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, 2S)

Test 1: uops

Code:

  st1 { v0.2s, v1.2s }, [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)03l1i tlb fill (04)l1d tlb fill (05)mmu table walk instruction (07)mmu table walk data (08)09l2 tlb miss instruction (0a)l2 tlb miss data (0b)18191e1f23243a3f464951schedule 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)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)a9acafbcl1d cache miss st nonspec (c0)l1d tlb miss nonspec (c1)c2c9cfd0d2l1i 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
620062964323741200511061004687291441118385300010001000100010001000100050001089480001000217382920329490310300010011000300020002945029557116100110001000100120010010111001131101313994346903316106620903328438161954552877810001654513491144831000100010002951229513294502925929445
62004294942360100001100100460829290001850030001000100010001000100010005000109108000900217382919729484710300010001000300020002933129413116100110001000100133110010211000131201329794616875317805020868340238111053512890510001614913234143241000100010002946629608295992951629316
620042951423611010010001004626292720018590300010001000100010001000100050001090380001100216852928929415111030001000100030002000293712940411610011000100010032211001014011000131001309191756951317105120785326938141855582871610001617113150147081000100010002935529439294782937129468
62004294862361101001000100474929235001852530001000100010001000100010005000109348000100021702290482947081030001000100030002000294242948611610011000100010032311001013861001131101327693546925321705220824331738111156502876510001612713546145061000100010002941929507294272946929469
62004295152360101001110100472129237111846130001000100010001000100010015000109068000600217212911329435310300010001000300020002938929433116100110001000100213110010111000101101322593966924313305120963325438101462512884810001600113478146071000100010002963129515296812957829647
620042965723821010010001004672292851018375300010001000100010001000100050001090880001000217142911329525310300010001000300020002927229387116100110001000100313110010011000101001328493356933313604620800333938101753552870710001612913137143411000100010002926829330293582928829386
62004293272350101001000100457829287001829530001000100010001000100010005000109018000600217442911029227310300010001000300020002928129204116100110001000100223110011111000101001322293416938320305520682318938071150482879710001629613299143551000100010002955929445294552936629369
6200429358238110100100144100460829238001829630001000100010001000100010005000109008000610217372898029349310300010001000300020002942829510116100110001000100123210010211000131201318592386895313816120686329438171560552874610001620213382144081000100010002938229444294672944329279
62004293762360100000000100458729232001842630001000100010001000100010005000109088000300217592913929421310300010001000300020002930029298116100110001000100220210010111000131101332793476931319105520842337638111053562876410001600213176143581000100010002948429413293942928929472
620042947623801010010061004757290400018421300010001000100010001000100050001090580001000217242910229370310300010001000300020002930329438116100110001000100333010010111000101101316594986933316305520802336238071161512860910001598413474142041000100010002933929446296292939529437

Test 2: throughput

Count: 8

Code:

  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [x6], x8
  st1 { v0.2s, v1.2s }, [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)09l2 tlb miss data (0b)18191e1f2224373a3f46494f51schedule 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 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)c2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16020680040620100000200347508002588025242329801008196980000801008000080000435901437588486529068001508004080040599243599982401002008000080000200240000160000800408004011802011009910010080000800001008000001728080001022800011170051101161180037800008000080000801008004180041800418004180041
16020480410643000101794200128518002580325244395801008011580000801008000080000435901437755466435258022508004080319603873599982401002008000080000200240000160000800408004011802011009910010080000800001008000001729080001204800001190051101161180037800008000080000801008004180041800418004180041
1602048004065200000123001160080025881252402138010080096800008010080116800004359014375884867374880015080040800405998635999824010020080000800002002400001600008004080040318020110099100100800008000010080000017008000020780001100051102161180037800008000080000801008004180041800418016380041
160204801616420101021400117080025883257251549820218516180000801008011580000435901437588486479298001508004080040599243599982401002008000080120200240000160000800408004011802011009910010080000800001008000002100800010012800021210051101161180037800008000080000801008016380041800418004180041
16020480040644000001414005192080025887125242329801918115080000801008000080000435901437630846404808001508004080040599243599982404402008000080000200240000160000802858004011802011009910010080000800001008000002100800010013800021210051271161180037800008000080000801008004180163801638004180041
160204800406470110021920034030800258812524019980100852808000080100800008010843590143758848640378801200800408004059924359998240100200800008000020024000016000080040800401180201100991001008000080000100800000220080001202480001102051101161180037800008000080000801008004180041800418136980413
160204800406430000012300117080025883252455728010084303800008010080000804324363838376313265531880015080040800405992436016124010020080000801202002400001602408004080040118020110099100100800008000010080000017008006110437800001170051102161280037801838000080000801008004180041800418004180041
1602048004064300000320012160801448002524018680284823098000080100801158000043590143758848652906800150800408004059924359998240100200801208000020024000016000080040800402180201100991001008000080000100801200029080000102619800010174051101251180037800008000080000801008004180041800418004180041
1602048028665300000285300197908015088025240217801008517480000801008023680000436853437630846402708001508004080160599243600812401002008000080120200240000160000801628004011802011009910010080000800001008000001700800000024580001100051101161180037800008000080000801008004180041800418004180041
1602048004064300000123001454080025801252415808010082673800008010080000800004359014375884865550680015080040800405992435999824010020080000800002002400001600008004080040118020110099100100800008000010080000017008000100226800011170051101161180037800008000080000801008004180041800418004180041

1000 unrolls and 10 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)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)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)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)c2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160026800406201010009016561800251111225241389800108473880000800108000080000435841737588486542310800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080000725008000801880001125710502021633800378000008000080000800108004180041800418004180041
1600248004062000000090201800251002252400318001082822800008001080000800004358409375884865423108001580040800405994636002024001020800008000020240000160000800408004011800211091010800008000010800077250280008011180001825710502031622800378000008000080000800108004180041800418004180041
1600248004062010000127056851800258112252400338001081379800008001080000800004358409375884865408308001580040800405994636002024001020800008000020240000160000800408004011800211091010800008000010800077250080008001180001725700502021633800378000008000080000800108004180041800418004180041
1600248004062110000120016193800251111125241781800108375880000800108000080000435840537588486400530800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080007725018000012148000180720502021633800378000008000080000800108004180041800418004180041
160024800406211000012901519180025910625244752800108178080000800108000080000435841337588486441700800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080000725008000700148000170700502031633800378000008000080000800108004180041800418004180041
160024800406211100009046981800250822524116380010800278000080010800008000043584293758848651367080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000702500800080088000080000502031622800378000008000080000800108004180041800418004180041
16002480040621111000120568608002511112252400238001084742800008001080000800004358405375884864005108001580040800405994636002024001020800008000020240000160000800408004011800211091010800008000010800077170180008001180000825700502021622800378000008000080000800108004180041800418004180041
160024800406211000009046981800250101252447528001081380800008001080000800004358417375884864174308001580040800405994636002024001020800008000020240000160000800408004011800211091010800008000010800077250180008011480001825700502031633800378000008000080000800108004180041800418004180041
160024800406201000024902355180025110225240020800108069580000800108000080000435840937588486434440800158004080040599463600202400102080000800002024000016000080040800401180021109101080000800001080007725008000811280001125710502021622800378000008000080000800108004180041800418004180041
160024800406200000001201185180025111122524207980010813788000080010800008000043584053758848645173080015800408004059946360020240010208000080000202400001600008004080040118002110910108000080000108000782500800080088000180700502031622800378000018000080000800108004180041800418004180041