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, H to X)

Test 1: uops

Code:

  fcvtmu x0, 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)03mmu table walk instruction (07)09l2 tlb miss data (0b)1e1f3f51schedule 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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140000043253000100020002000180000522541541248327420002000200054154111100110000007311622538100010001000542542542542542
200454140000043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007321611538100010001000542542542542542
200454140000043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007511611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007511611538100010001000542542542542542
200454140000043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtmu x0, 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)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)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)acbranch mispred nonspec (cb)cfd0d5map dispatch bubble (d6)dbddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3020413003810080000013002311941725401001010020000100001002000010000500621497914801034113004413003813003812549331263063010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039
3020413003810080000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262783010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039
3020413006897400072013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262473010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130067
302041300389740000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262513010020010000200002001000020128130038130038112020110099100101001000010001000000013101216032129525100000100001000010100130039130039130039130042130039
302041300389740000013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262483010020010000200002001000020000130038130038112020110099100101001000010001000000013101217022129525100000100001000010100130039130039130039130039130039
302041300389740000013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547731262463010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039
302041300389740000013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010001000000013101217122129525100000100001000010100130039130039130039130039130039
302041300389740001287013002311941725401001010020000100001002000010000551621521914801034013001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039
30204130038974000828013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039
3020413003897400069013002311941725401001010020000100001002000010000500621497914801034013001313003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010001000000013101216022129525100000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk instruction (07)l2 tlb miss data (0b)181e1f3f4f51schedule 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)accdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3002413003897400000130023119417254001010010200001000010200001000050621497914800025113001301300381300991255003126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119417254001010010200001000010200001000050621497914800025113001301300411300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119417254001010010200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161212952710000100001000010010130039130039130039130039130039
30024130038973000001300231194172540010100102000310000102000010000506214979148000251130013013003813003912549831262683001020100002000020100002000013003813003811200211091010010100001010000221012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119417254001010010200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130079130042130039130040
3002413003897400000130023119420254001010010200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119417254001010010200001000110200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000130023119417254001010010200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130048
30024130039974000792340130023119417474001010010200001000010200001000050621497914833658113033801303691301201254983126268300102010000200002010122200001300381300383120021109101001010000101000009750012702161212952510000100001000010010130039130039130039130039130039
3002413003897400060130023119417254001010010200001000010200001000050621497914800025113007401300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000012701161112952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtmu x0, h8
  fcvtmu x1, h8
  fcvtmu x2, h8
  fcvtmu x3, h8
  fcvtmu x4, h8
  fcvtmu x5, h8
  fcvtmu x6, h8
  fcvtmu x7, 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)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)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfmap dispatch bubble (d6)dde0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160204400623110222252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
16020440041311032252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
16020440041310032252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
160204400413111274252401048010016000410016002050014401320400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
16020440041310032252401048010016000410016002050014420490400223400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
160204400413220975252401048010016000410016002050014401320400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
16020440041310032252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042401864004240042
160204400413100549252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117160400388000080000801004004240042400424004240042
16020440041311332252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032400414004111802011009910080100100001115117161400388000080000801004004240042400424004240042
16020440041311032252401048010016000410016002050014401321400220400414004119977619992160120200160032200160032401264004111802011009910080100100001115117160400388000080000801004004240042400424004240042

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)18191e1f3a3f51schedule 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)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 tlb access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9abacc2cfd0d2l1i tlb miss demand (d4)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16002440042310000000422524001080010160000101600005014400000040022400414004119996032002116001020160000201600004004140041118002110910800101000000000502000041644400388000080000800104004240042400424004240042
16002440041310000000422524001080010160000101600005014400000040022400414004119996032002116001020160000201600004004140041118002110910800101000000000502000041644400388000080000800104004240042400424004240042
16002440041310000000792524001080010160000101600005014400000040022400414004119996032002116001020160000201600004004140041118002110910800101000300000502000041643400388000080000800104004240042400424004240042
16002440041311001000422524001080010160000101600005014400000040022400414004119996532002116001020160000201600004004140041118002110910800101000000000502000041643402988000080000800104004240042400424004240042
16002440041311000000422524001080010160000101600005014400000040022400414004119996032002116001020160000201600004004140041118002110910800101002000030502000041644400388000080000800104004240042400424004240042
1600244004131000000021327824342781162162138101616285014616540040787408944100620274093205571623962016259420161788410604091113180021109108001010000120741005220000313344408238112780000800104059741070411474108341306
16002441054317100000193820624176880816161176101609845014507520040344404244028320164041202831608262016143622161040403624067871800211091080010102021001868051710010057047410728154480000800104155641453413874146541075
160024412303341121628621672282484824001080010160000101600005014400000041410411544004119996010820428162680201630942016287441297411471618002110910800101020010012282502150049834401068000080000800104004240042400424004240042
16002440041321000000842524001080010160000101600005014400001040022400414004119996032002116001020160000201600004004140041118002110910800101000000000502000041634400388000080000800104004240042400424004240042
16002440041310000000422524001080010160000101600005014400001040022400414004120017032002116001020160000201600004004140041118002110910800101000000000502000031644400388000080000800104004240042400424004240042