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, integer, 4S from 4S)

Test 1: uops

Code:

  scvtf v0.4s, v0.4s
  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)03181e1f3f4e51schedule 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
10043037220006125472510001000100039816013018303730372414328951000100010003037303711100110000973216332629100030383038303830383038
100430372200061254725100010001000398160030183037303724143289510001000100030373037111001100002173316332629100030383038303830383038
100430372300015625472510001000100039816003018303730372414328951000100010003037303711100110000073316332629100030383038303830383038
10043037230006125472510001000100039816003018303730372414328951000100010003037303711100110000073316332629100030383038303830383038
10043037220001044254725100010001000398160030183037303724143289510001000100030373037111001100002473316332629100030383038303830383038
1004303723000842547251000100010003981600301830373037241432895100010001000303730371110011000010273316332629100030383038303830383038
10043037230006125472510001000100039816003018303730372414328951000100010003037303711100110000973316332629100030383038303830383038
100430372300061254725100010001000398160130183037303724143289510001000100030373037111001100004573316332629100030383038303830383038
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000073316332629100030383038303830383038
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000073316332629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf v0.4s, v0.4s
  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)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)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)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
102043003722500147295472510100100100001001000050042771600300183003730037282716287401010020010008200100083003730037111020110099100100100001000011171701600296450100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282716287411010020010008200100083003730037111020110099100100100001000011171701600296450100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282716287401010020010008200100083003730037111020110099100100100001000011171701600296450100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282717287401010020010008200100083003730037111020110099100100100001000011171701600298550100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500145295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500919295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372240061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500145295472510100100100001001000050042771600300183003730037282753287451010020010000200100003003730037111020110099100100100001000000071011621296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk instruction (07)mmu table walk data (08)l2 tlb miss instruction (0a)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)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 access (a0)l1d tlb miss (a1)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372250000030191295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306407166429678010000103003830038300383003830038
100253003722510000120103295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306425168629629010000103003830038300383003830038
10024300372250000000166295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306406165629629010000103003830038300383003830038
100243003722500000120233295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306405165329631010000103003830038300383003830038
100243003722500000120187295472510010101000010100005042771603001830037300372828632876710012201000020100003003730037111002110910101000010000000306405165529629010000103003830038300383003830038
100243003722500000120235295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306406166429629010000103003830038300383003830038
100243003722500000120166295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010306406166629629010000103003830038300383003830038
100243003722500000120187295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000050306406167629629010000103003830038300383003830038
100243003722500000120208295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000010006405166429629210000103003830038300383003830038
100243003722500000120254295472510010101000010100005042771603001830037300372828632876710010201000020100003003730037111002110910101000010000000306405165729629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  scvtf v0.4s, v8.4s
  scvtf v1.4s, v8.4s
  scvtf v2.4s, v8.4s
  scvtf v3.4s, v8.4s
  scvtf v4.4s, v8.4s
  scvtf v5.4s, v8.4s
  scvtf v6.4s, v8.4s
  scvtf v7.4s, v8.4s
  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 instruction (07)mmu table walk data (08)l2 tlb miss instruction (0a)18191e1f3a3f51schedule 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 access (a0)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420058150101000023725801081008000810080020500640132200202003920039997769990801202008003220080032200392003911802011009910010080000100000111512281681020036800001002004020040200402004020040
8020420039150101000023725801081008000810080020500640132200202003920039997769990801202008003220080032200392003911802011009910010080000100000111512281610520036800001002004020040200402004020040
80204200391501010000237258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000020711151228169920036800001002004020040200402004020040
802042003915010100002372580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151223163820036800001002004020040200402004020040
802042003915010100002372580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151229169920036800001002004020040200402004020040
8020420039150101000023725801081008000810080020500640132200202003920039997769990801202008003220080032200392003911802011009910010080000100000111512210163920036800001002004020040200402004020040
802042003915010100002372580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151223168820036800001002004020040200402004020040
802042003915010100002372580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151228168820036800001002004020040200402004020040
802042003915010100002372580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151228168920036800001002004020040200402004020040
8020420039150101000023082580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151228168820036800001002004020040200402004020040

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)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)60696b6d6emap stall dispatch (70)simd prf full (72)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
800242005115002782258001010800001080000506400000200200200392003999960310019800102080000208000020039200391180021109101080000101350201316552003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200203200392003999960310019800102080000208000020039200391180021109101080000100350201216452003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200200200392003999960310019800102080000208000020039200391180021109101080000100350205161062003680000102004020040200402004020040
800242003915000822580010108000010800005064000012002002003920039999603100198001020800002080000200392003911800211091010800001013502010164102003680000102004020040200402004020040
80024200391500082258001010800001080000506400000200200200392003999960310019800102080000208000020039200391180021109101080000101350201116382003680000102004020040200402004020040
80024200391500456125800101080000108000050640000120020020039200399996031001980010208000020800002003920039118002110910108000010105020516382003680000102004020040200402004020040
8002420039150051822580010108000010800005064000012002002003920039999603100198001020800002080000200392003911800211091010800001013502011161052003680000102004020040200402004020040
800242003915000705258001010800001080000506400000200200200392003999960310019800102080000208000020039200391180021109101080000101350209161162003680000102004020040200402004020040
800242003915001240258001010800001080000506400001200200200392003999960310019800102080000208000020039200391180021109101080000100350205161052003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020020039200399996031001980010208000020800002003920039118002110910108000010005020516652003680000102004020040200402004020040