Apple M1 Microarchitecture Research by Dougall Johnson

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

SQSHRN (D)

Test 1: uops

Code:

  sqshrn s0, d0, #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)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
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073316112629100030383038303830383038
1004303723306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723012425472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037231836125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723216125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303722126125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723010325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038308430383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  sqshrn s0, d0, #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)0307080a0b18191e1f3f4e51inst 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)9fa0a6a8acc2c5branch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000002006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
102043003722500011012010329547251010010010000100100005004277160130018300373003728277328745101002001000020010000300373003711102011009910010010000100001600071051611296330100001003003830038302293003830038
10204300372250000000010329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037225000000006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830183300383003830038
10204300372250000001206129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037225000000006129547251010013010000100100005004277160130018300373003728264328745101002001000020010000302283003711102011009910010010000100000000071011611296330100001003003830038300383003830038
1020430037225000001144886129547251010010010000100100005004277160130018300373003728264328745101002001016520010000300373003711102011009910010010000100002000071011611296330100001003003830038300383003830038
10204300372250000200061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000200710116112963314100001003003830038300383003830038
1020430037225000000006129537251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038
10204300372240000000010329547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030708090b18191e1f3a3f4e5051inst 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)9fa0a1a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002430037224000000000612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006405165429629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771600300183008430037282863287671001020100002010000300373003711100211091010100001000000006404164529629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771600300183008430037282863287671001020100002010000300373003711100211091010100001000000006405164529629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006405165529629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006404165529629010000103003830038300383003830038
1002430037225000000600612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006404164529629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006405165529629010000103003830038300383003830038
1002430037225000000000612954702510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000000006405165429629010000103003830038300383003830038
1002430037225011077927528040532949301371007713100481610428714286807030270303233018028310332888111063241107722111653036730320811002110910101000010202021972807955725629809510000103037030326304173037330404
1002430275227411177801616010729547025100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010040001922807705646529903210000103032030369303703037030267

Test 3: throughput

Count: 8

Code:

  sqshrn s0, d8, #3
  sqshrn s1, d8, #3
  sqshrn s2, d8, #3
  sqshrn s3, d8, #3
  sqshrn s4, d8, #3
  sqshrn s5, d8, #3
  sqshrn s6, d8, #3
  sqshrn s7, d8, #3
  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)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)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)9fa0a1acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420058150030258010810080008100800205006401320200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
80204200391501530258010810080008100800205006401320200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
80204200391503630258010810080008100800205006401321200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
8020420039150030258010810080008100800205006401320200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
80204200391503630258010810080008100800205006401320200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
802042003915042302580108100800081008002050064013202002002003920039997769990801202008003220080032200392003911802011009910010080000100005711151180160020036800001002004020040200402004020040
80204200391502430258010810080008100800205006401321200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
80204200391500302580108100800081008002050064013202002002003920039100126999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020103200402004020040
80204200391500695258010810080008100800205006401320200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040
8020420039150030258010810080008100800205006401321200200200392003999776999080120200800322008003220039200391180201100991001008000010000011151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0308181e1f3f51inst 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)9fa0a1a6a8acc2cfd0d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200501500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000006050200251625252003680000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200261626262007780000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200251614252003680000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200271621282003680000102004020040200402004020040
800242003915000120402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200171625152003680000102004020040200402004020040
80024200391500000404380010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200261628272003680000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200271615272003680000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200281628272003680000102004020040200402004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200251626282003680000102004020040200912004020040
80024200391500000402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000000050200271628282003680000102004020040200402004020040