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

UQXTN (4S)

Test 1: uops

Code:

  uqxtn v0.4h, v0.4s
  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:

  uqxtn v0.4h, v0.4s
  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)
102043003310101101100001001000030076890510100200100062000100061010000100
102043003310101101100001001000030076890510100200100042000100041010000100
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
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010

Test 3: throughput

Count: 8

Code:

  uqxtn v0.4h, v8.4s
  uqxtn v1.4h, v8.4s
  uqxtn v2.4h, v8.4s
  uqxtn v3.4h, v8.4s
  uqxtn v4.4h, v8.4s
  uqxtn v5.4h, v8.4s
  uqxtn v6.4h, v8.4s
  uqxtn v7.4h, v8.4s
  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 ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
802044009780105101800041008000830032003680108200800122000800141080000100
802044003580107101800061008001030032003680108200800122000800121080000100
802044003580105101800041008000830032003680108200800122000800121080000100
802044003580105101800041008000830032003680108200800122000801141080000100
802044004480105101800041008000830032003680108200800122000800121080000100
802044003580105101800041008000830032003680108200800122000800121080000100
802044004480105101800041008000830032003680108200800122000800121080000100
802044003580105101800041008000830032003680108200800122000800121080000100
802044003580105101800041008000830032004480110200800142000800121080000100
802044003580105101800041008000830032003680108200800122000800121080000100

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)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)
800244020180029218000802080012070032004480030200800162080000118000010
800254007080063218004202080054070032000080020200800002080000118000010
8050242608804993008004315625880055070032000080020200800002080000118000010
80025400708005721800360208004451171300285697624957176089121615895623252080000118000010
800244003580021218000002080000070032000080020200800002080000118000010
800244011180029218000802080012070032004480030200800162080000118000010
800244003580021218000002080000070032000080020200800002080000118000010
800244003580021218000002080000070032000080020200800002080000118000010
800244003580021218000002080000070032000080020200800002080000118000010
800244003580021218000002080000070032000080020200800002080000118000010