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

UCVTF (scalar, fixed-point, S from X)

Test 1: uops

Code:

  ucvtf s0, x0, #3
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 2.000

Issues: 2.000

Integer unit issues: 0.000

Load/store unit issues: 1.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)031e3f4f51schedule uop (52)schedule simd uop (54)schedule ldst uop (55)dispatch simd uop (57)dispatch ldst uop (58)simd uops in schedulers (5a)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map ldst uop (7d)map simd uop (7e)map ldst uop inputs (80)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd alu (9a)a5ld unit uop (a6)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)f5f6f7f8fd
20043763036102520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043763036132520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043763036102520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043763036102520001000100010001000140752282003573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043763036102520001000100010001000140752282003573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043762036102520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377378377
20043763036102520001000100010001000140752282003573763767231092000100010001000100037637611100110000100020731161137310001000377377377377382
20043762036202520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377
20043763036102520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377381377377
20043763036102520001000100010001000140752282013573763767231092000100010001000100037637611100110000100000731161137310001000377377377377377

Test 2: Latency 1->2 roundtrip

Code:

  ucvtf s0, x0, #3
  fmov x0, d0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 13.0032

retire uop (01)cycle (02)03mmu table walk data (08)0918191e1f3a3f4f51schedule 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)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
302041301099740000660013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310121633129519100000100001000010100130033130033130033130033130033
30204130032974000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310131633129520100000100001000010100130033130033130033130033130033
30204130032974000000013001711940825401371010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310121632129519100000100001000010100130033130033130033130033130033
30204130032974000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002061006120000130032130032112020110099100101001000010000100000000001310121623129519100000100001000010100130033130372130033130033130033
30204130032973000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310131632129519100000100001000010100130033130037130033130033130033
30204130032974000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310131622129519100000100001000010100130033130033130033130034130033
30204130032975000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310121623129519100000100001000010100130033130033130033130033130033
30204130032974000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310121632129519100000100001000010100130033130033130033130033130033
30204130032974000090013001711940825401001010020000100001002000010000500621449714802709113001313003513003212546631262443010020010000200002001000020000130032130032112020110099100101001000010000100000000001310131633129519100000100001000010100130034130033130033130036130034
30204130032974000000013001711940825401001010020000100001002000010000500621449714802709113001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010000100000000001310131632129519100000100001000010100130033130033130033130033130033

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0032

retire uop (01)cycle (02)03mmu table walk data (08)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)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 miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
30024130032974000013002311940825400101001020000100001020000100005062144971480052811300131300321300321254903126262300102010000200002010000200001300351300321120021109101001010000100100001000012706494212952210000100001000010010130381130200130101130229130033
300241300329740000130017119409254001010010200001000010200001000050621449714800528013001613003213003212549031262623001020100002000020100002000013003213003211200211091010010100001001000000169890012703163312952210000100001000010010130033130033130092130047130033
30024130032973000013001711948425400101001020000100001020000100005062171101480052811301091300321300321254893126262300102010000200002010000200001300321300411120021109101001010000100100000000012703173312951910000100001000010010130033130033130033130075130033
30024130032974000013001711941125400101001020000100001020000100005062144971480052801300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012703163312951910000100001000010010130033130033130073130062130033
30024130032995000013001711941025400101001020000100001020000100005062144971480052811300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012702164312951910000100001000010010130033130033130033130150130033
30024130032974009013001711941125400101001020000100001020000100005062144971480052801300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012703163312951910000100001000010010130033130033130033130101130033
30024130032974000013001711947025400101001020009100001020000100005062144971480052801300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012703163312951910000100001000010010130033130034130082130046130033
300241300329740027013001711941825400101001020000100001020000100005062144971480052801300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012702163312951910000100001000010010130033130033130033130090130033
30024130032974000013001711941525400101001020000100001020000100005062145451480052801300131300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012703163312951910000100001000010010130075130034130033130156130033
30024130032974000013001711940925400101001020000100001020000100005062144971480052801300131300321300331254893126262300102010000200002010000200001300321300321120021109101001010000100100000000012703163312951910000100001000010010130118130037130035130033130033

Test 3: throughput

Count: 8

Code:

  ucvtf s0, x8, #3
  ucvtf s1, x8, #3
  ucvtf s2, x8, #3
  ucvtf s3, x8, #3
  ucvtf s4, x8, #3
  ucvtf s5, x8, #3
  ucvtf s6, x8, #3
  ucvtf s7, x8, #3
  mov x8, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.3339

retire uop (01)cycle (02)031e3a3f4f51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)dde0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160204267112070026702025160100100800008000010080020800155001168951188692312669026709267096632666581601362008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671126712267102671526710
160204267092070026697025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706280000800001002671026710267102671026710
160204267092070026716025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267102671026710
160204267092070026707025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267102671026714
1602042670920712026797025160100100800008000010080020800155001168951187292412669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267102671026710
160204267092070026700025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267102671026710
160204267092070026698025160100100800008000010080020800155001168951188416312669026709267096636666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267102671026710
160204267092070026704025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026706080000800001002671026710267142671026710
160204267092070026710025160100100800008000010080020800155001168951188416312669026709267096632666581601352008002080020200800208002026709267101180201100991001008000010080000001115117016026706080000800001002671026710267102671026710
160204267092070026716025160100100800008000010080020800155001168951188416312669026713267096636666581601352008002080020200800208002026709267091180201100991001008000010080000001115117016026711080000800001002671026710267102671026710

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.3339

retire uop (01)cycle (02)03mmu table walk data (08)0918191e1f3f4f51schedule 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)simd prf full (72)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)a9acbranch mispred nonspec (cb)cfd5map dispatch bubble (d6)d9ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024267092000000002669402516001010800008000010800008000050116888018840321266902670926709665303703716001020800008000020800008000026709267091180021109101080000100080000000050202160112670608000080000102677926722267152671026710
160024267091990000002669402516001010800008000010800008000050116888018840320266902670926709665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112671008000080000102672526714267102671026710
160024267092000000002669402516001010800008000010800008000050116888018840320267552670926709665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671026710267102671026710
160024267092000000002671702516001010800008000010800008000050116888018840320266902670926709665303669516001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671026710267102671026710
160024267132000000002669402516001010800008000010800008000050116902418840320266902670926709665303668916001020800008000020800008000026709267171180021109101080000100080000000050201160112670608000080000102671026710267102671026710
160024267092000000002669402516001010800008000010800008000050116888018840320266902670926716665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671326718267102671026710
160024267092000000002669402516001010800008000010800008000050116888018840320266902670926709665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671026710267102671026710
160024267092000000002669402516001010800008000010800008000050116888018840321266902670926709665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671026710267102671026710
1600242670920000000026694025160010108000080000108000080000501168880188403202669026709267096653036689160010208000080000208000080000267092670911800211091010800001000800001600050201160112670608000080000102671026710267102671026710
160024267092000000002681502516001010800008000010800008000050116888018840320266902670926709665303668916001020800008000020800008000026709267091180021109101080000100080000000050201160112670608000080000102671026710267102671026710