Icestorm: LDRSB (register, uxtw, 32-bit) measurements

Code:

  ldrsb w0, [x6, w7, uxtw]

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	654	1027	1	1026	1000	8166	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000
1004	543	1001	1	1000	1000	8040	1000	1000	2000	1	1000

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

Chain cycles: 3

Code:

  ldrsb w0, [x6, w7, uxtw]
  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)	ldst uops in schedulers (5b)	dispatch uop (78)	map int uop (7c)	map ldst uop (7d)	map simd uop (7e)	map int uop inputs (7f)	map ldst uop inputs (80)	map simd uop inputs (81)	? int output thing (e9)	? ldst retires (ed)	? simd retires (ee)	? int retires (ef)
40206	70273	40116	30113	10003	30162	10003	1859437	693831	0	40106	30210	10004	0	60220	20008	0	30003	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	30002	10000	0	30100
40204	70040	40102	30102	10000	30103	10003	1859392	693993	0	40106	30212	10004	0	60224	20008	0	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	70164	40018	30017	10001	30040	10003	1859677	693716	40016	30030	10004	60020	20000	30003	10000	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70056	40013	30013	10000	30010	10000	1859787	694767	40010	30020	10000	60020	20000	30003	10000	30010
40025	70165	40021	30019	10002	30045	10660	1897182	714707	41671	31415	10765	60020	20000	30003	10000	30010
40024	70052	40013	30013	10000	30010	10000	1859733	694745	40010	30020	10000	60020	20000	30003	10000	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010
40024	70054	40013	30013	10000	30010	10000	1859949	694833	40010	30020	10000	60020	20000	30003	10000	30010
40024	70049	40013	30013	10000	30010	10000	1859706	694734	40010	30020	10000	60020	20000	30003	10000	30010

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

Chain cycles: 3

Code:

  ldrsb w0, [x6, w7, uxtw]
  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): 4.0049

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)
40205	70152	40108	30107	10001	30130	10003	1859587	693941	40106	30210	10004	60220	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10015	1860169	694262	40150	30247	10017	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100
40204	70049	40103	30103	10000	30103	10003	1859635	694083	40106	30212	10004	60224	20008	30003	10000	30100

1000 unrolls and 10 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)
40025	70333	40018	30017	10001	30040	10003	1859623	693696	40016	30030	10004	60020	20000	30003	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40025	70070	40020	30018	10002	30045	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70040	40012	30012	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30003	10000	30010
40024	70043	40012	30012	10000	30010	10000	1859787	694776	40010	30020	10000	60020	20000	30002	10000	30010

Test 4: throughput

Count: 8

Code:

  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]
  ldrsb w0, [x6, w7, uxtw]

Initialization

  mov x7, 8

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5007

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	40218	80125	101	80024	100	80008	300	248190	80108	200	80012	200	160024	1	80000	100
80204	40059	80105	101	80004	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100
80204	40052	80101	101	80000	100	80008	300	640196	80108	200	80012	200	160024	1	80000	100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.5007

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	40519	80037	11	80026	10	80008	30	400262	80018	20	80012	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	641894	80010	20	80000	20	160000	1	80000	10
80024	40072	80011	11	80000	10	80000	30	640382	80010	20	80000	20	160000	1	80000	10
80024	40054	80011	11	80000	10	80000	30	640238	80010	20	80000	20	160000	1	80000	10

LDRSB (register, uxtw, 32-bit)

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