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

FCVTAS (scalar, H to H)

Test 1: uops

Code:

  fcvtas h0, h0
  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)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
10043037231261254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723961254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100073116112629100030383038303830383038
1004303722061254725100010001000398160030183037303724143289510001000100030373037111001100073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtas h0, h0
  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)0318191e1f3f4e51schedule 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)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100070071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100010071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100002671011611296330100001003003830038300383003830038
102043003722400006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000360371011611296330100001003003830038300383003830038

1000 unrolls and 10 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)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)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003724166129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000640216222962910000103003830038300383003830038
100243003723906129547251001010100001010000504277160030018030037300372828632876710010201000020100003003730037111002210910101000010000640216222962910000103003830038300383003830038
100243003723306129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000640224222962910000103003830038300383003830038
100243003723306129547251001010100001010000504277160030018030037300372828632876710010201000020100003003730037111002110910101000010000640216222962910000103003830038300383003830038
1002430037233053629547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000640216222962910000103003830038300383003830038
100243003723206129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010100640216222962910000103003830038300383003830038
1002430037241071929547251002714100001010000504277160030018030037300372828632876710010201000020100003003730037111002110910101000010030640216222962910000103003830038300383003830038
100243003723306129547251001010100001010000504277160030018030037300372828632876710010201000020100003003730084111002110910101000010000640216222962910000103003830038300383003830038
100243003723306129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000640216332962910000103003830038300383003830038
100243003724106129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtas h0, h8
  fcvtas h1, h8
  fcvtas h2, h8
  fcvtas h3, h8
  fcvtas h4, h8
  fcvtas h5, h8
  fcvtas h6, h8
  fcvtas h7, h8
  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)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)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)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
802042003915600000000742580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000002000111511801600200360800001002004020040200402004020040
802042003916100000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111513401600200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040
802042003915600000000302580108100800081028002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040
8020420039155000000006952580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040
8020420039156000000001832580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801610200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000001000111511801600200360800001002004020040200402004020040
802042003916100000000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000200000111511801610200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000000111511801610200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e1f3a3f5051schedule 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)5f60696d6emap 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
800242005115500084025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000101350208164122003680000102004020111200402011420040
8002420039155000400258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000502041612102003680000102004020040200402004020040
80024200391550004002580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010405020616992003680000102004020040200402004020040
8002420039155000400258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001030502061611102003680000102004020040200402004020040
800242003915500040025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050207164112003680000102004020040200402004020040
80024200391550006102580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020516492003680000102004020040200402004020040
8002420039155000400258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000502011161262003680000102004020040200402004020040
800242003915500040025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100350209161242003680000102004020040200402004020040
800242003915500040025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050205161152003680000102004020040200402004020040
80024200391550004002580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020616452003680000102004020040200402004020040