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

CMN (register, asr, 64-bit)

Test 1: uops

Code:

  cmn x0, x1, asr #17
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 2.000

Integer unit issues: 2.001

Load/store unit issues: 0.000

SIMD/FP unit issues: 0.000

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001

Test 2: Latency 3->1

Chain cycles: 1

Code:

  cmn x0, x1, asr #17
  cset x0, cc
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 1 chain cycle): 2.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
20204300303010130101201067892312010520210302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302783001510100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 1 chain cycle): 2.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)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)? int output thing (e9)? int retires (ef)
20024300303001130011200150789381020015200300300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789792020050200760300203000110010
20024300303001130011200150789380020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010
20024300303001130011200100789438020010200200300203000110010

Test 3: Latency 3->2

Chain cycles: 1

Code:

  cmn x0, x1, asr #17
  cset x1, cc
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 1 chain cycle): 2.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
20204300303010130101201067893112010520210302153000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 1 chain cycle): 2.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
20024300303001130011200157893802001020020300203000110010
20024300303001130011200107897922005020076300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010

Test 4: throughput

Count: 8

Code:

  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  cmn x0, x1, asr #17
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.6675

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
80204534041601171601178012811775638012580226160248160014100
80204534021601141601148012311776318012380224160248160014100
80204534021601141601148012311776038012380224160248160014100
80204534021601141601148012311776318012380224160248160014100
80204534021601141601148012311776038012380224160248160014100
80204534021601141601148012311776318012380224160248160014100
80204534021601141601148012311776038012380224160248160014100
80204534021601141601148012311776318012380224160248160014100
80204534021601141601148012311776038012380224160248160014100
80204534021601141601148012311776318012380224160248160014100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.6671

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
8002453376160036160036800451170309800478004816015216007710
8002453383160021160021800201170032800208002016002016001110
8002453371160021160021800201172006800208002016002016001110
8002453371160021160021800201173267801728017216002016001110
8002453371160021160021800201173352800598005916002016001110
8002453371160021160021800201181544800978009716002016001110
8002453371160021160021800201174146800958009516002016001110
8002453371160021160021800201170032800208002016002016001110
8002453471160147160147800961170032800208002016002016001110
8002453470160153160153800991170032800208002016009416007810