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

FCVTPU (scalar, D to W)

Test 1: uops

Code:

  fcvtpu w0, 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)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045415043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045415643253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtpu w0, 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)03l1i tlb fill (04)mmu 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)77dispatch 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)acc2branch cond mispred nonspec (c5)branch 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
30204130038974000000013002311945525401001010020000100001002000010000526621497914801034013001301300381300381254836126241030100200100022000620010002200061300381300381120201100991001010010000100010000002111131801161112953410000100001000010100130039130039130039130042130039
3020413003897400121156013002311941725401001010020000100001002000010000500621502714801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131013162212952510000100001000010100130039130363130039130039130042
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126249030100200100002061120610186200001301181300381120201100991001010010000100010007042830000131012163312952510000100001000010100130039130039130039130039130039
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001701300381300381254763126246030100200100002000020010000200001305191300382120201100991001010010000100010000000000131012163212952510000100001000010100130039130039130039130039130039
302041300389740000012013002311941732401001010020000100001002000010000500621497914801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131012162312952510000100001000010100130039130039130039130039130039
30204130038974000000013002311941825401001010020000100001002000010000500621497914801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131012162312952510000100001000010100130039130039130039130039130039
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000300000131013163212952510000100001000010100130039130039130039130039130039
30204130038974000000013002311943625401001010020000100001002000010000500621497914801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131013162212952510000100001000010100130039130070130039130039130039
30204130038974000000013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131013162212959710000100001000010100130039130039130039130039130039
30204130038974000000013027811941725401001010020000100001002000010000500621502714801034013008701300381300391254763126246030100200100002000020010000200001300381300381120201100991001010010000100010000000000131012162212958610000100001000010100131396131028130696132279132386

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)5f60696d6emap 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)a9acc2branch cond mispred nonspec (c5)cfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3002413003897400000013002311941725400101001020000100001020000100005062149791480002501130013130038130043125498312626830010201000020000201000020000130038130038112002110910100101000010001000010000012700002160401112952510000100001000010010130039130040130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148003670113008513003813003812550031262683001020100002000020100002000013003813003811200211091010010100001000100000000012700001160001112952510000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250013001413003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012700001160001112952510000100001000010010130041130039130039130137130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250013001313003813003812549831262713001020100002000020100002000013003813009311200211091010010100001000100000000012700001160001112961010000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250013001313003813003812549831262683001020100002000020100652000013003813003811200211091010010100001000100000000012700001160001112952510000100001000010010130039130039130039130039130041
300241300389740000001300231194172540010100102000010000102000010000506214979148000250013001313003813003812549831262683001020100002024620100622000013008313009311200211091010010100001000100000000012700001160002112952510000100001000010010130039130039130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250113001313003813012912549931262683001020100002000020100002000013003813007811200211091010010100001000100001042880012700001160001112952510000100001000010010130066130042130039130039130039
300241300389740000001300231194172540010100102000010000102000010000506214979148000250013001313003813003812549831262683001020100002000020100002000013006213003911200211091010010100001000100000000012700001160001212952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002501130013130038130038125536312626830010201000020131201000020000130038130084112002110910100101000010221001312187480012700001160001112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062156991480658900130015130038130038125522912626830180201000020000201000020240130373130144212002110910100101000010001000040912012700001160011112952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtpu w0, d8
  fcvtpu w1, d8
  fcvtpu w2, d8
  fcvtpu w3, d8
  fcvtpu w4, d8
  fcvtpu w5, d8
  fcvtpu w6, d8
  fcvtpu w7, 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)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)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 ldst (9b)9fl1d tlb access (a0)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? simd retires (ee)? int retires (ef)f5f6f7f8fd
1602044006430005072524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041403601997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010001000001115117016004003880000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03181e1f3f51schedule 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)9fl1d cache writeback (a8)accfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)daddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16002440055311000422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010005020000216011400388000080000800104004240042400424004240042
16002440041311000702524001080010160000101600005014400001140022400414004119996320021160010201600002016000040041401281180021109108001010005038000216011400388000080000800104004240042400424004240042
160024400413100301372524001080010160000101600005014400001040033400414004119996320021160010201600002016000040041400411180021109108001010005020000116011400388000080000800104004240042400424004240042
16002440041311000422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010005020000116011400388000080000800104004240042400424004240042
16002440041321000422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010005020000216011400388000080000800104004240042400424004240042
160024400413210002132524027280303160000101600005014400001140022400414004120019320021160010201600002016021440041400412180021109108001010005020300116011400388000080000800104004240042400424004240042
160024400413100001402524001080010160000101600005014400000040022400414004119996320021160010201600002016020040041400411180021109108001010005020000116011400388000080000800104004240042400424004240042
16002440041310000842524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010005020000116011400388000080000800104004240042400424004240042
160024400413100120422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010005020000216011400388000080000800104004240042400424004240042
16002440041310000422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010065020000144011400388000080000800104004240042400424004240042