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, 2S)

Test 1: uops

Code:

  fsqrt v0.2s, v0.2s
  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)03mmu table walk data (08)181e1f3f4e51schedule 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 cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004100377600006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
10041003775002106186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
10041003775000061864825100010001000351941100181003710037939539895100010001000100371003711100110002407311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
100410037750030306186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810038100381003810038
1004100377500006186482510001000100035194110018100371003793953989510001000100010037100371110011000007311611957810001003810086100381003810038

Test 2: Latency 1->2

Code:

  fsqrt v0.2s, v0.2s
  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)0318191e1f3f4e51schedule 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 tlb miss (a1)l1d cache writeback (a8)acbranch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
102041000377490060726896382510105108100001041019050035835770100053010003710003798245039884010100205100002001005510003710003791102011009910010010000100221307101161199578010000100100038100038100038100038100038
10204100037749000061896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000061896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000061896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
102041000377490000726896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
102041000377490000618964825101001001000310010000500358294101000180100037100037982450398745101002021000020010000100037100037111020110099100100100001000006607101161199578010000100100038100038100038100038100038
10204100037749000061896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037749000061896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
10204100037750000061896482510100100100001001000050035831490100018010003710003798245039874510100200100002001000010008410003711102011009910010010000100000007101161199578010000100100038100038100038100038100038
102041000377500000536896482510100100100001001000050035829410100018010003710003798245039874510100200100002001000010003710003711102011009910010010000100000007101161199578010000100100038100038100038100038100038

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 access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)a9acc2branch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024100037750000018002262896482510010101000010100005035829411100018100037100037982673987671001022100002010000100037100037111002110910101000010000003006403162299578001000010100038100038100038100038100038
1002410003775000000002275896482510010101000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
1002410003774900000002116896482510010101000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
1002410003775000000003003896482510010101000010100005035829411100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
100241000377490000000634896482510010101000010100005035829411100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
100241000377500000000147896482510010101000010100005035829411100018100037100070982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
1002410003774900000002196896482510010101000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
1002410003775000000002184896482510010101000010100005035829411100158100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100038
1002410003774900000001420896482510010121000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578101000010100038100038100038100038100038
100241000377500000000147896482510010101000010100005035829410100018100037100037982673987671001020100002010000100037100037111002110910101000010000000006402162299578001000010100038100038100038100038100226

Test 3: throughput

Count: 8

Code:

  fsqrt v0.2s, v8.2s
  fsqrt v1.2s, v8.2s
  fsqrt v2.2s, v8.2s
  fsqrt v3.2s, v8.2s
  fsqrt v4.2s, v8.2s
  fsqrt v5.2s, v8.2s
  fsqrt v6.2s, v8.2s
  fsqrt v7.2s, v8.2s
  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)03mmu table walk instruction (07)l2 tlb miss instruction (0a)l2 tlb miss data (0b)18191e1f3f4e51schedule 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)9fl1d cache writeback (a8)acc2branch 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
80204160045119911000390617993725801001008000010080000500567798401600260160045160045149928614999980100200800082008000816004516004511802011009910010080000100000111511721611159983080000100160046160046160046160046160046
802041600451198110000014417993725801001008000010080000500567798411600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711611159983080000100160046160046160046160046160046
8020416004511991100000617993725801001008000010080000500567798401600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711611159983180000100160046160046160046160046160046
80204160045119911000007267993725801001008000010080000500567798401600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711621160052080000100160046160046160046160046160046
8020416004511991100090617993725801001008000010080000500567798401600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511721611159983080000100160046160046160046160046160046
80204160045119911000630617993725801001008000010080000500567798411600263160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711611159983080000100160046160046160046160046160046
8020416004511981100000617993725801001008000010080000500567809701600260160045160045149928614999980100200800082008000816004516004511802011009910010080000100000111511711611159983080000100160046160046160046160046160046
802041600451199110000061799372580100100800001008000050056779840160026016004516004514989561499998010020080008200800081600451600451180201100991001008000010001890111511711611159983080000100160046160046160046160046160046
8020416004511991100000617993742801001008000010080000500567798401600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711611159983080000100160046160046160046160046160046
8020416004511991100000617993725801001008000010080000500567798401600260160045160045149895614999980100200800082008000816004516004511802011009910010080000100000111511711611159983080000100160046160046160046160046160046

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e1f3f4e51schedule 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)6061696b6d6emap 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)acc2cfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)dadbddfetch restart (de)e0? int output thing (e9)eaebec? simd retires (ee)? int retires (ef)f5f6f7f8fd
800241600451198006179937258001010800001080000505677984101600260160045160045149910315002580010208007620800001600451600451180021109101080000100005020000111600121215997200008000010160046160046160046160046160046
80024160045119900617993725800101080000108000050567798400160026016004516004514991031500258001020800002080000160045160045118002210910108000010000502000013160012815997200008000010160046160046160046160046160046
800241600451199006179937258001010800001080000505677984101600260160045160045149910315002580010208000020800001600451600451180021109101080000100005020000121600111215997200008000010160046160046160046160101160046
8002416004511990025179937258001010800001080000505677984101600260160045160045149960315002580010208000020800001600451600451180021109101080000100005020000121600121515997200008000010160101160046160046160046160046
800241600451199006179937258001010800001080000505677984001600260160045160045149910315002580010208000020800001600451600451180021109101080000101005037000131600141115997200008000010160046160046160046160046160046
8002416004511980072679937258001010800001080000505677984001600260160045160045149910315002580010208000020800001600451600451180021109101080000100005020000125800121315997200008000010160046160046160046160046160046
800241600451199006179937258001010800001080000505677984101600260160045160045149910315002580010208000020800001600451600451180021109101080000100005020000131600111415997200008000010160046160046160046160046160046
800241600451199006179937258001010800001080000505677984001600260160045160045149910315002580010208000020800001600451600451180021109101080000100005020000121600111115997200098000010160046160046160101160046160046
8002416004511990061799372580010108000010800005056779840016002601600451600451499103150025800102080000208000016004516004511800211091010800001001890502000012160081315997200008000010160046160046160046160046160046
800241600451198006179937258001010800001080000505677984001600260160045160045149910315002580010208000020800001600451600451180021109101080000100005085000111600131115997200008000010160046160046160046160046160046