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

FCVTAU (scalar, S to X)

Test 1: uops

Code:

  fcvtau 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)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
2004541404325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541408525300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000152254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541504325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541504325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541434325300010002000200018000052254154124832742000200020005415411110011000007321622538100010001000542542542542542
2004541504325300010002000200018000154654154124832742000200020005415411110011000037321622538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtau 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)03l2 tlb miss data (0b)191e1f3f4f51schedule 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)acc2branch cond mispred nonspec (c5)cfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
302041300389740000130023119417254010010100200041000010020000100005006214979148010340130013013009413005712547631262463010020010000200002001000020000130038130068112020110099100101001000010000100000000131012162212971110000100001000010100130039130039130039130039130039
302041300389740000130023119417254010010100200001000010020000100005006214979148010340130013013007413004112547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131013162212952510000100001000010100130039130039130039130039130039
302041300389740000130023119417254010010100200051000010020000100005006214979148010340130013013004113003812547631262463010020010000200002001000020000130077130055112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039
30204130076974003301300231194172540100101002000010000100200001000050062149791480103411300130130098130048125476312624630100200100002000020010000200001300381300381120201100991001010010000100001000501859520131013253213002710017100001000010100130039130039130039130116130039
3020413003897400001300231194172540100101002000010000100200001000050062149791480103411300130130040130038125476312624630100200100002000020010000201291300511300381120201100991001010010000100001000005100131012162212952510000100001000010100130039130039130039130039130039
302041300389740000130023119417254010010100200001000010020000100005006214979148010340130013013006613003912547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130072130039130039130039
302041300389740000130023119417254010010100200001000010020000100005006214979148010340130013013008013007112547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212966210000100001000010100130039130039130039130039130039
302041300389740000130024119417254010010100200001000010020000100005006214979148010340130013013006513004112547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000130023119417254010010100200001000010020000100005006214979148010340130013013005713004212547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039
302041300389740000130023119417254010010100200001000010020000100005006214979148010340130013013008113003812547631262463010020010000200002001000020000130038130038112020110099100101001000010000100000000131012162212952510000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)0309l2 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)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)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
300241300381036000000130023119456254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000127051611129525100000100001000010010130039130039130039130086130039
300241300381008000000130023119429254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300681300381120021109101001010000100010000000000127011611129525100000100001000010010130039130039130039130090130039
300241300381007000000130023119417254001010010200001000010200001000050621497914800025113001301300381300381255073126268300102010000200002010000200001300381300381120021109101001010000100010000000000127011611129525100000100001000010010130039130049130258130443130039
3002413003997400000598130526119440254001010019200031000010200001000050621497914800025013001301300381301241254983126268300102010000200002010000200001300381300381120021109101001010000100010000000300127011611129527100000100001000010010130039130039130102130079130039
30024130038974000000130023119420254001010053200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000127011611129525100000100001000010010130039130039130039130087130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010005000000127011611129525100020100001000010010130043130039130090130053130039
30024130038974000000130023119417254001010010200001000010200001000050621497914800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000129511611129525100000100001000010010130039130039130086130055130039
30024130038974000000130023119436254001010010200031000010200001000050621526714800025113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000127011611129525100000100001000010010130039130039130039130105130039
30024130038974000000130023119421254001010010200001000010200001000050621497914800025013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000127011611129525100020100001000010010130039130042130039130066130039
300241300401072000000130061119418254001010010200001000010200001000050621497914800253013005901300381300381254983126268300102010000200002010000200001300381300381120021109101001010000100010000000000127011611129525100000100001000010010130039130039130133130043130039

Test 3: throughput

Count: 8

Code:

  fcvtau x0, s8
  fcvtau x1, s8
  fcvtau x2, s8
  fcvtau x3, s8
  fcvtau x4, s8
  fcvtau x5, s8
  fcvtau x6, s8
  fcvtau 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)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 tlb miss (a1)l1d cache writeback (a8)branch 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
1602044006229905772524010480100160004100160020500144013224002240041400411997761999216030020016003220016003240041400411180202100991008010010000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400413000532524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400412990322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111516901600400388000080000801004004240042400424004240042
160204400413740322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400413000322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
160204400412990322524010480100160004100160020500144013214002240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042
1602044004131118322524010480100160004100160020500144013214028240041400411997761999216012020016003220016003240041400411180201100991008010010000111511701600400388000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e3a3f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)accfd2l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024400553000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200015161714400388000080000800104004240042400424004240042
1600244004130000232252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200010161515400388000080000800104004240042400424004240042
160024400413220042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200014161015400388000080000800104004240042400424004240042
160024400412990042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200011161212400388000080000800104004240042400424004240042
160024400413000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200016161512400388000080000800104004240042400424004240042
160024400412990063252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200013161310400388000080000800104004240042400424004240042
160024400413000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200015161512400388000080000800104004240042400424004240042
160024400412990042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200016161217400388000080000800104004240042400424004240042
160024400413070042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200013161116400388000080000800104004240042400424004240042
160024400413000042252400108001016000010160000501440000040022400414004119996032002116001020160000201600004004140041118002110910800101000050200016161516400388000080000800104004240130400424004240042