Apple M1 Microarchitecture Research by Dougall Johnson

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

SQXTN (H)

Test 1: uops

Code:

  sqxtn b0, h0
  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
1004303722186125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038308630383038
1004303723126125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038308630383038
10043037233914525472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  sqxtn b0, h0
  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)030b181e1f3f4e51inst 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)9fa8acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372240000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
10204300372250000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
102043003722500003462954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
10204300372250000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
102043003722500001562954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
10204300372250000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010003071011611296330100001003003830038300383003830038
102043003722500005362954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
10204300372250000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
102043003722500006312954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038
102043003722400005362954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030708090a0b18191e1f3a3f4e51inst 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)9fa0a1a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250000000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000000006129547251001010100001010000504277160130018030037300372828632876710010201000020100003003730037111002110910101000010000004806402162229629010000103003830038300383003830038
10024300372250000000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
10024300372250000000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000000001242953825100101010000101030050427851213001803003730037282867287861001020100002010000300373003711100211091010100001000030006402163529629010000103003830038300383008530038
1002430037225000000012880612954742100101110000101000050427716013001803003730037282863287671001020100002010000300853003731100211091010100001000010006402162229629110000103003830038300383003830038
100243003722501100000003462954725100101110000101000050427986413001803003730037282887287671001020101682010329300853003721100211091010100001000200006612162229629010000103003830038300383003830038
1002430037224000000008807262954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000010306402162229629010000103003830038300853003830038
10024300372250000000000612954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722500000000001032954725100101010000101000050427716013001803003730037282863287671001020100002010000300373003711100211091010100001000000006612162229629010000103003830086300383003830038

Test 3: throughput

Count: 8

Code:

  sqxtn b0, h8
  sqxtn b1, h8
  sqxtn b2, h8
  sqxtn b3, h8
  sqxtn b4, h8
  sqxtn b5, h8
  sqxtn b6, h8
  sqxtn b7, h8
  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)03081e3f51inst 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)9facc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200591500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100011151180160020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100011151180160020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100022251291231120088800001002004920049200502005020050
80204200491501064268011610080016100800285006401960200292004820048997699986801282008003820080038200492004911802011009910010080000100022251291231120046800001002004920049200502005020049
80204200481500064278011610080016100800285006401960200292004920048997699986801282008003820080038200492004811802011009910010080000100022251281231120046800001002004920049200492005020050
80204200481500064268011610080016100800285006401960200292004820049997699986801282008003820080038200482004811802011009910010080000100022251281231120045800001002005020050200502005020049
80204200481500064268011610080016100800285006401960200292004920048997699986801282008003820080038200482004911802011009910010080000100022251281231120045800001002004920050200502005020049
802042004815000642680116100800161008002850064019602002920048200489976109986801282008003820080038200492004811802011009910010080000100322251291231120046800001002005020049200492004920049
8020420048150027642780116100800161008002850064019602002920049200489976109986801282008003820080038200482004811802011009910010080000100022251281231120045800001002004920049200492005020050
80204200491500064278011610080016100800285006401960200292004920049997699986801282008003820080038200482004811802011009910010080000100022251281231120046800001002005020050200492004920049

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03041e3f51inst 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)9fa8acc2cficache miss (d3)d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420050150104025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200216232003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200316322003680000102004020040200892004020040
8002420039151004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200316332003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200216332003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200316332003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200216232003680000102004020040200402004020040
8002420039149004025800101080000108000050640000120020200392003999963100198001020800002080000200892009111800211091010800001000050200316332003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200216332003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001020050200216322003680000102004020040200402004020040
8002420039150004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000050200316332003680000102004020040200402004020040