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

FCVTZU (scalar, integer, H to X)

Test 1: uops

Code:

  fcvtzu x0, h0
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 2.000

Issues: 3.000

Integer unit issues: 1.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 2.000

retire uop (01)cycle (02)031e3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)696d6emap 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 int alu (97)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
200454140432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541512432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454140432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454140432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454140432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454140432530001000200020001800052654154124832742000200020005415411110011000007311611538100010001000542542542542542
200454150432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454150432530001000200020001800052254154124832742000200020005415411110011000037311611538100010001000542542542542542
200454140432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542
200454150432530001000200020001800052254154124832742000200020005415411110011000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtzu x0, h0
  fmov d0, x0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03l1i tlb fill (04)l2 tlb miss data (0b)18191e1f3a3f4f51schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)map int uop inputs (7f)map ldst uop inputs (80)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)acbranch cond mispred nonspec (c5)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547691262893010020010000200002021000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000013006911941725401001010020000100001002000010000500621497914801034013001313003813004512547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130042130039
30204130038974000000013002311941725401201010020000100001002000010000500621497914801034113001313008813004012547631262463010020010000200002001000020000130038130038112020110099100101001000010000100020000131012162212952710000100001000010100130039130039130039130039130040
30204130038974100000013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000201292001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547691267493010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162312952510000100001000010100130039130039130039130039130039
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812550131262463010020010000200002001000020000130038130038112020110099100101001000010000100000000133612162212952510000100001000010100130039130072130039130042130039
30204130038974000000013002311941725401001010020000100001002000010000500621544514806243013004213003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012163212952510000100001000010100130039130039130039130039130039
30204130038974000000013002311946125401001010020000100001002000010000500621497914801034013001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000300131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000013005211941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000133712162212952510000100001000010100130039130039130039130039130039
302041300389740000810013002311941725401001010020000100001002000010049500621497914801034013001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk instruction (07)l2 tlb miss data (0b)18191e1f3f4f51schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)ldst uops in schedulers (5b)60696b6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)map int uop inputs (7f)map ldst uop inputs (80)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)a9acbranch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126319300102010000200002010000200001300381300381120021109101001010000100100000000012703162312952510000100001000010010130039130039130039130043130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000012703164312952810000100001000010010130039130039130039130039130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126281301022010000200002010066200001300381300381120021109101001010000100100000000012703163412952510000100001000010010130039130039130039130039130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000012702163412952510000100001000010010130039130039130039130039130039
300241300381111000000130023119417254001010013200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000012703162312952510000100001000010010130039130039130039130039130039
30024130040974000000130023119417254001010010200001000110200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000012704163312952510000100001000010010130039130039130039130039130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001601300381300381254983126323300102010000200002010000200001300381300381120021109101001010000100100000000012703163212952510000100001000010010130039130039130039130039130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025113001301300381300381254983126306300102010000200002010000200001300381300381120021109101001010000100100000000012702162312962210000100001000010010130039130039130039130039130040
30024130040974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126323300102010000200002010000200001300381300381120021109101001010000100100000000012703163212952510000100001000010010130039130039130039130039130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126318300102010000200002010000200001300381300381120021109101001010000100100000000012702163212952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtzu x0, h8
  fcvtzu x1, h8
  fcvtzu x2, h8
  fcvtzu x3, h8
  fcvtzu x4, h8
  fcvtzu x5, h8
  fcvtzu x6, h8
  fcvtzu x7, h8
  mov x8, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5005

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)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)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)9fl1d tlb access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)fetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160204400412990000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400413000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400413000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400412990000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400413000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400412990000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400412990000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400412990000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
16020440041310000012012725240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
160204400413000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.5005

retire uop (01)cycle (02)0318191e1f3f51schedule 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)5f6061696b6d6emap 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)9fl1d tlb access (a0)ld unit uop (a6)l1d cache writeback (a8)acc2cfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)d9daddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244005530000005182524001080010160000101600005014400000004002204177341715204991572101116454620162434201645364187941312221800211091080010100201382505362009110188011314412668233180000800104140041808420204188141941
160024420313252423259220243356435246943823791638681016411450147428200040022040041400411999632002116001020160000201653164163742105261800211091080010100000050200005161065401218000080000800104004240042400424004240042
16002440041310000042252400108001016000010160000501440000000400220400414004119996320021160010201600002016000040041400411180021109108001010000162050200006160054400388000080000800104004240042400424004240042
160024400413000000422524001080010160192101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010100000050200005160054400388000080000800104004240042400424004240042
160024400413000000422524001080010160000101600005014400000104015204004140133199963200211600102016000020160000400414004111800211091080010100010050200005160054400388000080000800104004240042400424004240042
160024400413000000422524001080010160000101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010100000050200006160055400388000080000800104004240042400424004240042
160024400412990000842524001080010160000101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010102020050560005160054400388000080000800104004240042400424004240042
1600244004130000120842524001080010160000101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010100003050200004160056400388000080000800104004240042400424004240042
1600244004129900120842524001080010160000101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010100000050200005160045400388000080000800104004240042400424004240042
1600244004130000240422524001080010160000101600005014400000004002204004140041199963200211600102016000020160000400414004111800211091080010100000050200006160155400388000080000800104004240042400424004240042