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

MRS (CNTPCT_EL0)

Test 1: uops

Code:

  mrs x0, cntpct_el0

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 1.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 0.000

retire uop (01)cycle (02)031e3a3f51schedule uop (52)schedule int uop (53)6d6emap stall dispatch (70)map rewind (75)map stall (76)8283flush restart other nonspec (84)85inst all (8c)l1d tlb access (a0)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
10041034801101926100010001034103486538821034164111001010752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001003752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001010752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034701101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035
10041034801101926100010001034103486538821034164111001000752262210311000100010351035103510351035

Test 2: throughput

Count: 8

Code:

  mrs x0, cntpct_el0
  mrs x1, cntpct_el0
  mrs x2, cntpct_el0
  mrs x3, cntpct_el0
  mrs x4, cntpct_el0
  mrs x5, cntpct_el0
  mrs x6, cntpct_el0
  mrs x7, cntpct_el0

(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)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3f51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)60696a6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9fl1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
8020480075620000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036
8020480035620000000800202680100801001005000497713180035800356996636998410020020080035164118020110099100100100000305110225228003280000801008003680036800368003680036
8020480035620000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100001005110225228003280000801008003680036800368003680036
8020480035621000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036
8020480035620000000800202680100801001005000497391980035800356996636998410020020080035164118020110099100100100000305110225228003280000801008003680036800368003680036
8020480035620000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036
8020480035621000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036
8020480035620000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100001005110225228003280000801008003680036800368003680036
8020480035621000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036
8020480035621000000800202680100801001005000497695580035800356996636998410020020080035164118020110099100100100000005110225228003280000801008003680036800368003680036

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03mmu table walk data (08)1e3f51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)5f60696a6b6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9fld unit uop (a6)l1d cache writeback (a8)a9accfl1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? int retires (ef)f5f6f7f8fd
8002480050621008002026800108001010501149769550800358003569988370006102020800351641180021109101010000050200132518680032800000800108003680036800368003680036
80024800356210080020268001080010105001497695508003580035699883700391020208003516411800211091010102000502001725171780032800000800108003680036800368003680036
8002480035620008002026800108001010500149769550800358003569988370006122020800351641180021109101010000350200172571480032800000800108003680036800368003680036
800248003562000800202680010800101050014976955080035800356998837000610202080035164118002110910101000005020072581780032800000800108016980210800368003680036
8002480035621008002026800108001010500149769550800358003569988370006102020800351641180021109101010000050200152517880032800000800108003680036800368003680036
80024800356200128002026800108001010500149769550800358003569988370006102020800351641180021109101010000050200172581780032800000800108003680036800368003680036
80024800356200080020268001080010105001497695508003580035699883700061020208003516411800211091010100003502001725171780032800000800108003680036800368003680036
8002480035620008002026800108001010501149769620800358003569988870006102020800351641180021109101010000050200132517880032800000800108004380036800368003680036
800248003562000800202680010800101050004976955080035800356998837000610202080042164118002110910101000035020082517880032800000800108003680036800368003680036
8002480035621008002026800108001010500149769550800358003569988370006102020800351641180021109101010000050200142515880032800000800108003680036800368003680036