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

SDIV (slow, 32-bit)

Test 1: uops

Code:

  sdiv w0, w1, w2
  mov w1, #0x7fffffff
  mov w2, #3

(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)? int retires (ef)
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000
10041303020012001100011553210001000200020011000

Test 2: Latency 1->2

Chain cycles: 2

Code:

  sdiv w0, w1, w2
  eor x1, x1, x0
  eor x1, x1, x0
  mov w1, #0x7fffffff
  mov w2, #3

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 2 chain cycles): 13.0030

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)map ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
30204150030402014020130203401801430203302106029600401040030100
30204150030402014020130203401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100
30205150060402064020630232401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100
30205150060402044020430231401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100
30204150030402014020130203401807030203302126022400401010030100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 2 chain cycles): 13.0030

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)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
300241500304001140011300130401831700300133003000600204000130010
300241500304001140011300100401832900300103002000600204000130010
300251500604001440014300410401832900300103002000600204000130010
300241500304001140011300100401832900300103002000600204000130010
300241500304001140011300100401832900300103002000601164000430010
300241500304001140011300100401832900300103002000600204000130010
300251500604001440014300410401867000300403006500600204000130010
300241500304001140011300100401867900300423006800600204000130010
300241500304001140011300100401832900300103002000600204000130010
300241500304001140011300100401832900300103002000600204000130010

Test 3: Latency 1->3

Chain cycles: 2

Code:

  sdiv w0, w1, w2
  eor x2, x2, x0
  eor x2, x2, x0
  mov w1, #0x7fffffff
  mov w2, #3

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 2 chain cycles): 13.0030

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)map ldst uop inputs (80)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
3020415003040201402013020340180143020330210602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340184113023230248602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340184033023230252602240401010030100
3020415003040201402013020340180703020330212602240401010030100
3020415003040201402013020340180703020330212602240401010030100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 2 chain cycles): 13.0030

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)
3002415003040011400113001340182983001030020601204000430010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020601164000430010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020600204000130010
3002415003040011400113001040183293001030020600944000430010
3002415003040011400113001040183293001030020600204000130010

Test 4: throughput

Code:

  sdiv w0, w1, w2
  mov w1, #0x7fffffff
  mov w2, #3

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 13.0030

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)
10204130030201012010101010011598321010010206202162000110100
10204130030201012010101010011598321010010208202162000110100
10204130030201012010101010011598321010010208202162000110100
10204130030201012010101010011598321010010208202162000110100
10204130030201012010101010011599541011110226202162000110100
10204130030201012010101010011598321010010208202162000110100
10204130030201012010101010011598321010010208202162000110100
10204130030201012010101010011598321010010208202482000410100
10204130030201012010101010011599481010910224202162000110100
10204130030201012010101010011598321010010208202162000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0030

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)map ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
10025130060200242002410029115959210020100282002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202006800200140010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10024130030200212002110020115959210020100202002000200110010010
10025130060200242002410029115959210020100202002000200110010010