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

FCVTMS (scalar, H to W)

Test 1: uops

Code:

  fcvtms 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)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
20045413643253000100020002000180001522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414643253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180001522541541248327420002000200054154111100110007321622538100010001000542542542542542
200454141843253000100020002000180001522541541248327420002000200054154111100110007321622538100010001000542542542542542
20045414043253000100020002000180001522541541248327420002000200054154111100110007321622538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtms 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): 13.0038

retire uop (01)cycle (02)03191e1f3f4f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3020413003897400013002311949625401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130081
3020413003897400013002311941725401331010020000100081232081110343597623778214856101113001313037713037912584531262923010020010000201222001000020122130038130038212020110099100101001000010010000300000131012162212952510000100001000010100130040130039130039130039130039
3020413003897403388130023119417254010010100200001000010020000100005006214979148013701130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100100103412903000131012162212952510000100001000010100130042130039130039130039130039
3020413003897400013002311945065401001010020000100001002000010000500621497914801148113001413004213003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130045130039130039130039130110
3020413003897400013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020513003897400013002311941725401001010020000100021002011610000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000132512162212952510019100001000010100130039130039130039130039130039
30204130038974112013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262473010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000130023119417254010010100200001000010020000100005006214979148010341130013130038130038125476312624630100200100002000020010000200001300381300381120201100991001010010000100100073000000131012162212952510000100001000010100130039130070130039130039130039
3020413003897400013005711942125401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262673010020010000200002001000020000130038130038112020210099100101001000010010000000010131012162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)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)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)ld unit uop (a6)l1d cache writeback (a8)acc2branch cond mispred nonspec (c5)cfl1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974000901300301194172540010100102000010000102000010000506214979148000251300150130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010010000016500127001161112952510000100001000010010130039130039130039130039130039
300241300389741000013002311941725400101001020000100001020000100005062149791480002513001301300381300381254983126268300102010000200002010000200001300391300421120021109101001010000100100000000127001161112952510000100001000010010130039130039130039130039130039
30024130103973000001300231194172540010100102000010000102000010000506214979148000251300130130038130039125528312626830010201000020000201000020000130038130038112002110910100101000010010000116000127001161112952510000100001000010010130044130039130039130039130039
300241300389740000013002311941725400101001020000100001020000100005062149791480002513001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000127002161112952510000100001000010010130039130039130039130039130039
300241300389730000013002311942125400101001020000100011020000100005062342241480002513001301300381300381257903126794300102010000200002010000203591300381300381120021109101001010000102100000000127001161112952510000100001000010010130039130042130039130039130039
3002413003897400000130023119493254001010010200001000010200001000050621497914800025130013013003813003812549831262683001020100002000020100002000013007913004711200211091010010100001001000001500127001161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119520254001010010200001000010200001000050621497914800025130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001001000079000127001171112952510000100001000010010130039130039130039130039130039
300241300389740000013002311941725400101001020000100001020000100005062149791480002513001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000127001161112952510000100001000010010130039130039130039130039130039
300241300389740000013002311941725400101001020000100001020000100005062149791480002513001301300381300381254983126268300102010000200002010000200001300381300741120021109101001010000100100000000127001161112952510000100001000010010130039130039130039130039130039
300241300389740000013002311941725400101001020000100001020000100005062149791480002513001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100100000000127002161112958710000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtms w0, h8
  fcvtms w1, h8
  fcvtms w2, h8
  fcvtms w3, h8
  fcvtms w4, h8
  fcvtms w5, h8
  fcvtms w6, h8
  fcvtms 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 data (08)0918191e1f3f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)dde0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1602044005330002000032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151172160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401320400834004140041199776199921601202001602482001600324004140041118020110099100801001000040011151170160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000100011151170160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401321400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004129900006032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324011940277118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401320400864004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004129900000032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004130000000055252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042
1602044004130000000032252401048010016000410016002050014401320400224004140041199776199921601202001600322001600324004140041118020110099100801001000000011151170160400388000080000801004004240042400424004240042

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)6061696d6emap 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)a9acbranch cond mispred nonspec (c5)cfd0d2d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244005530007072524001080010160000101600005014400001040022400414004119996320021160010201600002016000040041400411180021109108001010000000050205061654400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000540022400414004119996320021160010201600002016000040041400411180021109108001010000000050205051645400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400000540022400414004119996320021160010201600002016000040041400411180021109108001010000000050205251664400388000080000800104004240042400424004240042
160024400412990422524001080010160000101600005014400001040022400414004119996320080160010201600002016000040041400411180021109108001010000000050205271667400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000000050375261654400388000080000800104004240042400424004240042
160024400412990422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000000050205261655400388000080000800104004240042400424004240042
160024400413140422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000200050205261666400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000100050205251665400388000080000800104004240042400424004240042
1600244004130018422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000000050208251666400388000080000800104004240042400424004240042
160024400413000422524001080010160000101600005014400001540022400414004119996320021160010201600002016000040041400411180021109108001010000000050205251656400388000080000800104004240042400424004240042