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

FCVTMS (vector, 4H)

Test 1: uops

Code:

  fcvtms v0.4h, v0.4h
  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:

  fcvtms v0.4h, v0.4h
  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)
1020430033101011011000010010000030007689051010020001000620010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000031407710891023620401016620010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000030007689051010020001000420010004110000100
1020430033101011011000010010000030007689051010020001000420210046210000100
1020430033101011011000010010000030007689051010020001000420210042210000100

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:

  fcvtms v0.4h, v8.4h
  fcvtms v1.4h, v8.4h
  fcvtms v2.4h, v8.4h
  fcvtms v3.4h, v8.4h
  fcvtms v4.4h, v8.4h
  fcvtms v5.4h, v8.4h
  fcvtms v6.4h, v8.4h
  fcvtms v7.4h, v8.4h
  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 simd uop inputs (81)? int output thing (e9)? simd retires (ee)? int retires (ef)
8020440055801051018000410080008300320036801082008001220080012180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100
8020440035801071018000610080010300320044801102008001420080014180000100

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)
80024402308002721800062080010703200528003220800182080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010
80024400358002121800002080000703200008002020800002080000118000010