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

CLZ (vector, 8H)

Test 1: uops

Code:

  clz 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 tlb access (a0)l1d cache writeback (a8)a9cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004203715061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203716061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203716061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203716061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037151261168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  clz 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): 2.0037

retire uop (01)cycle (02)03mmu table walk data (08)l2 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)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)9fld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)accfd0d2d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020210099100100100001000000710001161119791100001002003820038200382003820038
1020420037150006611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
10204200371500002511968625101001001000010010000500284752100200182003720037184213187451027020010000204100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150100611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037149000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038
1020420037150000611968625101001001000010010000500284752100200182003720037184213187451010020010000200100002003720037111020110099100100100001000000710001161119791100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

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 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)st unit uop (a7)l1d cache writeback (a8)a9acc2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1002420037150000000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006403162219786010000102003820038200382003820038
10024200371500000000063819686251001010100001010000502847521120018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038
1002420037150100000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000016402162219786010000102003820038200382003820038
1002420037150000000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102008520038201802003820038
1002420037150000009008619686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038
1002420037150000000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038
10024200371500100000025119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038
1002420037150000000008219686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038
1002420037150000000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786110000102003820038200382003820038
1002420037150000000006119686251001010100001010000502847521020018200372003718443318767100102010000201000020037200371110021109101010000100000000006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  clz v0.8h, v8.8h
  clz v1.8h, v8.8h
  clz v2.8h, v8.8h
  clz v3.8h, v8.8h
  clz v4.8h, v8.8h
  clz v5.8h, v8.8h
  clz v6.8h, v8.8h
  clz 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): 0.2506

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)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 tlb miss (a1)ld unit uop (a6)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? simd retires (ee)? int retires (ef)f5f6f7f8fd
802042005715011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000011151183163220035800001002003920039200392003920039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000011151181162220035800001002003920039200392003920039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200801362003820038118020110099100100800001000001011151183163220035800001002003920039200392003920039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000011151183163320035800001002003920039200392003920039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000011151183162320035800001002011320039200392010020039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000003311151183162320035800001002003920039200392003920039
802042008815111029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001009000011151183163220035800001002003920039200392003920039
8020420038150119182258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000011151183163220035800001002003920039200392003920039
802042003815011029258010810080008100800205006401322001920038200389977699898012020080032200800322003820038118020110099100100800001000000022251285235520045800001002005020050200492004920049
802042004815011075278010010080000100800005006400002002820047200479971699938010020080000200800002004720047118020110099100100800001000000011151207247620044800001002004820048200482004820048

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)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)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 access (a0)l1d tlb miss (a1)l1d cache writeback (a8)accfd2l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200511500873925800101080000108000050640000002001920038200389996310018800102080000208000020038200381180021109101080000100000502000181616162003580000102003920039200392003920039
800242003815000392580010108000010800005064000001200192003820038999631001880010208000020800002003820038118002110910108000010000050200016166162003580000102003920039200392003920039
80024200381500039258001010800001080000506400000020019200382003899963100188001020800002080000200382003811800211091010800001000005020006161662003580000102003920039200392003920039
80024200381500427042580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000050200016161452003580000102003920039200392003920039
800242003815000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000050200016165162003580000102003920039200392003920039
800242003815000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000050200116161662003580000102003920039200392003920039
800242003815000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000050201015166132003580000102003920039200392003920039
8002420038150003925800101080000108000050640000002001920038200389996310018800102080000208000020038200381180021109101080000100000502000131616162003580000102003920039200392003920039
8002420038150003925800101080000108000050640000002001920038200389996310018800102080000208000020038200381180021109101080000100000502000161616162003580000102003920039200392003920039
800242003815000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000050200016161662003580000102003920039200392003920039