Apple M1 Microarchitecture Research by Dougall Johnson

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

SQXTN (8H)

Test 1: uops

Code:

  sqxtn v0.8b, v0.8h
  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)03081e3f4e51inst 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)a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
100430372200147254725100010001000398160130183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
10043037230061254725100010001000398160030183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
10043037220061254725100010001000398160030183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100020073316332629100030383038303830383038
10043037231061254725100010001000398160030183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
10043037230061254725100010001000398160030183037303724143289510001000100030373037111001100000073316332629100030383038303830383038
10043037230061254725100010001000398160130183037303724143289510001000100030373037111001100000073216332629100030383038303830383038
10043037220061254725100010001000398160030183037303724143289510001000100030373037111001100000073316322629100030383038303830383038
10043037230061254725100010001000398160030183037303724143289510001000100030373037111001100000073316332629100030383038308630383038

Test 2: Latency 1->2

Code:

  sqxtn v0.8b, v0.8h
  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)031e3f4e51inst 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)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)9fa1a8acbranch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372240612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037302161110201100991001001000010000007101161129669100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
10204300372250612954725101001001000010010000500427716030018300373003728264032874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03080b18191e1f3f4e51inst 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)9fa0a1a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372240000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000010006402162229629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  sqxtn v0.8b, v8.8h
  sqxtn v1.8b, v8.8h
  sqxtn v2.8b, v8.8h
  sqxtn v3.8b, v8.8h
  sqxtn v4.8b, v8.8h
  sqxtn v5.8b, v8.8h
  sqxtn v6.8b, v8.8h
  sqxtn v7.8b, v8.8h
  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)03080a0b1e3f51inst 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)9fa8a9acc5branch mispredict (cb)cdcfd5d6e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420061150000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
8020420039150000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
80204200391500001230258010810080008100800205006401320200202003920039997769990801202008003220080032200392030921802011009910010080000100100111511801620036800001002004020040201432014420040
8020420039150100030258010810080008100800205846401321200202003920039997769990801202008003220080032200392010311802011009910010080000100020111511801620036800001002004020040200402004020040
80204200391500000255258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
8020420039150000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
8020420039150000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
8020420039150000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200992004020040
8020420039150011030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801620036800001002004020040200402004020040
80204200391500001230258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100003111511801620036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0308181e3f51inst 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)9fa0a1a6a8a9cfd5d6dbddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200511500006725800101080000108000050640000120020320039200399996310019800102080000208000020039200391180021109101080000100000050209160962003680000102004020040200402004020040
800242003915000784025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050209160792003680000102004020040200402004020040
800242003915000046258001010800001080000506400001200200200392003999963100198001020800002080000200392003911800211091010800001000000502071617112003680000102004020040200402004020040
80024200391500002302580010108000010800005064000012002002003920039999631001980010208000020800002003920039118002110910108000010000005020916011112003680000102004020040200402004020040
8002420039150000402580010108000010800005064000012002002003920039999631001980010208000020800002003920039118002110910108000010000005020101609112003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050206160792003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050201116011112003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050206160792003680000102004020040200402004020040
80024200391500094025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050201116011122003680000102004020040200402004020040
80024200391500004025800101080000108000050640000120020020039200399996310019800102080000208000020039200391180021109101080000100000050209160962003680000102004020040200402004020040