Apple M1 Microarchitecture Research by Dougall Johnson

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

USHR (vector, 8H)

Test 1: uops

Code:

  ushr v0.8h, v0.8h, #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)031e3f4e51inst 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)a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10042037150611686251000100010002645212018203720371571318951000100010002037203711100110000073216111786100020382038203820382038
10042037160611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
10042037160611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
100420371501031686251000100010002645212018203720371571318951000100010002037203711100110001073116111786100020382038203820382038
10042037150611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
10042037150611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
10042037169611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
10042037160611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038
10042037150611686251000100010002645212018203720371571318951000100010002037203711100110009073124111786100020382038203820382038
10042037160611686251000100010002645212018203720371571318951000100010002037203711100110000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  ushr v0.8h, v0.8h, #3
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)03090b18191e1f3a3f4e51inst 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)9fa0a1a6a8acbbc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)ea? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820137
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000300000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475210200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
1020420037155000000061196862510100100100001001000050028475211200182003720037184213187641010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038
10204200371550000120061196862510100100100001001000050028475210200182003720037184213187451010020010000200100002003720037111020110099100100100001000001000000710116111979100100001002003820038200382003820038
102042003715600001200110196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000000710116111979100100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)030a0b18191e1f3f4e51inst 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)9fa1a6a7a8a9acdcache load miss (bf)c2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002420037150000060611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
10024200371500000270821968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000003006402162219786010000102003820038200382003820038
1002420037150000060611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162419786010000102003820038200382003820038
1002420037149000000611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
10024200371500000270611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000001110611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  ushr v0.8h, v8.8h, #3
  ushr v1.8h, v8.8h, #3
  ushr v2.8h, v8.8h, #3
  ushr v3.8h, v8.8h, #3
  ushr v4.8h, v8.8h, #3
  ushr v5.8h, v8.8h, #3
  ushr v6.8h, v8.8h, #3
  ushr v7.8h, 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): 0.2505

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)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)9fa8a9acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420057155007125801081008000810080020500640132200192003820038997769989801202008003220080032200382003811802011009910010080000100270611151180160020035800001002003920039200392003920039
8020420038155005042580108100800081008002050064013220019200382003899776998980120200800322008003220038200381180201100991001008000010040011151180160020035800001002003920039200392003920039
802042003815600292580108100800081008025050064019620028200482004899769998680128200800382008003820048200481180201100991001008000010030022251281231120045800001002004920049200502004920049
802042004915500642780116100800161008002850064019620028200482004899769998680128200800382008003820049200481180201100991001008000010000022251281231120045800001002005020049200492004920049
8020420048156006426801161008001610080028500640196200282004820048997610998680128200800382008003820049200491180201100991001008000010000022251281231120045800001002004920049200502004920049
8020420049155006426801161008001610080028500640196200282004820048997610998680128200800382008003820049200491180201100991001008000010000022251281231120046800001002004920049200492004920049
8020420048155006426801161008001610080028500640196200282004820048997610998680128200800382008003820049200481180201100991001008000010000022251291231120045800001002005020050200502004920049
8020420048155006926801161008001610080028500640196201512004820048997610998680128200800382008003820048200481180201100991001008000010000022251281231120045800001002004920049200492004920049
80204200481560064268011610080016100800285006401962002820048200489976999868012820080038200800382004920048118020110099100100800001003201222251291231120045800001002004920049200492005020050
8020420048155006427801161008001610080028500640196200282004820049997699986801282008003820080038200482004811802011009910010080000100700622251281231120045800001002005020050200492004920050

1000 unrolls and 10 iterations

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

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)5f6061696d6edispatch 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)9fa0a1a8a9accfd0d2d5d6ddinst fetch restart (de)e0eb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200501550123925800101080000108000050640000010200192003820038999631001880010208000020800002003820038118002110910108000010000005020006166620035080000102003920039200392003920039
80024200381550123925800101080000108000050640000000200192003820038999631001880010208000020800002003820038118002110910108000010001005020007166620035080000102003920039200392003920039
800242003815600392580010108000010800005064000001020019200382003899963100188001020800002080000200382003811800211091010800001000104905020006169720075080000102003920102200392003920039
80024200381561039258001010800001080000506400000102001920038200389996310018800102080000208000020038200381180021109101080000100000215020006166720035080000102003920039200392003920039
8002420038155006025800101080000108000050640000010200192003820038999631001880010208000020800002003820038118002110910108000010000005020007166620035080000102003920039200392003920039
8002420038156003925800101080000108000050640000010200192003820038999631001880010208000020800002003820038118002110910108000010000005020006167720035080000102003920039200392003920039
80024200381550032425800101080000108000050640000010200192003820038999631001880010208000020800002003820038118002110910108000010001005020006166720035080000102003920039200392003920039
8002420038155033925800101080000108000050640000110200192003820038999631001880010208000020800002003820038118002110910108000010000005020006166720035080000102003920039200392003920039
80024200381550039258001010800001080000506400000102001920038200389996310018800102080000208000020038200381180021109101080000100000845020006167620035080000102003920039200392003920039
8002420038155003925800101080000108000050640000000200192003820038999631001880010208000020800002003820038118002110910108000010000005020007167720035080000102003920039200392003920039