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

FCVTNS (scalar, D to D)

Test 1: uops

Code:

  fcvtns d0, d0
  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)ld unit uop (a6)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723082254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037240103254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037230501254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303724061254725100010001000398160030183037303724143289510001000100030373037111001100000073216112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100000373116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100020073116112629100030383038303830383038
10043037240151254725100010001000398160030183037303724143289510001000100030373037111001100000073216212629100030383038303830383038
100430372312412254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtns d0, d0
  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)030f18191e1f3f4e51schedule 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)6061696d6emap 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)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037233000831061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
10204300372330000061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
102043003723300000156295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
10204300372330000061295472510100100100001001000050042771601030037300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
1020430037233000144061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000103000071001161129633100001003003830038300383003830038
10204300372330000061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
10204300372330000061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001251129633100001003003830038300853003830038
1020430037233002168061295472510100100100001001000050042771600030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038
10204300372330000061295472510100100100001001000050042771601030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000020071001161129633100001003003830038300383003830038
102043003723200000251295472510100100100001001000050042771601030018300373003728264328749101002001000020010000300373003711102011009910010010000100000000000071001161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03181e3f4e51schedule 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)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 tlb access (a0)l1d tlb miss (a1)l1d cache writeback (a8)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372330186129547251001010100001010000504277160030018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038
1002430037232006129547251001010100001010000504277160130018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038
1002430037233006129547251001010100001010000504277160030018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038
1002430037232006129547251001010100001010000504277160030018300373003728286032876710010201000020100003003730178111002110910101000010000006403163329629010000103003830038300383003830038
10024300372410053629547251001010100001010000504277160130018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038
10024300372250072629547251001010100001010000504277160130018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286032876710010201000020100003003730037111002110910101000010003066403163329629210000103003830038300383003830038
10024300372331330329547251001010100001010000504277160130054300373003728286032876710010201000020100003003730037111002110910101000010001066403163329629010000103003830038300383003830038
100243003722502112629547251001010100001010000504277160130018300373003728286032876710010201000020100003016630037111002110910101000010000006403163329629010000103003830038300383003830038
10024300372250010329547251001010100001010000504277160130018300373003728286032876710010201000020100003003730037111002110910101000010000006403163329629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtns d0, d8
  fcvtns d1, d8
  fcvtns d2, d8
  fcvtns d3, d8
  fcvtns d4, d8
  fcvtns d5, d8
  fcvtns d6, d8
  fcvtns d7, d8
  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)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)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 cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)fetch restart (de)e0ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200491552472258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
80204200391552130258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000311151180160200360800001002004020040200402004020175
80204200391560695258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
8020420039155930258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
80204200391563930258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
8020420039155630258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
8020420039155930258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
8020420039155030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
80204200391551830258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040
80204200391552730258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000011151180160200360800001002004020040200402004020040

1000 unrolls and 10 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)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)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 mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242003915500068258001010800001080000506400000200200200392003999963100198022120800002080000200392003911800211091010800001000050201616782003680000102004020040200402004020040
80024200391560004025800101080000108000050640000020020020039200399996310019800102080000208000020039200391180021109101080000101005020616962003680000102004020040200402004020040
8002420039155009040258001010800001080000506400000200200200392003999963100198001020800002080000200392003911800211091010800001000050208167102003680000102004020040200402004020040
8002420039155003951525800101080000108000050640000020020020039200399996310019800102080000208000020039200391180021109101080000100005020916782003680000102004020040200402004020040
8002420039155005740258001010800001080000506400000200200200392003999963100198001020800002080000200392003911800211091010800001000050206161092003680000102004020040200402004020040
800242003915500394025800101080000108000050640000020020020039200399996310019801222080000208000020039200391180021109101080000100005020516682003680000102004020040200402004020040
80024200391560004025800101080000108000050640000020020020039200399996310019800102080000208000020039200391180021109101080000100005020516862003680000102004020040200402004020040
800242003915600544025800101080000108000050640000020020020039200399996310019800102080000208000020039200391180021109101080000100005020816982003680000102004020040200402004020040
800242003915600394025800101080000108000050640000020020020039200399996310019800102080000208000020039200391180021109101080000100005020716852003680000102004020040200402004020040
8002420039156008440258001010800001080000506400000200200200392003999963100198001020800002080000200392003911800211091010800001000050209161092003680000102004020040200402004020040