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, 8B)

Test 1: uops

Code:

  clz v0.8b, v0.8b
  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)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100420371501051686251000100010002645211201820372037157131895100010001000203720371110011000073216111786100020382038203820382038
10042037160611686251000100010002645210201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
100420371501031686251000100010002645210201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037150611686251000100010002645210201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037160611686251000100010002645211201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
100420371501261686251000100010002645211201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037150611686251000100010002645210201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037150611686251000100010002645211201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037150821686251000100010002645211201820372037157131895100010001000203720371110011000073116111786100020382038203820382038
10042037160611686251000100010002645210201820372037157131895100010001000203720371110011000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  clz v0.8b, v0.8b
  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)18191e1f3f4e51schedule 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)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204200371500000510611968625101001001000010010000500284752112001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
10204200371500000150611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752112001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420084150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
10204200841500000005361968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500285155302001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000000071021622197910100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

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)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)acc2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024200371500061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001000040640316331978610000102008620038200382003820038
10024200371500061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
100242003715000536196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
10024200371500061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
10024200371500061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
10024200371500061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
10024200371500061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
10024200371500061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
100242003715001561196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000000640316331978610000102003820038200382003820038
1002420037150006119686251001010100001010000502847521120018200372003718443318767100102010000201000020037200371110021109101010000100012000640316331978610000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  clz v0.8b, v8.8b
  clz v1.8b, v8.8b
  clz v2.8b, v8.8b
  clz v3.8b, v8.8b
  clz v4.8b, v8.8b
  clz v5.8b, v8.8b
  clz v6.8b, v8.8b
  clz v7.8b, v8.8b
  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)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)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)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420048150010292580108100800081008002050064013212001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039
8020420038150110292580108100800081008002050064013202001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039
80204200381501102925801081008000810080020500640132020019200382003899776998980120200800322008003220038200382180201100991001008000010001511151181161120035800001002003920039200392003920039
8020420038150110292580108100800081008002050064013212001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039
8020420038150110292580108100800081008002050064013212001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039
8020420038150110292580108100800081008002050064013212001920038200389977699898012020080032200800322003820038118020110099100100800001001311151181161120035800001002003920039200392003920039
8020420038150110292580108100800081008002050064013202001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039
802042003815011029258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100013511151181161120035800001002003920039200392003920039
802042003815011029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100011411151181161120035800001002003920039200392003920039
80204200381501127292580108100800081008002050064013202001920038200389977699898012020080032200800322003820038118020110099100100800001000011151181161120035800001002003920039200392003920039

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)09l2 tlb miss instruction (0a)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)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)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391500000000962580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000020635020131613132003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000035035020161612162003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000020005020171613112003580000102003920039200392003920039
800242003815000000006025800101080000108000050640000012001920038200389996310018800102080000208000020038200381180021109101080000100000320695020111613182003580000102003920039200392003920039
8002420038150000000039258001010800001080000506400000120019200382003899963100188001020800002080000200382003811800211091010800001000000005020111611112003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000000200192003820038999631001880010208000020800002003820038118002110910108000010000036035020131616122003580000102003920039200392003920039
8002420038150000000039258001010800001080000506400000120019200382003899963100188001020800002080000200382003811800211091010800001000000035020161617152003580000102003920039200392003920039
8002420038150000000039258001010800001080000506400000120019200382003899963100188001020800002080000200382003811800211091010800001000000005020171612182003580000102003920039200392003920039
8002420038150000000039258001010800001080000506400000120019200382003899963100188001020800002080000200382003811800211091010800001000000005020151613132003580000102003920039200392003920039
8002420038150000000039258001010800001080000506400000120019200382003899963100188001020800002080000200382003811800211091010800001000000005020121615152003580000102003920039200392003920039