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, 8H)

Test 1: uops

Code:

  frsqrte v0.8h, v0.8h
  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)
1004403310011100010005060810001000100011000
1004403310011100010005077110171027100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000
1004403310011100010005060810001000100011000

Test 2: Latency 1->2

Code:

  frsqrte v0.8h, v0.8h
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 4.0033

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)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)
10204400331010110110000010010000300509608101002001000620010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420210030210000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010004110000100
10204400331010110110000010010000300509608101002001000420010032110000100

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0033

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)
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002540066100252110004201001770509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010
1002440033100212110000201000070509608100202010000200100001101000010

Test 3: throughput

Count: 8

Code:

  frsqrte v0.8h, v8.8h
  frsqrte v1.8h, v8.8h
  frsqrte v2.8h, v8.8h
  frsqrte v3.8h, v8.8h
  frsqrte v4.8h, v8.8h
  frsqrte v5.8h, v8.8h
  frsqrte v6.8h, v8.8h
  frsqrte v7.8h, v8.8h
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 2.0004

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)
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802051600708011010180009100800220300019999328012220008003220080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080036180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100
802041600358010110180000100800000300019997698010020008000420080004180000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 2.0004

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)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)
80024160035800212180000020800007019997698002020800042080000118000010
80024160035800212180000020800007019997698002020800002080000118000010
80024160035800212180000020800007019997698002020800002080062118000010
80024160035800212180000020800007019999328004220800322080000118000010
80024160035800212180000020800007019997698002020800002080000118000010
80024160035800212180000020800007019997698002020800002080000118000010
80024160035800212180000020800007019997698002020800002080000118000010
80025160070800302180009020800227019997698002020800042080000118000010
80024160035800212180000020800007019997698002020800002080000118000010
80024160035800212180000020800007019997698002020800002080000118000010