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

FCVTNS (vector, 2D)

Test 1: uops

Code:

  fcvtns v0.2d, v0.2d
  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:

  fcvtns v0.2d, v0.2d
  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)
102043003310101101100001001000030076890510100200100062000100041010000100
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
10024300331002121100002010000697689051002020100042010006111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010
10024300331002121100002010000707689051002020100002010000111000010

Test 3: throughput

Count: 8

Code:

  fcvtns v0.2d, v8.2d
  fcvtns v1.2d, v8.2d
  fcvtns v2.2d, v8.2d
  fcvtns v3.2d, v8.2d
  fcvtns v4.2d, v8.2d
  fcvtns v5.2d, v8.2d
  fcvtns v6.2d, v8.2d
  fcvtns v7.2d, v8.2d
  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)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)
8020440059801051018000410080008030003200368010820008001220080014180000100
8020440035801071018000610080010030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100
8020440035801051018000410080008030003200368010820008001220080012180000100

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 ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
8002440113800272180006208001070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010
8002440035800212180000208000070320000800202080000200800001108000010