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 (scalar, fixed-point, D from D)

Test 1: uops

Code:

  scvtf d0, d0, #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)03181e3f4e51schedule 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)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000373216332629100030383038303830383038
1004303723039525472510001000100039816013018303730372414328951000100010003037303711100110000373416332629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110000075316332629100030383038303830383038
1004303722006125472510001000100039816003018303730372414328951000100010003037303711100110000373316332629100030383038303830383038
10043037230010325472510001000100039816003018303730372414328951000100010003037303711100110000373416332626100030383038303830383038
100430372301210325472510001000100039816003018303730372414328951000100010003037303711100110000673316332626100030383038303830383038
1004303722006125472510001000100039816013018303730372414328951000100010003037303711100110001373316332629100030383038303830383038
10043037230126125472510001000100039816013018303730372414328951000100010003037303711100110000373416332629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110001373316332629100030383038303830383038
100430372301210325472510001000100039816013018303730372414328951000100010003037303711100110000373316442626100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf d0, d0, #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)09l2 tlb miss data (0b)1e3f4e51schedule 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)696d6emap 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 miss (a1)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204300372330003310329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
10204300372250001210329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
1020430037225000010329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
10204300372250001210329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
1020430037225000126129547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000100071011611296330100001003003830038300383003830038
1020430037224000012429547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000100071011611296330100001003003830038300383003830038
1020430037224000010329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
1020430037225000010329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038
1020430037225000010329547251010010010000100100005004277160300183003730037282643287451010020010000200100003003730037111020110099100100100001000103071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3a3f4e51schedule 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)60696b6d6emap 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)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372250000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000003402954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000001662953825100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402163429924410000103041730424304643045330371
100243041622711881068704049942947516910080161006412112005542866241303060304523046128309222889611214241119224111453041330452911002110910101000010002042234307933813329629010000103003830038300383003830038
1002430037225000014647921530729475171100791410072131120065428932813034203046130463283214028936103692211326261081530448304179110021109101010000100021225160280931012329977310000103046330369303243041530455
10024304182280199118879203105294661591008512100691911350714287976130378030607306052832548289591151724116362011812305573055412110021109101010000104220030518087441054330102010000103003830038300383003830038
1002430037233000012005949294571701006313100001010000504277160130018030273305092828632876710162241147222113133036830560101100211091010100001020310028083953229917410000103041830558304133003830038
1002430037233010214196804100295472510010101000010100005542920321301620304643041728332442897011213201115024113163031930556711002110910101000010003101670506402562230006510000103032330321306053027530469
100243045123711139119179204252952061100281410016141060071427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  scvtf d0, d8, #3
  scvtf d1, d8, #3
  scvtf d2, d8, #3
  scvtf d3, d8, #3
  scvtf d4, d8, #3
  scvtf d5, d8, #3
  scvtf d6, d8, #3
  scvtf d7, d8, #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)031e1f3f51schedule 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)acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200581503072258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100030111511801600200360800001002004020040200402004020040
80204200391502410872258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100030111511801600200360800001002004020040200402004020040
802042003915027072258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
8020420039150120722580108100800081008002050064013212002020039200399977610068801202008003220080032200392003911802011009910010080000100100111511801600200360800001002004020040200402004020040
80204200391500072258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
802042003915012030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100132111511801600200360800001002004020040200402004020040
802042003915024030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
802042003915030357258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100030111511801600200360800001002004020040200402004020040
802042003915012030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
802042003915012072258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801600200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03l2 tlb miss instruction (0a)1e3f51schedule 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)accfl1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391500102402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050201111611122003680000102004020040200402004020040
800242003915000402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200121614122003680000102004020040200402004020040
800242003915000402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200131612112003680000102004020040200402004020040
800242003915001540258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010005020012161292003680000102004020040200402004020040
8002420039150027402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200111613112003680000102004020040200402004020040
8002420039150001142580010108009710803175064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200131614122003680000102004020040200402004020040
800242003915000402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200151613112003680000102004020040200402004020040
8002420039150015402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200131612122003680000102004020040200402004020040
8002420039150015402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200111611112003680000102004020040200402004020040
800242003915600402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100050200111611122003680000102004020040200402004020040