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

SCVTF (vector, fixed-point, 4H from 4H)

Test 1: uops

Code:

  scvtf v0.4h, v0.4h, #3
  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)031e3f4e51schedule uop (52)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map simd uop (7e)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd alu (9a)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073316112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
10043037231261254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf v0.4h, v0.4h, #3
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)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 alu (9a)9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache writeback (a8)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722500000061295382510100100100081051000050042771601300543003730131282758287621010020010166200100003008530037111020110099100100100001000000071031611296330100001003003830038300383003830038
1020430037225000000266295472510100100100001001000050042771601300183003730037282643287451010020010000204100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722400000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037225000087061295472510111126100001001000050042771601300183003730037282643287821010020210000204100003008530037111020110099100100100001000000071011621296330100001003003830038300383003830038
102043003722501000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296930100001003003830038300383003830038
102043003722500004200103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500000061295472510100100100001001000050042771601300183003730037282643287451010020010000204100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372240000171061295472510100100100001001000050042771601300183003730070282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03l2 tlb miss data (0b)18191e1f3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)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 alu (9a)9fl1d tlb access (a0)l1d tlb miss (a1)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acc2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003722500012019829547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000003006403162229629010000103003830038300383003830038
100243003722500012010329547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000100006402162229629010000103003830038300383003830038
100243003722500012010329547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000103006402162229629010000103003830038300383003830038
100243003722500012010329547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000003006402162229629010000103003830038300383003830038
10024300372250001206129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000100006402162229629010000103003830038300383003830038
100243003722400000103295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001020211019233207686644429878310000103035730320303683036730321
1002430360227077924528487829493150100711410056131105060428679803023430367303672832029289031106320111462210989303703036971100211091010100001044202418461006402162229629010000103003830038300853003830038
100243003722518794817640222948415710069161004814110507042866240303063036930413283091828897110632411135221132930371303669110021109101010000100200208548207932644229916510000103037030367300383037130369
100243035722501794870470942945720810094161006418115006642893280303423050830500283134028957115112411482221164630508305141011002110910101000010002004167212085321222330024410000103055830545302753055830084
10024300372250001201530294461731008611100801611500824287976030378305583055828323452897011534261177024111623051030560141100211091010100001004001022383006402164429845310000103036930371305573032130370

Test 3: throughput

Count: 8

Code:

  scvtf v0.4h, v8.4h, #3
  scvtf v1.4h, v8.4h, #3
  scvtf v2.4h, v8.4h, #3
  scvtf v3.4h, v8.4h, #3
  scvtf v4.4h, v8.4h, #3
  scvtf v5.4h, v8.4h, #3
  scvtf v6.4h, v8.4h, #3
  scvtf v7.4h, v8.4h, #3
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2505

retire uop (01)cycle (02)03mmu table walk data (08)09l2 tlb miss data (0b)191e1f3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)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 alu (9a)9fl1d tlb access (a0)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)fetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200391500000120722580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118116020036800001002004020040200402004020040
8020420039150000013813230258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100012251115118016020036800001002004020040200402004020040
8020420039150000000722580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
8020420039150000012030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100011351115118016020036800001002004020040200402004020040
80204200391500000120722580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
80204200391500000120302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118016020036800001002004020040200402004020040
80204200391500000360722580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000131115118016020036800001002004020040200402004020040
802042003915000001206212580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
80204200391500000120302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000231115118016020036800001002004020040200402004020040
80204200391500000120722580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118016020036800001002004020040200402004020040

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2505

retire uop (01)cycle (02)03l2 tlb miss data (0b)1e1f3a3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)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 alu (9a)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391500120245258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010105024151616152003680000102004020040200402004020040
80024200391500120287258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010035024181617162003680000102004020040200402004020040
80024200391500120245258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010105024151617142003680000102004020040200402004020040
80024200391510120287258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135024171617182003680000102004020040200402004020040
80024200391500120245258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135024131614122003680000102004020040200402004020040
800242003915001202351258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010035024181619182003680000102004020040200402004020040
8002420039150012028725800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502417161792003680000102004020040200402004020040
8002420039150000287258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135024161617142003680000102004020040200402004020040
8002420039150000245258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135024171717142003680000102004020040200402004020040
8002420039150000245258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010005024161619162003680000102004020040200402004020040