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

SUBS (register, 64-bit)

Test 1: uops

Code:

  subs x0, x0, x1
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 1.001

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)? int retires (ef)
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000
100410301001100110002504310001000200010011000

Test 2: Latency 1->2

Code:

  subs x0, x0, x1
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 1.0030

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)
10204100301010110101101062515621010910210202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 1.0030

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)
10024100301002110021100302532921002810030200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010

Test 3: Latency 1->3

Code:

  subs x0, x1, x0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 1.0030

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)
10204100301010110101101092515981010810210202201000110100
10204100301010110101101062517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101072517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100
10204100301010110101101082517741010810208202161000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 1.0030

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)
10024100301002110021100292532561002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010
10024100301002110021100202531611002010020200201001110010

Test 4: Latency 4->2

Chain cycles: 1

Code:

  subs x0, x1, x2
  cset x1, cc
  mov x0, 1
  mov x1, 2
  mov x2, 3
  mov x3, 4
  mov x4, 5

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 1 chain cycle): 1.0030

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)
20204200302010120101201085194342010720212302212000120100
20205200602011720117201495194342010720214302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 1 chain cycle): 1.0030

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)
20024200302001120011200185198442005920083301102001520010
20024200302001120011200185195072001720032300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20025200602002520025200505195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010

Test 5: Latency 4->3

Chain cycles: 1

Code:

  subs x0, x1, x2
  cset x2, cc
  mov x0, 1
  mov x1, 2
  mov x2, 3
  mov x3, 4
  mov x4, 5

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 1 chain cycle): 1.0030

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)
20204200302010120101201075193202010820214302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100
20204200302010120101201085195482010820216302242000120100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 1 chain cycle): 1.0030

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)
20024200302001120011200175194982001820036300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020301132001520010
20024200302001120011200105195982001020020300202000120010
20024200302001120011200105195982001020020300202000120010

Test 6: throughput

Count: 8

Code:

  subs x0, x8, x9
  subs x1, x8, x9
  subs x2, x8, x9
  subs x3, x8, x9
  subs x4, x8, x9
  subs x5, x8, x9
  subs x6, x8, x9
  subs x7, x8, x9
  mov x8, 9
  mov x9, 10
  mov x10, 11

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5010

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)
802044010180110801108011324034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100
802044008180112801128011524034580115802161602328001280100

1000 unrolls and 10 iterations

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

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)
800244009780031800318003424010880034800341600528002280010
800244005380034800348003724006580020800201600208001180010
800244003080021800218002024048280158801581600208001180010
800244003080021800218002024006580020800201600208001180010
800244003080021800218002024006580020800201600208001180010
800244003080021800218002024006580020800201600208001180010
800244003080021800218002024006580020800201600208001180010
800244003080021800218002024006580020800201601208005280010
800244003080021800218002024006580020800201600208001180010
800244003080021800218002024006580020800201600208001180010