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

FCVTMU (scalar, S to W)

Test 1: uops

Code:

  fcvtmu 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)03181e1f3f51schedule 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)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542623542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414000432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414060432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542
20045414030432530001000200020001800015225415412483274200020002000541541111001100000007321622538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtmu 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)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)st unit uop (a7)l1d cache writeback (a8)a9acc2branch 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
302041300439740000000130046119417254010010100200001000010020000100005006214979148010341130013130038130038125483612624230100200100022000620010002200061300381300381120201100991001010010000100001000000000111131701161112953410000100001000010100130039130039130039130039130039
302041300389740000000130033119417254010010100200001000010020000100005006214979148010340130013130038130038125483612624130100200100022000620010002200061300381300381120201100991001010010000100001000000000111131701161112953310000100001000010100130039130039130039130039130039
302041300389740000000130037119417254010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012162212952510021100001000010100130039130039130039130039130039
302041300389740000000130047119417254010010100200001000010020000100005006214979148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012162112952810000100001000010100130039130039130039130075130074
302041300389750000105600130027119417254010010100200001000010020000100005006214979148010341130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012163212952510000100001000010100130039130039130039130039130039
302041300459740000000130023119417254010010100200001000010020000100005006215444148010340130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000000130023119417254010010100200001000010020000100005006214979148010341130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000001300681194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000020001705162223413134310060100001000010100132113132340132342132264132419
3020413227599111282350553080113157312005346940260101702006710043132210451044150062327921480103411311341305521319941265581851278863559225211896244902381263425228132871132856411202011009910010100100001004410062000340001855061862212952510000100001000010100130039130039130039130039130039
302041300389740000000130023119417254010010100200001000010020000100005006214979148010341130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000000000000131012162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk instruction (07)mmu table walk data (08)0918191e1f3a3f4f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3002413004010080000000013002311941725400101001020000100001020000100005062149791480002511300130130038130041125498312626830010201000020000201006320000130038130038112002110910100101000010100000000127021611129525100000100001000010010130039130039130039130039130039
3002413003810082000000013002411941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127011611129525100000100001000010010130039130039130039130039130039
3002413004110070000000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127011611129525100000100001000010010130039130039130039130039130039
3002413003810080000000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127011611129525100000100001000010010130039130039130039130039130039
3002413003810080000000013002311941725400101001020000100001020000100005062149791480002511300130130038130038125498312626830010201000020000201000020000130038130038112002210910100101000010100000000127011621129525100000100001000010010130039130039130039130039130039
30024130038100800000000130023119414254001010010200001000010200001000050621497914800025113001301300401300431254983126268300102010000200002010000200001300381300381120021109101001010000101000063000127011611129525100000100001000010010130039130039130039130039130039
3002413003810080100000013002311942025400101001020000100001020000100005062149791480002511300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000010127011611129552100000100001000010010130039130039130039130039130039
3002413003810080000000013002311941725400101001020000100001020000100005062149791480002511300130130038130038125498312626830010201000020000201000020131130082130040112002110910100101000010100000000127011611129525100000100001000010010130039130039130039130039130039
300241300389740000000013002311941725400101001020000100001020000100005062149791480002511300160130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127011611129525100000100001000010010130039130039130039130039130039
300241300389740000000013002311941725400101001020000100001020000100005062149791480002511300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127011611129529100000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtmu w0, s8
  fcvtmu w1, s8
  fcvtmu w2, s8
  fcvtmu w3, s8
  fcvtmu w4, s8
  fcvtmu w5, s8
  fcvtmu w6, s8
  fcvtmu 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)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)9fl1d 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
1602044004129903225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
16020440041299022225240104801001600041001600205001440132140022400414004119977619992160120200160032200160456400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004129903225240104801001600041001600205001440132040108400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004129907425240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004130003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
16020440041300035925240104801001600041001600205001440132140022401964020419977619992160120200160032200160248401214004111802011009910080100100000111511704310401738000080000801004004240042400424004240042
1602044004130007425240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100100111511701601400388000080000801004004240042400424004240042
1602044004131303225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100103111511701600400388000080000801004004240042400424004240042
1602044004130003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100200111511701600400388000080000801004004240042400424004240042
160204400413001232252401048010016000410016002050014401320400224004140041199776199921601202001604602001600324004140120118020110099100801001000012111511701600400388000080000801004004240042400424004240042

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)acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd2d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244005529904225240010800101600001016000050144189814002204004140041199963200211600102016000020160000400414004111800211091080010100900005020041625400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010015000005020041642400388000080000800104004240042400424004240042
16002440041300042252400108001016000010160000501440000040022040041400411999632002116001020160000201600004004140041118002110910800101007200005020041646400388000080000800104004240042400424004240042
160024400413100422524001080104160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010012900005020041642400388000080000800104004240042400424004240042
160024400413000256252400108001016000010160000501440000140022040041400411999632002116001020160000201600004004140041118002110910800101001520005020021634400388000080000800104004240042400424004240042
1600244004130004225240010800101600001016000050144000014002204004140041199963200211600102016000020160000400414004111800211091080010100000005020041642400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010016800005020021624400388000080000800104004240042400424004240042
160024400412990883252400108001016000010160000501440000040022040041400411999632002116001020160000201600004004140041118002110910800101001800005020021642400388000080000800104004240042400424004240042
160024400412990422524001080010160000101600005014400000400220400414004119996320021160010201600002016000040041400411180021109108001010018000005020041624400388000080000800104004240042400424004240042
16002440041300042252400108001016000010160000501440000140022040041400411999632002116001020160000201600004004140041118002110910800101001800005020021624400388000080000800104004240042400424004240042