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

LSR (register, 32-bit)

Test 1: uops

Code:

  lsr w0, w0, w1
  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)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000
100410301001100100100002560310001000200010011000

Test 2: Latency 1->2

Code:

  lsr w0, w0, w1
  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)
10204100301010110101101082593291010710214202281000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10205100601011710117101502595391010710212202241000110100
10204100301010110101101072595391010710213202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100

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)
10024100301002110021100282596281002810036200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010

Test 3: Latency 1->3

Code:

  lsr w0, w1, w0
  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)
10204100301010110101101072593291010710214202281000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100
10204100301010110101101072595391010710212202241000110100

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)
10024100301002110021100282594741002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010
10024100301002110021100202595911002010020200201001110010

Test 4: throughput

Count: 8

Code:

  lsr w0, w8, w9
  lsr w1, w8, w9
  lsr w2, w8, w9
  lsr w3, w8, w9
  lsr w4, w8, w9
  lsr w5, w8, w9
  lsr w6, w8, w9
  lsr w7, w8, w9
  mov x8, 9
  mov x9, 10

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.3342

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)
802042687880115801158012017907659695597761602428001580100
802042676880115801158012024036080120802221602488001580100
802042674880115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100
802042673780115801158012024036080120802241602488001580100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.3343

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule ldst uop (55)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)
8002427974800398003908004428281580042800451600208001180010
8002426797800218002108002028273880020800201600208001180010
8002426739800218002108002028273880020800201600208001180010
8002426739800218002108002028273880020800201600208001180010
8002426743800218002108002028273880020800201600208001180010
8002426741800218002108002028273880020800201600208001180010
8002426749800218002108002028273880020800201600208001180010
8002426747800218002108002028273880020800201600208001180010
8002426741800218002108002028273880020800201600208001180010
8002426739800218002108002028273880020800201600208001180010