memory traffic. Matching this result establishes instruction effects, not whether a later pipeline avoids stalls.
Expected result¶
These are the fixture's explicit final-state assertions. Unlisted registers are not implicitly zero; their values follow the assembly. The store table enumerates every written byte, including zero-valued writes.
| Item | Expected value | Meaning |
|---|---|---|
x1 |
0x00000041 |
Single accumulator, starting at 1 |
PC |
0x00000104 |
EBREAK address |
Attempts |
66 | Checkpoints I0–I65 |
HALTED |
1 | Project halt |
TRAPPED |
0 | No exception |
TRAP_CAUSE |
0 | None, a project enum code |
| Start address | Bytes, in increasing address order |
|---|---|
| None | — |
No data writes occur; the initial data image is unchanged. The repeated assembly is fully expanded so every loaded instruction address can be matched to a checkpoint.
Simulation and checkpoints¶
For a headless functional check, run build/rv32i_experiment --core single --program 18 --period 4000 --max-cycles 4096 --allocation-limit-mib 512. Select baseline or advanced for the same fixture on another core; add --fidelity reference for the structural-datapath reference profile. The explicit period is a scheduling choice, not a performance result. Use the campaign procedure for clock-certified measurements.
All 66 instruction attempts are included, with absolute simulator time and checkpoint number. The terminating EBREAK is included. The table is scrollable in both directions. Observation conventions distinguish these attempts from loaded word addresses and hardware cycles.
All 66 instruction-attempt checkpoints of RV32ISingleCycleSystemTest/program-18, with a behavioral core. Times are absolute simulator units, not milliseconds or an ISA latency.
| Checkpoint | Time | Instruction / address | Expected architectural effects |
|---|---|---|---|
| I0 | 7080 | ADDI @ 0x00000000 | raw=0x00100093, pc_after=0x00000004, wb=x1=0x00000001, mem=None, flow=next |
| I1 | 11080 | ADDI @ 0x00000004 | raw=0x00108093, pc_after=0x00000008, wb=x1=0x00000002, mem=None, flow=next |
| I2 | 15080 | ADDI @ 0x00000008 | raw=0x00108093, pc_after=0x0000000c, wb=x1=0x00000003, mem=None, flow=next |
| I3 | 19080 | ADDI @ 0x0000000c | raw=0x00108093, pc_after=0x00000010, wb=x1=0x00000004, mem=None, flow=next |
| I4 | 23080 | ADDI @ 0x00000010 | raw=0x00108093, pc_after=0x00000014, wb=x1=0x00000005, mem=None, flow=next |
| I5 | 27080 | ADDI @ 0x00000014 | raw=0x00108093, pc_after=0x00000018, wb=x1=0x00000006, mem=None, flow=next |
| I6 | 31080 | ADDI @ 0x00000018 | raw=0x00108093, pc_after=0x0000001c, wb=x1=0x00000007, mem=None, flow=next |
| I7 | 35080 | ADDI @ 0x0000001c | raw=0x00108093, pc_after=0x00000020, wb=x1=0x00000008, mem=None, flow=next |
| I8 | 39080 | ADDI @ 0x00000020 | raw=0x00108093, pc_after=0x00000024, wb=x1=0x00000009, mem=None, flow=next |
| I9 | 43080 | ADDI @ 0x00000024 | raw=0x00108093, pc_after=0x00000028, wb=x1=0x0000000a, mem=None, flow=next |
| I10 | 47080 | ADDI @ 0x00000028 | raw=0x00108093, pc_after=0x0000002c, wb=x1=0x0000000b, mem=None, flow=next |
| I11 | 51080 | ADDI @ 0x0000002c | raw=0x00108093, pc_after=0x00000030, wb=x1=0x0000000c, mem=None, flow=next |
| I12 | 55080 | ADDI @ 0x00000030 | raw=0x00108093, pc_after=0x00000034, wb=x1=0x0000000d, mem=None, flow=next |
| I13 | 59080 | ADDI @ 0x00000034 | raw=0x00108093, pc_after=0x00000038, wb=x1=0x0000000e, mem=None, flow=next |
| I14 | 63080 | ADDI @ 0x00000038 | raw=0x00108093, pc_after=0x0000003c, wb=x1=0x0000000f, mem=None, flow=next |
| I15 | 67080 | ADDI @ 0x0000003c | raw=0x00108093, pc_after=0x00000040, wb=x1=0x00000010, mem=None, flow=next |
| I16 | 71080 | ADDI @ 0x00000040 | raw=0x00108093, pc_after=0x00000044, wb=x1=0x00000011, mem=None, flow=next |
| I17 | 75080 | ADDI @ 0x00000044 | raw=0x00108093, pc_after=0x00000048, wb=x1=0x00000012, mem=None, flow=next |
| I18 | 79080 | ADDI @ 0x00000048 | raw=0x00108093, pc_after=0x0000004c, wb=x1=0x00000013, mem=None, flow=next |
| I19 | 83080 | ADDI @ 0x0000004c | raw=0x00108093, pc_after=0x00000050, wb=x1=0x00000014, mem=None, flow=next |
| I20 | 87080 | ADDI @ 0x00000050 | raw=0x00108093, pc_after=0x00000054, wb=x1=0x00000015, mem=None, flow=next |
| I21 | 91080 | ADDI @ 0x00000054 | raw=0x00108093, pc_after=0x00000058, wb=x1=0x00000016, mem=None, flow=next |
| I22 | 95080 | ADDI @ 0x00000058 | raw=0x00108093, pc_after=0x0000005c, wb=x1=0x00000017, mem=None, flow=next |
| I23 | 99080 | ADDI @ 0x0000005c | raw=0x00108093, pc_after=0x00000060, wb=x1=0x00000018, mem=None, flow=next |
| I24 | 103080 | ADDI @ 0x00000060 | raw=0x00108093, pc_after=0x00000064, wb=x1=0x00000019, mem=None, flow=next |
| I25 | 107080 | ADDI @ 0x00000064 | raw=0x00108093, pc_after=0x00000068, wb=x1=0x0000001a, mem=None, flow=next |
| I26 | 111080 | ADDI @ 0x00000068 | raw=0x00108093, pc_after=0x0000006c, wb=x1=0x0000001b, mem=None, flow=next |
| I27 | 115080 | ADDI @ 0x0000006c | raw=0x00108093, pc_after=0x00000070, wb=x1=0x0000001c, mem=None, flow=next |
| I28 | 119080 | ADDI @ 0x00000070 | raw=0x00108093, pc_after=0x00000074, wb=x1=0x0000001d, mem=None, flow=next |
| I29 | 123080 | ADDI @ 0x00000074 | raw=0x00108093, pc_after=0x00000078, wb=x1=0x0000001e, mem=None, flow=next |
| I30 | 127080 | ADDI @ 0x00000078 | raw=0x00108093, pc_after=0x0000007c, wb=x1=0x0000001f, mem=None, flow=next |
| I31 | 131080 | ADDI @ 0x0000007c | raw=0x00108093, pc_after=0x00000080, wb=x1=0x00000020, mem=None, flow=next |
| I32 | 135080 | ADDI @ 0x00000080 | raw=0x00108093, pc_after=0x00000084, wb=x1=0x00000021, mem=None, flow=next |
| I33 | 139080 | ADDI @ 0x00000084 | raw=0x00108093, pc_after=0x00000088, wb=x1=0x00000022, mem=None, flow=next |
| I34 | 143080 | ADDI @ 0x00000088 | raw=0x00108093, pc_after=0x0000008c, wb=x1=0x00000023, mem=None, flow=next |
| I35 | 147080 | ADDI @ 0x0000008c | raw=0x00108093, pc_after=0x00000090, wb=x1=0x00000024, mem=None, flow=next |
| I36 | 151080 | ADDI @ 0x00000090 | raw=0x00108093, pc_after=0x00000094, wb=x1=0x00000025, mem=None, flow=next |
| I37 | 155080 | ADDI @ 0x00000094 | raw=0x00108093, pc_after=0x00000098, wb=x1=0x00000026, mem=None, flow=next |
| I38 | 159080 | ADDI @ 0x00000098 | raw=0x00108093, pc_after=0x0000009c, wb=x1=0x00000027, mem=None, flow=next |
| I39 | 163080 | ADDI @ 0x0000009c | raw=0x00108093, pc_after=0x000000a0, wb=x1=0x00000028, mem=None, flow=next |
| I40 | 167080 | ADDI @ 0x000000a0 | raw=0x00108093, pc_after=0x000000a4, wb=x1=0x00000029, mem=None, flow=next |
| I41 | 171080 | ADDI @ 0x000000a4 | raw=0x00108093, pc_after=0x000000a8, wb=x1=0x0000002a, mem=None, flow=next |
| I42 | 175080 | ADDI @ 0x000000a8 | raw=0x00108093, pc_after=0x000000ac, wb=x1=0x0000002b, mem=None, flow=next |
| I43 | 179080 | ADDI @ 0x000000ac | raw=0x00108093, pc_after=0x000000b0, wb=x1=0x0000002c, mem=None, flow=next |
| I44 | 183080 | ADDI @ 0x000000b0 | raw=0x00108093, pc_after=0x000000b4, wb=x1=0x0000002d, mem=None, flow=next |
| I45 | 187080 | ADDI @ 0x000000b4 | raw=0x00108093, pc_after=0x000000b8, wb=x1=0x0000002e, mem=None, flow=next |
| I46 | 191080 | ADDI @ 0x000000b8 | raw=0x00108093, pc_after=0x000000bc, wb=x1=0x0000002f, mem=None, flow=next |
| I47 | 195080 | ADDI @ 0x000000bc | raw=0x00108093, pc_after=0x000000c0, wb=x1=0x00000030, mem=None, flow=next |
| I48 | 199080 | ADDI @ 0x000000c0 | raw=0x00108093, pc_after=0x000000c4, wb=x1=0x00000031, mem=None, flow=next |
| I49 | 203080 | ADDI @ 0x000000c4 | raw=0x00108093, pc_after=0x000000c8, wb=x1=0x00000032, mem=None, flow=next |
| I50 | 207080 | ADDI @ 0x000000c8 | raw=0x00108093, pc_after=0x000000cc, wb=x1=0x00000033, mem=None, flow=next |
| I51 | 211080 | ADDI @ 0x000000cc | raw=0x00108093, pc_after=0x000000d0, wb=x1=0x00000034, mem=None, flow=next |
| I52 | 215080 | ADDI @ 0x000000d0 | raw=0x00108093, pc_after=0x000000d4, wb=x1=0x00000035, mem=None, flow=next |
| I53 | 219080 | ADDI @ 0x000000d4 | raw=0x00108093, pc_after=0x000000d8, wb=x1=0x00000036, mem=None, flow=next |
| I54 | 223080 | ADDI @ 0x000000d8 | raw=0x00108093, pc_after=0x000000dc, wb=x1=0x00000037, mem=None, flow=next |
| I55 | 227080 | ADDI @ 0x000000dc | raw=0x00108093, pc_after=0x000000e0, wb=x1=0x00000038, mem=None, flow=next |
| I56 | 231080 | ADDI @ 0x000000e0 | raw=0x00108093, pc_after=0x000000e4, wb=x1=0x00000039, mem=None, flow=next |
| I57 | 235080 | ADDI @ 0x000000e4 | raw=0x00108093, pc_after=0x000000e8, wb=x1=0x0000003a, mem=None, flow=next |
| I58 | 239080 | ADDI @ 0x000000e8 | raw=0x00108093, pc_after=0x000000ec, wb=x1=0x0000003b, mem=None, flow=next |
| I59 | 243080 | ADDI @ 0x000000ec | raw=0x00108093, pc_after=0x000000f0, wb=x1=0x0000003c, mem=None, flow=next |
| I60 | 247080 | ADDI @ 0x000000f0 | raw=0x00108093, pc_after=0x000000f4, wb=x1=0x0000003d, mem=None, flow=next |
| I61 | 251080 | ADDI @ 0x000000f4 | raw=0x00108093, pc_after=0x000000f8, wb=x1=0x0000003e, mem=None, flow=next |
| I62 | 255080 | ADDI @ 0x000000f8 | raw=0x00108093, pc_after=0x000000fc, wb=x1=0x0000003f, mem=None, flow=next |
| I63 | 259080 | ADDI @ 0x000000fc | raw=0x00108093, pc_after=0x00000100, wb=x1=0x00000040, mem=None, flow=next |
| I64 | 263080 | ADDI @ 0x00000100 | raw=0x00108093, pc_after=0x00000104, wb=x1=0x00000041, mem=None, flow=next |
| I65 | 267080 | EBREAK @ 0x00000104 | raw=0x00100073, pc_after=0x00000104, wb=None, mem=None, flow=next, halted=true |