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

FCVTNU (scalar, H to H)

Test 1: uops

Code:

  fcvtnu 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)03mmu table walk data (08)l2 tlb miss instruction (0a)191e3f4e51schedule 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)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372300007312547251000100010003981600301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
10043037240000612547251000100010003981601301830373037241432895100010001000303730371110011000000173216222629100030383038303830383038
10043037230000612547251000100010003981601301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
10043037240000892547251000100010003981600301830373037241432895100010001000303730371110011000003073216222629100030383038303830383038
10043037240100612547251000100010003981600301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
10043037230000612547251000100010003981600301830373037241432895100010001000303730371110011000003073216222629100030383038303830383038
100430372300001032547251000100010003981601301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
100430372300001032547251000100010003981601301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
100430372300001032547251000100010003981601301830373037241432895100010001000303730371110011000103073216222629100030383038303830383038
10043037240000612547251000100010003981600301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtnu 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)031e3f4e5051schedule 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)a9acc2branch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204300372320842954702510100100100001041000050042785121300183003730084282647287801010020010064208100003003730037311020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723301032954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723303442954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723304652954706310100100100001001000050042771601300183008530037282643287451010020610000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723301032954702510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000074111611296330100001003003830038300383003830038
10204300372330612954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372330612954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001001030071011611296330100001003003830038300383003830038
1020430037232125072954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372320842954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003724101922954702510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000002071011611296330100001003003830038300383003830038

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)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)branch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
1002430037224061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250451295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250105295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250151295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216232962910000103003830038300383003830038
10024300372250481295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250145295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250147295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250105295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372250105295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372240170295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtnu h0, h8
  fcvtnu h1, h8
  fcvtnu h2, h8
  fcvtnu h3, h8
  fcvtnu h4, h8
  fcvtnu h5, h8
  fcvtnu h6, h8
  fcvtnu 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)l2 tlb miss instruction (0a)l2 tlb miss data (0b)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)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)st unit uop (a7)l1d 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
8020420058155000000001112580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000003111511801610200360800001002004020040200402004020040
802042003915500000000512580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
80204200391550000069003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000021111511801600200360800001002004020040200402004020040
802042003915500000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
802042003915600000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
802042003916100000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
802042003915600000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
8020420039155000001200302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040
802042003915600000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000111511801600200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)0318191e3f51schedule 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 tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9accdcfd0d2d5map dispatch bubble (d6)dadbddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242005015500082258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200021600112003680000102004020040200402004020040
800242003915600040258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200011600112003680000102004020040200402004020040
800242003915500082258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200011600112003680000102004020040200402004020040
8002420039156000515258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000150200111600112003680000102004020040200402004020040
800242003915500040258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200011600112003680000102004020040200402004020040
800242003915500040258001010800001080000506400000120020200392003999963100198001020800002080000200392003911800211091010800001000000050200021600112003680000102004020040200402004020040
800242003915500082258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203011600122003680000102004020040200402004020040
800242003915600040258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200011600112003680000102004020040200402004020040
8002420039156000515258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200011600112003680000102004020040200402004020040
800242003915500040258001010800001080000506400000120020200392003999963100198001020800002080000200392003911800211091010800001000000050200021600112003680000102004020040200402004020040