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

FSUB (scalar, H)

Test 1: uops

Code:

  fsub h0, h0, h1
  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)
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000
1004303310011100010007590510001000200011000

Test 2: Latency 1->2

Code:

  fsub h0, h0, h1
  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)
102043003310101101100001001000030076890510100200100062000200121010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100
102043003310101101100001001000030076890510100200100042000200081010000100

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)
10024300331002121100002010000070076890510020200100062020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000068076924710051200100482020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010
10024300331002121100002010000070076890510020200100002020000111000010

Test 3: Latency 1->3

Code:

  fsub h0, h1, h0
  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)
1020430033101011011000010010000300769247101312001004520020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020012110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100

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)
10024300331002121100002010000707689051002020100062020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020086111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010

Test 4: throughput

Count: 8

Code:

  fsub h0, h8, h9
  fsub h1, h8, h9
  fsub h2, h8, h9
  fsub h3, h8, h9
  fsub h4, h8, h9
  fsub h5, h8, h9
  fsub h6, h8, h9
  fsub h7, h8, h9
  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): 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)
80204400748010510180004100800083003200448011020080014200160026180000100
80204400358010710180006100800103003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80205400718014310180042100800543003200448011020080013200160024180000100
80204400358010510180004100800083003200488011120080014200160028180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100

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)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)
800244012780027218000620800106732005280032208001820160000118000010
800244003580021218000020800006432021680076208006320160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010