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, D to W)

Test 1: uops

Code:

  fcvtms w0, d0
  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
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541504325300010002000200018000052254154124832742000200020005415411110011000037311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541464325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541504325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtms w0, d0
  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 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)st unit uop (a7)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30204130038974101000001130023119474254010010100200001000010020000100005006214979148010340130013013003813003812548361262423010020010002200062001000220006130038130038112020110099100101001000010000100000000111131702162212953710000100001000010100130039130039130039130039130039
302041300389741010000011300231194582540100101002000010000100200001000050062149791480103401300130130038130074125487312624630100200100002000020010000200001300381300381120201100991001010010000100001000003000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000000130034119492254010010100200001000010020000100005006214979148010340130013013004213003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000000130023119474254010010100200001000010020000100005006214979148010340130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162212952510003100001000010100130039130039130039130039130039
30204130038974000000000130023119472254010010100200001000010020000100005006214979148010340130013013003813003812550531262463010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162212952510000100001000010100130039130039130039130039130039
30204130038974000000000130023119441254010010100200001000010020000100005006214979148010340130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000100000131012162212952510000100001000010100130039130039130108130039130039
30204130038974000000000130023119435254010010100200001000010020000100005006214979148010340130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162312952510000100001000010100130039130039130039130100130039
30204130038974000000000130023119417254010010100200001000010020000100005006214979148010340130013013003813003812547631262463010020010000200002001000020000130038130038212020110099100101001000010000100000000000131012162212952510000100001000010100130039130039130097130046130039
30204130040974000000000130023119419254010010100200001000010020000100005006214979148010340130013013003813003812547631262493010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162212952510000100001000010100130039130039130142130039130042
30204130038974000000000130023119440254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000000131012162212952510000100001000010100130039130039130039130064130039

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)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)l1d cache miss st (a2)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)acbranch 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
30024130038100800000420130023119417324001010010200001000010200001000050621497914800025013001313003813003812550831262683001020100002000020100002000013003813003811200211091010010100001000010000000012701161112952510000100001000010010130039130039130039130070130039
3002413003810080000000130023119417254001010010200001000010200001000050621497914800025013001313003813003812554631262683001020100002000020100002000013003813003811200211091010010100001000010000000012701161112952510000100001000010010130039130039130039130039130039
3002413003810080000000130023119417254001010010200001000010200001000050621512314800025013001313003813003812555531262683001020100002000020100002000013003813003811200211091010010100001000010000000012701161212952510000100001000010010130039130039130039130039130039
3002413003810080000000130039119417254001010010200001000010200001000050621497914800025013001313003813003812554731262683001020100622000020100002000013003813003811200211091010010100001000010000000012701161112952510000100001000010010130039130039130039130039130039
30024130038974000000013002311941725400101001020000100001020000100005062149791480002501300131300381300381255413126268300102010000200002010000200001300381300381120021109101001010000100001000032380012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000001300231194172540010100102000010000102000010000506214979148000250130013130038130038125554312626830010201000020000201000020000130038130038112002110910100101000010000100000680012701161112952510000100001000010010130039130039130039130039130039
300241300389740000000130049119417254001010010200001000010200001000050621497914800025013001313003813003812551231262683001020100002000020100002000013003813003811200211091010010100001000010000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000000130023119417254001010010200001000010200001000050621497914800025113001313003813003812554231262683001020100002000020100002000013003813003811200211091010010100001000010000003012701161112952510000100001000010010130039130039130039130039130039
300241300389740000000130023119417254001010010200001000010200001000050621497914800025013001313003813003812553431262683001020100622000020100002000013003813003811200211091010010100001000010000000012701161112952510000100001000010010130039130039130039130039130039
300241300389740000000130023119417254001010010200001000010200001000050621497914800025013001313003813010812549831262683001020100002000020100002000013003813010511200211091010010100001000010000003012701161112952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtms w0, d8
  fcvtms w1, d8
  fcvtms w2, d8
  fcvtms w3, d8
  fcvtms w4, d8
  fcvtms w5, d8
  fcvtms w6, d8
  fcvtms w7, d8
  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)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)9facbranch 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
160204400662990322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001003111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130008612524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400413000532524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400412990322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400412990322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480182160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701610400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042

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)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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244004230000000042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020316224003880000080000800104004240042400424004240042
16002440041300000000707252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996320195160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000065020216224003880000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
1600244004130000000042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
16002440041300000000196252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000035020216224003880000080000800104004240042400424004240042
160024400413000000267042252400108001016000010160000501440000040022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042
160024400413000000558042252400108001016000010160000501440000140022400414004119996320021160010201600002016000040041400411180021109108001010000005020216224003880000080000800104004240042400424004240042