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

FDIV (vector, 8H)

Test 1: uops

Code:

  fdiv v0.8h, v0.8h, v1.8h
  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.001

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)dispatch uop (78)map simd uop (7e)map simd uop inputs (81)? int output thing (e9)? simd retires (ee)
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000
10048033100111000100010225010001000200011000

Test 2: Latency 1->2

Code:

  fdiv v0.8h, v0.8h, v1.8h
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 8.0033

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
10204800331010110110000100100003001029250101002001000620020008110000100
10205800661010310110002100100153001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100
10205800661010310110002100100153001029250101002001000420020008110000100
10204800331010110110000100100003001029250101002001000420020008110000100

1000 unrolls and 10 iterations

Result (median cycles for code): 8.0033

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
100248003310021211000020100007010292501002020100062020012111000010
100248003310021211000020100007010292501002020100002020064111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020054111000010
100248003310021211000020100007010292501002020100002020000111000010

Test 3: Latency 1->3

Code:

  fdiv v0.8h, v1.8h, v0.8h
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 8.0033

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map simd uop (7e)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)
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100062000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100
1020480033101011011000010010000300102925010100200100042000200081010000100

1000 unrolls and 10 iterations

Result (median cycles for code): 8.0033

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
100248003310021211000020100007010292501002020100062020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020056111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010
100248003310021211000020100007010292501002020100002020000111000010

Test 4: throughput

Count: 8

Code:

  fdiv v0.8h, v8.8h, v9.8h
  fdiv v1.8h, v8.8h, v9.8h
  fdiv v2.8h, v8.8h, v9.8h
  fdiv v3.8h, v8.8h, v9.8h
  fdiv v4.8h, v8.8h, v9.8h
  fdiv v5.8h, v8.8h, v9.8h
  fdiv v6.8h, v8.8h, v9.8h
  fdiv v7.8h, v8.8h, v9.8h
  movi v8.16b, 9
  movi v9.16b, 10

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 2.0005

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)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)map ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
802041600398010110180000100800000300019999828012420008003620001600081080000100
802041600398010110180000100800000300019997698010020008000420001600081080000100
802041600398010110180000100800000300019997698010020008000420001600081080000100
802041600398010110180000100800000300019997698010020008000420001600081080000100
802051600788011210180011100800240300019999828012420008004020001600081080000100
802041600398010110180000100800000300019997698010020008000420001600081080000100
802041600398010110180000100800000300019997698010020008000420001600721080000100
802041600398010110180000100800000300019997698010020008000420001600721080000100
802041600398010110180000100800000300019997698010020008000420001600721080000100
802051600788011210180011100800240300019997698010020008000420001600081080000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 2.0005

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
80024160039800212180000208000070199976980020208000420160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80025160078800322180011208002470199976880020208000020160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80024160039800212180000208000070199976980020208000020160000118000010
80024160039800212180000208000070199976980020208000020160072118000010
80024160039800212180000208000070199976980020208000020160000118000010