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

LD1R (8B)

Test 1: uops

Code:

  ld1r { v0.8b }, [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, 1
  mov x1, 2
  mov x8, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 2.000

Issues: 2.003

Integer unit issues: 0.000

Load/store unit issues: 1.000

SIMD/FP unit issues: 1.003

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk instruction (07)mmu table walk data (08)09l2 tlb miss instruction (0a)l2 tlb miss data (0b)0e0f1e22243a3f43464951schedule 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 load (98)inst ldst (9b)9dl1d tlb access (a0)l1d tlb miss (a1)l1d cache miss ld (a3)ld unit uop (a6)l1d cache writeback (a8)a9acafb5bbl1d cache miss ld nonspec (bf)l1d tlb miss nonspec (c1)c2cfd0d2l1i cache miss demand (d3)l1i tlb miss demand (d4)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0eaebec? ldst retires (ed)? simd retires (ee)f5f6f7f8fd
620052856121311510151004810525727939001162922001100410001000100050001193820022710283062833931020001000100010001000282012821011610011000100001003131002021100013100138481016572103452955196003366382510464027904147011245013288100010002809128142281652825228307
62004283002120150016000386105263280231111646620001004100010001000500011924500226942804128194310200010001000100010002835228082116100110001000010000210030011003013001351710084704233971237196713240381710404327959138971279013301100010002821128509284242833828066
6200428390213012001710030310488327970110164472002100410001000100050001194830022680280732836931020001000100010001000281792808511610011000100001000031003003100313200135441011271493450838194843339381712343227813146791225113315100010002812828240283232834628236
620042825721201300150001510508327988111163652004100410001000100050001194970022685280922846831020001000100010001000282672817511610011000100001000001003001100101200138461028572443341936196293399381911383627901139521253313319100010002819028222281962804828434
62004284022110170019000311051912803311116206200210021000100010005000119407002267528131281543102000100010001000100028306283521161001100010000100003100300110031130013627985570613397114019489349138149373528027153191214113427100010002833728335283272839428293
620042809621301800180110104965282570101628220041002100010001000500011928100022699283772821631020001000100010001000280762838211610011000100011000031001000100003300139621032769933414838197993341381514394327808145131252413342100010002803328233282272822928237
6200428500213019001300026104991279510111612620001004100010001000500011943900226522826228594310200010001000100010002839328217116100110001000010000210000001000133001388810168720234621038196233387380814404427998147701256713610100010002815728292283442822528267
620042832221201300160004105090280420111623120041004100010001000500011947120022664284822836831020001000100010001000281572820511610011000100001000031000003100310300138731039172633230123619817342438089364227991145271227413119100010002820028180281612821128316
620042823021201600200002321051502822911116198200010041000100010005000119078002272428240285103102000100010001000100028225283131161001100010000100003100100310012330013920105367198348183119704331938128423827971143711241313323100010002831428325284662822128281
620042837621101700160002900518728068110162182004100410001000100050001190090022708281382822831020001000100010001000283092837711610011000100001000031000003100020300139861036873033425732195263414381812443927883140461238113172100010002822828269282552816228490

Test 2: Latency 1->2 roundtrip

Chain cycles: 3

Code:

  ld1r { v0.8b }, [x6]
  fmov x0, d0
  eor x8, x8, x0
  eor x8, x8, x0
  add x6, x6, x8
  mov x0, 1
  mov x1, 2
  mov x8, 0

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code, minus 3 chain cycles): 11.0047

retire uop (01)cycle (02)03mmu table walk data (08)090e0f18191e1f22233f4d4f51schedule 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)696b6d6emap 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 load (98)inst ldst (9b)9d9fl1d tlb access (a0)l1d cache miss ld (a3)ld unit uop (a6)l1d cache writeback (a8)acafb5bbl1d cache miss ld nonspec (bf)c2branch cond mispred nonspec (c5)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
60205140094104900110042401014003513941012936225701004010020003100003024220000100001264045669368514308701140026014003514003513183231323996010030200100002000060200100002000014003514003511502011009910040100100001000001001000001000023710910000101000321011221113954640000069100001000040100140051140052140157140051140036
602051400791058000000229901014005914064013014088970483403242010010037343272303411477133523767571461445052814221901428951431761324344741338776952635152115992276869762116382309514290514270431150201100991004010010000100000100100451100210310001000200321011221013954640000909100001000040100140051140379140051140051140048
6020414005010521100310916440001400321394101293592570102401002000210000301002000010000126404566935381431063314002301400351400501317923132402601003020010000200006020010000200001400501400471150201100991004010010000100000100100001100000010000101000321011271113955240000906100001000040100140051140036140048140051140036
60204140035104900000010011400351394071293472570100401002000210000301002000010000126380366929471431063314002601400351400471318253132402601003020010000200006020010000200001400501400471150201100991004010010000100000100100001100003010000001000321011271113954640006609100001000040100140051140051140036140036140048
602041400351049000000250011400321394071293622570102401002000210000301002000010000126413666929471431112814001101400471400361318513132382601003020010000200006020010000200001400501400471150201100991004010010000100001100100000100000010000101000321011391113954640000906100001000040100140036140036140048140036140048
60204140035104900000010011400201394101293622570102401002000010002301002000010000126404566935381431073714002601400501400501317923132403601003020010000200006020010000200001400351400351150201100991004010010000100000100100001100000010000101000321011221113955240000909100001000040100140036140051140051140051140036
60204140047104901000000011400201394101293592570102401002000210000301002000010000126413666929951430870114001101400351400501317923132382601003039410000200006020010000200001400471400471150201100991004010010000100000100100001100000010000000000321011221113954640000660100001000040100140051140051140051140051140051
60204140047104900000010001400321394101293622570102401002000010000301002000010000126413666936851431112814001101400471400501317923132402601003020010000200006020010000200001400501400471150201100991004010010000100000100100001100000010000101000321011221113965240000660100001000040100140048140051140051140051140048
60204140050104900000000001400321394061293592570102401002000010000301002000010000126404566935381430870114002301400351400471318373132382601003038910000200006020010000200001400501400471150201100991004010010000100000100100000100000010000101000321011271113955540000669100001000040100140051140051140051140036140051
60204140050104900000010001400201394101294142570102401002000210001301002000010000126404566941141431094514002301400471400521318573132402601003020010000200006020010000200001400351400351150201100991004010010000100000100100001100000010000100000321011271113954640000960100001000040100140048140048140051140036140036

1000 unrolls and 10 iterations

Result (median cycles for code, minus 3 chain cycles): 11.0047

retire uop (01)cycle (02)03090e0f18191e22233f4d4f51schedule 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)int prf full (71)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 load (98)inst ldst (9b)9d9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache miss ld (a3)ld unit uop (a6)l1d cache writeback (a8)acafb5l1d cache miss ld nonspec (bf)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
6002514004910481007511014080313979812937025700124001020002100003001020000100001264443669541014328846014002314004714005013181503132431600103002010000200006002010000200001400501400351150021109104001010000100001101000001100000010000110314061134213955440000960100001000040010140051140036140051140051140051
6002414004710481000010014002013939412936225700124001020002100003001020000100001264443669627414326216014002614005014005013181803132420600103002010000200006002010000200001400351400351150021109104001010000100000101000001100001010000100314021134513956940000009100001000040010140036140036140048140051140051
6002414003510490000000014003513939712935925700124001020002100003001020000100001264443669496314325931014002314003514004713180303132420600103020710000200006002010000200001400501400471150021109104001010000100000101000001100000010000010314041134313956640000969100001000040010140051140036140051140051140036
6002414005010490000001014003213939412936225700104001020002100003001020000100001264443669733014325829014002614005014004713181803132498600103002010000200006002010000200001400471400351150021109104001010000100000101000001100000010000101314021132413956940000999100001000040010140148140048140051140051140051
6002414005010490010011014003513939412935925700124001020000100003001020000100001264974669358614321442014001114005014003513181803132433600103002010000200006002010000200001400501400471150021109104001010000100000101000001100000010000110314021113413956940000069100001000040010140051140048140051140036140036
6002414003510490000011014002013939712935952700104001020000100003001020000100001264888669353814321442014002614005014005113181803132430600103002010000200006002010000200001400501400471150021109104001010000100000101000001100000010000110314051133513956940000000100001000040010140036140036140048140051140048
6002414004710491000001014002013939712936225700124001020000100003001020000100001264443669661014326445014002614004714005013181803132430600103002010000200006002010000200001400501400351150021109104001010000100000101000001100000010000110314041134413959140000660100001000040010140051140036140051140048140051
6002414005010491000010014003513939712936225700124001020002100003001020000100001264443669718614325829014002614005014005013181503132433600103002010000200006002010000200001400501400351150021109104001010000100000101000001100000010000010314041114213955840000999100001000040010140051140048140036140048140036
60024140050104900000131014003513939712934725700124001020000100003001020000100001264429669569814326112014001114004714005013181803132430600103002010000200006002010000200001400351400471150021109104001010000100000101000000100000010000110314031113513956640000666100001000040010140036140036140036140048140048
6002414003510490000011014003513939412936225700124001020000100003001020000100001264443669549114326345014001114003514005013180303132433600103002010000200006002010000200001400351400471150021109104001010000100000101000001100000010000010314041134213955440000009100001000040010140051140051140051140051140048

Test 3: throughput

Count: 8

Code:

  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [x6]
  ld1r { v0.8b }, [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): 0.3341

retire uop (01)cycle (02)0309l2 tlb miss data (0b)0e0f1e1f22233a3f4346494f51schedule 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)simd prf full (72)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 load (98)inst ldst (9b)9d9fl1d tlb access (a0)l1d cache miss ld (a3)a5ld unit uop (a6)l1d cache writeback (a8)acafb5b6bbl1d cache miss ld nonspec (bf)branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1602052672720010102430101267062121219251601411008004580000100800208001550011701791884588026709267282672866520666771601352008002080020200800208002026708267231180201100991001008000080000110080000390800390358003960354311151170161026725106080000800001002670926724267242672926729
16020426728200001041010126719001216251601001008004580000100800208001550011759111887539026709267082670866320666771601342008002080020200800208002026831267081180201100991001008000080000010080000390800390080039613543111511701600267251010080000800001002672926709267292672926729
16020426728200000141000126693212011251601411008004180000100800008000050011731831884444026704267282670866300366661601002008000080000200800008000026723267231180201100991001008000080000010080000008000000800390104300051101161126725010080000800001002670926709267292672926729
160204267282000000001012671920121625160145100800458000010080000800005001168754188401112668926708267286650036686160100200800008000020080000800002670826708118020110099100100800008000001008000039080035039800390135390005110116112672006080000800001002672926729267292670926729
160204267282000000450001267082120162516010010080045800001008000080000500116888018840111267042672326728663003668616010020080000800002008000080000267282672311802011009910010080000800000100800003908003900800396139430005110116112672006080000800001002672926729267292672926709
16020426728200000045000126797212121625160100100800438000010080000800005001168880188401102670926728267286630036666160100200800008000020080000800002672326723118020110099100100800008000001008000039080035039800356139390005110116112670566080000800001002670926709267292670926729
160204267282000000000012671901212025160141100800458000010080000800005001174628188732812670926728267286630036686160100200800008000020080000800002672326723118020110099100100800008000001008000039080000039800396035000051101161126705610080000800001002670926729267242672426729
16020426728200000045000126699212120251601451008004180000100800008000050011731831884444126689267282672866500366661601002008000080000200800008000026723267081180201100991001008000080000010080000008000000800006039000051101161126726610080000800001002670926729267292670926729
16020426728200000000001267172181216251601411008004580000100800008000050011687541884011026709267082670866500366861601002008000080000200800008000026708267231180201100991001008000080000010080000390800390080039613539000511011611267251010080000800001002674126729267092672426729
16020426708200000045000126713201216251601001008004580000100800008000050011688801884011026709267232672366300366811601002008000080000200800008000026708267081180201100991001008000080000110080000390800390398000001353900051101161126725106080000800001002672926724267292672426709

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.3342

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk instruction (07)mmu table walk data (08)09l2 tlb miss data (0b)0e0f1e2223243a3f4346494f51schedule 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)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)92inst branch cond (94)inst int alu (97)inst simd load (98)inst ldst (9b)9d9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache miss ld (a3)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acafb5b6bbl1d cache miss ld nonspec (bf)l1d tlb miss nonspec (c1)c2cdcfd0l1i tlb miss demand (d4)d5map dispatch bubble (d6)dbddfetch restart (de)e0eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600252673820010000016610032673207922251600291080064800001080000800005011673711886603126696267152673766813669516001020800008000020800008000026715267371180021109010108000080000110800202045800191016380169615943191050200041602226734131328000080000102673826738267162673826738
1600242673720010101006610032670307720251600291080065800001080000800005011701791887750126723267372673966813669516001020800008000020800008000026715267151180021109010108000080000010800202043800190016180000601943191050200021602226734131328000080000102671826738267382673826716
160024267372001010100671003267090771925160074108006580000108000080000501167371187893712671826715268406805367171600102080000800002080000800002673826737118002110901010800008000001080020204380059100618004061584319005020002160332673413018000080000102673826716267162673826738
160024267372001000100211003267353002125160074108006580000108000080000501168291188319002671826715267156682366951600102080000800002080000800002673726737118002110901010800008000001080020204380060100218004001590190050200031603326734131308000080000102671626738267382673826738
1600242673720010000006700032673127920251600291080063800001080000800005011677221886406026718267372673766823671716001020800008000020800008000026737267371180021109010108000080000010800211943800191016480040605843191050200021602226713131328000080000102673826716267382671626716
1600242673720011000006600032737807020251600291080019800001080000800005011692351878296126718267372673766813671716001020800008000020800008000026737267151180021109010108000080000010800201943801931016080040605943192050200021602326712131328000080000102673826738267382671626738
160024267372001000000661003267313700251600731080019800001080000800005011677221886409126718267372671566813671716001020800008000020800008000026737267371180021109010108000080000010800192043800591216180039611943190050200021602226734131328000080000102673826738267382671626716
16002426737200101000167000326709307125160075108006580000108000080000501169774187893712671826715267376681367171600102080000800002080000800002673726737118002110901010800008000001080020200800580006180039611944190050209021602226734131308000080000102673926738267382673826738
160024267372011000000210003267313772025160029108006580000108000080000501178590187893712671826737267376682367171600102080000800002080000800002671526737118002110901010800008000001080020204380058002218004260580192050200021602226734131308000080000102673826738267192673826738
16002426715200100000021000326730370025160073108006380000108000080000501168291187716012671826737267376681367171600102080000800002080000800002673726715118002110901010800008000011080019200800190006180040011943190050200021602226737131318000080000102673826738267162673826738