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

SMULL2 (by element, 4S)

Test 1: uops

Code:

  smull2 v0.4s, v0.8h, v1.h[1]
  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:

  smull2 v0.4s, v0.8h, v1.h[1]
  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)
1020430033101011011000010010000300768905101002001000620020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000620020012110000100
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)
10024300331002121100002010000707689051002020100062020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100042020008111000010
10024300331002121100002010000707689051002020100002020000111000010

Test 3: Latency 1->3

Code:

  smull2 v0.4s, v1.8h, v0.h[1]
  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)
1020430033101011011000010010000300769247101312001004220020012110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
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)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)
100243003310021211000002010000707689051002020100062020008111000010
100243003310021211000002010000707689051002020100002020000111000010
100243003310021211000002010000707689051002020100062020000111000010
100243003310021211000002010000707694511005320100402020000111000010
12326363571209926868044136925508069707689051002020100002020000111000010
100243003310021211000002010000707689051002020100002020000111000010
100253006610027211000602010031687692471005120100472020008111000010
100243008510031231000802210033687699971008620100872020236111000010
100243018710045211002402010099737710891015422101592020076111000010
100243003310021211000002010000707689051002020100002020000111000010

Test 4: throughput

Count: 8

Code:

  smull2 v0.4s, v8.8h, v9.h[1]
  smull2 v1.4s, v8.8h, v9.h[1]
  smull2 v2.4s, v8.8h, v9.h[1]
  smull2 v3.4s, v8.8h, v9.h[1]
  smull2 v4.4s, v8.8h, v9.h[1]
  smull2 v5.4s, v8.8h, v9.h[1]
  smull2 v6.4s, v8.8h, v9.h[1]
  smull2 v7.4s, v8.8h, v9.h[1]
  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)
80204400588010510180004100800083003200448011020080014200160028180000100
80204400358010710180006100800103003200448011020080014200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160128180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
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)
800244017480029218000820800126832000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160134118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010