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, H to W)

Test 1: uops

Code:

  fcvtpu w0, h0
  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
2004541504325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541434325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541408525300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000107311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414124325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtpu w0, h0
  fmov d0, x0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 13.0075

retire uop (01)cycle (02)03l1i tlb fill (04)mmu 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)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30204130136975000000021300231194172540100101002000010000100200001000050062149791480103401300130130038130038125476312624630100200100002000020010000200001300381300391120201100991001010010000100010000041413149168912952510000100001000010100130039130039130039130039130039
302041300389750000000213002311941725401001010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013148167812952510000100001000010100130039130039130039130039130039
302041300389740000000213002311941725401001010020012100061002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013149167812952510000100001000010100130039130039130039130039130039
30204130038975000000021300231194172540100101002000010000100200001000050062151231480103401300133130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100010000025213148167812952510000100001000010100130039130039130039130039130041
302041301059760002000213002311941725401001010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013149167812952510000100001000010100130039130039130039130039130039
302041300389740000000213002311941725401001010020000100001002000010000500621512314801034113001301300381300381254763126246301002001000020000200100002000013003813011211202011009910010100100001000100000013145168812952510000100001000010100130039130039130039130039130039
302041300389750000000213002311941725401001010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013149167912952510000100001000010100130039130039130039130039130039
302041300389750000000213002311941725401001010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013149167812952510000100001000010100130039130039130039130077130077
302041300829750000000213002311941725401001010020000100001002000010000500621507514801034013001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000100000013148165612952510000100001000010100130039130039130039130039130039
302041300389751001000213002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246301002001000020128200100002000013003813003811202011009910010100100001000100000013148167812952510000100001000010100130039130039130039130039130042

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)09l2 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)9fld unit uop (a6)l1d cache writeback (a8)a9accfl1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974000000013002311941725400101001320000100001020000100005062149791480002501300130130038130074125498312626830010201000020000201000020000130038130039112002110910100101000010100000001270011611129525100000100001000010010130039130039130039130039130039
3002413003897300000738013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000001270011612129525100000100001000010010130039130039130039130039130039
30024130038974000000013002311941725400101001020000100051220000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130074130038112002110910100101000010100000001270011611129525100000100001000010010130039130039130039130039130039
30024130038974000000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000001270021611129525100000100001000010010130039130039130039130039130039
30024130038974000000013002311941725400101001020000100001020000100005062149791480002501300130130048130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000001270011611129525100000100001000010010130039130039130040130039130039
30024130038974000000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000001270011611129525100000100001000010010130039130039130039130039130039
30024130038974000000013002411941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130040112002110910100101000010100000001270011611129525100000100001000010010130039130039130039130039130039
3002413003897400000579013002311941725400101001020000100021020000100005062149791480002511300130130038130038125498312626830010201000020000201000020000130041130038112002110910100101000010100001031270011611129525100000100001000010010130039130039130039130039130039
30024130038974000009013002311941725400101001020000100001020000100005062149791480002511300130130038130039125498312626830010201000020000201000020000130038130038112002110910100101000010100003001270011611129525100000100001000010010130044130162130041130039130039
30024130038974000000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000001270011622129525100000100001000010010130042130039130042130039130039

Test 3: throughput

Count: 8

Code:

  fcvtpu w0, h8
  fcvtpu w1, h8
  fcvtpu w2, h8
  fcvtpu w3, h8
  fcvtpu w4, h8
  fcvtpu w5, h8
  fcvtpu w6, h8
  fcvtpu w7, h8
  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)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)fetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16020440062300000006303225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
1602044004130000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
16020440041300000001803225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
1602044004130000010003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
16020440041300000000069725240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
1602044004130000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
1602044004130000000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
1602044004130000000003225240104801001600041001600205001440132040022400414004119977619992160312200160032200160032400414004111802011009910080100100000000011151171160400388000080000801004004240042400424004240042
1602044004130000000003225240104801821600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042
16020440041299000002403225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000000011151170160400388000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03mmu table walk data (08)191e3f51schedule 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)5f60696b6d6emap 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)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)acc2branch mispred nonspec (cb)cdcfd0l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024400423000004225240010800101600001016000050144000000400220400414004119996320021160010201600002016000040041400411180021109108001010000000005020061116644003880000080000800104004240042400424004240042
16002440041300000422524001080010160000101600005014400000140022040041400411999632002116001020160000201600004004140041118002110910800101000000000502005416464003880000080000800104004240042400424004240042
16002440041299000422524001080010160000101600005014400000140068340041400411999632002116001020160000201600004004140041118002110910800101000000000502005616664003880000080000800104012440042400424004240042
16002440041300000422524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000000502004716564003880000080000800104004240042400424004240042
160024400413000004225240010800101600001016000050144186200400220400414004119996320021160010201600002016000040041400411180021109108001010000450000502005616464003880000080000800104004240042400424004240042
16002440041299000422524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000000502005616754003880000080000800104004240042400424004240042
16002440041300000842524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000010502005616554003880000080000800104004240042400424004240042
16002440041300000422524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000000502005616764003880000080000800104004240042400424004240042
16002440041299000422524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000000502004616644003880000080000800104004240042400424004240099
16002440041300000422524001080010160000101600005014400000040022040041400411999632002116001020160000201600004004140041118002110910800101000000000502004416664003880000080000800104004240042400424004240042