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 W)

Test 1: uops

Code:

  fcvtps 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)03l2 tlb miss data (0b)191e3a3f51schedule 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)ld unit uop (a6)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
2004541500004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000010007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000010007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtps 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)03l2 tlb miss data (0b)0e18191e1f3a3f4f51schedule 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)a9acc2branch cond mispred nonspec (c5)branch ret indir mispred nonspec (c8)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3020413037310080040000130032119417254010610118200001000010620000100005006214979148010341130013130038130038125476312630230769200100612000020410000200001300381300381120201100991001010010000100001001010001001310141622129525100000100001000010100130039130039130039130039130039
3020413003810080000000130023119418254010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310121622129525100000100001000010100130039130039130039130039130211
3020413003810080000000130023119417254010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001303691300381120201100991001010010000100001000000900001310121622129525100000100001000010100130039130039130041130039130039
3020413004810110000000130023119417254010010109200001000010020000100005006214979148014790130013130038130380125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310121622129527100000100001000010100130039130039130039130039130039
30204130038100700000001300231194172540129101002000010000100200001000064462149791480103411300131300381300381254762212624930100204100002000020010000200001300381300395120201100991001010010000100001000000000001310121622129525100000100001000010100130039130039130039130039130039
3020413003810080000001130023119417254010010100200001000210020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310121622129558100000100001000010100130040130039130039130039130039
30204130038100802003935201300231194171104010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310121622129525100000100001000010100130039130039130039130039130039
3020413003810070000000130023119545254010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310125022129525100000100001000010100130373130039130039130039130039
3020413003810080000000130023119550254010010100200001000010020000100005006224986148013711130013130038130038125476312624630100200100002000020010122200001300381300381120201100991001010010000100001000000000001310121622129526100000100001000010100130039130039130039130039130039
302041300381008000057900130023119417254014010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000001310121623129525100000100001000010100130039130039130039130041130039

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)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)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)a9acc2branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130039104500000001300231194172540010100102000010000102000010000506214979148000251130013013003913003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000000012702161112952510000100001000010010130039130039130046130041130039
30024130038100811000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000000012701161112952510000100001000010010130039130039130039130039130039
30024130038100700000001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000005000012701161112952810000100001000010010130039130039130039130039130039
30024130038100800000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000000012701161112952510000100001000010010130039130039130039130039130039
30025130038100800009001300231194172540022100102000010000102000010000506214979148000251130013013003813003812550231262683001020100002000020100002000013003813003811200211091010010100001001000000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000001300231194172540010100102000010002102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813012611200211091010010100001001000000000012701162112933610000100001000010010130039130039130039130039130039
3002413003897400000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003913004111200211091010010100001001000000000012701161512956110001100001000010010130039130042130039130039130039
3002413004197401000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000413030012701161112952510000100001000010010130039130039130040130041130039

Test 3: throughput

Count: 8

Code:

  fcvtps w0, d8
  fcvtps w1, d8
  fcvtps w2, d8
  fcvtps w3, d8
  fcvtps w4, d8
  fcvtps w5, d8
  fcvtps w6, d8
  fcvtps 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)03l2 tlb miss instruction (0a)l2 tlb miss data (0b)0f1e3a3f51schedule 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)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
160204400633100001213425240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511891698400388000080000801004004240042400424004240042
16020440041310000013425240104801001600041001600205001440132040022040041400411997761999216012020016003220016003240041400411180201100991008010010003111511881689400388000080000801004004240042400424004240042
16020440041311000013425240104801001600041001600205001440132040022040041400411997761999216012020016003220016003240041400411180201100991008010010010111511881688400388000080000801004004240042400424004240042
16020440041311000016225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881689400388000080000801004004240042400424004240042
16020440041310000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511861666400388000080000801004004240042400424004240042
16020440041310000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881688400388000080000801004004240042400424004240042
16020440041310000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881688400388000080000801004004240042400424004240042
16020440041311000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881688400388000080000801004004240042400424004240042
16020440041310000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881668400388000080000801004004240042400424004240042
16020440041310000013225240104801001600041001600205001440132140022040041400411997761999216012020016003220016003240041400411180201100991008010010000111511881683400388000080000801004004240042400424004240042

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)60696d6emap stall dispatch (70)rob full (74)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)accfd2l1i cache miss demand (d3)d5map dispatch bubble (d6)daddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16002440054310052252400108001016000010160000501440000140022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000140022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000140022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000502001116011400388000080000800104004240042400424004240042
16002440041310942252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101010502000116011400388000080000800104004240042400424004240042
16002440041311042252400108001016000010160000501440000140022400414004119996032002116001020160000201600004004140041118002110910800101003502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000140022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000502000116011400388000080000800104004240042400424004240042