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, S to X)

Test 1: uops

Code:

  fcvtms x0, 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)031e1f3f51schedule 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 tlb access (a0)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
200454140043253000100020002000180000522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140085253000100020002000180001522541541248327420002000200054154111100110000067311611538100010001000542542542542542
200454150043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454143043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140085253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
2004541400432530001000200020001800015225415412483274200020002000541541111001100000127311611538100010001000542542542542542
200454140043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140043253000100020002000180001522541541248327420002000200054154111100110000007311611538100010001000542542542542542
200454140043253000100020002000180001522541541248327420002000200054154111100110000037311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtms x0, 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)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)l1d tlb miss (a1)ld 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
302041300389740000981013002311941725401001010020000100001002000010000500621497914801034113001313003813003812547629126259301002021000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130041130041130039130039130039
302041300389740031115201300231194172540100101312000010000100200001000050062149791480114601300131300381300381254763126274301002001000020000200100002000013003813003811202011009910010100100001000010000203000131012162212952510000100001000010100130039130039130039130039130039
30204130038973000095101300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003851202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000001300231194172540100101002000010000100200001000050062151711482197511300151300381300391256183126246301002001000020000200100002000013035713003811202011009910010100100001000010010000400131014162212952510000100001000010100130039130271130039130039130039
302041300389740000132901300231194172540100101002000010000103200001000050062149791480103401300131300381300381254763126246301002001000020483200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000582013002311941725401001010020000100001002000010196500621497914801034013001313003813003812547631262473076620010000200002001000020000130038130038112020110099100101001000010002100000017127000131012162212952510000100001000010100130071130039130039130039130039
302041303719740000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000420000131012162212982210000100001000010100130039130357130041130039130039
302041300389740004001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126252301002001024620000200100002000013003813003811202011009910010100100001000010000000000131012162312952510000100001000010100130039130039130039130039130039
302041300389740000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126269301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000196901300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131015162212952510000100001000010100130361130039130039130039130039

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)l2 tlb miss instruction (0a)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 access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch 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
3002413003810080000000001300231194172540019100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012706165412952510000100001000010010130039130039130039130039130039
300241300389740000000001300231194172540036100102000010000102000010000506214979148000250130013013050513014012549831262683001020100002000020100002013113003813003811200211091010010100001000100000000012705165412952510000100001000010010130039130039130039130039130039
300241300389740000000001300231194172540010100102000010000102000010000506214979148000251130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012705165312952510000100001000010010130039130039130039130039130039
300241300419740000000001300231194173340010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012704164512952510000100001000010010130039130039130039130039130039
300241300389740000000001300231194172540010100102000010002102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003911200211091010010100001000100000000012705163512952510000100001000010010130039130039130039130096130039
300241300389740000000001300231194662540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013004113003811200211091010010100001000100000000012705165412996510000100001000010010130604130630130479130530130548
300241306389781021000001300231194522540010100132000010000102000010000506214979148000250130023013003813003812549831262683001020100002000020100002000013003813014111200211091010010100001000100000000012703164512952510000100001000010010130039130039130039130039130039
300241300389740000000001300231194552540010100102000010000102000010000556215123148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012704164412952510000100001000010010130039130039130039130086130039
30024130038974000000672001300961194332540010100102000010000102000010000506214979148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012704164512952510000100001000010010130039130039130039130118130039
300241300389740000000001300231194182540010100102000010000102000010000506215444148000250130013013003813003812549831262683001020100002000020100002000013003813003811200211091010010100001000100000000012704164512952510000100001000010010130039130039130108130040130039

Test 3: throughput

Count: 8

Code:

  fcvtms x0, s8
  fcvtms x1, s8
  fcvtms x2, s8
  fcvtms x3, s8
  fcvtms x4, s8
  fcvtms x5, s8
  fcvtms x6, s8
  fcvtms x7, 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)03181e3f51schedule 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 tlb access (a0)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ec? simd retires (ee)? int retires (ef)f5f6f7f8fd
1602044006230000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117017004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
16020440041300006972524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000031115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000101115117016004003880000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042
1602044004130009742524010480100160004100160020500144013204002204004140041199776199921601202001600322001600324004140041118020110099100801001000001115117016004003880000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03l2 tlb miss instruction (0a)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 tlb access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024400423000000004225240010800101600001016000050144000004002240041400411999603200211600102016000020160000400414004111800211091080010100000030000502081669400388000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000000144000502081677400388000080000800104004240042400424004240042
16002440041300000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000002310005020101688400388000080000800104004240042401284004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000000147000502091657400388000080000800104004240042400424004240042
16002440041300000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000009600050205161111400388000080000800104004240042400424004240042
16002440123301000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000001560005020101688400388000080000800104004240042400424004240042
16002440041300000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000001680005020716109400388000080000800104004240042400424004240042
160024400413000000007072524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000001620005020101668400388000080000800104004240042400424004240042
16002440041300000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000002280005020101668400388000080000800104004240042400424004240042
16002440041300000000422524001080010160000101600005014400000400224004140041199960320021160010201600002016000040041400411180021109108001010000003000502071668400388000080000800104004240042400424004240042