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, lsr, 32-bit)

Test 1: uops

Code:

  cmn w0, w1, lsr #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)
1004699200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001
1004698200120011000146781000100020002001

Test 2: Latency 3->1

Chain cycles: 1

Code:

  cmn w0, w1, lsr #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)
20204300303010130101201057892472010820214302183000110100
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)
20024300303001130011200157893812001520030300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010

Test 3: Latency 3->2

Chain cycles: 1

Code:

  cmn w0, w1, lsr #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)
20204300303010130101201067892472010820214302153000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302183000110100
20204300303010130101201057893692010520212302893001610100
20204300303010130101201057893692010520212302183000110100
20205300603011530115201437893692010520212302183000110100
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)
20024300303001130011200157893812001520030300383000110010
20025300603002530025200527894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010
20024300303001130011200107894382001020020300203000110010

Test 4: throughput

Count: 8

Code:

  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #17
  cmn w0, w1, lsr #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)
80204534081601191601198012911776138013080230160252160016100
80204534021601141601148012311781598023880339160248160014100
80204534021601141601148012311776278012380224160248160014100
80204534021601141601148012311776038012380224160248160014100
80204534021601141601148012311776118012380224160248160014100
80204534021601141601148012311776078012380224160248160014100
80204534021601141601148012311780408027980381160248160014100
80204534021601141601148012311773178016380264160248160014100
80204534021601141601148012311776278012380224160248160014100
80204534021601141601148012311776038012380224160248160014100

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)
8002453402160039160039800461170032800208002016015016007510
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110
8002453371160021160021800201170032800208002016002016001110