Apple M1 Microarchitecture Research by Dougall Johnson

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

SSHR (vector, 2S)

Test 1: uops

Code:

  sshr v0.2s, v0.2s, #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)030b1e3f4e51inst 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)a1a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150082168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715012661168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
100420371600611686251000100010002645210201820372037157131895100010001000203720371110011000002173116111786100020382038203820382038
100420371601561168625100010001000264521020182037203715713189510001107100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  sshr v0.2s, v0.2s, #3
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)03090b18191e1f3f4e51inst 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)9fa6a8accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204200371502000690611968625101001001000010010000500284752112001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037150000060611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037150003000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000073511611197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
10204200371500000005361968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
102042003715000004206119686251010010010000100100005002847521020018200372003718421318745101002001000020010000200372003711102011009910010010000100000710116111979122100001002008720038200382003820038
10204200851500100006501967525101001001000010010000500284752102001820037200371842131874510100200100002041000020037200371110201100991001001000010000071011611197910100001002008720086200382003820038
1020420037150100412108611968625101001001000010010000500284752112001820037200371842131874510100200100002001000020037200371110201100991001001000010020071011611197910100001002003820038200382003820038
1020420037150000000611968625101001001000010010000500284752102001820037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

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)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)9fa1a8accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100242003715066611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786210000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371506611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
100242003715027611968625100101010000101000050284752120018200372003718450318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
10024200371500611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038
100242003715033821968625100101010000101000050284752120018200372003718443318767101622010000201000020037200371110021109101010000100006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  sshr v0.2s, v8.2s, #3
  sshr v1.2s, v8.2s, #3
  sshr v2.2s, v8.2s, #3
  sshr v3.2s, v8.2s, #3
  sshr v4.2s, v8.2s, #3
  sshr v5.2s, v8.2s, #3
  sshr v6.2s, v8.2s, #3
  sshr v7.2s, v8.2s, #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)03181e3f51inst 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)6061696d6edispatch 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)9fc2c5branch mispredict (cb)cdcfd0d2d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420048150057292580108100800081008002050064013200200192003820038997706998980120200800322008003220038200381180201100991001008000010001115118000160020035800001002003920039200392003920039
80204200381500180292580108100800081008002050064013200200192003820038997706998980120200800322008003220038200381180201100991001008000010001115118000160020035800001002003920039200392003920039
8020420038150004092580108100800081008002050064013210200192003820038997706998980120200800322008003220038200381180201100991001008000010001115118000160020035800001002003920039200392003920039
802042003815000292580108100800081008002050064013210200192003820038997706998980120200800322008003220038200381180201100991001008000010001115118000160020035800001002003920039200392003920039
802042003815000642680116100800161008002850064019610200282004820049997609998680128200800382008003820048200491180201100991001008000010002225128001231120045800001002005020049200492004920050
8020420048150012642780116100800161008002850064019610200282004820049997609998680128200800382008003820048200481180201100991001008000010002225128001231120045800001002004920049200492004920049
8020420048150008526801161008001610080028500640196102002820049200489976710998680128200800382008003820048200491180201100991001008000010002225129001231120046800001002004920050200492004920049
8020420048150007292780116100800161008002850064019600200282004920048997609998680128200800382008003820048200481180201100991001008000010002225128001231120045800001002005020049200492004920049
8020420048150006427801161008001610080028500640196002002820048200489976010998680128200800382008003820049200481180201100991001008000010002225128001231120045800001002004920049200492005020049
802042004815000642780116100800161008002850064019600200282004920049997609998680128200800382008003820049200481180201100991001008000010002225129001231120045800001002004920050200502005020050

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0304080b18191e1f3f51inst 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)9fa0a1a6a8a9acc2cdcfd2d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242005115000000330392580010108000010801085064000002001920038200389996310018800102080000208000020038200381180021109101080000100000000050200316552003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000002001920038200389996310018800102080000208000020038200381180021109101080000100000000050200516352003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100000000050200416442003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000002001920038200389996310018800102080000208000020038200381180021109101080000100000000050200416432003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100000000050200216442003580000102003920039200392003920039
800242003815000000150392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100000000050200416432003580000102003920039200392003920039
80024200381500000030392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100000000050200316332003580000102003920039200392003920039
80024200381500000000392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100000004050360328442007580000102008920088200982008920102
80024200881510111115010426843801031080093108009950640768120059201452014610004121004280108208009620800982008720136318002110910108000010223006800050370528552007380000102003920039200392003920039
800242003815000003360812580010108000010800005064000002001920038200389996310018800102080000208000020038200381180021109101080000100000000050200516552003580000102003920039200392003920039