Apple M1 Microarchitecture Research by Dougall Johnson

Firestorm: Overview | Base Instructions | SIMD and FP Instructions
Icestorm:  Overview | Base Instructions | SIMD and FP Instructions

FCVTPU (scalar, D to D)

Test 1: uops

Code:

  fcvtpu d0, d0
  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 (01)cycle (02)031e3f4e51inst issue (52)~issue fp/simd (54)~dispatch fp/simd (57)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op fp/simd (7e)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)91inst neon or fp (9a)acc3cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10043037231261254725100010001000398160030183037303724143289510001000100030373037111001010000091216222629100030383038303830383038
1004303722061254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
10043037232761254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
10043037233661254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
10043037225461254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
1004303722061254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
100430372296125472510001000100039816003018303730372414328951000100010003037303711100101000108073216222629100030383038303830383038
1004303723961254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038
1004303723361254725100010001000398160030183037303724143289510001000100030373037111001010000073216222629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtpu d0, d0
  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 (01)cycle (02)030b191e3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a1a8acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003723300061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372330030673295472510100100100001001000050042771600300183003730037282643287631010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723200061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037233004561295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723300061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723300061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730082111020110099100100100001002412758071011611296330100001003003830038300383003830038
102043003723300061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037232000103295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723300061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723200061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)0318191e1f3a3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696b6d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a8a9acc2cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372810000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
10024300372260000061295472510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
10024300372240000061295472510010101000010100005042771600300180300373008528286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
1002430037224001590061295382510010101000010100005042771600300180300373003728286328767100102010000201000030037300371110021109101010000100000006402162229916010000103003830038300383003830038
100243003722500603520612954725100101010000101000050427716003005503003730037282863287671001020100002010000300373003711100211091010100001000221006402162229629010000103003830038300383003830038
100243003724100001257295472510010101000010100005042771600300180300703003728286328767100102010000201000030037302241110021109101010000102000006402162229629010000103013130038300383003830038
100243003722400000220295472510010101000010100005042771601300180300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
10024300372240000061295472510010101000010100005042771601300180300373003728286328767100102010000201000030037300372110021109101010000100000006402162229667010000103003830038300383003830038
10024300372250000061295472510010101000010100005042771601300180300373003728286328767101622010000201000030226300371110021109101010000100000006402162229629010000103003830038300383003830038
100243003722500210061295472510010101000010100005042771600300180300373003728286328767100102210000201000030037300371110021109101010000100000006402162229629010000103003830085300853018030038

Test 3: throughput

Count: 8

Code:

  fcvtpu d0, d8
  fcvtpu d1, d8
  fcvtpu d2, d8
  fcvtpu d3, d8
  fcvtpu d4, d8
  fcvtpu d5, d8
  fcvtpu d6, d8
  fcvtpu d7, d8
  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 (01)cycle (02)031e3f51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa6a7a8a9acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200681500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000070011151180160020036800001002004020040200402004020040
80204200391550302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000060911151180160020036800001002004020040200402004020040
8020420039155011425801081008000810080020500640132020020200392003999773399908012020080036200800382003920039118020110099100100800001000030011151180160020036800001002004020040200402004020040
80204200391550302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000010022251281231120045800001002005020049200492004920049
80204200481500852780116100800161008002850064019602002920049200489976999868012820080038200800382004820048118020110099100100800001000000022251281231120046800001002004920049200492004920050
802042004815006427801161008001610080028500640196020029200492004899761099868012820080038200800382004820048118020110099100100800001000000022251281231120045800001002005020049200492004920049
8020420048160064278011610080016100800285006401961200292004920090997610998680128200800382008003820048200481180201100991001008000010000510022251281231120045800001002005020050200502005020049
80204200481500642780116100800161008002850064019602002920048200489976999868012820080038200800382004820048118020110099100100800001000002322251291231120045800001002004920049200492004920050
8020420048150064278011610080016100800285006401961200292004820048997699986801282008003820080038200482004811802011009910010080000100006016822251281231120045800001002004920049200502004920049
8020420049150064268011610080016100800285006401960200292004820048997610998680128200800382008003820048200481180201100991001008000010000250022251281231120045800001002004920049200492004920049

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0308191e3f51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a6a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200391501004025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005037416112003680000102004020040200402004020040
800242003915000214025800101080000108000050640000200612003920039999631001980010208000020800002003920039118002110910108000010000005020216112003680000102004020040200402004020040
800242003915000274025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
800242003915000244025800101080000108000050640000200202009120039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
8002420039150002884025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
800242003915000124025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
800242003915000921125800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
800242003915000214025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020095200402004020040
800242003915000051525800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040
8002420039150003274025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000005020116112003680000102004020040200402004020040