Apple Microarchitecture Research by Dougall Johnson

M1/A14 P-core (Firestorm): Overview | Base Instructions | SIMD and FP Instructions
M1/A14 E-core (Icestorm):  Overview | Base Instructions | SIMD and FP Instructions

FABS (scalar, H)

Test 1: uops

Code:

  fabs h0, h0

Initialization

  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.001

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

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

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule simd uop (54)	dispatch simd uop (57)	ldst uops in schedulers (5b)	dispatch uop (78)	map simd uop (7e)	map simd uop inputs (81)	? int output thing (e9)	? simd retires (ee)
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000
1004	2033	1001	1	1000	1000	50248	1000	1000	1000	1	1000

Test 2: Latency 1->2

Code:

  fabs h0, h0

Initialization

  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0033

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

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule simd uop (54)	dispatch int uop (56)	dispatch simd uop (57)	int uops in schedulers (59)	ldst uops in schedulers (5b)	dispatch uop (78)	map int uop (7c)	map simd uop (7e)	map int uop inputs (7f)	map simd uop inputs (81)	? int output thing (e9)	? simd retires (ee)	? int retires (ef)
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10006	200	10006	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10006	202	10046	2	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100
10204	20033	10101	101	10000	100	10000	300	509248	10100	200	10004	200	10004	1	10000	100

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0033

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

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule simd uop (54)	schedule ldst uop (55)	dispatch int uop (56)	dispatch simd uop (57)	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 simd uop inputs (81)	? int output thing (e9)	? simd retires (ee)	? int retires (ef)
10024	20033	10021	21	10000	0	20	10000	0	70	0	509247	10020	20	0	10006	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	65	0	509248	10020	20	0	10005	20	10006	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
22720	50470	23036	3436	17509	2091	3495	17535	0	70	0	509247	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10
10024	20033	10021	21	10000	0	20	10000	0	70	0	509248	10020	20	0	10000	20	10000	11	10000	10

Test 3: throughput

Count: 8

Code:

  fabs h0, h8
  fabs h1, h8
  fabs h2, h8
  fabs h3, h8
  fabs h4, h8
  fabs h5, h8
  fabs h6, h8
  fabs h7, h8

Initialization

  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5004

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

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule simd uop (54)	dispatch int uop (56)	dispatch simd uop (57)	int uops in schedulers (59)	ldst uops in schedulers (5b)	dispatch uop (78)	map int uop (7c)	map simd uop (7e)	map int uop inputs (7f)	map simd uop inputs (81)	? int output thing (e9)	? simd retires (ee)	? int retires (ef)
80204	40085	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80014	1	80000	100
80204	40044	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40034	80105	101	80004	100	80008	300	320192	80150	200	80060	200	80014	1	80000	100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.5004

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

retire uop (01)	cycle (02)	schedule uop (52)	schedule int uop (53)	schedule simd uop (54)	dispatch int uop (56)	dispatch simd uop (57)	int uops in schedulers (59)	ldst uops in schedulers (5b)	dispatch uop (78)	map int uop (7c)	map simd uop (7e)	map int uop inputs (7f)	map simd uop inputs (81)	? int output thing (e9)	? simd retires (ee)	? int retires (ef)
80024	40169	80029	21	80008	20	80012	70	320044	80030	20	80016	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80025	40068	80055	21	80034	20	80042	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40034	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10