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

FCVTPS (scalar, D to X)

Test 1: uops

Code:

  fcvtps x0, d0
  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)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 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
2004541404325300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000107311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtps x0, d0
  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)031e3f4f51schedule 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 miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acbranch mispred nonspec (cb)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
302041300389740130023119417254010010100200001000010020000100005006214979148010341130013130070130038125476191262463010020010000200002001000020000130093130042112020110099100101001000010001000000001131012162212952510000100001000010100130039130039130039130039130087
30204130038974013002311941725401001010020000100001182000010000500621497914801034113001313003813003812547931262493010020010000200002001000020000130079130055112020110099100101001000010001000000000131012162212952510000100001000010100130039130039130039130075130039
302041300389743013005311941725401001010020000100001002000010000500621497914801034113001313003813003812547731262463010020010000200002001000020000130070130082112020110099100101001000010001000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262463010020010063200002001000020000130074130038112020110099100101001000010001000000010131012162212952510000100001000010100130039130039130039130039130039
30204130038974013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130081130050112020110099100101001000010001000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038975013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130085130039112020110099100101001000010001000000000131002162212952510000100001000010100130039130039130039130039130039
30204130038973013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130104130046112020110099100101001000010001000000000131012162312952610000100001000010100130043130039130039130039130039
30204130038974013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262463010020010000200002001000020000130103130058112020110099100101001000010001000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130091130051112020110099100101001000010001000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130075130041112020110099100101001000010001000000000131012162212960710000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)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 access (a0)l1d 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
300241300389740000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262743001020100002000020100002000013003813003811200211091010010100001000100000000012701171112952510000100001000010010130039130039130039130039130063
300241300389740000901300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952810000100001000010010130039130039130039130039130039
300241300389740000001300231194172540012100122000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002013113003813003811200211091010010100001000100000000012701161112952510002100001000010010130039130039130040130039130039
300241300389740000001300231194172540010100102000010000122000010000506214979148001390130013013003913007612549831262683001020100002000020100002000013003813003811200221091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001002100000000012701161412953110007100001000010010130039130039130039130039130039
300241300389740100001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001220100002000020100002000013003813003811200221091010010100001000100000000012701161112952510000100001000010010130044130045130039130039130046
300241300389740000001300231194142540012100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161212952510000100001000010010130042130039130039130039130039
300241300389740000001300231194172540010100102000010000122000010000606214968148000480130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtps x0, d8
  fcvtps x1, d8
  fcvtps x2, d8
  fcvtps x3, d8
  fcvtps x4, d8
  fcvtps x5, d8
  fcvtps x6, d8
  fcvtps x7, d8
  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 instruction (07)mmu 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)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
16020440053310100001207425240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004131000000003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004131100000003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004131000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000100111511701600400388000080000801004004240042400424004240042
16020440041310000000032120240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000100111511701600400388000080000801004004240042400424004240042
1602044004131000000003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
16020440041310000000069725240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004131000000003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004132200000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042
1602044004131100000007425240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000111511701600400388000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e3f51schedule 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)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024400543000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020516324003880000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400001400220400414004119996320021160010201600002016000040041400411180021109108001010005020316334003880000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020216234003880000080000800104004240042400424004240042
160024400412990632524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020316324003880000080000800104004240042400424004240042
160024400413000424924030880010160000101600005014400001401500401214004119996320021160010201600002016000040041400411180021109108001010005020316234003880000080000800104004240042400424004240042
1600244004130012842524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020316644003880000080000800104004240042400424004240042
1600244004130004225240010800101600001016000050144000014002204004140041199963200211600102016000020160000400414004111800211091080010101155020316334003880000080000800104004240042400424004240042
160024400412990422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020216234003880000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000400220400414004119996320021160010201602202016000040041400411180021109108001010005020316334003880000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010005020316324003880000080000800104004240042400424004240042