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

FCVTNU (scalar, S to S)

Test 1: uops

Code:

  fcvtnu s0, s0
  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)031e3f4e51schedule uop (52)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)696d6emap 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 simd alu (9a)l1d tlb access (a0)l1d tlb miss (a1)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303724061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303723061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303723061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303724061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
10043037230145254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
10043037240145254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303723061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303724084254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303724061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038
1004303724061254725100010001000398160301830373037241432895100010001000303730371110011000000073216222629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtnu s0, s0
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)031e3f4e51schedule 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)inst simd alu (9a)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722593101329547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722506129538251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722508229547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003721102011009910010010000100007101161129633100001003003830038300383003830038
102043003722506129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722506129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
1020430037225156129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722466129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722406129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010001237101161129633100001003003830038300383003830038
1020430037225366129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)191e1f3f4e51schedule 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)60696b6d6emap 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)inst simd alu (9a)9fld unit uop (a6)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)cfd0d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372330000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372330000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250030612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010000302263003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000006400316222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006404216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010653300373003711100211091010100001000006400216222962910000103003830038300383003830038
10024300372250000612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000006400216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtnu s0, s8
  fcvtnu s1, s8
  fcvtnu s2, s8
  fcvtnu s3, s8
  fcvtnu s4, s8
  fcvtnu s5, s8
  fcvtnu s6, s8
  fcvtnu s7, s8
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2505

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)simd prf full (72)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)inst simd alu (9a)9fl1d tlb miss (a1)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)fetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
802042006115503025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118116020036800001002004020040200402004020040
8020420039155011725801081008000810080108500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016120036800001002004020040200402004020040
8020420039155030258010810080008100800205006401321200202003920039997706999080120200800322008003220039200391180201100991001008000010000181115118016020036800001002004020040200402004020040
802042003915505825801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915603025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915507225801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2505

retire uop (01)cycle (02)03mmu table walk data (08)18191e3a3f51schedule 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)6061696d6emap 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)inst simd alu (9a)9fl1d tlb access (a0)l1d cache writeback (a8)a9acc2cfd0d2d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242003915600000402580010108000010800005064000010200202003920039999631001980010208000020800002003920039118002110910108000010000005020539166112003680000102004020040200402004020040
80024200391550000040258001010800001080000506400001520020200392003999963100198001020800002080000200392003911800211091010800001000000502053516542003680000102004020040200402004020040
800242003915500000402580010108000010800005064000015200202003920039999631001980010208000020800002003920039118002110910108000010000005020537166112003680000102004020088200402004020040
800242003915500000402580010108000010800005064000015200202003920039999631001980010208000020800002003920039118002110910108000010000005020004166112003680000102004020040200402004020040
800242003915600000402580010108000010800005064000005200202003920039999631001980010208000020800002003920039118002110910108000010010005020506165112003680000102004020040200402004020040
8002420039155000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100000050200011161162003680000102004020040200402004020040
8002420039155000005152580010108000010800005064000015200202003920039999631001980010208000020800002003920039118002110910108000010000005020541116452003680000102004020040200402004020040
80024200391610000040258001010800001080000506400001020020200392003999963100198001020800002080000200392003911800211091010800001004000502050716652003680000102004020040200402004020040
80024200391550000082258001010800001080000506400000520020200392003999963100198001020800002080000200392003911800211091010800001000000502054616642003680000102004020040200402004020040
800242003915500000105258001010800001080000506400001520020200392003999963100198001020800002080000200392003911800211091010800001000000502054616532003680000102004020040200402004020040