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

FSQRT (vector, 4S)

Test 1: uops

Code:

  fsqrt v0.4s, v0.4s
  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)03091e3f4e51schedule uop (52)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 simd alu (9a)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500618648251000100010003519410100181003710037939539895100010001000100371003711100110000757311611957810001003810038100381003810038
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500618648251000100010003519411100181003710037939539895100010001000100371003711100110000457311611957810001003810038100381003810038
100410037750961864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611958610001003810038100381003810038
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500618648251000100010003519411100181003710037939539895100010001000100371003711100110000607311611957810001003810038100381003810038
100410037750061864825100010001000351941110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038

Test 2: Latency 1->2

Code:

  fsqrt v0.4s, v0.4s
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 10.0037

retire uop (01)cycle (02)03l2 tlb miss data (0b)181e3f4e51schedule 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)acbranch 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
10204100037749000618964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100086100038100038100038100038
1020410003774900061896482510100100100001001000050035829411100018100037100037982453987451010020010000200100001000371000371110201100991001001000010002040007101161199578010000100100038100038100038100038100038
102041000377490007268964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294111000181000371000379824539874510143200100002001000010003710003711102011009910010010000100000007101171199578010000100100038100038100038100038100038
102041000377490003468964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294111000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294111000181000371000379824539874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000618964825101001001000010010000500358294101000181000371000379824539874510100200100002001000010003710003711102021009910010010000100000007101161199578010000100100038100038100038100038100038

1000 unrolls and 10 iterations

Result (median cycles for code): 10.0037

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3a3f4e51schedule 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 tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)acc2branch cond mispred nonspec (c5)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
100241000377490000900618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100038100038
10024100037750000060900618964825100101010000101000050358294111000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640224229957801000010100038100038100038100038100038
10024100037749000000061896482510010101000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010001036010640216229957801000010100038100038100038100038100038
100241000377500000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100038100038
100241000377490000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100081100038
100241000377490000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000372110021109101010000100003000640216229957801000010100038100038100038100038100038
100241000377490000600618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100070000640216229957801000010100038100038100038100038100038
100241000377490000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100038100038
100241000377500000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100038100038
100241000377490000000618964825100101010000101000050358294101000181000371000379826739876710010201000020100001000371000371110021109101010000100000000640216229957801000010100038100038100038100038100038

Test 3: throughput

Count: 8

Code:

  fsqrt v0.4s, v8.4s
  fsqrt v1.4s, v8.4s
  fsqrt v2.4s, v8.4s
  fsqrt v3.4s, v8.4s
  fsqrt v4.4s, v8.4s
  fsqrt v5.4s, v8.4s
  fsqrt v6.4s, v8.4s
  fsqrt v7.4s, v8.4s
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 2.0006

retire uop (01)cycle (02)03181e3f4e51schedule 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)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 access (a0)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)? simd retires (ee)? int retires (ef)f5f6f7f8fd
802041600451199006179937258010010080000100800005005677984116002601600451600451498950614999980100200800722008000816004516004511802011009910010080000100031000111511701600159981080000100160046160046160046160046160046
80204160045119900542799372580100100800001008000051156779841160026016004516004514989506149999801002008000820080008160045160045118020110099100100800001000123000111511701600159981080000100160046160046160046160046160046
802041600451198006179937258010010080000100800005005677984116002601600451600451498950614999980100200800082008000816004516004511802011009910010080000100040002111511701600160076080000100160046160046160046160046160046
80204160375119903010379937258010010080000100800005005677984116002601600451600451498950614999980100200800082008000816004516004511802011009910010080000100095000111511701600159981080000100160046160046160046160046160046
80204160045119900617993725801001008000010080000500567798411600260160045160045149895061499998010020080008200800081600451601001180201100991001008000010007000111511701600159981080000100160046160046160046160046160046
80204160045119900617993725801001008000010080000500567798411600260160045160045149927061499998010020080008200800081600451600451180201100991001008000010003030111511701700159981080000100160046160046160046160046160046
802041600451199007267993725801001008001610080000500567798411600260160045160045149895061499998015620080008200800081600451600451180201100991001008000010000000111511701600159981080000100160046160046160046160046160046
80204160045119900617993725801001008000010080000500567798411600260160045160045149895061499998010020080008200800081600451600451180201100991001008000010000090111511701600160037080000100160046160046160100160046160046
8020416004511980127267993725801001008000010080000500567798411600260160045160045149895061499998010020080008200800081600451600451180201100991001008000010000000111511701600159981080000100160046160046160046160046160046
802041600451199001247993725801001008000010080000500567798411600260160045160045149895061500458010020080008200800081600451600451180201100991001008000010000000111511701600159981080000100160046160046160046160046160046

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 2.0006

retire uop (01)cycle (02)031e3a3f4e51schedule 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)696d6emap 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 miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0eaeb? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024160045119800617993725800101080000108014450567798416002616004516004514991031500258001020803582080000160045160045118002110910108000010222002005037211611615997210808000010160046160046160046160046160046
800241600451199006179937258001010800001080000505677984160026160045160045149910315002580010208000020800001600451600451180021109101080000100000000050205169101599729308000010160046160046160046160046160046
800241600451198006179937258001010800001080000505677984160026160045160045149910315002580010208000020800001600451600451180021109101080000100000000050201016581599727708000010160046160046160046160046160046
80024160045119900617993725800101080000108000050567798416002616004516004514991031500258001020800002080000160045160045118002110910108000010000000005020416861599727708000010160046160046160046160046160046
80024160045119900617993725800101080000108000050567798416002616004516010014991031500258001020800002080000160045160045118002110910108000010000000005020816761599729308000010160046160046160046160046160046
800241600451199006179937258001010800001080000505677984160026160045160045149910315002580010208000020800001600451600451180021109101080000100000000050201116641599729308000010160046160046160046160046160046
8002416004511980061799372580010108000010800005056779841600261600451600451499103150025800102080000208000016004516004511800211091010800001000002700050208167151599727708000010160046160046160046160046160046
8002416004511993006179937258001010800001080000505677984160026160045160045149910315002580010208000020800001600451600451180021109101080000100000000050205167101599727708000010160046160046160046160046160046
8002416004511990061799372580010108000010800005056779841600261600451600451499103150025800102080000208000016004516004511800211091010800001000002010005020916681599727708000010160046160046160046160046160046
8002416004511990061799372580010108000010800005056779841600261600451600451499103150025800102080000208000016004516004511800211091010800001000000000502071614111599729308000010160046160046160046160046160046