Apple M1 Microarchitecture Research by Dougall Johnson

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

SQXTN (S)

Test 1: uops

Code:

  sqxtn h0, s0
  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)0308091e3f4e51inst issue (52)~issue fp/simd (54)~dispatch fp/simd (57)huge thing fp/simd (5b)696d6edispatch 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)a8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372300126125472510001000100039816030183037303724143289510001000100030373037111001100000073216112629100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007873116112629100030383038303830383038
100430372200061254725100010001000398160301830373037241432895100010001000303730371110011000004573116112629100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000002794116112629100030383038303830383038
100430372200061254725100010001000398160301830373037241432895100010001000303730371110011000001273116112629100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000004573116112629100030383038303830383038
10043037220006125472510001000100039816030183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730841110011000602773116112629100030383038303830383038
1004303723000160254725100010001000398160301830373037241432895100010001000303730371110011000005773116112629100030383038303830383038
100430372200061254725100010001000398160301830373037241432895100010001000303730371110011000003073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  sqxtn h0, s0
  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)03070818191e3f4e51inst 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)9fa0a6a8accdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003722500000612954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000010071011611296330100001003003830038300383003830038
10204300842250000011342954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500000612954725101001001000010010000500427716013001803003730037282923287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037225000002512954725101001001000012610000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037225000008262954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037225000005742954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372250000019412954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003722500000612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383008630038
1020430037225000009042954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
1020430037225000009662954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)0308090b18191e1f3a3f4e51inst 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)9fa6a8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250000000046829547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250000000034429547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500000000407295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001001048640216222962910000103003830038300383003830038
10024300372250000000040829547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250000100053329547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830085
10024300372250000000045529547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250000000041129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225000000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225000000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372240000000049829547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100100640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  sqxtn h0, s8
  sqxtn h1, s8
  sqxtn h2, s8
  sqxtn h3, s8
  sqxtn h4, s8
  sqxtn h5, s8
  sqxtn h6, s8
  sqxtn h7, s8
  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)03070a1e3f51inst 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)9fa8acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420061150010302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151183164520036800001002004020040200402004020040
8020420039150110302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185164520036800001002004020040200402004020040
8020420039150110952580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185164520036800001002004020040200402004020040
8020420039150110302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151183164420036800001002004020040200402004020040
80204200391501102042580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010010011151184164520036800001002004020040200402004020040
8020420039150110302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010010011151185165520036800001002004020040200402004020040
8020420039150110952580108100800081008002052464013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185165420036800001002004020040200402004020040
802042003915011011162580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185165420036800001002010020040200402004020040
8020420039150110302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185164520036800001002004020040200402004020040
8020420039150110302580108100800081008002050064013220020200392003999776999080120200800322008003220039200391180201100991001008000010000011151185165420036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)030b181e1f3f51inst 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)9fa8acc5cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420051150000057325800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020416322003680000102004020040200402004020040
800242003915000004025800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000101005020416442003680000102004020040200402004020040
8002420039150100012425800101080000108000050640000012002020039200399996310019800102080000208000020088200391180021109101080000100005020416442003680000102004020040200402004020040
80024200391500000119425800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100005020316342003680000102004020040200402004020040
8002420039150000066325800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000104414405020416442003680000102004020040200402004020040
800242003915000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020416442003680000102004020040200402004020040
800242003915000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020416442003680000102004020040200402004020040
80024200391500001084025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020316442003680000102004020040200402004020040
800242003915000004025800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100005020416332003680000102004020040200402004020040
8002420039150000099425800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020316452003680000102004020040200402004020040