Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTL2 (vector, 2D)

Test 1: uops

Code:

  fcvtl2 v0.2d, 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 (01)cycle (02)030a0b18191e1f3f4e51inst 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)a0a1a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10043037240000002832547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303723000000612547251000100010003981601301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
10043037240000001032547251000100010003981601301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303723000000612547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
10043037230000001322547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303723000000822547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303724000000612547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303723000000612547251000100010003981600301830373037241432895100010001000303730371110011000000100073116112629100030383038303830383038
1004303723000000612547251000100010003981601301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038
1004303723000000612547251000100010003981600301830373037241432895100010001000303730371110011000000000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtl2 v0.2d, 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): 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)9fa0a1a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372320000120010329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830086
102043008423311222641920139329529631013712410016126103005934279827130054301313013228272828776104092041033220810333300843008421102011009910010010000100022093040275923311296330100001003013330132300873008630134
1020430133233010030010329547251010010010000100100005004277160130018300373003728264328745105822001000020010000300373003711102011009910010010000100000000471011611296330100001003003830038300383003830038
102043003723300009006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037233000039006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
102043003723300006006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
102043003723200006006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037233000027900612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000020036071011611296330100001003003830038300383003830038
1020430037232000027006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037233000036006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030818191e1f3f4e51inst 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)9fa0a1a6a8a9acc2branch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500028806129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
10024300372250002406129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001002000537801640216222962910000103003830038300383003830038
100243003722500036025129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
100243003722400044406129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
100243003722500034806129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
10024300372250003906129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
10024300372250003306129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
10024300372250003306129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
100243003722500029106129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216222962910000103003830038300383003830038
10024300372240003306129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000000640216122962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtl2 v0.2d, v8.4s
  fcvtl2 v1.2d, v8.4s
  fcvtl2 v2.2d, v8.4s
  fcvtl2 v3.2d, v8.4s
  fcvtl2 v4.2d, v8.4s
  fcvtl2 v5.2d, v8.4s
  fcvtl2 v6.2d, v8.4s
  fcvtl2 v7.2d, v8.4s
  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)03080b18191e1f3f51inst 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)9fa6a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420049156000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151184160020036800001002004020040200402004020040
8020420039161000000302580108100800081008002050064013202002020039200399986699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
8020420039155000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000003011151180160020036800001002004020040200402004020040
802042003915500001203025801081008000810080020500640132020306204032039310043351020380532202808572008076220194203467180201100991001008000010031237680222526411291120371800001002044920399204612036420479
80204204591580188105970427962780100101800981008000050064000002002920048200489971699948020620080000200800002004820048118020110099100100800001000000011151202242220045800001002004920049200492004920049
8020420048155000000762580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
8020420039155000000302580108100800081008002050064013202002020358200989976699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
8020420039155000000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000006011151180160020036800001002004020040200402004020040
80204200391610000908625801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000015011151180160020036800001002004020040200402004020040
8020420039160100000302580108100800081008002050064013202008120039200399977699908012020080032200800322003920048118020110099100100800001000000022251281232120046800001002005020050200502005020050

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0307080a181e3f51inst 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)5f6061696d6edispatch 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)9fa8accfd0d2icache miss (d3)d5d6d9dadbddinst fetch restart (de)e0eaeb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242005015600000402580010108000010801065064000000020020200392003999967100728001020800002080000200392003911800211091010800001016502003041600043200360080000102008920040200402010520040
800242003915500200402580010108000010800005064000000520020200392003999963100198001020800002080000200392003911800211091010800001000502000041600043200360080000102004020040200402004020040
800242003915500200402580010108000010800005064000001520020200392003999963100198001020800002080000200392003911800211091010800001000502000041600044200360080000102004020040200402004020040
800242003915500203404380010108000010800005064000000520020200392003999963100198001020800002080000200392003911800211091010800001000502053041600044200360080000102004020040200402004020040
800242003915500200402580010108000010800005064000000520020200392003999963100198001020800002080000200392003911800211091010800001000502053051600054200360080000102004020040200402004020040
8002420039155002003482580010108000010800005064000001520020200392003999963100198001020800002080000200392003911800211091010800001000502000041600043200360080000102004020040200402004020040
800242003915500000402580010108000010800005064000001020020200392003999963100198001020800002080000200392003911800211091010800001010502000031600034200360080000102004020040200402004020040
800242003915500200402580010108000010800005064081201020020200392003999963100198001020800002080000200392003911800211091010800001000502000041600044200360080000102004020040200402004020040
800242003915500011540258001010800001080000506400007102002020039200399996310019800102080000208000020039200391180021109101080000100580502000041600044200360080000102004020091200402009020104
800242003915501000402580010108000010800005064000081020020200392003999963100198001020800002080000200392003911800211091010800001000502000031600044200360080000102004020040200402004020040