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

FCVTMU (vector, 8H)

Test 1: uops

Code:

  fcvtmu 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:

  fcvtmu 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 ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
102043003310101101100001001000030776921210135202100472000100061010000100
102043003310101101100001001000030076890510100200100062000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100
102043003310101101100001001000030076890510100200100042000100041010000100

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)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)
10024300331002121100002010000707689051002020100062010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707692471005120100442010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010

Test 3: throughput

Count: 8

Code:

  fcvtmu v0.8h, v8.8h
  fcvtmu v1.8h, v8.8h
  fcvtmu v2.8h, v8.8h
  fcvtmu v3.8h, v8.8h
  fcvtmu v4.8h, v8.8h
  fcvtmu v5.8h, v8.8h
  fcvtmu v6.8h, v8.8h
  fcvtmu 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)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)
8020440035801071018000610080010300320036801082008001220080012180000100
8020440035801071018000610080010300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020540070801431038004010280052300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020440035801051018000410080008300320036801082008001220080012180000100
8020440062801051018000410080008300320036801082008001220080012180000100

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)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)
80024402128002921800082080012070032005280032200800182080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080000118000010
80024400358002121800002080000070032000080020200800002080066118000010
80024400358002121800002080000070032000080020200800002080000118000010