Apple M1 Microarchitecture Research by Dougall Johnson

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

SUBHN (vector, 8H)

Test 1: uops

Code:

  subhn v0.8b, v0.8h, v1.8h
  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)0307090a3a3f4e51inst 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
100430372310126825482510001000100039831313018303730372415328951000100020003037303711100110000077516442630100030383038303830383038
100430372310126825482510001000100039831313018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372311126825482510001000100039831313018308530842415329071000100020003037303711100110000077416442630100030383038303830383038
100430372210126825482510001000110739831313018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372310126825482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372310126825482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372310126825482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372210126825482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372310126825482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038
100430372310129125482510001000100039831303018303730372415328951000100020003037303711100110000077416442630100030383038303830383038

Test 2: Latency 1->2

Code:

  subhn v0.8b, v0.8h, v1.8h
  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)03080b181e1f3f4e51inst 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)9fa0a6a8a9acc2cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000006129548251010010010000100100005004277313030018300373003728265328745101002001000020020000300373003711102011009910010010000100000030071031622296340100001003003830038300383003830038
1020430037225000006129548251010010010000100100005004277313030018300853003728269328762101002001016120020330300373003721102011009910010010000100001030071022522296340100001003003830085300383003830038
1020430037225000006129548251010010010000100100005004277313130018300373008428269328762102532021000020220000300373003721102011009910010010000100001000071022522296340100001003003830038300383003830038
1020430037225011006129548251010010010000100100005004277313030018300373003728268328763101002001000020020000300853003711102011009910010010000100220000071021622296340100001003003830038300383003830086
10204300372250001206129530451010010010000100100005004277313030018300373008528265328745101002041000020220000300373003711102011009910010010000100000000073221622296340100001003003830038300383003830038
1020430037225000006129548251010010010000100101495004277313030018300373003728265328745101002001000020020000300373003721102011009910010010000100001000071021622296700100001003003830038300383003830038
1020430037225000006129539451010010710000100100005004277313030054300373008428265328745101002041000020420000300833003711102011009910010010000100430002071021622296340100001003003830038300383003830086
1020430037224000006129548251010010010000100101495004277313030018300853003728265328763101002001000020020000300373003711102011009910010010000100001000071022622296340100001003003830086300383003830038
1020430037225100006129548251010010010000100100005004277313130126300373003728265328745101002001000020020000300373003711102011009910010010000100400700071022522296340100001003003830038300383008630038
1020430085225100006129548251010010010000100100005004277313030018300373003728265328745101002001000020020000300373003711102011009910010010000100020002071021622296340100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030b181e3f4e51inst 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)9fa0a1a6a8a9acc2cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010040000006402162229630010000103008530038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313030018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
100243003722500010229548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038
10024300372250006129548251001010100001010000504277313130018300373003728287032876710010201000020200003003730037111002110910101000010000000006402162229630010000103003830038300383003830038

Test 3: Latency 1->3

Code:

  subhn v0.8b, v1.8h, v0.8h
  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)03080b181e3f4e51inst 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)9fa0a8acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000961295482510100100100001001000050042773131300183003730037282726287411010020010008200200163003730037111020110099100100100001000031117180160029647100001003003830038300383003830038
1020430037224000061295482510100100100001001000050042773131300183003730037282726287411010020010008200200163003730037111020110099100100100001000001117170160029647100001003003830038300383003830038
1020430037225000061295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
1020430037224000061295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
1020430037224000061295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
1020430037225000061295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
10204300372250023661295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
1020430037225000061295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
1020430037225000061295482510100100100001001000050042773131300183003730037282653287451010020010000204200003003730037111020110099100100100001000000007101161129634100001003003830038300383003830038
10204300372250000654295482510100100100001001000050042773131300183003730037282653287451010020010000200200003003730084611020110099100100100001000000007101161129634100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)0318191e3f4e51inst 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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500061295392510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722500061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722500061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722400061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722500061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722520061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722500061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
100243003722400061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316302963010000103003830038300383003830038
100243003722500061295482510010101000010100005042773131300183003730037282873287671001020100002020000300373003711100211091010100001000640316332963010000103003830038300383003830038
1002430037225000612954825100101010000101000050427731313001830037300372828732876710010201000020200003003730037111002110910101000010021640316332963010000103003830038300383003830038

Test 4: throughput

Count: 8

Code:

  subhn v0.8b, v8.8h, v9.8h
  subhn v1.8b, v8.8h, v9.8h
  subhn v2.8b, v8.8h, v9.8h
  subhn v3.8b, v8.8h, v9.8h
  subhn v4.8b, v8.8h, v9.8h
  subhn v5.8b, v8.8h, v9.8h
  subhn v6.8b, v8.8h, v9.8h
  subhn v7.8b, v8.8h, v9.8h
  movi v8.16b, 9
  movi v9.16b, 10

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

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

retire (01)cycle (02)0318191e3f51inst 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)9fa6a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420058150000412580100100800001008000050064000002002020039200399973399978010020080000200160000200392003911802011009910010080000100000511021611200360800001002004020040200402004020040
8020420039150000412580100100800001008000050064000012002020039200399973399978010020080000200160000200392003911802011009910010080000100010511231711200360800001002004020040200402004020040
8020420039150003412580100100800001008000050064000002002020039200399973399978010020080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
802042003915000941258010010080000100800005006400001200202003920039997339997801002008000020016000020039200391180201100991001008000010000585511011611200360800001002004020040200402004020040
8020420039150009412580100100800001008000050064000002002020039200399973399968012520080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
8020420039150000402580100100800001008000050064000012002020039200399973399968010020080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
8020420039150000412580125125800001008000050064000012002020039200399973399968012520080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
8020420039150000852580100100800001008000050064000012002020039200399973399978010020080144200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
8020420089150006412580100100800001008000050064000012002020039200399973399978010020080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040
8020420039150000412580100100800001008000050064000012002020039200399973399978010020080000200160000200392003911802011009910010080000100000511011611200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03071e3f51inst 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)9faccdcfd5d6daddinst fetch restart (de)e0ea? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200481501040258001010800001080000506408280200202003920039999631001980010208000020160000200392003911800211091010800001000502017160121220036080000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020160000200392003911800211091010800001000502012160111220036080000102004020040200402004020040
800242003915002740258001010800001080000506400000200202003920039999631001980010208000020160000200392003911800211091010800001000502011160141120036080000102004020040200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020160000200392003911800211091010800001000502012160121220036080000102004020040200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020160000200392003911800211091010800001000502011160121220036080000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020160000200392003911800211091010800001000502012160121120036080000102004020090200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020160000200392003911800211091010800001000502011160111220036080000102004020040200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020160000200392003911800211091010800001000502012160121220036080000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020160000200392003911800211091010800001000502011160111220036080000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020160000200392003911800211091010800001000502013160121220036080000102004020040200402004020040