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

FCVTNU (scalar, S to W)

Test 1: uops

Code:

  fcvtnu w0, s0
  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)03091e1f3a3f51schedule 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 tlb access (a0)l1d tlb miss (a1)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
2004541400014325330410002000200018000152254154124832742000220820005415411110011000200007311611538100010001000542542542542542
20045414000012525300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000152254154124832742000200020005415411110011000000009011611538100010001000542542542542542
20045414108804325300010002000200019900152254154124832742000200020005415411110011000000007311611538100010001000542542542542542
200454140132004325300010002000200018000052254154124832742000200020005415411110011000020027311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000001007311611538100010001000542542542542542
2004541400004357300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542
2004541400004325300010002000200018000052254154124832742000200020005415411110011000000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtnu w0, s0
  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)03mmu table walk data (08)l2 tlb miss data (0b)181e3f4f51schedule 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)696b6d6emap 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)accdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002012813003813003811202011009910010100100001000010000000131002162212952510000100001000010100130039130039130039130039130039
30204130038974000301300231194172540100101002000010000100200001000050062149791480103413001331300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130075130039
3020413003897400091300231194172540100101002000410000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130041130039130039
3020513010097400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001006320000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400001300231196994740100101042000010000100201161000050062149791483527513001301300381300381254769126246301002001000020120202100002024113003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130039130041
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000001131012162212952510000100001000010100130039130039130039130039130039
3020413003897400001300231194172540100101002000010000100200001000050062149791480103413001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000131012162212952610000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)191e1f3f4f51schedule 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)ld unit uop (a6)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
300241300389800000130023119417254001010013200001000010200001000050621497914800025113009213003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000033012702161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113006213003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012702161112952510000100001000010010130039130039130071130039130039
300241300389740000130067119417254001010010200001000010200001000050621497914800025113005513003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012701161112952510000100001000010010130039130042130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113005013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113005913003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012700161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010012200001000010200001000050621497914800136113006713003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113006513003813003812549831262683001020100002000020100002000013003813003821200211091010010100001001000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113005913006913003812550431262683001020100002000020100002000013003813003811200211091010010100001001000000012701161012952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010201261000050621755714800139113001313004213003812549831262683001020100002000020100002000013003813003811200211091010010100001001000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000130023119417254001010010200001000010200001000050621497914800025113007513003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000010012702161212952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtnu w0, s8
  fcvtnu w1, s8
  fcvtnu w2, s8
  fcvtnu w3, s8
  fcvtnu w4, s8
  fcvtnu w5, s8
  fcvtnu w6, s8
  fcvtnu w7, s8
  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 instruction (0a)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)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16020440041311101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000000111511721611400388000080000801004004240042400424004240042
16020440041310101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000000111511711611400388000080000801004004240042400424004240042
16020440041311101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000030111511711611400388000080000801004004240042400424004240042
16020440041311101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000000111511711611400388000080000801004004240042400424004240042
16020440041310101000035252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000000111511711611400388000080000801004004240042400424004240042
16020440041311101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000000111511711611400388000080000801004004240042400424004240042
16020440041310101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000001000111511711611400388000080000801004004240042400424004240042
16020440041310101000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000030111511711611400388000080000801004004240042400424004240042
1602044004131010191028279249303032441448136016234410616249856014612861407974099341051202389720526161776204161904206162840410004108014180201100991008010010022004688821115337112411400388000080000801004004240042401244004240042
160204400413101110013448868763192436388116416234810616143658414638761407894104240990202621282084116322420216333820216355840839413121718020110099100801001002222293460111511711611401028000080000801004050240597413904107240042

1000 unrolls and 10 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)181e3f51schedule 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 tlb access (a0)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)d9ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244005430000000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010000010502013160119400388000080000800104004240042400424004240042
160024400413000000274225240010800101600001016000050144000004002204004140041199963200211600102016000020160000400414004111800211091080010100000005020111601211400388000080000800104004240042400424004240042
160024400413000000070725240010800101600001016000050144000014002204004140041199963200211600102016000020160000400414004111800211091080010104000005020121601213400388000080000800104004240042400424004240042
16002440041300000004225240010800101600001016000050144000004002204004140041199963200211600102016000020160000400414004111800211091080010100030005020131601312400388000080000800104004240042401224012140204
160024400412990001010725240010800101600001016020850144000014002204004140041199963200211600102016000020160000400414004111800211091080010100000005020101601311400388000080000800104004240042400424004240042
16002440041300010004225240010800101600001016000050144000004002204004140041199963200211600102016000020160000400414004111800211091080010100000005020131601212400388000080000800104004240042400424004240042
16002440041300000004225240010800101601921016000050144000014002204004140041199963200211600102016000020160000400414004111800211091080010100100005020121601311400388000080000800104004240042400424004240042
160024400412990000184225241113800101600001016000050144000014002204004140041199963200211600102016000020160000400414004111800211091080010109000005020131601213400388000080000800104004240042400424004240042
1600244004130000021810725240010800101600001016000050144000004002204004140041199963200211600102016000020160000400414004111800211091080010100000005020121601210400388000080000800104012840042400424004240042
16002440041299000004225240010800101600001016000050144000014002204004140041199963200211600102016000020160000400414004121800211091080010100000005043121601210400388000080000800104004240042400424004240042