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

FCMPE (scalar, H)

Test 1: uops

Code:

  fcmpe h0, h1
  mov x0, 1
  mov x1, 2
  mov x2, 3
  mov x3, 4

(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)
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001
10041034100111000100040001000100020001

Test 2: Latency 3->1

Chain cycles: 2

Code:

  fcmpe h0, h1
  fcsel d0, d2, d3, eq
  mov x0, 1
  mov x1, 2
  mov x2, 3
  mov x3, 4

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 2 chain cycles): 2.0033

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)
202044003320101101200000100200003001019248201002002000620050015110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019580201342002004820050015110000100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 2 chain cycles): 2.0033

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)
20024400332001111200001020000301019248200102020006205001511000010
20025400662001911200081020034301019248200102020004205001011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010

Test 3: Latency 3->2

Chain cycles: 2

Code:

  fcmpe h0, h1
  fcsel d1, d2, d3, eq
  mov x0, 1
  mov x1, 2
  mov x2, 3
  mov x3, 4

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 2 chain cycles): 2.0033

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)
202044003320101101200000100200003001019248201002002000620050015110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100
202044003320101101200000100200003001019248201002002000420050010110000100

1000 unrolls and 10 iterations

Result (median cycles for code, minus 2 chain cycles): 2.0033

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)
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024400332001111200001020000301019248200102020000205000011000010
20024401362003511200241020072301019248200102020000205000011000010
20024400332001111200001020000301020312200822020081205000011000010

Test 4: throughput

Count: 8

Code:

  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  fcmpe h0, h1
  movi v0.16b, 1
  movi v1.16b, 2

(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 ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
802048004880101101800001008000130032001480103200800102000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032009280124200800362000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100
802048003480101101800001008000130032000580101200800082000160016100100

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)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)? int retires (ef)
8002480034800222180001208000370320000800202080000201600781110
8002480034800212180000208000070320000800202080000201600001110
8002580075800392180018208002470320000800202080000201600721110
8002480042800212180000208000070320000800202080000201600001110
8002480034800212180000208000070320000800202080000201600001110
8002480034800212180000208000070320000800202080000201600001110
8002480034800212180000208000070320000800202080000201600001110
8002480034800212180000208000070320000800202080000201600561110
8002480034800212180000208000070320000800202080000201600001110
8002480034800212180000208000070320000800202080000201600001110