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

ST3 (multiple, 4H)

Test 1: uops

Code:

  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  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

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 4.000

Issues: 4.000

Integer unit issues: 0.000

Load/store unit issues: 2.000

SIMD/FP unit issues: 2.000

retire uop (01)cycle (02)03l1i tlb fill (04)mmu table walk instruction (07)mmu table walk data (08)l2 tlb miss instruction (0a)18191e1f22243a3f464951schedule uop (52)schedule simd uop (54)schedule ldst uop (55)dispatch simd uop (57)dispatch ldst uop (58)simd uops in schedulers (5a)ldst uops in schedulers (5b)5f6061696d6emap 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)c2c9cfd0d2l1i cache miss demand (d3)l1i tlb miss demand (d4)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0eaebec? ldst retires (ed)? simd retires (ee)f5f6f7f8fd
640072944723622102000144000459529201001829440002000200020002000216121600030021782290932953431040002000200040006000294082944111610011000100020000402000004702000400131649430695431651159204903314381514515328777163561329414812200020002947629489293582952629430
64004293512350150210012100479629280001818940002000200020002000216271600030021805290382935731040002000200040006000294202935411610011000100020000032000000200000013218935169493164953203693238381810485828692163111316914709200020002936329322294302952129524
640042937823601702000088004735291750018319400020002000200020002160916000100217982911629469310400020002000400460002932729415216100110001000200004020000002000400133829637690430961054203853395381712525528754159831313114757200020002943429428294132945529414
640042952623602401600001047272918600182174000200020002000200021630160160002184429109293503104000200020004000600029331294641161001100010002000040200000020004052613349951768803171854206723326381510495028865162011330815551200020002937429284293562930029324
6400429334236017014000000481229192001819240002000200020002000217021600020021847291392949531040002000200040006000293202944411610011000100020000402000000200042013410934369303180752203853252381613605828676161161325314887200020002944529454293802947129360
6400429458236023120011320004731292270018269400020002002200220022161116016008218522915029323329400420022000400060002932129293316100110001000200020220000032000429881324696557022316385220378323238158535828741160661356215043200020002948529451294952943729439
640042948223602301500132100473329200001823940082000200020022000216081600000021854291012932533040002002200240006006293162939421610011000100020000022000020200040013173938769523122961204593268381512535728738161191325614792200020002951029453291172982729560
6400429697238017020000000472929312001820940002000200020002000216221600000021803289822946331040002000200040006000293572927411610011000100020000402000000200040013085944169193138651203983254381712494128621162821319314825200020002945729397295172928129244
640042941023701801500000046982927800182754000200020002000200021608160001002186329017293993104000200020004000600029367292991161001100010002000040200000320004001331593926961313085020406321238149505028623162871317614769200020002934129381293642931629397
6400429445235018021000100468729376001828140002000200020002000216171600020021853290402932431040002000200040006000293742943011610011000100020000402000100200040013201940869323089550203643262381818494628906160431326715094200020002940329486293962945029404

Test 2: throughput

Count: 8

Code:

  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  st3 { v0.4h, v1.4h, v2.4h }, [x6]
  mov x7, x6
  mov x8, x6
  mov x9, x6
  mov x10, x6
  mov x11, x6
  mov x12, x6
  mov x13, x6

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 1.0006

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk data (08)l2 tlb miss data (0b)18191e1f22373a3f46494f51schedule 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)696d6emap 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)l1d tlb miss nonspec (c1)c2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
32020780059652120001217034771800371616048325069100162936160000100160000160000500255974113000398003780221800500334320100200160120160000200320000480000800508005321802011009910010080000800001001600162044011600162319160002164414051091317136800481600001600001008006380053800528005380052
32020480051643111001218061081800361616025324418100164978160000100160000160000500271979413001848002780050800510333320100200160000160000200320000480000800518005111802011009910010080000800001001600141400016001601211600021444140510915171515800481600001600001008005280053800618005180053
32020480051642100001518074621800371616025325944100164313160000100160000160000500279979113008688002780062800630329320100200160000160000200320000480000800518005311802011009910010080000800001001600151400016001600141600001644140510914171213800491600001600001008005280051800528005280052
32020480050643111001517036361800481600253201081001641311600001001600001600005002479917131335080026800528005003343201002001600001600002003200004800008005380051118020110099100100800008000010016001414440116001600201600001444140510913171414800481600001600001008006380054800538005180052
32020480047643111003170314318003616160253271531001642321600001001600001600005002559884130350480027800628005003333201002001600001600002003200004800008005280052118020110099100100800008000010016001414440216001610161600021644140510913171313801821600001600001008005280048800538005280050
3202048005064311000617037281800361616025324521100161939160000100160000160000500239992017878988002580047800500334320100200160000160000200320000480000800538005111802011009910010080000800001001600151444001600160223160002140141510913171413800461600001600001008005480051800528005380051
32020480053643100001517059811800361516025323238100164987160000100160000160000500367949813000078002680052800521335320100200160000160000200320000480000800518005111802011009910010080000800001001600151446001600160114160002164414051091317814800491600001600001008005480063800498005480063
32020480051643110001519039171800371616025321920100165451160000100160000160000500279976412974578002980062800500333320100200160000160000200320000480000800528005211802011009910010080000800001001600151544011600160017160002144414051098171410800491600001600001008005280052800538005180052
32020480062643111003180564118003516160253257231001647071600001001600001600005002559749129731680026800538005303333201002001600001600002003200004800008005180051118020110099100100800008000010016001514420116001601171600021644140510913171313800491600001600001008005180052800538006480048
32020480050643101003180399618003616160253247971001616161600001001600001600005002479902129003981487800518005203323201002001600001600002003200004800008005180051118020110099100100800008000010016001514440016001620221600021644140510911171515800471600001600001008005180052800548006380048

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.0006

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk data (08)l2 tlb miss instruction (0a)l2 tlb miss data (0b)18191e1f24373a3f46494f51schedule 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)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)c2branch mispred nonspec (cb)cfd0d2d5map dispatch bubble (d6)ddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
32002780058620100000019036401800360160253239001016487016000010160000160000502157526129531600800258004580045032732001020160000160000203200004800008004480044118002110901010800008000010160000044001600020021600002420005019003173380042160000160000108005280063800528005280052
32002480062643100000018045461800380160253227591016610616000010160000160000502559860129543700800268005280052133332001020160000160000203200004800008005280050118002110901010800008000010160000042001600021031600022420005019023173280039160000160000108004580044800458004580045
32002480046642000000030562608004816160253243201016439116000010160000160000502719782128367400800278005180051033332001020160000160000203200004800008006380050118002110901010800008000010160000044001600021021600022420005019003173380042160000160000108004880046800458004780045
320024800456430000000303875080030016025325810101646461600001016000016000050207902712959780080024800448004503273200102016000016000020320000480000800458004411800211092101080000800001016000000001600020021600022420005019003173380040160000160000108004680046800458004680045
3200248004564300000060040980800291616025326138101652981600001016000016000050223446212905861080024800438004403273200102016000016000020320000480000800458004511800211090101080000800001016000004200160000102160002000005019002173280041160000160000108004680046800468004780045
320024800446430000000305704080029000253257191016457816000010160000160000502078874130162800800248004580045032732001020160000160000203200004800008004580044118002110901010800008000010160000042001600001021600022420005019003173380041160000160000108004680046800458004680046
3200248004664200000004062660800450160253259461016647016000010160000160000501998802129355700800248004580044032732001020160000160000203200004800008004480048118002110901010800008000010160000042001600020021600022420005019003173380041160000160000108004580045800468004580046
3200248004464300000063043450800291600253230681016370016000010160000160000502079591130196800800238004680045032632001020160000160000203200004800008004680045118002110901010800008000010160000042001600020061600022420005019003173380042160000160000108004580046800468004580047
32002480044642000000030584708003716160253272251016451716000010160000160000502236386130229700800248004580045032732001020160000160000203200004800008004580045118002110901010800008000010160000042001600021061600020420005019003172380042160000160000108004680046800458004680046
32002480045643000000333050340800321600254220771016615816000010160000160000502306429129426600800288004480044032832001020160000160000203200004803608004580044118002110901010800008000010160000042001600021021600022420005047005263380197160000160000108021280213802118020880376