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

FCVTXN (vector, 2D)

Test 1: uops

Code:

  fcvtxn v0.2s, v0.2d
  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 instruction (07)mmu table walk data (08)l2 tlb miss data (0b)18191e1f3a3f4e51schedule 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 tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372410000000612547251000100010003981600301830373037241432895100010001000303730371110011000000003073316222626100030383038303830383038
100430372400000000822547251000100010003981600301830373037241432895100010001000303730371110011000000200073116112629100030383038303830383038
1004303723000001200612547251000100010003981600301830373037241332895100010001000303730371110011000000002230073116222626100030383038303830383038
10043037241000033600612547251000100010003981601301830373037241332895100010001000303730371110011000000103073116112629100030383038303830383038
100430372400000000612547251000100010003981601301830373037241432895100010001000303730371110011000000003073116112629100030383038303830383038
100430372410000000822547251000100010003981600305430373037241432895100010001000303730371110011000000000073116222629100030383038303830383038
100430372310000000612547251000100010003981600301830373037241332895100010001000303730371110011000000803075216112629100030383038303830383038
1004303723000009006125472510001000100039816013018303730372414328951000100010003037303711100110000001400077116112629100030383038303830383038
100430372410000000612547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
100430372300000000612547251000100010003981601301830373037241332895100010001000303730371110011000000000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtxn v0.2s, v0.2d
  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)03mmu table walk data (08)l2 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)a9acc2branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037225000013800612954725101291001001610610000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000028430071011611296330100001003003830086300383003830038
1020430037225000014100612954725101001001000010010000500427716013001830086301322826832874510100200100002001000030037300371110201100991001001000010000000030071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716003001830037300372826432874510100216100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000001000071011611296330100001003003830038300383003830038
10204300372250000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

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)ld 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
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372240000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830299300383008230038
10024300852410000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372410000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtxn v0.2s, v8.2d
  fcvtxn v1.2s, v8.2d
  fcvtxn v2.2s, v8.2d
  fcvtxn v3.2s, v8.2d
  fcvtxn v4.2s, v8.2d
  fcvtxn v5.2s, v8.2d
  fcvtxn v6.2s, v8.2d
  fcvtxn v7.2s, v8.2d
  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)mmu table walk data (08)l2 tlb miss instruction (0a)1e1f3f51schedule 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? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
802042005815510100183425801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611200360800001002004020040200402004020089
8020420039156101003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611200360800001002004020040200402004020040
8020420039155101003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611200360800001002004020040200402004020040
80204200391551010071825801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611201170800001002004020040200402004020040
8020420039161101003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010010111511811611200360800001002004020040200402004020040
8020420039155101003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611200360800001002004020040200402004020040
80204200391561011203025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511811611200360800001002004020040200402004020040
80204200391561010024825801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010010111511811611200360800001002004020040200402004020040
802042003915610149206426801161008001610080028500640196020029200482004999769998680128200800382008003820049200481180201100991001008000010000222512822332200840800001002005020049200492004920049
80204200481550000015026801161008001610080028500640196120029200482004999769998680128200800382008003820048200481180201100991001008000010000222512822322200450800001002004920049200502004920049

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)l2 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)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)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0eaeb? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391550004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000000502012161010200360080000102004020040200402004020040
80024200391560004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000502013161210200360080000102004020040200402004020040
800242003915600040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000005020616127200360080000102004020040200402004020040
80024200391550004025800101080000108000050640000020020200392003999963100198001020800002080106200392003911800211091010800001000000502011161212200360080000102004020040200402004020040
80024200391610004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000100502011161110200360080000102004020040200402004020040
80024200391550002442580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100000350201316129200360080000102004020040200402004020040
80024200391550034025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000003502012161212200360080000102004020040200402004020040
80024200391560004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000502010161212200360080000102004020040200402004020242
80024200391560004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000502011161111200360080000102004020040200402004020040
80024200391560004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000502012161211200360080000102004020040200402004020040