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

ST1 (multiple, post-index, 2 regs, 8B)

Test 1: uops

Code:

  st1 { v0.8b, v1.8b }, [x6], x8
  nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop
  mov x0, 0
  mov x8, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 2.000

Issues: 3.000

Integer unit issues: 1.000

Load/store unit issues: 1.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)03mmu table walk instruction (07)mmu table walk data (08)l2 tlb miss instruction (0a)l2 tlb miss data (0b)18191e1f22243a3f464951schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)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)5f696d6emap rewind (75)map stall (76)dispatch uop (78)map ldst uop (7d)map simd uop (7e)map ldst uop inputs (80)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd store (99)inst ldst (9b)l1d tlb access (a0)l1d tlb miss (a1)l1d cache miss st (a2)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acafl1d cache miss st nonspec (c0)c2c3c9cfd0d2l1i cache miss demand (d3)l1i tlb miss demand (d4)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0? int output thing (e9)eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
620062890923327022000120104787287990118026300010001000100010001000100050001090880003217292882029095310300610011000300020002894529009116100110001000100002310001031000300013036942669003162126420408326238322053572849610001611313087139171000100010002908929074290052908229111
62004289512341602800000104660288880118064300010001000100010001000100050001090980005216872880929180310300010001000300020002905229032116100110001000100002010000001000300013059939469233164115221404325638362256552845210001601612907140611000100010002916529056290582905229070
6200429054232200180010010462728951011803230001000100010001000100010005000109068000021738287052898431030001000100030002000290652885711610011000100010000301000002201000300013170929568783057116120369326038341360642838710001605012899140301000100010002889729019291032912528989
62004289992322002000001104619287671117897300010001000100010001000100050001090380007217332862228841310300010001001300020002891228907116100110001000100003010000031000300013066936769153080136320314321938251752552842210001590012790140831000100010002893328943288942900828955
62004289252322102600001104692287010117838300010011000100010001000100050001090380005217302869828864310300010001000300020002887628822116100110001000100002010000001000200013137938668173132145820210326738292060592833210001550612914138491000100010002899928907289702892828968
62004288522322202500001104792287311117858300010001001100010001000100050001090580002217222868228982310300310001000300020002876728854116100110001000100003210000001000300013163940569343184175620221319538282054562847410001614212805141571000100010002881128950289142889928869
62004289642311802510000104834287461117948300010001000100110001000100050001090680006216732865728948310300010001000300020002891128862116100110001000100003010000001000300013116945168863182165820315323338291858552829010001578012784140541000100010002889228824288652892128880
62004289402322502200001104745287400117793300010011000100010001000100050001090780005217022868828910310300010001000300020002884928885116100110001000100002010000001000300013103944968393077175620279319338292258622835710001580112585137421000100010002884128924289742896728928
620042888823218021000181104781286350117863300310001000100010001000100050001090580002217272859929004327300010001000300020002882528898116100110001000100002010000001000200013086920069423095175820191321038292557582842810001587212742140641000100010002889728954290862894128973
62004287862321602200000104690289040017915300010001000100010001000100050001090080005217492869028904310300010001000300020002880928857116100110001000100002010000001000200013010915669343172126220126324638292258542834410001556612650138041000100010002887228795287942874228847

Test 2: throughput

Count: 8

Code:

  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  st1 { v0.8b, v1.8b }, [x6], x8
  mov x7, x6
  mov x8, x6
  mov x9, x6
  mov x10, x6
  mov x11, x6
  mov x12, x6
  mov x13, x6
  mov x8, 0

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 1.0005

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk data (08)l2 tlb miss data (0b)18191e1f222324373a3f46494f51schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)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)60696d6emap stall dispatch (70)map rewind (75)map stall (76)77dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)map int uop inputs (7f)map ldst uop inputs (80)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)91inst branch cond (94)inst int alu (97)inst simd store (99)inst ldst (9b)9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache miss st (a2)a4ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acafbcl1d cache miss st nonspec (c0)l1d tlb miss nonspec (c1)c2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16020680040642110000900025301800259822524214980100851638000080100800008000043589903758848655525080015800408004059924359998024010020080000800002002400001600008004080040118020110099010010080000800001008000772900800080011800018297051101161180037800008000080000801008004180041800418004180041
1602048004064210100090002051180025892252402718010082052800008021680000800004358994375884865541508001580159800405992435999802401002008000080000200240000160000800408004011802011009901001008000080000100800078000800080014800018297051101161180037800008000080000801008004180041800418004180041
160204800406431000009000204818002599125245269801008010180000801008000080000435899037588486413960800158004080040599873599980240100200800008000020024000016000080040800401180201100990100100800008000010080007700080007118800008297051101161180037800008000080000801008004180041800418004180041
1602048004064410100070001441800259922524608680100801238000080100800008000043589943758848652764080015800408004059924359998024010020080000800002002400001602568004080040118020110099010010080000800001008000772900800080011800018297051101161180037800008000080000801008004180161800418004180041
1602048004064311000090003056180025903252461288010081223800008010080000800004358994375884865289608001580040800405992435999802401002008012080000200240000160000800408004011802011009901001008000080000100800088290080008201056800018297151101161180037800008000080000801008016380041800418004180041
1602048004064310100361200018291800258925424265480100801618000080100800008000043589943762940655598080015800408004059924359998024010020080000800002002400001600008004080040118020110099010010080000800001008000882900800080214800018297051101161180037800928000080000801008004180041800418004180041
16020480161643110010120002419180025902252431508010084312800008010080000800004358994375884864048308001580040800405992435999802401002008000080000200240000160000800408004011802011009901001008000080000100800077290080008001480001807051101161180037800008000080000801008004180041800418004180041
1602048004064211100070003050180025995532402228010080161800008010080000800004359002375884864652408011980040800405992435999802401002008000080000200240360160000800408004011802011009901001008000080000100800088290180008008800008297051101161180037800008000080000801008004180041800418004180041
1602048004064210000090004257180025991252401928010082530800008010080000800004361246375884864768008001580040800405998535999802401002008000080000200240000160000800408004011802011009901001008000080000100800089290080008018800018297151281161180037800008000080000801008004180041800418004180161
16020480040643100001290002169180025992252452578010084311800008010080000800004358990375884864924508001580040800405992435999802401002008000080000200240000160000800408004011802011009901001008000080000100800098060308144808780001807151101161180037800008000080000801008004180041800418004180041

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.0005

retire uop (01)cycle (02)03mmu table walk data (08)09l2 tlb miss data (0b)18191e1f23373a3f46494f51schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)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)6061696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)map int uop inputs (7f)map ldst uop inputs (80)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd store (99)inst ldst (9b)9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache miss st (a2)a4ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acafbcl1d cache miss st nonspec (c0)c2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eaeb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160026873796770000021301148080025080252400208001080463800008001080000800004358429375884864583500800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080000000080001001800011005020216228003780000008000080000800108004180041800418004180041
1600248004064300000640908002588025240473801018375580000800108000080000435842937588486400501580015800408004060018360020240010208000080000202400001600008004080040118002110910108000080000108000002100800010008000112105020216328003780000008000080000800108004180041800418004180041
1600248004059900000040469608002588125240590800108000780000800108000080000435842937588486434500080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000002100800010038000112105020216228003780000008000080000800108004180041800418004180041
160024800405990000004058008002508325240587800108001080000800108000080000435842937588486400450080015800408004059946360020240010208000080000202400001600008004080040218002110910108000080000108000001800800011028000111705020316238003780000008000080000800108004180041800418004180041
1600248004065200000030469408002508125241955800108375780000800108000080000435842937588486420900080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000001700800010028000111705020216228003780000008000080000800108004180041800418004180041
160024800406210000012309080025881252456418001084694800008001080000800004358429375884864209000800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080000017008000100178000112305020216338024680000008000080000800108004180286800418016280041
16002482336642000101220370800258812524262380010811508000080010800008000043584293758848640057008001580040800405994636002024001020800008000020240000160000800408004011800211091010800008000010800000000800010038000112105020316228003780000008000080000800108004180041800418004180041
16002480040620000000401308002588025240707800108000880000800108000080000435842937588486540840080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000002100800000068000112105038216228003780092008000080000800108004180041800418004180041
16002480040621000000405692080025880252411598001080015800008001080000800004358429375884865137000800158004080040599461560020240010208000080000202400001600008004080040118002110910108000080000108000002100800010048000012205020216338003780000008000080000800108004180166800418004180041
1600248004062100000040469408002588125240589800108473880000800108000080000435842937630366569120080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000002100800010038000112105038316228003780000008000080000800108004180041800418004180041