Program 19: Repeated load-use pairs

Program catalogue · Instruction reference · Executable reference

Purpose

Provide an unrolled sequence where each arithmetic instruction immediately consumes a loaded value.

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-19
Headless selection	--program 19
Visualizer scenario	rv32i-program19
Registered test	RV32ISingleCycleSystemTest/program-19
Instruction image	67 words, starting at 0x00000000; last word at 0x00000108
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
0x00000100	07 00 00 00

The table lists the complete preloaded data image, not instruction bytes. Data values use little-endian byte order.

Register	Role established by the program
x1	Fixed source address 0x100
x2	Loaded word, always 7
x3	Accumulator

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, 0x100             # 0x00000000 | 0x10000093
addi x3, x0, 0                 # 0x00000004 | 0x00000193
lw x2, 0(x1)                   # 0x00000008 | 0x0000A103
add x3, x3, x2                 # 0x0000000C | 0x002181B3
lw x2, 0(x1)                   # 0x00000010 | 0x0000A103
add x3, x3, x2                 # 0x00000014 | 0x002181B3
lw x2, 0(x1)                   # 0x00000018 | 0x0000A103
add x3, x3, x2                 # 0x0000001C | 0x002181B3
lw x2, 0(x1)                   # 0x00000020 | 0x0000A103
add x3, x3, x2                 # 0x00000024 | 0x002181B3
lw x2, 0(x1)                   # 0x00000028 | 0x0000A103
add x3, x3, x2                 # 0x0000002C | 0x002181B3
lw x2, 0(x1)                   # 0x00000030 | 0x0000A103
add x3, x3, x2                 # 0x00000034 | 0x002181B3
lw x2, 0(x1)                   # 0x00000038 | 0x0000A103
add x3, x3, x2                 # 0x0000003C | 0x002181B3
lw x2, 0(x1)                   # 0x00000040 | 0x0000A103
add x3, x3, x2                 # 0x00000044 | 0x002181B3
lw x2, 0(x1)                   # 0x00000048 | 0x0000A103
add x3, x3, x2                 # 0x0000004C | 0x002181B3
lw x2, 0(x1)                   # 0x00000050 | 0x0000A103
add x3, x3, x2                 # 0x00000054 | 0x002181B3
lw x2, 0(x1)                   # 0x00000058 | 0x0000A103
add x3, x3, x2                 # 0x0000005C | 0x002181B3
lw x2, 0(x1)                   # 0x00000060 | 0x0000A103
add x3, x3, x2                 # 0x00000064 | 0x002181B3
lw x2, 0(x1)                   # 0x00000068 | 0x0000A103
add x3, x3, x2                 # 0x0000006C | 0x002181B3
lw x2, 0(x1)                   # 0x00000070 | 0x0000A103
add x3, x3, x2                 # 0x00000074 | 0x002181B3
lw x2, 0(x1)                   # 0x00000078 | 0x0000A103
add x3, x3, x2                 # 0x0000007C | 0x002181B3
lw x2, 0(x1)                   # 0x00000080 | 0x0000A103
add x3, x3, x2                 # 0x00000084 | 0x002181B3
lw x2, 0(x1)                   # 0x00000088 | 0x0000A103
add x3, x3, x2                 # 0x0000008C | 0x002181B3
lw x2, 0(x1)                   # 0x00000090 | 0x0000A103
add x3, x3, x2                 # 0x00000094 | 0x002181B3
lw x2, 0(x1)                   # 0x00000098 | 0x0000A103
add x3, x3, x2                 # 0x0000009C | 0x002181B3
lw x2, 0(x1)                   # 0x000000A0 | 0x0000A103
add x3, x3, x2                 # 0x000000A4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000A8 | 0x0000A103
add x3, x3, x2                 # 0x000000AC | 0x002181B3
lw x2, 0(x1)                   # 0x000000B0 | 0x0000A103
add x3, x3, x2                 # 0x000000B4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000B8 | 0x0000A103
add x3, x3, x2                 # 0x000000BC | 0x002181B3
lw x2, 0(x1)                   # 0x000000C0 | 0x0000A103
add x3, x3, x2                 # 0x000000C4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000C8 | 0x0000A103
add x3, x3, x2                 # 0x000000CC | 0x002181B3
lw x2, 0(x1)                   # 0x000000D0 | 0x0000A103
add x3, x3, x2                 # 0x000000D4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000D8 | 0x0000A103
add x3, x3, x2                 # 0x000000DC | 0x002181B3
lw x2, 0(x1)                   # 0x000000E0 | 0x0000A103
add x3, x3, x2                 # 0x000000E4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000E8 | 0x0000A103
add x3, x3, x2                 # 0x000000EC | 0x002181B3
lw x2, 0(x1)                   # 0x000000F0 | 0x0000A103
add x3, x3, x2                 # 0x000000F4 | 0x002181B3
lw x2, 0(x1)                   # 0x000000F8 | 0x0000A103
add x3, x3, x2                 # 0x000000FC | 0x002181B3
lw x2, 0(x1)                   # 0x00000100 | 0x0000A103
add x3, x3, x2                 # 0x00000104 | 0x002181B3
ebreak                         # 0x00000108 | 0x00100073

Execution

1. Set the pointer to 0x100 and the accumulator to zero. Data word 0x00000007 is preloaded at that address.
2. Execute 32 unrolled LW/ADD pairs. Each LW rereads the same address; its following ADD adds 7 to x3.
3. The total is 32 × 7 = 224, with 2 + 32 × 2 + 1 = 67 attempts including EBREAK.

There are no branch instructions or pointer updates, so this isolates the load-to-consumer pattern from loop control. Instruction and data addresses can overlap numerically because the fixture uses separate memories.

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	0x00000100	Fixed source address 0x100
x2	0x00000007	Loaded word, always 7
x3	0x000000E0	Accumulator
PC	0x00000108	EBREAK address
Attempts	67	Checkpoints I0–I66
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. Data memory is read but never written. The page documents the workload, not a fixed number of load-use stall cycles.

Simulation and checkpoints

For a headless functional check, run build/rv32i_experiment --core single --program 19 --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 67 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 67 instruction-attempt checkpoints of RV32ISingleCycleSystemTest/program-19, 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=0x10000093, pc_after=0x00000004, wb=x1=0x00000100, mem=None, flow=next
I1	11080	ADDI @ 0x00000004	raw=0x00000193, pc_after=0x00000008, wb=x3=0x00000000, mem=None, flow=next
I2	15080	LW @ 0x00000008	raw=0x0000a103, pc_after=0x0000000c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I3	19080	ADD @ 0x0000000c	raw=0x002181b3, pc_after=0x00000010, wb=x3=0x00000007, mem=None, flow=next
I4	23080	LW @ 0x00000010	raw=0x0000a103, pc_after=0x00000014, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I5	27080	ADD @ 0x00000014	raw=0x002181b3, pc_after=0x00000018, wb=x3=0x0000000e, mem=None, flow=next
I6	31080	LW @ 0x00000018	raw=0x0000a103, pc_after=0x0000001c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I7	35080	ADD @ 0x0000001c	raw=0x002181b3, pc_after=0x00000020, wb=x3=0x00000015, mem=None, flow=next
I8	39080	LW @ 0x00000020	raw=0x0000a103, pc_after=0x00000024, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I9	43080	ADD @ 0x00000024	raw=0x002181b3, pc_after=0x00000028, wb=x3=0x0000001c, mem=None, flow=next
I10	47080	LW @ 0x00000028	raw=0x0000a103, pc_after=0x0000002c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I11	51080	ADD @ 0x0000002c	raw=0x002181b3, pc_after=0x00000030, wb=x3=0x00000023, mem=None, flow=next
I12	55080	LW @ 0x00000030	raw=0x0000a103, pc_after=0x00000034, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I13	59080	ADD @ 0x00000034	raw=0x002181b3, pc_after=0x00000038, wb=x3=0x0000002a, mem=None, flow=next
I14	63080	LW @ 0x00000038	raw=0x0000a103, pc_after=0x0000003c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I15	67080	ADD @ 0x0000003c	raw=0x002181b3, pc_after=0x00000040, wb=x3=0x00000031, mem=None, flow=next
I16	71080	LW @ 0x00000040	raw=0x0000a103, pc_after=0x00000044, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I17	75080	ADD @ 0x00000044	raw=0x002181b3, pc_after=0x00000048, wb=x3=0x00000038, mem=None, flow=next
I18	79080	LW @ 0x00000048	raw=0x0000a103, pc_after=0x0000004c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I19	83080	ADD @ 0x0000004c	raw=0x002181b3, pc_after=0x00000050, wb=x3=0x0000003f, mem=None, flow=next
I20	87080	LW @ 0x00000050	raw=0x0000a103, pc_after=0x00000054, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I21	91080	ADD @ 0x00000054	raw=0x002181b3, pc_after=0x00000058, wb=x3=0x00000046, mem=None, flow=next
I22	95080	LW @ 0x00000058	raw=0x0000a103, pc_after=0x0000005c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I23	99080	ADD @ 0x0000005c	raw=0x002181b3, pc_after=0x00000060, wb=x3=0x0000004d, mem=None, flow=next
I24	103080	LW @ 0x00000060	raw=0x0000a103, pc_after=0x00000064, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I25	107080	ADD @ 0x00000064	raw=0x002181b3, pc_after=0x00000068, wb=x3=0x00000054, mem=None, flow=next
I26	111080	LW @ 0x00000068	raw=0x0000a103, pc_after=0x0000006c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I27	115080	ADD @ 0x0000006c	raw=0x002181b3, pc_after=0x00000070, wb=x3=0x0000005b, mem=None, flow=next
I28	119080	LW @ 0x00000070	raw=0x0000a103, pc_after=0x00000074, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I29	123080	ADD @ 0x00000074	raw=0x002181b3, pc_after=0x00000078, wb=x3=0x00000062, mem=None, flow=next
I30	127080	LW @ 0x00000078	raw=0x0000a103, pc_after=0x0000007c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I31	131080	ADD @ 0x0000007c	raw=0x002181b3, pc_after=0x00000080, wb=x3=0x00000069, mem=None, flow=next
I32	135080	LW @ 0x00000080	raw=0x0000a103, pc_after=0x00000084, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I33	139080	ADD @ 0x00000084	raw=0x002181b3, pc_after=0x00000088, wb=x3=0x00000070, mem=None, flow=next
I34	143080	LW @ 0x00000088	raw=0x0000a103, pc_after=0x0000008c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I35	147080	ADD @ 0x0000008c	raw=0x002181b3, pc_after=0x00000090, wb=x3=0x00000077, mem=None, flow=next
I36	151080	LW @ 0x00000090	raw=0x0000a103, pc_after=0x00000094, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I37	155080	ADD @ 0x00000094	raw=0x002181b3, pc_after=0x00000098, wb=x3=0x0000007e, mem=None, flow=next
I38	159080	LW @ 0x00000098	raw=0x0000a103, pc_after=0x0000009c, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I39	163080	ADD @ 0x0000009c	raw=0x002181b3, pc_after=0x000000a0, wb=x3=0x00000085, mem=None, flow=next
I40	167080	LW @ 0x000000a0	raw=0x0000a103, pc_after=0x000000a4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I41	171080	ADD @ 0x000000a4	raw=0x002181b3, pc_after=0x000000a8, wb=x3=0x0000008c, mem=None, flow=next
I42	175080	LW @ 0x000000a8	raw=0x0000a103, pc_after=0x000000ac, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I43	179080	ADD @ 0x000000ac	raw=0x002181b3, pc_after=0x000000b0, wb=x3=0x00000093, mem=None, flow=next
I44	183080	LW @ 0x000000b0	raw=0x0000a103, pc_after=0x000000b4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I45	187080	ADD @ 0x000000b4	raw=0x002181b3, pc_after=0x000000b8, wb=x3=0x0000009a, mem=None, flow=next
I46	191080	LW @ 0x000000b8	raw=0x0000a103, pc_after=0x000000bc, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I47	195080	ADD @ 0x000000bc	raw=0x002181b3, pc_after=0x000000c0, wb=x3=0x000000a1, mem=None, flow=next
I48	199080	LW @ 0x000000c0	raw=0x0000a103, pc_after=0x000000c4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I49	203080	ADD @ 0x000000c4	raw=0x002181b3, pc_after=0x000000c8, wb=x3=0x000000a8, mem=None, flow=next
I50	207080	LW @ 0x000000c8	raw=0x0000a103, pc_after=0x000000cc, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I51	211080	ADD @ 0x000000cc	raw=0x002181b3, pc_after=0x000000d0, wb=x3=0x000000af, mem=None, flow=next
I52	215080	LW @ 0x000000d0	raw=0x0000a103, pc_after=0x000000d4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I53	219080	ADD @ 0x000000d4	raw=0x002181b3, pc_after=0x000000d8, wb=x3=0x000000b6, mem=None, flow=next
I54	223080	LW @ 0x000000d8	raw=0x0000a103, pc_after=0x000000dc, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I55	227080	ADD @ 0x000000dc	raw=0x002181b3, pc_after=0x000000e0, wb=x3=0x000000bd, mem=None, flow=next
I56	231080	LW @ 0x000000e0	raw=0x0000a103, pc_after=0x000000e4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I57	235080	ADD @ 0x000000e4	raw=0x002181b3, pc_after=0x000000e8, wb=x3=0x000000c4, mem=None, flow=next
I58	239080	LW @ 0x000000e8	raw=0x0000a103, pc_after=0x000000ec, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I59	243080	ADD @ 0x000000ec	raw=0x002181b3, pc_after=0x000000f0, wb=x3=0x000000cb, mem=None, flow=next
I60	247080	LW @ 0x000000f0	raw=0x0000a103, pc_after=0x000000f4, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I61	251080	ADD @ 0x000000f4	raw=0x002181b3, pc_after=0x000000f8, wb=x3=0x000000d2, mem=None, flow=next
I62	255080	LW @ 0x000000f8	raw=0x0000a103, pc_after=0x000000fc, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I63	259080	ADD @ 0x000000fc	raw=0x002181b3, pc_after=0x00000100, wb=x3=0x000000d9, mem=None, flow=next
I64	263080	LW @ 0x00000100	raw=0x0000a103, pc_after=0x00000104, wb=x2=0x00000007, mem=Read Word @0x00000100 -> 0x00000007, flow=next
I65	267080	ADD @ 0x00000104	raw=0x002181b3, pc_after=0x00000108, wb=x3=0x000000e0, mem=None, flow=next
I66	271080	EBREAK @ 0x00000108	raw=0x00100073, pc_after=0x00000108, wb=None, mem=None, flow=next, halted=true

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