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 (single, post-index, H)

Test 1: uops

Code:

  st1 { v0.h }[1], [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)09l2 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)5e5f6061696d6emap 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)e0? int output thing (e9)eaebec? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
620062902023222001800001004675286991117899300010001000100010001000100050001090280000111921828286912887231030001000100030001000289542883511610011000100010000301000040100004013181934668593148125420504320938121863582835610001586212797140191000100010002892428834288332895629030
6200428851233250022000132100467228740101791830001000100010001000100110005000109048000070021756286202892131030001000100030001000287872888811610011000100010000201000000100030013183933568203082125820286327538111761582840110001580912831140401000100010002897828867288922903928915
620042898023218001800008800464428640011779030061000100010001000100110005000109138000011082168228612288713473000100010003000100028760287942161001100010001002003100200010020401292293676862314865720305314638121665612833210011571412986140541000100010002906829189290482962629550
6200429562240251116054528529004430289040117830300010001000100010001000100050001090980000710216942849028721910300010001000300010012870828702216100110001000100403010000225100030013142933769743156124920074319338082559632815710001520412681139621000100010002913929034290432889229004
62004288752342710220001321004793287570017593300010011001100010011000100050001090180000300217022848028776710300310001001300010012880628871116100110001000100020010001048510002001323795426877313185920225322538141557642842910001582113005138931000100010002885928896290302888828876
6200428864232240020000010048422857310177463000100010001000100010001000500010904800003182170228488287173103000100010003000100028670287051161001100010001000000100000010000001329795596896316095620180324938111658482836110001570412946136031000100010002869228806289662881128765
6200428723230230022000010048032863711176733000100010001000100010001000500010900800007182173428539286543103000100010003000100028672288291161001100010001000030100000010003022213001920968903134116020515333138092955572852810001573612957141831000100010002904629001290942909528949
620042906823319002500000004542289140018030300010001000100010001000100050001090780000500217272882429084330300010001001300010002909629103116100110001000100043010000038510003001314192076848311475520555326738091357572860810001606413034141011000100010002911829142293102913229046
62004291422351910240000100466428960101798530001000100010001000100010005000109048000080021754285902903931030001000100030001000288822887511610011000100010030301000000100020013214939268833151116120313325438171051612827410001580412871139071000100010002891828915288692893628896
6200429038232240018010132100475528846111808930001000100010001000100010005000109088000081021718287042901531030001000100030001000288402887711610011000100010000001000100100020013134919968683143145220033321838111959632847610001556112791137771000100010002891529035289102892228879

Test 2: throughput

Count: 8

Code:

  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [x6], x8
  st1 { v0.h }[1], [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)03mmu table walk data (08)09l2 tlb miss data (0b)18191e1f22243a3f46494f51schedule 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)branch mispred nonspec (cb)cfd5map dispatch bubble (d6)dbddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160206800406200000027000180025080252401048010080004800008010480004800004359034375884864002880015080040800405992435999824010020080000800002002400008000080040800401180201100991001008000080000100800000180080000105800011170511011601180037800008000080000801008004180041800418004180041
160204800406200000012310080025881252401008010080000800008010080000800004359014375884864000080015080040800405992435999824010020080000800002002400008000080040800401180201100991001008000080000100800000170080001004800011170511221602280037800008000080000801008004180041800418004180041
1602048004062100000040008002508025240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000000080001172800011170511221602280037800008000080000801008004180041800418004180041
1602048004062100000300000800258012524010080100800008000080100800008000043590143758848640000800150800408004059924359998240100200800008000020024000080000800408004011802011009910010080000800001008000000008000100280000100511221602280037800008000080000801008004180041800418004180041
1602048004062000000000008002508025240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000000080001202800000170511211601280037800008000080000801008004180041800418004180041
1602048004062000000030018002588125240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000017008000100080001100511011602280037800008000080000801008004180041800418004180041
1602048004062000000000018002580125240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000000080001002800011170511211602180037800008000080000801008004180162800418004180041
16020480040621000002130008014788125240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000017008000000280001100511221601180037800938000080000801008004180041800418004180041
1602048004062100000000018002588125240100801008000080000801008000080000435901437588486400008001508004080040599243599982401002008000080000200240000800008004080040118020110099100100800008000010080000000080001001067800011170511211601180037800008000080000801008004180041800418004180041
160204800406200000012300080025803252401008010080116800008010080000800004359014375884864000080015080040800405992435999824010020080000800002002400008000080040802851180201100991001008000080000100800000180080001100800011170511221602180037800008000080000801008004180041800418004180041

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)09l2 tlb miss data (0b)18191e1f22233a3f46494f51schedule 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)c2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600268004062000000063000800251111325240010800108000080000800108000080000440863938625406400000800158004080040599463600202400102080000800002024000080000800408004011800211091010800008000010800000170080001002800011000502018161898003780000368000080000800108004180041800418004180041
160024800406200000000000080025111122524001080010800008000080010800008000043584093758848640000080015800408004059946360020240010208000080000202400008000080040800401180021109101080000800001080000017008000100580001017005020341617188003780000198000080000800108004180041800418004180041
160024800406200000001220008002511101252400108001080000800008001080000800004358409375884864000008001580040800405994636002024001020800008000020240000800008004080040118002110910108000080000108000001700800011028000112000502019161914800378000008000080000800108004180041800418004180041
1600248004062100000003000800258832524001080010800008000080010800008000043584293758848640000080015800408004059946360020240010208000080000202400008000080040800401180021109101080000800001080007725008000800118000182571502019161818800378000008000080000800108004180041800418004180041
160024800406211010000120018002588325240010800108000080000800108000080000435842937588486400000800158004080040599463600202400102080000800002024000080000800408004011800211091010800008000010800000000800000038000101700502018161819800378000008000080000800108004180041800418004180041
16002480040620100000127001800251191252400108001080000800008001080000800004358413375884864000008001580040800405994636002024001020800008000020240000800008004080040118002110910108000080000108000001700800010048000111800502016431020800378000008000080000800108004180041800418004180041
1600248004062000000002000800251101252400108001080000800008001080000800004360753375884864000008001580040800405994636002024001020800008000020240000800008004080040118002110910108000080000108000782500800081088000182570502018161810800378000008000080000800108016280041800418004180041
16002480040620000000030008002580452524001080010800008000080010800008000043584293758848640000080015800408004059946360020240010208000080000202400008000080040800401180021109101080000800001080000017008006100280001000050201716817800378000008000080000800108004180041800418004180041
16002480040621000000000008002588325240010800108000080000800108000080000435842937629886400000800158004080040600073600202400102080000800002024000080000800408004011800211091010800008000010800000000800000028000111700502018161710801418000008000080000800108004180041800418004180041
160024800406200000000310080025083252400108001080000800008001080000800004358429375884864000008001580040800406007227600202400102080000800002024000080000800408004011800211091010800008000010800000000800011428000111700502013161818800378000008000080000800108004180041800418004180041