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

UMULL2 (by element, 4S)

Test 1: uops

Code:

  umull2 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:

  umull2 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)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)
1020430033101011011000010010000030007689051010020001000420020012110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100
1020430033101011011000010010000030007689051010020001000420020008110000100

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 ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
1002430033100212110000201000070768905100202010006200200001101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200881101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200001101000010
1002430033100212110000201000070768905100202010000200200881101000010
1002430033100212110000201000070768905100202010000200200001101000010

Test 3: Latency 1->3

Code:

  umull2 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)
1020430033101011011000010010000300768905101002001000620020012110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020430033101011011000010010000300768905101002001000420020008110000100
1020530066101071011000610010031300768905101002001000420020008110000100
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
10024300331002121100002010000707689051002020100002020096111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020094111000010
10024300331002121100002010000707689051002020100002020010111000010
10024300331002121100002010000707689051002020100002020000111000010
10024300331002121100002010000707689051002020100002020000111000010

Test 4: throughput

Count: 8

Code:

  umull2 v0.4s, v8.8h, v9.h[1]
  umull2 v1.4s, v8.8h, v9.h[1]
  umull2 v2.4s, v8.8h, v9.h[1]
  umull2 v3.4s, v8.8h, v9.h[1]
  umull2 v4.4s, v8.8h, v9.h[1]
  umull2 v5.4s, v8.8h, v9.h[1]
  umull2 v6.4s, v8.8h, v9.h[1]
  umull2 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)
80204400758010510180004100800083003200448011020080014200160028180000100
80204400358010710180006100800103003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204401098015610180055100800593003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80205400708014310180042100800543003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204400358010510180004100800083003200368010820080012200160024180000100
80204401098015410180053100800573003200368010820080012200160024180000100

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)
800244018280027218000620800106832000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800254007180058218003720800456532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010
800244003580021218000020800006532000080020208000020160000118000010