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

FCVTNS (scalar, H to X)

Test 1: uops

Code:

  fcvtns 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 data (08)1e3f51schedule 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
20045414004325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414005625300010002000200018000152254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414004325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414008725300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414008725300010002000200018000052254154124832742000200020005415411110011000007511611538100010001000542542542542542
20045415008525300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414004325300010002000200018000052254154124832742000200020005415411110011000007511611538100010001000542542542542542
20045414004325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414004325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
20045414004325300010002000200018000052254154124832742000200020005415411110011000107311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtns 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)09l2 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 cond mispred nonspec (c5)branch mispred nonspec (cb)cfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
302051300609740000000013002311941725401001010020000100001002000010000500621497914801034113003301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038212020110099100101001000010000100002200000131012162212952510000100001000010100130039130039130039130039130042
302041300389740000000013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000000013002311941725401001010020000100001002000010000500621741314801373113001301300381300381254763126246301002001000020000200100002000013007013003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130041
302041300389740000000013002311941725401001010020000100001002000010000500621512314801034013001301300381300381254763126246301002001000020000200100642000013003813003811202011009910010100100001000010000103000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000000013002311941725401001010020000100011002000010000500621497914801034113001301300381300421254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130041130039130039
302041300389740010000013002311941725401001010020000100001002000010000500621497914801034113001601300381300451254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000000013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131012162212952510000100001000010100130039130039130040130039130039
302041300389750102218688013002311941725401001010020000100001002000010000500621497914801376013001301300381300381254763126247301002001000020000200100002000013003813003811202011009910010100100001000010000003000131013163212952510000100001000010100130039130039130039130039130039
302041300389740000060013002311941725401001010020000100001002000010000500621497914801034013001301300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000131013162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)1e1f3f4f51schedule 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)acbranch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974000013002311941725400101001020000100001020000100005062149791480002501300133130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127031644129525100000100001000010010130041130052130039130039130039
30024130038988000013002311941725400101001020003100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127051633129525100000100001000010010130052130039130039130039130039
30024130038974000013002311941725400101001020000100001020000100005062149791480002501300160130040130038125500312626830334221024620000201000020000130038130038112002110910100101000010100000000127051654129525100000100001000010010130039130039130039130039130039
30024130038974000013002311942225400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127061645129525100000100001000010010130063130039130039130039130039
30024130038974000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127041655129528100000100001000010010130044130078130042130039130039
30024130041974000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127041655129525100000100001000010010130043130039130039130039130039
30024130038974000013004911941725400101001020000100101020000100005062149791480036701300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000300127051656129525100000100001000010010130067130039130039130039130039
30024130038973000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127061646129525100000100001000010010130045130039130039130039130039
30024130038974000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020000130038130038112002110910100101000010100000000127041645129525100000100001000010010130040130039130039130039130039
30024130038974000013002311941725400101001020000100001020000100005062149791480002501300130130038130038125498312626830010201000020000201000020126130078130038212002110910100101000010100000000127041645129525100000100001000010010130040130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtns x0, h8
  fcvtns x1, h8
  fcvtns x2, h8
  fcvtns x3, h8
  fcvtns x4, h8
  fcvtns x5, h8
  fcvtns x6, h8
  fcvtns 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)03mmu table walk data (08)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)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)st unit uop (a7)l1d cache writeback (a8)a9acc2branch 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
1602044012531100002400322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000000000111511701600402928000080000801004004240042400424004240042
160204400413110000000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000000000111511701600400388000080000801004004240042400424004240042
160204400413110000000322524010480100160004100160020500144013204002240041400411997761999216012020016003220016003240041400411180201100991008010010000000000111511701600400388000080000801004004240042400424004240042
160204400413100000000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000001000111511701600400388000080000801004004240042400424004240042
160204400413110000000532524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000000000111511701600400388000080000801004004240042400424004240042
1602044004131000000002462524010480100160004100160020500144013214002240041400411997761999216012020016003220216003240041400411180201100991008010010000000000111511701600403008000080000801004004240042400424004240042
1602044004131000001200322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000001000111511701600400388000080000801004004240042400424004240042
160204400413110000000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000000000111511701610400388147080000801004116741243412344115041246
160204412433190016152112132015951376244734814261633161061632285051469331141121412874130320386619992160120200160032200160032400414004111802011009910080100100222002706801115413016021410848106680000801004130441340413134129641313
16020441316321111615224479213225240104801001600041001600205001440132040855409934084420237110205681628022001626222001618784092241066131802011009910080100100020000878521115378015100410098133880000801004067541240413204123741330

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03l2 tlb miss data (0b)1e3a3f51schedule 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)5f60696d6emap 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)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)d9ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244004230000084325240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020516032400388000080000800104004240042400424004240042
16002440041300000137125240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316042400388000080000800104004240042400424004240042
16002440041300000184425240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316043400388000080000800104004240042400424004240042
16002440041300000112225240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316052400388000080000800104004240042400424004240042
16002440041300000110125240010800101600001016000050144000000400694004140041199963200211600102016000020160000400414004111800211091080010100000005020316032400388000080000800104004240042400424004240118
1600244004129900076725240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316033400388000080000800104004240042400424004240042
16002440041300000153625240010800101600001016000050144149800400224004140041199963200211600102016000020160000400414004111800211091080010100000005020216034400388000080000800104004240042400424004240042
16002440041312000108925240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316033400388000080000800104004240042400424004240042
16002440041299000129225240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000105020316032400388000080000800104004240042400424004240042
16002440041300000142325240010800101600001016000050144000000400224004140041199963200211600102016000020160000400414004111800211091080010100000005020316033400388000080000800104004240042400424004240042