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

FCVTPS (scalar, H to W)

Test 1: uops

Code:

  fcvtps 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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
2004541404325300010002000200018000152254154124832742000200020005415411110011000007331622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000137321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
20045414124325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtps 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)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)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)a9acc2branch 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
3020413003897400000130023119416254010010100200001000010020000100005006214979148012621130013013006913004112547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003997400000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131013162212952510000100001000010100130039130039130039130039130039
3020413016197500000130023119417254010010100200001000010020000100005006214979148010340130013013003813006812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000130023119417254010010100200001000010220117100005006214979148010341130013013003813003812550431262493010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000130024119417254010010100200001000010020000100495006215075148010340130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130039112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039
3020413003897400000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000000131013162212952510000100001000010100130039130039130039130039130039
3020413003897400000130085119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020000130038130038112020110099100101001000010010000000001131012162212952510000100001000010100130039130039130039130039130039
3020413003997400000130023119417254010010100200001000010020000100005006214979148010341130013013003813003812547631262463010020010000200002001000020132130038130038112020110099100101001000010010000000000131012162212952510000100001000010100130039130039130039130039130039

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)18191e3f4f51schedule 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)acbranch cond mispred nonspec (c5)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381301021120021109101001010000100010000000012702161112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012704161112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012701161212952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381301191120021109101001010000100010000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012701163112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300681120021109101001010000100010000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897400000013002311941725400101001020000100001020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000112701161112952510000100001000010010130039130039130039130039130039
30024130038974000008413002311941725400101001020000100011020000100005062149791480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012701161112952510000100001000010010130039130039130039130039130039
3002413003897300000013005311941725400101001020000100001020113100005062241271480002511300131300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000012701161112952510000100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtps w0, h8
  fcvtps w1, h8
  fcvtps w2, h8
  fcvtps w3, h8
  fcvtps w4, h8
  fcvtps w5, h8
  fcvtps w6, h8
  fcvtps w7, h8
  mov x8, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.5006

retire uop (01)cycle (02)03l2 tlb miss data (0b)18191e3f51schedule 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)9fld unit uop (a6)acc2branch 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
1602044004131000003225240104801001600041001600205001440132140022400414004119972619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004131000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004131000003225240104801001600041001600205001440132140022400414004119977619992160120200160032200160032400414004111802011009910080100100000111511701600400388000080000801004004240042400424004240042
1602044004131000003225240104801001600041001600205001440132040022400414004119977619992160120200160032200160032400414004111802011009910080100100000222512712411400488000480000801004005240052400524005340053
1602044005131000006627240116801041600121001600285001440202040032400514005119976919989160128200160038200160038400514005211802011009910080100100000222512812411400488000480000801004005340053400524005240052
16020440051310000012226240116801041600121001600285001440202140032400524005219976919989160128200160038200160038400514005211802011009910080100100000222512812411400488000480000801004005240052400534005340053
1602044005231000006627240116801041600121001600285001440202140032400514005119976919989160128200160038200160038400524005111802011009910080100100000222512712411400488000480000801004005340052400524005240052
1602044005231000006627240116801041600121001600285001440202140032400514005219976919989160128200160038200160038400524005211802011009910080100100000222512812411400498000480000801004005340053400524005240052
16020440052310000066272401168010416001210016002850014402021400324005140051199761019989160128200160038200160038400514005111802011009910080100100000222512712411400498000480000801004005240052400524005240052
1602044005131000006626240116801041600121001600285001440202140032400524005119976919989160128200160038200160038400524005111802011009910080100100000222512712411400498000480000801004005340053400534005340053

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)1e1f3a3f51schedule 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)91inst branch cond (94)inst int alu (97)9fl1d cache writeback (a8)accfd0d2d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244005531000004225240010800101600001016000050144000004002240041400411999632002116001020160000201600004004140041118002110901080010100050200091600588400388000080000800104004240042400424004240042
160024400413110000422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211090108001010005020009160031110400388000080000800104004240042400424004240042
1600244004131000009825240010800101600001016000050144000004002240041400411999632002116001020160000201600004004140041118002110901080010100050200091600499402278000080000800104004240042400424004240042
16002440041310100042252400108001016000010160000501440000140022400414004119996320021160010201600002016000040041400411180021109010800101019502000416003811400388000080000800104004240042400424004240042
16002440041310000042252400108001016000010160000501440000140022400414004119996320021160010201600002016000040041400411180021109010800101000502000916004128400388000080000800104004240042400424004240042
16002440041311000042252400108001016000010160000501440000140022400414004119996320021160010201600002016000040041400411180021109010800101000502000916003124400388000080000800104004240042400424004240042
1600244004131000004225240010800101600001016000050144000004002240041400411999632002116001020160000201600004004140041118002110901080010100050200091600449400388000080000800104004240042400424004240042
160024400413110000422524001080010160000101600005014400000400224004140041199963200211600102016000020160000400414004111800211090108001010005020009160031316400388000080000800104004240042400424004240042
16002440041321000042252400108001016000010160000501440000140022400414004119996320021160010201600002016000040041400411180021109010800101000502000516003104400388000080000800104004240042400424004240042
1600244004131100007025240010800101600001016000050144000004002240041400411999632002116001020160000201600004004140041118002110901080010100050200051600383400388000080000800104004240042400424004240042