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, 8B)

Test 1: uops

Code:

  st3 { v0.8b, v1.8b, v2.8b }, [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, 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)l2 tlb miss instruction (0a)l2 tlb miss data (0b)18191e1f23243a3f464951schedule 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)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)st unit uop (a7)l1d cache writeback (a8)acafl1d cache miss st nonspec (c0)cfd0d2l1i cache miss demand (d3)l1i tlb miss demand (d4)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0eaebec? ldst retires (ed)? simd retires (ee)f5f6f7f8fd
6400429562344133000930146552855200182864000200020002000200021610160002721794289212940231040002000200040006000291472921211610011000100020000620026592000012878952869213093846203983196381515514628439160441306714739200020002935129366292812939329245
64004292932270201501031004535290990018335400020002000200020002162316000121759289492942232840002000200040006000292892911211610011000100020000020006532000013161923868463082547203863300381511505228612163211315715071200020002929529426293152940029366
6400429486228016240001321104675290390018246400020002000200020002161216000921798288872930531040002000200040006000292272928321610011000100020000420007632000413374921069043169650202533262381313474128578159641317014809200020002932929292291452940129407
64004293332280161400000104727290370018153400020002000200020002161716000521779288532924231040002000200040006000292872914411610011000100020000020006162000412832916268503016951203413329381514474828578163001336914675200020002929229397292312934429455
64004293452280162000000004559289750218174400020002000200020002161916000121828289442924531040002000200040006000291822910611610011000100020000020002020004129969277688531711150203423258380815544728533161371312514583200020002968029525298832956929459
6400429401238021170004510500472329252001839340002000200020002000216001600002186129162294513104000200020004000600028871289791161001100010002000062002302002013046951669823157949196913239380721494928338151741239314053200020002869128749288492864728685
64004285972210161400003004787285142217727400020002000200020002161216000212177728497288233104000200020004000600028843287731161001100010002000062000022000413271931968993080446198373242381810524928241157021271614416200020002883928894289162890528763
64004287512320162100001004630286822217859400020002000200020002162816000102176028651288863104000200020004004600028943289362161001100010002000042000002000013330947168833138650197643226380720454628242151731261814159200020002874328666287422880228785
640042881722302218000010046882875922176714000200020002000200021611160001021770285062867831040002000200040006000287862867111610011000100020000420003020024132139212697131301146197963257380818485328251154621250614152200020002866828875287432879228736
64004287402220191800001004665286080017666400020002000200020002162516000821786285422885331040002000200040006000287262875411610011000100020000420000020004132039461693131341045197773197381310495528241157621253714379200020002888928882287612879128750

Test 2: throughput

Count: 8

Code:

  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [x6]
  st3 { v0.8b, v1.8b, v2.8b }, [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): 1.0007

retire uop (01)cycle (02)03l1d tlb fill (05)mmu table walk data (08)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)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)c2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3202078023562310001413138195106170180378161619371324845100166424160060102160236160108500250813113039748018580381802171791313332032620016024016012020032048048072080217802214180201100991001008000080000100160000140011600160020160002163614000510911711800461600001600001008005280051800608004580049
3202048006062011000012141026681800351616025325405100165010160000100160000160000500263984712978178003580050800580341320100200160000160000200320000480000800578005811802011009910010080000800001001600140420016001610201600021600000510911711800481600001600001008005280059800518005980051
3202048004562011000009105019080035161602532523610016000516000010016000016000050020793781284018800258005880060033108320100200160000160000200320000480000800458005011802011009910010080000800001001600151534001600160019160002143614000510911711800461600001600001008005280059800608005180059
32020480060620110100017103575180044161602532383710016430716000010016000016000050023998891293719800338005880058034232010020016000016000020032000048000080048800451180201100991001008000080000100160000150001600160117160002143614100510911711800411600001600001008005980060800538005980052
320204800506211000000170045471800431616025326100100165339160000100160000160000500231988712999518002580058800580332320100200160000160000200320000480000800608005821802011009910010080000800001001600150340116001600171600022360000510933511800551600001600001008043880231800598005080051
320204800456200000000191042151800351616025326574100162915160000100160000160000500231989912980318002580058800500330320100200160000160000200320000480000800498005911802011009910010080000800001001600151434101600160018160002163614000510911711800471600001600001008005380060800498005180050
320204800606211010000141047071800441616025325790100164226160000100160000160000500247987912969408003380050800600349320100200160000160000200320000480000800598004911802011009910010080000800001001600151436001600160121160002163614000510911711800481600001600001008005180059800518005180050
32020480059620100100123103636180033160025325364100163816160000100160000160000500367914413074178003380050800580340320100200160000160000200320000480000800588005711802011009910010080000800001001600151536001600020121160000163614100510911711800471600001600001008005280059800458005980050
32020480049620100000014105641180044161602532322510016507216000010016000016000050025598681307287800358005080058033132010020016000016000020032000048000080051800591180201100991001008000080000100160014154220160014001816000216014000510911711800461600001600001008004680059800608004580059
32020480060621100100020103832180035016025324843100164504160000100160000160000500239992012836868002480060800470326320100200160000160000200320000480000800508005011802011009910010080000800001001600151436001600161018160002163614000510911711800551600001600001008005180047800538005980051

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f222324373f46494f51schedule 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)6061696b6d6emap stall dispatch (70)flags prf full (73)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? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
32002780072620000063000455680029160025325020101641491600001016000016000050214998513169740080023080045800440032732001020160000160000203200004800008004880048118002110910108000080000101600000340016000010912160002034050193174380042160000160000108004680211800468004580045
32002480049620000063000632880034016025324068101646461600001016000016000050223977013026510080024080048800440033132001020160000160000203200004800008004580045118002110910108000080000101600000340016000000216000020050193173480387160000160000108004680046800508004680045
3200248004462010000300039348003416160253265631016459916000010160000160000502158255129549700800240800448004300326320010201600001600002032000048000080045820282918002110910108000080000101600000340016000000216000420050193173380042160000160000108004680045800458004580213
320024800446200000030004802800301616025324006101647681600001016000016000050223974212950400080025080045800450033132001020160000160000203200004800008004580045118002110910108000080000101600000340016000200016000220050193173380042160000160000108004580045800458005080045
3200248004662100000300062518003001602532442010166251160000101601181600005020791071290369008002408004480045890326320010201600001600002032000048000080044800451180021109101080000800001016006003400160002002160002234050193173380042160000160000108004680046800508004580045
320024800446200000030004502800301616025324348101651211600001016000016000050207939512949730080024080046800440032632001020160000160000203200004800008004980044118002110910108000080000101600000340016000200516000000050193173380046160000160000108004680045800498004580045
32002480044621000003000396080034000253241991016399616000010160118160000502217011131068000800230800458004300326320010201600001600002032000048000080049800491180021109101080000800001016000003400160000108160002234050193173380046160000160000108004580050800458004580044
3200248004462000010300058478003116160253243581016756216000010160000160000502078935130050800800250800458004400326320010201600001600002032000048000080044800451180021109101080000800001016000003400160002002160002234250193179380041160000160000108004580046802128004680044
3200248004962000003300042658003516160253257341016264316000010160000160000502169115129654900800230800458004500327320010201600001600002032000048000080044800441180021109101080000800001016000003400160002002160000234050192173380041160000160000108004680050800468004680044
320024800496210000132300051218003016160253242891016605316000010160000160000502158439129638700800230800448004800326320268201601201600002032000048000080045800491180021109101080000800001016000003400160000002016006220050193172380041160000160000108004680050802088004580049