Apple M1 Microarchitecture Research by Dougall Johnson

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

SQXTN (4S)

Test 1: uops

Code:

  sqxtn v0.4h, 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)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)a7a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303722061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303722264251254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004308522061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303723061254725100010001000398160030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
1004303722061254725100010001000398160030183037303724143289510001000100030373037211001100000073116112629100030383038303830383038
1004303723061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  sqxtn v0.4h, 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)0308090b18191e1f3f4e51inst 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)9fa0a1a6a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000001506129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000073521611296330100001003003830038300383003830038
102043003722400000006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830086
102043003722400000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000100000071011611296330100001003003830038300383003830038
102043003722500000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000103000071011611296330100001003003830038300383008130038
1020430037225000003906129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030b18191e1f3a3f4e51inst 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)9fa1a6a8a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500000012829538251004510100081010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372240000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277634130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  sqxtn v0.4h, v8.4s
  sqxtn v1.4h, v8.4s
  sqxtn v2.4h, v8.4s
  sqxtn v3.4h, v8.4s
  sqxtn v4.4h, v8.4s
  sqxtn v5.4h, v8.4s
  sqxtn v6.4h, v8.4s
  sqxtn v7.4h, 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)030818191e1f3f51inst 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)9fa0a1a6a7a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200581510000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000200011151180160020036800001002004020040200402004020040
80204200391500009264302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000002606011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000000211151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000300011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000100011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000000011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000100011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401962002020039200399977699908012020080032200800322003920039118020110099100100800001000000000011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000100011151180160020036800001002004020040200402004020040
80204200391500000030258010810080008100800205006401322002020039200399977699908012020080032200800322003920039118020110099100100800001000000000011151180160020077800001002004020040200402004020092

1000 unrolls and 10 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)9fa0a1a8accdcficache miss (d3)d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200511500402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000100000050200111612122003680000102004020040200402004020040
80024200391500402580010108009910800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100200050200131613122003680000102004020040200402004020040
800242003915004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000012050200121614132003680000102004020040200402004020040
800242003915004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000120050200111612132003680000102004020040200402004020040
8002420039150061258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000123050200131613132003680000102004020040200402004020040
80024200391500402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100010050200131613112003680000102004020040200402004020040
80024200391500402580107108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100010050200111613122003680000102004020040200402004020040
80024200391500402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100006050200121613102003680000102004020040200402004020040
800242003915004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000256050200121611112003680000102004020040200402004020040
80024200391500402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100020050200121613132003680000102004020040200402004020040