Icestorm: LDRB (register) measurements

Code:

  ldrb w0, [x6, x7]

Initialization

  mov x7, #4
  mov x8, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.001

Load/store unit issues: 1.000

SIMD/FP unit issues: 0.000

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch ldst uop (58)	simd uops in schedulers (5a)	dispatch uop (78)	map ldst uop (7d)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)
1005	661	1027	1	1026	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000
1004	550	1001	1	1000	1000	8166	1000	1000	2000	1	1000

Test 2: Latency 1->2 (with chain penalty)

Chain cycles: 3

Code:

  ldrb w0, [x6, x7]
  eor x8, x8, x0
  eor x8, x8, x0
  add x6, x6, x8

Initialization

  mov x7, #4
  mov x8, 0

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 3 chain cycles): 4.0040

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? simd retires (ee)	? int retires (ef)
40205	70156	40108	30107	10001	30130	10003	1859344	693851	40106	30210	10004	60220	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	40106	30212	10004	60224	20008	30002	10000	0	30100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 3 chain cycles): 4.0049

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? int retires (ef)
40025	70265	40018	30017	10001	30040	10000	1859760	694756	40010	30020	10000	60020	20000	30003	10000	30010
40024	70058	40013	30013	10000	30010	10000	1859814	694778	40010	30020	10000	60020	20000	30003	10000	30010
40024	70059	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70052	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70050	40013	30013	10000	30010	10000	1859733	694745	40010	30020	10000	60020	20000	30003	10000	30010
40024	70051	40013	30013	10000	30010	10000	1859760	694756	40010	30020	10000	60122	20034	30009	10000	30010
40024	70051	40013	30013	10000	30010	10000	1859787	694767	40010	30020	10000	60020	20000	30003	10000	30010
40024	70052	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70053	40013	30013	10000	30010	10000	1859760	694755	40010	30020	10000	60020	20000	30003	10000	30010
40024	70052	40013	30013	10000	30010	10000	1859841	694789	40010	30020	10000	60020	20000	30003	10000	30010

Test 3: Latency 1->3 (with chain penalty)

Chain cycles: 3

Code:

  ldrb w0, [x6, x7]
  eor x8, x8, x0
  eor x8, x8, x0
  add x7, x7, x8

Initialization

  mov x7, #4
  mov x8, 0

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 3 chain cycles): 4.0040

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? int retires (ef)
40205	70153	40108	30107	10001	30130	10003	1859539	693896	40106	30210	10004	60220	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40205	70138	40110	30108	10002	30135	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100
40204	70042	40102	30102	10000	30103	10003	1859446	694013	40106	30212	10004	60224	20008	30002	10000	30100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 3 chain cycles): 4.0049

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? simd retires (ee)	? int retires (ef)
40025	70159	40018	30017	10001	30040	10003	1859677	693716	40016	30030	10004	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70173	40013	30013	10000	30010	10000	1859976	694843	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859760	694756	40010	30020	10000	60122	20034	30009	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	0	30010

Test 4: throughput

Count: 8

Code:

  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]
  ldrb w0, [x6, x7]

Initialization

  mov x7, 8

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5006

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? int retires (ef)
80205	40190	80131	101	80030	100	80008	300	280190	80108	200	80012	200	160028	1	80000	100
80204	40046	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80205	40098	80138	101	80037	100	80010	300	568362	80110	200	80014	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80008	300	640070	80108	200	80012	200	160024	1	80000	100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.5006

Recorded non-zero counters (first 10 of 64 runs)

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule ldst uop (55)	dispatch int uop (56)	dispatch ldst uop (58)	int uops in schedulers (59)	simd uops in schedulers (5a)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map int uop inputs (7f)	map ldst uop inputs (80)	? int output thing (e9)	? ldst retires (ed)	? int retires (ef)
80025	40283	80043	11	80032	10	80010	30	640208	80020	20	80014	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40166	80011	11	80000	10	80000	30	640562	80010	20	80000	20	160000	1	80000	10
80024	40066	80011	11	80000	10	80000	30	640346	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10
80024	40050	80011	11	80000	10	80000	30	640166	80010	20	80000	20	160000	1	80000	10

LDRB (register)

Test 1: uops

1000 unrolls and 1 iteration

Test 2: Latency 1->2 (with chain penalty)

100 unrolls and 100 iterations

1000 unrolls and 10 iterations

Test 3: Latency 1->3 (with chain penalty)

100 unrolls and 100 iterations

1000 unrolls and 10 iterations

Test 4: throughput

100 unrolls and 100 iterations

1000 unrolls and 10 iterations