Apple M1 Microarchitecture Research by Dougall Johnson

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

UCVTF (vector, fixed-point, 4S from 4S)

Test 1: uops

Code:

  ucvtf v0.4s, v0.4s, #3
  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)inst neon or fp (9a)a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372406125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
100430372406125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
100430372406125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
1004303723126125472510001000100039816013018303730372414328951000100010003037303711100110000373216222629100030383038303830383038
1004303725126125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
100430372406125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000373216222629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000373216222629100030383038303830383038
100430372406125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038

Test 2: Latency 1->2

Code:

  ucvtf v0.4s, v0.4s, #3
  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)03081e1f3f4e51inst 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)9fa0a6a8acbranch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372320006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
10204300372330006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
10204300372320006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
102043003723301206129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
1020430037233017406129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101251129633100001003003830085300383003830038
10204300372330006129547251010010010000100100005004277160030018300373003728265328745101002001000020010000300373003711102011009910010010000100020007101161229633100001003003830038300383003830038
10204300372331006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
10204300372320006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
10204300372320006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038
10204300372330006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03080b18191e1f3a3f4e51inst 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)9fa0a6a8a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500000001052954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722500000003932954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038301813003830038
10024300372250000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722500000011452954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722500000002142954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722500000001242954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000000822954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722500000001032954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
100243003722400000001452954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  ucvtf v0.4s, v8.4s, #3
  ucvtf v1.4s, v8.4s, #3
  ucvtf v2.4s, v8.4s, #3
  ucvtf v3.4s, v8.4s, #3
  ucvtf v4.4s, v8.4s, #3
  ucvtf v5.4s, v8.4s, #3
  ucvtf v6.4s, v8.4s, #3
  ucvtf v7.4s, v8.4s, #3
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2506

retire (01)cycle (02)03080b18191e1f3a3f51inst 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)72scheduler 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)9fa0a1a6a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042003915500000003025801081008000810080020500640132020020200392007599770699908012020080032200800322003920039118020110099100100800001000000000111511806100202800800001002009220350203472036120359
8020420247156116680452802906140806051008060310280548500645094020271201512020010033035101198086420080672202806712037020366718020110099100100800001004002028480222523018711202920800001002041620363201492041420408
80204203141581156924880642780116100800161008002850064019602002920049200489976017100378033720280249200803522010220152318020110099100100800001002221214200222515405200201571800001002019920148201952036320195
80204201991571000156007225801081058011210080020500642616020020200392003999770699908012020080032200800322003920039118020110099100100800001000004301440222512912311200450800001002004920049200492004920049
8020420049156000012006427801161008001610080028500640196120029200492004899760999868012820080038200800382004920048118020110099100100800001000000000222512812311200450800001002004920049200492004920049
80205200481550000000642680116100800161008002850064019602002920048200499976010998680212200800382008003820048200481180201100991001008000010000000120222512812311200450800001002005020050200492005020050
802042004815600100006426801161008001610080028500640196020029200482004899760999868012820080038200800382004820049118020110099100100800001000000000222512812311200460800001002004920049200492005020049
8020420049155000024006426801161008001610080028500640196120029200482004899760999868012820080038200800382004820048118020110099100100800001000000030222512812311200460800001002004020040200402004020040
802042003915500006007225801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040
8020420039155000078005825801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000000111511801600200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)030b1e3f51inst 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)5f60696d6edispatch 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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242003915500822580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010105020616562003680000102004020040200402004020040
800242003915500402580010108000010800005064000011200202003920039999631001980010208000020800002003920039118002110910108000010005020616552003680000102004020040200402004020040
800242003915500402580010108000010800005064081601200202003920039999631001980010208000020800002003920039118002110910108000010005020516552003680000102004020040200402004020040
800242003915500402580010108000010800005064000011200202003920039999631001980010208000020800002003920039118002110910108000010005020516452003680000102004020040200402004020040
800242003915500822580010108000010800005064000001200202003920039999631001980010208000020800002003920039118002110910108000010035020516552003680000102004020040200402004020040
800242003915600402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020516452003680000102004020040200402004020040
800242003915500402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020516662003680000102004020040200402004020040
800242003915600402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020616552003680000102004020040200402004020040
80024200391550028772580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010105020516442003680000102004020040200402004020040
800242003915500402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010105020516552003680000102004020040200402004020040