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

FCVTMS (vector, 8H)

Test 1: uops

Code:

  fcvtms v0.8h, v0.8h
  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)
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000
1004303310011100010007590510001000100011000

Test 2: Latency 1->2

Code:

  fcvtms v0.8h, 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): 3.0033

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)
1020430033101011011000010010000300768905101002001000620010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430033101011011000010010000300769247101312021004620010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430188101291051002410410099300768905101002001000420010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100
1020430033101011011000010010000300768905101002001000420010004110000100

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0033

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)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 simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
10024300331002121100002010000070076890510020200100062010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076890510020200100002010000111000010
10024300331002121100002010000070076924710051200100442010000111000010

Test 3: throughput

Count: 8

Code:

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

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

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

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)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)
80204402008010510180004010080008300320036801082008001220080012180000100
80204400358010710180006010080010300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80205400708014310180042010080054300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100
80204400358010510180004010080008300320036801082008001220080012180000100

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)schedule simd uop (54)schedule ldst uop (55)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)
800244017480027218000602080010703200448003020800162080000118000010
800244018680119218009802080098703200008002020800002080000118000010
800244003580021218000002080000703200008002020800002080000118000010
800244003580021218000002080000673204048012120801012080000118000010
800244003580021218000002080000703200008002020800002080000118000010
800244003580021218000002080000703200008002020800002080051118000010
800244003580021218000002080000703200008002020800002080163118000010
800244016480121218010002080100703200008002020800002080000118000010
800244003580021218000002080000703200008002020800002080000118000010
800244044080118218009702080097703200008002020800002080000118000010