Apple M1 Microarchitecture Research by Dougall Johnson

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

SQSHRN2 (8H)

Test 1: uops

Code:

  sqshrn2 v0.16b, v1.8h, #3
  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)031e1f3f4e51inst 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)a0a8c2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372300145254825100010001000398313030183037303724153289510001000200030373037111001100000073116112702100030383038303830383038
1004303722132061254825100010001000399230130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
100430372212061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
100430372212061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
10043037230061254825100010001000398313030183037303724153289510001000200030373037111001100000073116112630100030863038303830383038
10043037220061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
10043037220061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
10043037230061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
1004303722132061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038
10043037220061254825100010001000398313130183037303724153289510001000200030373037111001100000073116112630100030383038303830383038

Test 2: Latency 1->1

Code:

  sqshrn2 v0.16b, v1.8h, #3
  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)696b6d6edispatch 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
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000017101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000307101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037225061295392510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001001007101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037224061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038
1020430037225061295482510100100100001001000050042773133001803003730037282653287451010020010000200200003003730037111020110099100100100001000007101161129634100001003003830038300383003830038

1000 unrolls and 10 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)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)9fa0a1a6a7a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000010006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000020006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000020006402162229630010000103003830038300383003830038
100243003722500000006129548251001010100001010000504277313030018300373003728287732876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
1002430037225000000061295482510010101000010100005042773130300183003730037282870328767100102010000202000030037300371110021109101010000103230421659327912724229884310000103036830367303693032330272
1002430367228000779366164592294761611007115100641410894604286812030270303693012028313030289171091022111492022300304173036611100211091010100001062013541935126402242229630010000103003830038300383003830038

Test 3: Latency 1->2

Code:

  sqshrn2 v0.16b, v0.8h, #3
  movi v0.16b, 1

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030918191e3f4e51inst 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)9fa1a8a9acc2c5branch mispredict (cb)cdcfd6e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000061295472510100100100001001000050042771600300183003730037282717287401010020010008200200163003730037111020110099100100100001000009011171716296450100001003003830038300383003830038
1020430037224000061295472510100100100001001000050042771600300183003730037282717287401010020010008200200163003730037111020110099100100100001000000011171816296450100001003023030038300383003830038
10204300372250000726295472510131100100001001000050042771601300183003730037282716287411010020010008200200163003730037111020110099100100100001000000411171816296450100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282717287401010020010008200200163003730037111020110099100100100001000000011171816296460100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282716287401010020010008200200163003730037111020110099100100100001000000011171716296460100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282716287401010020010008200200163003730037111020110099100100100001000000011171816296450100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282717287401010020010008200200163003730037111020110099100100100001000000011171716296450100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282717287411025420010008200200163003730037111020110099100100100001000122808011171716296450100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771601300183003730037282717287401010020010008200200163003730037111020110099100100100001000000011171816296450100001003003830038300383003830038
1020430037225000061295472510100100100001001000050042771600300183003730037282717287411010020010008200200163003730037111020110099100100100001000000011171816296450100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030809181e1f3f4e51inst 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)9fa1a6a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002430037225000005362954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100010640224322962910000103003830038300383027230086
100243003722501000612954725100101010000101000050427716030018300373003728286328767101622010000202033630084300371110021109101010000102110640216222962910000103003830038300383003830038
1002430037224000007262954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500000612954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500000612954725100101010000101000050427787930018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500000612954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300853008630038
100243003722500000612954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500000612954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722400000612954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225000009242954725100101010000101000050427716030018300373003728286328767100102010000202000030037300371110021109101010000100000640216222962910000103003830038300383003830038

Test 4: throughput

Count: 8

Code:

  movi v0.16b, 0
  sqshrn2 v0.16b, v8.8h, #3
  movi v1.16b, 0
  sqshrn2 v1.16b, v8.8h, #3
  movi v2.16b, 0
  sqshrn2 v2.16b, v8.8h, #3
  movi v3.16b, 0
  sqshrn2 v3.16b, v8.8h, #3
  movi v4.16b, 0
  sqshrn2 v4.16b, v8.8h, #3
  movi v5.16b, 0
  sqshrn2 v5.16b, v8.8h, #3
  movi v6.16b, 0
  sqshrn2 v6.16b, v8.8h, #3
  movi v7.16b, 0
  sqshrn2 v7.16b, v8.8h, #3
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2508

retire (01)cycle (02)0308091e3f51inst 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)60696d6escheduler 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)9fa8acc5branch mispredict (cb)cdcfd6e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1602042009115000029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066200662006620066
1602042006515000029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002013220066200662006620066
1602042006515000029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066200662006620066
16020420065150000409258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066200662006620066
1602042006515010029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066201342006620066
1602042006515000029258011610080016100800285006401960200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066200662006620066
1602042006515100029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011917200621600001002006620066200662006620066
1602042006515000504292580116100800161008002850064019612004520065200656128012820080028200160056200652006511160201100991001001600001000541111011916200621600001002006620066200662006620066
1602042006515000029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100031111011916200621600001002006620066200662006620066
1602042006515000029258011610080016100800285006401961200452006520065612801282008002820016005620065200651116020110099100100160000100001111011916200621600001002006620066200662006620066

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2506

retire (01)cycle (02)033f51inst 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)5f6061696d6escheduler 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)e0eaec? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1600242009015045278001010800001080000506400001102003220051200513228001020800002016000020051200511116002110910101600001000100273214252113420048202160000102005220052200522005220052
1600242005115045278001010800001080000506400001152003220051200513228001020800002016000020051200511116002110910101600001010100278413252114420048201160000102005220052200522005220052
1600242005115045278001010800001080000506400001002003220051200513228001020800002016000020051200511116002110910101600001010100278524252114520048201160000102005220052200522005220372
16002420051150546278001010800001080000506400001002003220051200513228001020800002016000020051200511116002110910101600001000100278414252114320048201160000102005220052200522005220052
1600242005115045278001010800001080000506400001152003220051200513228001020800002016000020051200511116002110910101600001000100278413252113420048401160000102005220052200522005220052
1600242005115145278001010800001080000506400001052003220051200513228001020800002016000020051200511116002110910101600001010100268114252114420048201160000102005220052200522005220052
1600242005115045278001010800001080000506400001152003220051200513228001020800002016000020051200511116002110910101600001000100278414252114420048201160000102005220052200522005220052
1600242005115045278001010800001080000506400001152003220051200513228001020800002016000020051200511116002110910101600001000100278415252114320048201160000102005220134200522005220052
1600242005115045278001010800001080000506400001152003220051200513518001020800002016000020051200511116002110910101600001000100288415252113420048201160000102005220052200522005220052
1600242005115045278001010800001080000506400001152003220051200513228001020800002016000020051200511116002110910101600001000100278413252113420048201160000102005220052200522005220052

Test 5: throughput

Count: 16

Code:

  sqshrn2 v0.16b, v16.8h, #3
  sqshrn2 v1.16b, v16.8h, #3
  sqshrn2 v2.16b, v16.8h, #3
  sqshrn2 v3.16b, v16.8h, #3
  sqshrn2 v4.16b, v16.8h, #3
  sqshrn2 v5.16b, v16.8h, #3
  sqshrn2 v6.16b, v16.8h, #3
  sqshrn2 v7.16b, v16.8h, #3
  sqshrn2 v8.16b, v16.8h, #3
  sqshrn2 v9.16b, v16.8h, #3
  sqshrn2 v10.16b, v16.8h, #3
  sqshrn2 v11.16b, v16.8h, #3
  sqshrn2 v12.16b, v16.8h, #3
  sqshrn2 v13.16b, v16.8h, #3
  sqshrn2 v14.16b, v16.8h, #3
  sqshrn2 v15.16b, v16.8h, #3
  movi v16.16b, 17

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2502

retire (01)cycle (02)03080b191e1f3f51inst 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)9fa6a8acc2c5branch mispredict (cb)cdcfd0d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
16020440061300000003025160108100160008100160020500128013214002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081689400361600001004004040040400404004040040
16020440039300000003025160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118071687400361600001004004040040400404004040040
16020440039300000003025160108100160008100160020500128013214002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081687400361600001004004040040400404004040040
16020440039299000003025160108100160008100160020500128013214002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081678400361600001004004040040400404004040040
16020440039300000003025160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081688400361600001004004040040400404004040040
16020440039300000005825160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081688400361600001004004040040400404004040040
16020440039299000003025160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081788400361600001004004040040400404004040040
16020440039299000003025160108100160008100160020500128013204002040039400391997762002416012020016003220032006440039400391116020110099100100160000100000011110118081688400361600001004004040040400404004040040
16020440039300000003025160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118081638400361600001004004040040400404004040040
16020440039300000003025160108100160008100160020500128013204002040039400391997761999016012020016003220032006440039400391116020110099100100160000100000011110118071688400361600001004004040040400404004040040

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2502

retire (01)cycle (02)0307080a191e1f3a3f51inst 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)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)9fa0a8a9acc2cfd0d2icache miss (d3)itlb miss (d4)d5d6d9dadbddinst fetch restart (de)e0eaeb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
16002440050300000000046251600101016000010160000501280000110400204003940039199960320019160010201600002032000040039400391116002110910101600001000000100223110221621121194003621118160000104004040040400904004040040
1600244003930000000004625160010101600001016000050128000011540020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022841019162111317400362081160000104004040040400404004040040
1600244003930000000004625160010101600001016000050128000010540020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022841120161111820400362167160000104004040040400404004040040
160024400393000000000711251600101016000010160000501280000105400204003940039199960320019160010201600002032000040039400391116002110910101600001000000100221141019161112115400362154160000104004040040400404004040040
1600244003930000000004625160010101600001016000050128000011540020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022811014161211617400362054160000104004040040400404004040040
1600244003930000000004625160010101600801016000050128000001040020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022341020161111713400362065160000104004040040400404004040040
1600244003930000000004625160010101600001016000050128000010040020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022811018162211718400364077160000104004040040400404004040040
1600244003930000000006725160010101600001016000050128000011040020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022841018163111919400364077160000104004040040400404004040040
16002440039299000000052125160010101600001016000050128000010540020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022811017162111420400364055160000104004040040400404004040040
16002440039300000039004625160010101600001016000050128000011540020400394003919996032001916001020160000203200004003940039111600211091010160000100000010022341017162121819400362054160000104004040040400404004040040