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

FCVTZU (scalar, integer, H to W)

Test 1: uops

Code:

  fcvtzu 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
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541494325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541408425300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541504325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541404325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542
2004541408325300010002000200018000052254154124832742000200020005415411110011000007311611538100010001000542542542542542

Test 2: Latency 1->2 roundtrip

Code:

  fcvtzu 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)03l2 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)st unit uop (a7)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd0l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30204130038974000001300231194172540100101002000010000100200001000050062149791480103411300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194142540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103421300131300411300381254763126246301002001000020366200100602000013003813003811202011009910010100100001000010000000000013101041632129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021612129525100000100001000010100130039130039130039130039130039
30204130041974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000000000013101021622129525100000100001000010100130039130039130039130039130039
30204130038974000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013003813003811202011009910010100100001000010000010000013101021622129525100000100001000010100130039130039130039130039130039
30204130038973000001300231194172540100101002000010000100200001000050062149791480103401300131300381300381254763126246301002001000020000200100002000013006113004311202011009910010100100001000010000000000013101022522129525100000100001000010100130039130039130039130039130039

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0038

retire uop (01)cycle (02)03mmu table walk data (08)0e191e1f3f4f51schedule 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)5f60696b6d6emap 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)acc2branch mispred nonspec (cb)cfd5map dispatch bubble (d6)dbddfetch restart (de)e0? int output thing (e9)ea? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130038974020001300231194173840010100102000010000102000010000506214979148000250013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000201288117011129525100000100001000010010130057130043130039130039130040
30024130040974000601300231194172540010100102000010000102000010000506214979148000250013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000001270116011129525100000100001000010010130071130039130039130039130039
30024130038974000001300231194172540010100102000010000102000010000506214979148000250013001301300391300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000001270116011129525100000100001000010010130072130040130039130039130039
300241300381008000001300231194172540010100102000010000102023410049506215027148000250013001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000001270116011129525100000100001000010010130093130039130042130039130040
30024130038973000001300231194172540010100102000010000102000010000506214979148000250013001501301191301101255979126398301782010000200002010000202451302791301393120021109101001010000101000003001270116011129525100000100001000010010130091130039130039130039130039
30024130039974000901301031194172540010100102000010000102000010000506214979148000250013001601301221300461255043126271303412010000200002010000200001300411300401120021109101001010000101000000001270116011129525100000100001000010010130055130041130039130039130039
30024130038974000011213273012044664540204100462010010050102000010000506214979148000250013001301301861300421254983126268300102010000200002010000200001300381300381120021109101001010000101000000001270116011129525100000100001000010010130061130039130039130039130039
30024130038974000001300231194172540010100102000010000102000010000506214979148000250013001301300381300381254983126268300102010000200002010000200001300391300381120021109101001010000101000000001270116011129525100000100001000010010130136130078130042130039130039
300241300381008002001300231194172540010100102000010000102000010000506214979148000250113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000003001270116011129525100000100001000010010130039130039130039130039130039
3002413012110081002101300231194172540010100102000010000102000010000506214979148003610113001301300381300381254983126268300102010000200002010000200001300381300381120021109101001010000101000000001270116011129525100020100001000010010130039130039130039130039130039

Test 3: throughput

Count: 8

Code:

  fcvtzu w0, h8
  fcvtzu w1, h8
  fcvtzu w2, h8
  fcvtzu w3, h8
  fcvtzu w4, h8
  fcvtzu w5, h8
  fcvtzu w6, h8
  fcvtzu 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)03191e3f51schedule 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
1602044004129900322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130000532524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130000532524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511711600400388000080000801004004240042400424004240042
1602044004129900322524010480100160004100160020500144013204008640041400411997706199921601202001600322001600324004140041118020110099100801001003111511701600400388000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004129900322524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004130000322524010480100160004100160020500144013204002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042
1602044004129900322524010480100160004100160020500144013214002240041400411997706199921601202001600322001600324004140041118020110099100801001000111511701600400388000080000801004004240042400424004240042

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)0318191e3f51schedule 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)a9acc2cfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)d9dadbddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
1600244004331000042252400108001016000010160000501440000004002240122400411999632002116001020160000201600004004140041118002110910800101000005020000616000534003880000080000800104012240042400424004240042
16002440041310000422524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010002105020000316000534003880000080000800104004240042400424004240042
1600244004131000042252400108001016000010160000501440000004002240041400411999632002116001020160000201600004004140041118002110910800101010005020000516000554003880000080000800104004240042400424004240042
1600244004131000042252400108001016000010160000501440000014002240041400411999632002116001020160000201600004004140041118002110910800101000305020000516000534003880000080000800104004240042400424004240042
160024400413210001111252400108001016000010160000501440000004002240041400411999632002116001020160000201600004004140041118002110910800101000005020000316000534003880000080000800104004240042400424004240042
160024400413100041742252400108001016000010160000501440000014002240041400411999632002116001020160000201600004004140041118002110910800101000905020000316000354003880000080000800104004240042400424004240042
1600244004131100042252400108001016000010160000501440000004002240041400411999632002116001020160000201600004004140041118002110910800101000045020300516000634003880000080000800104004240042400424004240042
160024400413100148702524001080010160000101600005014400000040022400414004119996320021160010201600002016000040041400411180021109108001010000050200105162103540038800002080000800104004240042400424004240042
1600244004131000042252400108001016000010160000501440000004002240041400411999632002116001020160000201600004004140041118002110910800101000005020000416000454003880000080000800104004240042400424004240042
1600244004131000042252400108001016000010160000501440000004002240041400411999632002116001020160000201600004004140041118002110910800101000005020000316000354003880000080000800104004240042400424004240042