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 (vector, 2S)

Test 1: uops

Code:

  fcvtas v0.2s, v0.2s
  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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303723022425472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724126125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724010325472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723012525472510001000100039816003018303730372414328951000100010003037303711100110000073116112700100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723633625472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtas v0.2s, v0.2s
  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)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)st unit uop (a7)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd0l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204300372330000000822953825101001001000010010000500427716000300183003730037282716287411010020010008200100083003730037111020110099100100100001000000001117180001600296450100001003003830038300383003830038
102043003723200001200612954725101001001000010010000500427716000300183003730037282717287401010020010008200100083003730037111020110099100100100001000000000007100011611296330100001003003830038300383003830038
10204300372330000000612954725101001001000010010000500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000000001007100011611296330100001003003830038300383003830038
102043003723200000001262954725101001001000010010000500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000010000007100011611296330100001003003830038300383003830038
102043013223310000007262954725101001001000010010000500427716000300183003730037282643287451025720010000200100003003730037111020110099100100100001000000000007100011611296330100001003003830038300383003830038
10204300372320000000612954725101001001000010010000500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000000000007391011611296330100001003003830038300383003830038
10204300372320000000612954725101001001000010010000500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000000000007100011611296330100001003003830038300383003830038
10204300832330100144007932952063101001001000810010150500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000001000007100011611296330100001003003830038300383003830038
10204300372320000000612954725101001001000010010000500427716000300183003730037282643287451056620010000200100003003730037111020110099100100100001000001030007100011611296330100001003003830038300383003830038
10204300372330000000612954725101001001000010010000500427716000300183003730037282643287451010020010000200100003003730037111020110099100100100001000000000007100011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk instruction (07)181e1f3f4e51schedule 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 tlb miss (a1)l1d cache writeback (a8)a9acbranch mispred nonspec (cb)cfd2d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1002430037241000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030071300371110021109101010000100000064002162229629010000103003830038300383003830038
1002430037233000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162329629010000103003830038300383003830038
1002430037233000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162229629010000103003830038300383003830038
1002430037233003061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162329629010000103003830038300383003830038
10024300372320000103295472510010101000010100005042771601300180300373003728286328767100102010000201000030037300371110021109101010000100000064002164229629010000103003830038300383003830038
1002430037232000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162229629010000103003830038300383003830038
1002430037233000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002163229629010000103003830038300383003830038
1002430037233000066295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162229629010000103003830038300383003830038
1002430037233000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002163229629010000103003830038300383003830038
1002430037232000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000064002162229629110000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtas v0.2s, v8.2s
  fcvtas v1.2s, v8.2s
  fcvtas v2.2s, v8.2s
  fcvtas v3.2s, v8.2s
  fcvtas v4.2s, v8.2s
  fcvtas v5.2s, v8.2s
  fcvtas v6.2s, v8.2s
  fcvtas v7.2s, v8.2s
  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)03l1i tlb fill (04)mmu table walk data (08)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 access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acbranch 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
8020420039156000000540030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111511811600200360800001002004020040200402004020040
802042003915500000000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111511801600200360800001002004020040200402004020040
802042003915600000000030258010810080008100800205006401321200792003920039997769990801202008003220080032200392003911802011009910010080000100000000111511801600200360800001002004020040200402004020040
802042003915500000000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111511801600200360800001002004020040200402004020040
802042003915600000000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111511801600200360800001002004020040200402004020040
802042003915600000000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000003111511801600200360800001002004020040200402004020040
802042003915500000090030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111511801600200360800001002004020040200402004020040
802042003915500000000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000200111511801600200360800001002004020040200402004020040
8020420039155000000120030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000003111511801700200360800001002004020040200402004020040
802042003916100000000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000000111512001600200360800001002004020040200402004020040

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)5f6061696d6emap 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)accfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242003915503051525800101080000108000050640000010200202003920039999631001980010208000020800002003920039118002110910108000010005020003316552003680000102004020040200402004020040
8002420039156004025800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020000216222003680000102004020040200402004020040
8002420039155004025800101080000108000050640000015200202003920039999631001980010208000020800002003920039118002110910108000010035020000416432003680000102004020040200402004020040
8002420039155004025800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020000216422003680000102004020040200402004020040
80024200391610031225800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020000316322003680000102004020040200402004020040
8002420039156004025800101080000108000050640000015200202003920039999631001980010208000020800002003920039118002110910108000010105020000216322003680000102004020040200402004020040
8002420039156008225800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020000216332003680000102004020040200402004020040
8002420039156004025800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020540216322003680000102004020040200402004020040
8002420039155004025800101080000108000050640000000200202003920039999631001980010208000020800002003920039118002110910108000010005020001216332003680000102004020040200402004020040
8002420039156008225800101080000108000050640000010200202003920039999631001980010208000020800002003920039118002110910108000010005020000316222003680000102004020040200402004020040