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

FRINTN (scalar, H)

Test 1: uops

Code:

  frintn 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	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000
1004	3033	1001	1	1000	1000	75905	1000	1000	1000	1	1000

Test 2: Latency 1->2

Code:

  frintn 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): 3.0033

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)	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	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10006	200	10006	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100
10204	30033	10101	101	10000	0	100	10000	300	768905	10100	200	10004	200	10004	1	10000	100

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0033

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)
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10006	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10044	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	769247	10051	20	10044	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10
10024	30033	10021	21	10000	20	10000	70	768905	10020	20	10000	20	10000	11	10000	10

Test 3: throughput

Count: 8

Code:

  frintn h0, h8
  frintn h1, h8
  frintn h2, h8
  frintn h3, h8
  frintn h4, h8
  frintn h5, h8
  frintn h6, h8
  frintn 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	40455	80352	101	80251	100	80255	300	321032	80357	200	80261	200	80264	1	80000	100
80204	40337	80304	101	80203	100	80207	300	320836	80308	200	80212	200	80258	1	80000	100
80204	40267	80259	103	80156	102	80160	300	320832	80307	200	80211	202	80214	2	80000	100
80204	40333	80303	101	80202	100	80206	303	321028	80357	202	80260	200	80213	1	80000	100
80204	40288	80252	101	80151	100	80155	300	320632	80257	200	80161	200	80207	1	80000	100
80204	40345	80302	101	80201	100	80205	300	320844	80310	200	80214	200	80209	1	80000	100
80204	40437	80353	101	80252	100	80256	307	320604	80255	202	80162	200	80012	1	80000	100
80204	40035	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40035	80105	101	80004	100	80008	300	320036	80108	200	80012	200	80012	1	80000	100
80204	40035	80105	101	80004	100	80008	300	320448	80211	200	80115	200	80211	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	40138	80029	21	80008	20	80012	70	320044	80030	20	80016	20	80018	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10
80024	40035	80021	21	80000	20	80000	70	320000	80020	20	80000	20	80000	11	80000	10