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 W)

Test 1: uops

Code:

  ucvtf s0, w0, #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)ld unit uop (a6)l1d cache writeback (a8)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)f5f6f7f8fd
200437639361025200010001000100010001407522820035737637672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437636361025200010001000100010001407522820035737937672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437630361025200010001000100010001407522820035738037672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437630361025200010001000100010001407522820035739037672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437620361025200010001000100010001407522820035737637672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437620361025200010001000100010001407522820035737737872310920001000100010001000376376111001100010000732162237310001000377377377377377
200437630361025200010001000100010001407522820035737637672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437630361025200010001000100010001407522820035737637672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437620361025200010001000100010001407522820035737637672310920001000100010001000376376111001100010000732162237310001000377377377377377
200437630361025200010001000100010001407522820135737737972310920001000100010001000376376111001100010000732162237310001000377377377377377

Test 2: Latency 1->2 roundtrip

Code:

  ucvtf s0, w0, #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)0309l2 tlb miss data (0b)1e1f3a3f4f51schedule 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)5f60696d6emap 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)ld unit uop (a6)l1d cache writeback (a8)a9acc2cfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
3020413003210080000013001711940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003211202011009910010100100001000100000000131012162212951910000100001000010100130033130033130033130033130033
3020413003210070100013001711940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003221202011009910010100100001000100010002131012162212953110000100001000010100130033130033130033130033130033
302041301371008002701133097120527556401611019120111100661432500810147736627135414979320441130013132711132940126889195126841316262001000020000200100002000013003213003211202011009910010100100001000100000000131012162412954610000100001000010100130033130033130033130033130033
3020413003210080000013001711940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003211202011009910010100100001000100000000131012162212951910000100001000010100130033130033130033130033130033
3020413003210080000013002511940825401001010020000100001002000010000500621449714802709001300151300321300321254663126240301002001000020000200100002000013003213003211202011009910010100100001000100000000131012163212951910000100001000010100130033130033130033130033130035
3020513003210080000013002011940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003211202021009910010100100001000100003000131012162212956410000100001000010100130033130033130036130033130033
3020413003210080000013001711940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003211202011009910010100100001000100000000131012162212951910000100001000010100130033130033130033130033130033
3020413003210080000013001711940825401001010020000100001002000010049500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003211202011009910010100100001000100000000131012162412953710000100001000010100130033130033130033130033130033
3020413003210070000013001711940825401001010020000100001002000010000500621449714802709001300131300321300321254663126240301002001000020000200100002000013003213003221202011009910010100100001000100000000131012163212951910000100001000010100130033130033130033130033130033
30204130032100800000130017119408254010010100200001000010020000100005006214497148027090013001313003213003212546631262403010020010000200002001000020000130032130032112020110099100101001000010021001600386500131012163212952010002100001000010100130033130454130033130033130795

1000 unrolls and 10 iterations

Result (median cycles for code): 13.0032

retire uop (01)cycle (02)03mmu table walk instruction (07)mmu table walk data (08)09l2 tlb miss instruction (0a)181e3a3f4f51schedule 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 miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch 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
3002413003297310010021300171194082540010100102000010000102000010000506215000148005281130013013012513003212548931262623001020100002000020100002000013003213003211200211091010010100001001000000300012741616151412951910000100001000010010130033130033130033130035130033
3002413003297410010021300171194082540010100102000010000102000010000506214497148005280130013013003213003212548931262623001020100002000020100002000013003213003211200211091010010100001001000000001012741416121412951910000100001000010010130125130033130033130033130033
3002413003297410010021300171194082540010100102000010000102000010000506214497148005280130013013003213003212548931262623001020100002000020100002000013003213003211200211091010010100001001000000000012741316101412951910000100001000010010130033130069130077130033130033
3002413003297410010782130017119408254001010010200001000010200001000050621449714800528013001301300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000001274141614812952310000100001000010010130033130033130033130033130033
3002413003297410010021300171194082540010100102000010000102000010000506214497148005280130013013003213003212548931262623001020100002000020100002000013003213003211200211091010010100001021000000000012741616151012952310000100001000010010130033130033130033130036130033
3002413003297410010021300171194082540010100132000010000102000010000506214497148005280130013013003213003212548931262623001020100002000020100002000013003213003211200211091010010100001001000000000013191316131512952110000100001000010010130033130033130033130033130033
30024130032974100106392130017119408254001010010200001000010200001000050621449714800528013001301300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000001274151614912973710000100001000010010130033130033130033130033130033
3002413003297410010021300171194082540010100102000010000102000010000506214497148005281130013013003213003212548931262623001020100002000020100002000013003213014811200211091010010100001001000000000112741516121512951910000100001000010010130033130033130033130033130033
3002413003297410010021300171194082540010100192002410002112000010000506214497148005281130013013003213003212548931262623001020100002000020100002000013003213003211200211091010010100001001000000000012741516161412951910000100001000010010130033130033130033130033130033
3002413003297410010212130017119408254001010010200001000010200001000050621449714800528013001301300321300321254893126262300102010000200002010000200001300321300321120021109101001010000100100000000001274131614812951910000100001000010010130033130033130033130033130033

Test 3: throughput

Count: 8

Code:

  ucvtf s0, w8, #3
  ucvtf s1, w8, #3
  ucvtf s2, w8, #3
  ucvtf s3, w8, #3
  ucvtf s4, w8, #3
  ucvtf s5, w8, #3
  ucvtf s6, w8, #3
  ucvtf s7, w8, #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)03l2 tlb miss data (0b)1e243f4f51schedule 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)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
16020426712207012026694025160100100800008000010080020800155001168951188416312669026709267096632066658160135200800208002020080020800202670926709118020110099100100800001000080000000011151172160026706080000800001002671026710267102671026710
1602042670920700026694125160100100800008000010080020800155001168951188416302669026709267096633066658160135200800208002020080020800202670926709118020110099100100800001000080000000011151170160026706080000800001002671026710267142671026710
1602042670920700026694025160100100800008000010080020800155001168951188416302669026709267096632066874160136200800208002020080020800202670926709118020110099100100800001000080000000011151170160026706080000800001002671026710267102671026710
1602042670920700026694025160100100800008000010080020800155001168951188416312669026709267096636066658160136200800208002020080020800202670926709118020110099100100800001000080000003011151170160026706080000800001002671026710267102671026710
1602042670920703026694025160100100800008000010080020800155001168951188416312669026709267096632066658160136200800208002020080020800202670926709118020110099100100800001000080000000011151170160026706080000800001002671026710267102671026710
1602042670920700026864025160100100800008000010080020800155001168951188416302669026709267096632066658160135200800208002020080024800202670926709118020110099100100800001000080000003011151170160026706080000800001002671026710267152671426710
1602042670920700026694325160100100800008000010080020800155001170516188416312669026709267096632066658160135200800208002020080020800202670926709118020110099100100800001000080000100011151170160026706080000800001002671026710267122671026710
1602042670921400026694025160100100800008000010080020800155001168951188416302669526709267096632066658160136200800208002020080020800202670926709118020110099100100800001000080000000011151170160026706080000800001002671026710267102671026710
1602042670920700026694025160100100800008000010080020800155001168951188416302669026709267096632066658160135200800208002020080020800202670926709118020110099100100800001000080000000011151170160026706080000800001002671226710267102671026710
1602042670920700026694025160100100800008000010080020800155001168951188416302669026709267126632066658160136200800208002020080020800202671026709118020110099100100800001000080000000011151170160026710080000800001002671026710267102671326715

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03l2 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)5f60696b6d6emap 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)9fld unit uop (a6)l1d cache writeback (a8)accfd0d2d5map dispatch bubble (d6)d9daddfetch restart (de)e0? ldst retires (ed)? simd retires (ee)? int retires (ef)f5f6f7f8fd
160024267112070002669402516001010800008000010800008000050116888018840320026690026709267096653036689160010208000080000208000080000267092670911800211091010800001080000005020001916001717267068000080000102671026710267102671026710
160024267092070120266940251600101080000800001080000800005011688801884032112669002670926709665303668916001020800008000020800008000026709267091180021109101080000108000009502000816001715267068000080000102671026710267102671026710
1600242670920700026694025160010108000080000108000080000501168880188403200266900267092671066530366931600102080000800002080000800002671426779118002110910108000010800000050200061600178267068000080000102671026710267102671026710
160024267092070002669402516001010800008000010800008000050116888018869630026690026709267096653036689160010208000080000208000080000267092670911800211091010800001080000005020001716001717267088000080000102671026710267102671026710
16002426709207000266940251600101080000800001080000800005011688801884032012669002670926709665303668916001020800008000020800008000026718267181180021109101080000108000000502000121600617267068000080000102671026710267102671026710
1600242670920700026694025160010108000080000108000080000501168880188403200266900267092670966580366891600102080000800002080000800002670926710118002110910108000010800000050200071600817267068000080000102671026710267102671026710
160024267092070002669422516001010800008000010800008000050116831118837660026690026709267136653036689160010208000080000208000080000267092685011800211091010800001080000705020001716001717267068000080000102671026710267102671026710
1600242670920700026694025160010108000080000108000080000501168880188403200266900267092670966530366891600102080000800002080000800002670926709118002110910108000010800000050200061600178267068000080000102671026710267102671026710
1600242670920700026694025160010108000080000108000080000501168880188403211266900267092670966530366891600102080000800002080000800002671026709118002110910108000010800001050200083400714267068000080000102671026710267102671426710
16002426709207000266940251600101080000800001080000800005011688801884032002669002670926709665303668916001020800008000020800008000026709267091180021109101080000108000000502001171600817267068000080000102671026710267102671026710