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

FCVTZS (scalar, integer, H to W)

Test 1: uops

Code:

  fcvtzs 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)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
200454141243253000100020002000180001522541541248327420002000200054154111100110000007321611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414943253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414064253000100020002000180000522541541248327420002000200054154111100110000307311611538100010001000542542542542542
200454141243253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
20045414043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtzs 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)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 access (a0)l1d tlb miss (a1)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)acc2branch 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
30204130038974000130028119417254010010100200001000010020000100005006214979148010340130016013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000140000131012162312952510000100001000010100130039130039130039130039130039
3020413003897400013002311941725401081010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202021009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000130023119542254010010100200031000010020000100005006214979148010341130013013003813003812547616126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012172212952510000100001000010100130039130039130039130039130039
302041300389743564013002311941725401001010020000100001002000010000500621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038100800013002311941725401001010020000100001002000010000500621497914801034113001301300381301091254763126246301002001000020000200100002000013003813003811202011009910010100100001000210000000000131012162212959510000100001000010100130039130039130039130039130039
302041300419740576013002311941725401001010020000100001002000010000637621497914801034113001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130040130039130039130039
30204130038974000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000012000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400013002311941725401001010020000100001002000010049500621497914801034113001301300381300381254763126246301002001000020000200100002000013003913003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246301002001000020000200100002000013011413003811202011009910010100100001000010000000000131012162212952510000100001000010100130067130081130039130039130045
3020413004197400013002311941725401001010020000100001002000010000500621497914801034013001331300381300381254763126246301002001000020000200100002000013003813004111202011009910010100100001000010000005450000131012162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03181e3f4f51schedule 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 access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002024020100002000013003813003811200211091010010100001000100000000012702161112952510000100001000010010130039130039130077130039130039
300241300389740211300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
30024130038974001300231194172540010100102000010000102000010000506215445148051230130014013003813003812549831262693001020100002000020100002000013007213004011200211091010010100001000100000000012701161112955910000100001000010010130039130039130039130039130039
30024130038974001300231194172540010100102000010000102000010000506214979148000250130013613004013003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
30024130553978001300231194172540010100102000310000102000010000506215171148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701162112952510000100001000010010130039130039130039130039130039
30024130038974001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020102442000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
30024130038974001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130040130040130039130039
300241300381014001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130069130039
30024130038974001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831263203001020100002000020100002000013003813003811200211091010010100001000100000000012701161112952510000100001000010010130039130039130039130039130039
30024130038974001300231194172540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000112961161112952510000100001000010010130039130048130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtzs w0, h8
  fcvtzs w1, h8
  fcvtzs w2, h8
  fcvtzs w3, h8
  fcvtzs w4, h8
  fcvtzs w5, h8
  fcvtzs w6, h8
  fcvtzs 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)03l1i tlb fill (04)mmu table walk instruction (07)mmu table walk data (08)l2 tlb miss instruction (0a)l2 tlb miss data (0b)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)60696d6emap 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 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
16020440041300010100000134252401048010016000410016002050014401320400224004140041199770619992160120200160032200160032400414004111802011009910080100100000111511871699400388000080000801004004240042400424004240042
160204400413000101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118916109400388000080000801004004240042400424004240042
160204400413000101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118916119400388000080000801004004240042400424004240042
160204400412990101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118616611400388000080000801004004240042400424004240042
16020440041300010100000134252401048010016000410016002050014401321400224004140041199770619992160120200160032200160032400414004111802011009910080100100000111511871677400388000080000801004004240042400424004240042
160204400413000101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118916910400388000080000801004004240042403684004240042
1602044004130001010000108134252401048010016000410016002050014401321400224004140041199770619992160120200160032200160032400414004111802011009910080100100000111511841677400388000080000801004004240042400424004240042
160204400413000101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118916910400388000080000801004004240042400424004240042
160204400412990101000001342524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001003001115118101699400388000080000801004004240042400424004240042
1602044004129901010000012242524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000001115118101699400388000080000801004004240042400424004240042

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)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)acc2cdcfd2l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024400433100105252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000050200071677400388000080000800104004240042400424004240042
160024400413100422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211091080010100000502000101666400388000080000800104004240042400424004240042
160024400413100230252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010030050200071656400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501441768040022400414004119996320021160010201600002016000040041400411180021109108001010000050200081677400388000080000800104004240042400424004240042
160024400413100422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211091080010100000502000111685400388000080000800104004240042400424004240042
160024400413100422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211091080010100000502000101675400388000080000800104004240042400424004240042
160024400413100422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211091080010100000502000111677400388000080000800104004240042400424004240042
16002440041310042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000050200081675400388000080000800104004240042400424004240042
16002440041311042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000050200071677400388000080000800104004240042400424004240042
160024400413110422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211091080010100300502000101666400388000080000800104004240042400424004240042