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

FRSQRTE (vector, 2S)

Test 1: uops

Code:

  frsqrte v0.2s, v0.2s
  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)
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000
1004303310011100010003769410001000100011000

Test 2: Latency 1->2

Code:

  frsqrte v0.2s, v0.2s
  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)
1020430033101011011000010010000300379694101002001000620010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100
1020430033101011011000010010000300379694101002001000420010004110000100

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)
10024300331002121100002010000703796941002020100062010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010
10024300331002121100002010000703796941002020100002010000111000010

Test 3: throughput

Count: 8

Code:

  frsqrte v0.2s, v8.2s
  frsqrte v1.2s, v8.2s
  frsqrte v2.2s, v8.2s
  frsqrte v3.2s, v8.2s
  frsqrte v4.2s, v8.2s
  frsqrte v5.2s, v8.2s
  frsqrte v6.2s, v8.2s
  frsqrte v7.2s, v8.2s
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 1.0004

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)
8020480049801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320100801262008004020080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100
8020480035801011018000010080001300320005801012008000820080008180000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.0004

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)
80024800508002121800002080002070032001080022200800082080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000068032008280042200800292080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010
80024800358002121800002080000070032000080020200800002080000118000010