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, integer, S from S)

Test 1: uops

Code:

  scvtf s0, s0
  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)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073316112629100030383038303830383038
100430372396125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372208225472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303722361254725100010001000398160130183037303724143289510001000100030373037111001100004873116112629100030383038303830383038
1004303723126125472510001000100039816003018303730372414328951000100010003037303711100110002073116112629100030383038303830383038
10043037230612547251000100010003981600301830373037241432895100010001000303730371110011000112673116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf s0, s0
  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)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)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)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)acbranch 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
10204300372250000000138295472510100100100001001000050042771601300183003730037282716287411010020010008204100083003730037111020110099100100100001000001011171701601296450100001003003830038300383003830038
1020430084225000051880103295472510100100100001001000050042771601300183003730037282716287411010020010008200100083008630037111020110099100100100001000001011171801600296460100001003003830038300383003830038
102043003722500001200166295472510100100100001001000050042771601300183003730037282643287451010020010165200100003003730037111020110099100100100001000001300071011611296330100001003003830038300383003830038
10204300372240000001170295472510100100100001001000050042771601300183003730037282643287581010020010000200100003003730037111020110099100100100001000001300071011611296330100001003003830038300383003830038
102043003722500001200103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000001300071011611296330100001003003830038300383003830038
10204300372250000000103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000300071011611296330100001003003830038300383003830038
10204300372250000120061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000300071011611296330100001003003830038300383003830038
10204300372250000120061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000011300071011611296330100001003003830038300383003830038
102043003722400001200189295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000001000071011611296330100001003003830038300383003830038
102043003722500001200103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000300071011611296330100001003003830038300383003830038

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)18191e1f3a3f4e4f51schedule 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)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1002430037225000012001262954702510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000010306404164329629010000103003830038300383003830038
1002430037225000012001242954702510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000010006404164329629010000103003830038300383003830038
10024300372250000120012629547025100101010000101000050427716003001830037300372828632876710010201000020100003003730037211002110910101000010000102306404164229629010000103003830038300383003830038
100243003722500000006129547025100101010000101000050427716003001830037300372828632876710010201000020101623003730037111002110910101000010000102479828304564329973110000103046630320305093051030516
1002430496229114101197880060132945709810094191008015115008842906800303783046330464283254328954115202011474261048430507302251111002110910101000010000022798308517967529953310000103046530461304603046630465
10024304582280110913208801674129547025100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010222021105607267337429629010000103003830038300383003830038
100243003722501866724400362829511025100101010000101000050427716003001830037300372828632876710164201000020114523017830275811002110910101000010000001407506403164429629010000103032230038303693037230226
10024304172260117118835203060295380185100651710000101000065427716003001830121304052830737288231091424113112010486304633022691100211091010100001002000306405244629629210000103003830134300383041830038
10024302632260084150005243295474622510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006404164329629010000103003830038300383003830038
100243003722500000004612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006404163429629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  scvtf s0, s8
  scvtf s1, s8
  scvtf s2, s8
  scvtf s3, s8
  scvtf s4, s8
  scvtf s5, s8
  scvtf s6, s8
  scvtf s7, s8
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2506

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200491500000007625801081008000810080020500640132020108201122003999771510015802302008003220080032200392003911802011009910010080000100010311151181350020036800001002010020091200522009320040
802042003915000001202594580212100800121008012850064016402006120097201009987181001780228202801432008013720098200882180201100991001008000010030447511151360520020036800001002010220099200952010320091
8020420144150011116888321648021310080108100801325006409640200622003920039997769990801202008013820280142201092010121802011009910010080000100000011151180510020086800001002004020040200402004020040
80204200391501000120722580108100800081008002050064013202007320090200909987129990802322028013320080140200982009111802011009910010080000100010611151180160120036800001002004020040200402004020040
80204200391500000120156258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100010611151180160020036800001002004020040200402004020040
8020420039150000030114258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151180160020036800001002004020040200402004020040
802042003915000000093258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100010311151180160020036800001002004020040200402004020040
8020420039150000012030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151180160020036800001002004020040200402004020040
8020420039150000012072258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100010011151180160020036800001002004020040200402004020040
8020420039150000012072258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100010311151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e3f51schedule 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)5f696d6emap 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
800242005015004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000502015166162003680000102004020040200402004020040
80024200391500822580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100050206166162003680000102004020040200402004020040
800242003915008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000502016165132003680000102004020040200402004020040
8002420039150040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020161615162003680000102004020040200402004020040
800242003915008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000502016161652003680000102004020040200402004020040
8002420039150154525800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001010502016161462003680000102004020040200402004020040
800242003915001242580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100050206161662003680000102004020040200402004020040
80024200391500837258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020161613162003680000102004020040200402004020040
8002420039150124025800101080000108000050640000020020200392003999963100198043320800002080000200392003911800211091010800001000502061613162003680000102004020040200402004020040
800242003915008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000502016166162003680000102004020040200402004020040