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, 8H from 8H)

Test 1: uops

Code:

  scvtf v0.8h, v0.8h
  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
1004303722126125472510001000100039816003018303730372414328951000100010003037303711100110000073116112699100030383038303830383038
100430372312612547251000100010003981600301830373037241432895100010001000303730371110011000116873116112629100030383038303830383038
1004303723126125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100011273116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303722126125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100003373116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf v0.8h, v0.8h
  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)03l2 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)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)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722501210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001030071011611296330100001003003830038300383008230038
102043003722501210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001030071011611296330100001003003830038300383003830038
102043003722401210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001000071011611296330100001003003830038300383003830038
102043003722501210329547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100001000071011611296330100001003003830038300383003830038
10204300372250126129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001000071011611296330100001003003830038300383003830038
102043003722401210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001030071011611296330100001003003830038300383003830038
102043003722501210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100001030071011611296330100001003003830038300383003830038
102043003722501210329547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100001000071011611296330100001003003830038300383003830038
1020430037225006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000030073511611296330100001003003830038300383003830038
102043003722501210329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100004000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)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 miss (a1)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acbcc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1002430037225000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
1002430037224000000612954725100101010000161000050427851213001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100003506006402162229629010000103003830038300383003830038
1002430037225000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000409006402162229629010000103003830038300383003830038
1002430037225000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000300006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100002106006402162229629010000103003830038300383003830038
1002430037224000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
1002430037225000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000406006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767101602010000201000030037300371110021109101010000100004103006402162229629010000103003830038300383003830038
1002430037225000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000003006402272229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  scvtf v0.8h, v8.8h
  scvtf v1.8h, v8.8h
  scvtf v2.8h, v8.8h
  scvtf v3.8h, v8.8h
  scvtf v4.8h, v8.8h
  scvtf v5.8h, v8.8h
  scvtf v6.8h, v8.8h
  scvtf v7.8h, v8.8h
  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)03091e3f51schedule 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)fetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200611500030618010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100101115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030808010810080008100800205006401321200202003920039997769990801202008003220080032200922003921802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391490030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118116020036800001002004020040200402004020040
802042003915000220258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03mmu table walk data (08)181e3f51schedule 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)5f60696b6d6emap 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)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8002420051150000822580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001001035020416662003680000102004020040200402004020040
80024200391500012822580010108000010800005064000011200200200392003999963100198001020800002080000200392003911800211091010800001005035020516542003680000102004020040200402004020040
80024200391500012822580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001001005020516662003680000102004020040200402004020040
80024200391500012822580010108000010800005064000001200200200392003999963100198001020800002080000200392003911800211091010800001001005020316562003680000102004020040200402004020040
800242003915000129642580010108000010800005064000001200200200392003999963100198001020800002080000200392003911800211091010800001001035020516552003680000102004020040200402004020040
8002420039150000822580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001002035020416552003680000102004020040200402004020040
800242003915000122722580010108000010800005064000001200200200392003999963100198001020800002080000200392003911800211091010800001001035020616662003680000102004020040200402004020040
80024200391500012822580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001001005020516552003680000102004020040200402004020040
80024200391500012822580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001000035020416642003680000102004020040200402004020040
8002420039150000402580010108000010800005064000000200200200392003999963100198001020800002080000200392003911800211091010800001001035020516662003680000102004020040200402004020040