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, 2S from 2S)

Test 1: uops

Code:

  scvtf v0.2s, v0.2s
  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
1004303722061254725100010001000398160030183037303724143289510001000100030373037111001100017073116112629100030383038303830383038
1004303723040625472510001000100039816013018303730372414328951000100010003037303721100110000073116112629100030383038303830383038
1004303722126125472510001000100039816013018303730372414328951000100010003037303711100110008073116112629100030383038303830383038
100430372206125472510001000100039816003018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110009373116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100010373116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110005073116112629100030383038303830383038
1004303722126125472510001000100039816003018303730372414328951000100010003037303711100110003373116112629100030383038303830383038
10043037231261254725100010001000398160030183037303724143289510001000100030373037111001100021073116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100010073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf v0.2s, v0.2s
  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)031e3f4e51schedule 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)accdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204300372250103295472510100100100001001000050042771601300183003730037282643287451027220010000200100003003730037411020110099100100100001003607101161129633100001003003830038300383003830038
102043003722512103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001307101161129633100001003003830038300383003830038
102043003722512103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003008430037111020110099100100100001000307101161129633100001003003830038300383003830038
10204300372250103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001007101161129633100001003003830038300383003830038
10204300372250103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001307101161129633100001003003830038300383003830038
1020430037225061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001307101161129633100001003003830038300383003830038
102043003722512103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001307101161129633100001003003830038300383003830038
10204300372250768295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001007101161129633100001003003830038300383003830038
102043003722512103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001001307101161129633100001003003830038300383003830038
10204300372251261295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000307101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)09l2 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 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 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
100243003722500010000536329466171100801210048161135067428797613027030417304132833439289191076324113242401097830461304511011002110910101000010000122491308275883529982310000103027430416304613045330371
1002430452232111981212880058572946617310079131006415113506042879760303423046530459282994028938113622411458200106553055430512101100211091010100001000010306402162229667010000103031430462302283027430134
1002430320229111271188352068629547251001913100081010000664283920030162301303045228313412882410312201066922011147303213031981100211091010100001000000348083484229917210000103041630275302253003830038
1002430037225000002100518829493981007913100641110300724282568030018300373003728286328767100102010163200100003003730037111002110910101000010222022250506402162229629010000103027630320305083027630273
100243046523501067795704157272954725100101010000101000050427716003030630131301322828624289171001020100002031810000300373003711100211091010100001000010306402162229629010000103003830038300383003830038
100243003723200000000612954725100101010000101000050427716013001830037300372828632876710010201000020010000300373003711100211091010100001000010006402162229629010000103003830038300383003830038
100243003722400000000612954725100101010000101000050427716003001830037300372828632876710010201000020010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
1002430037224000000001452954725100101010000101000050427716003001830037300372828632876710010201000020010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716013001830037300372828632876710010201000020010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372330000039004762954725100101010000101000050427716013001830037300372828632876710010201000020010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  scvtf v0.2s, v8.2s
  scvtf v1.2s, v8.2s
  scvtf v2.2s, v8.2s
  scvtf v3.2s, v8.2s
  scvtf v4.2s, v8.2s
  scvtf v5.2s, v8.2s
  scvtf v6.2s, v8.2s
  scvtf v7.2s, v8.2s
  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)l2 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)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200581501112302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020040200402004020040
80204200391501112302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000311151181161120036800001002004020040200402004020040
80204200391501112722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020040200402004020040
8020420039150110722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020091200402004020040
80204200391501131602580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000311151181161120036800001002004020040200402004020040
80204200391501112722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020040200402004020040
80204200391501136722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020040200402004020040
80204200391501112722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000011151181161120036800001002004020040200402004020040
802042003915011125472580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000311151181161120036800001002004020040200402004020040
80204200391501112722580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001001311151181161120036800001002004020040200402004020040

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)1e1f3f51schedule 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)9fst unit uop (a7)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391500908225800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020151612162003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020141615162003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020151614112003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020121616132003680000102004020040200402004020040
8002420039150000102725800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001002005020131613162003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020141616132003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020141616132003680000102004020040200402004020040
8002420039150000402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100000502011169142003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020151613132003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020161616122003680000102004020040200402004020040