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

Code:

  ldrsb w0, [x6, w7, sxtw]

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	653	1027	1	1026	1000	8238	1000	1000	2000	1	1000
1004	554	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000
1004	547	1001	1	1000	1000	8112	1000	1000	2000	1	1000

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

Chain cycles: 3

Code:

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

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	70151	40108	30107	10001	30130	10003	1859539	693896	40106	30210	10004	60224	20008	30003	10000	30100
40204	70053	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
40205	70079	40111	30109	10002	30135	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

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	70288	40018	30017	10001	30040	10000	1859706	694734	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10015	1862095	694953	40060	30067	10017	60020	20000	30002	10000	30010
40024	70046	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10015	1859881	694776	40060	30067	10017	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1859517	694664	40010	30020	10000	60020	20000	30002	10000	30010
40024	70042	40012	30012	10000	30010	10000	1861596	695511	40010	30020	10000	60020	20000	30002	10000	30010

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

Chain cycles: 3

Code:

  ldrsb w0, [x6, w7, sxtw]
  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): 4.0047

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	70304	40108	30107	10001	30130	10003	1859701	693962	40106	30210	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859581	694063	40106	30212	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859581	694063	40106	30212	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859581	694063	40106	30212	10004	60224	20008	30003	10000	30100
40205	70084	40114	30112	10002	30137	10003	1860472	694426	40106	30212	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859608	694074	40106	30212	10004	60224	20008	30003	10000	30100
40204	70048	40103	30103	10000	30103	10003	1859635	694085	40106	30212	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10015	1859926	694142	40150	30247	10017	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859581	694063	40106	30212	10004	60224	20008	30003	10000	30100
40204	70047	40103	30103	10000	30103	10003	1859581	694063	40106	30212	10004	60224	20008	30003	10000	30100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 3 chain cycles): 4.0047

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	70161	40018	30017	10001	30040	10000	1859604	693654	40010	30020	10000	60114	20034	30008	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70051	40013	30013	10000	30010	10000	1859625	694710	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60098	20026	30008	10000	30010
40024	70047	40013	30013	10000	30010	10000	1859463	694644	40010	30020	10000	60020	20000	30002	10000	30010

Test 4: throughput

Count: 8

Code:

  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]
  ldrsb w0, [x6, w7, sxtw]

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	40167	80125	101	80024	100	80008	300	280262	80108	200	80012	200	160024	1	80000	100
80204	40064	80105	101	80004	100	80008	300	640142	80108	200	80012	200	160024	1	80000	100
80204	40050	80101	101	80000	100	80008	300	640142	80108	200	80012	200	160024	1	80000	100
80204	40049	80101	101	80000	100	80008	300	640142	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
80205	40345	80131	101	80030	100	80010	300	640208	80110	200	80014	200	160024	1	80000	100
80204	40045	80101	101	80000	100	80059	300	644914	80159	200	80072	200	160024	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

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	40257	80045	11	80034	10	80010	30	400142	80020	20	80014	20	160000	1	80000	10
80024	40058	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40047	80011	11	80000	10	80000	30	640112	80010	20	80000	20	160000	1	80000	10
80024	40061	80011	11	80000	10	80000	30	640562	80010	20	80000	20	160000	1	80000	10

LDRSB (register, sxtw, 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