Apple M1 Microarchitecture Research by Dougall Johnson

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

USUBW (vector, 8H)

Test 1: uops

Code:

  usubw v0.8h, v0.8h, v1.8b
  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)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)a8cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073316111787100020382038203820382038
10042037150061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
100420371599061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037150061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
10042037160061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038
100420371512061168725100010001000264680201820372037157231895100010002000203720371110011000073116111787100020382038203820382038

Test 2: Latency 1->2

Code:

  usubw v0.8h, v0.8h, v1.8b
  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)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)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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037155000124196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715504061196872510100100100001001000050028476801200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715600061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100107101161119791100001002003820038200382003820038
102042003715600061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002008720038200382003820038
102042003715600061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200842003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715510061196872510115100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007341161119791100001002003820038200382003820038
102042003715500061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715600061196872510100100100001001000050028476801200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715500061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101162119791100001002003820038200382003820038
102042003715500061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)0304080a0b18191e1f3a3f4e51inst 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)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)9fa0a1a6a8a9accfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002420037155000000000611968725100101010000101000050284768015200182003720037184443187671001020100002020000200372003711100211091010100001000000064044163619785010000102003820038200382003820038
1002420037155000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
1002420037155000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
1002420037156000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
100242003715500000000019011968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
1002420037155000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
1002420037155000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
10024200371550000001200611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038
1002420037155000000300611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000010064043163319785010000102003820038200382003820038
1002420037155000000000611968725100101010000101000050284768014200182003720037184443187671001020100002020000200372003711100211091010100001000000064043163319785010000102003820038200382003820038

Test 3: Latency 1->3

Code:

  usubw v0.8h, v1.8h, v0.8b
  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)030818191e1f3a3f4e51inst 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)9fa0a1a6a7a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037155000000611968725101001001000010010152500284768012001820037200371842231874510100200100002002000020037200371110201100991001001000010000002509000071011611197910100001002003820038200382003820038
102042003715500000068196872510100100100001001000050028476801200182003720037184223187451010020010000200200002003720037111020110099100100100001000000600000071011611197910100001002003820038200382003820038
1020420037155000000611968725101001001000010010000500284768012001820037200371842231874510100200100002002000020037200371110201100991001001000010000001003000071011611197910100001002003820038200382003820038
102042003715500024006119687251010010010000100100005002847680020018200372003718422318745101002001000020020000200372003711102011009910010010000100000050186000071011611197910100001002003820038200382003820038
10204200371550000003461968725101001001000010010000500284768012001820037200371842231874510100200100002002000020037200371110201100991001001000010000000066000071011611197910100001002003820038200382003820038
102042003715600000061196872510100100100001191000050028476801200182003720037184223187451010020010000200200002003720037111020110099100100100001000000503000071011611197910100001002003820038200382003820038
102042003715500000061196872510100100100001001000050028476800200182003720037184223187451010020010000200200002003720037111020110099100100100001000000503000071011611197910100001002003820038200382003820038
102042003715500000061196872510100100100001001000050028476801200182003720037184223187451010020010000200200002003720037111020110099100100100001000000003000071011611197910100001002003820038200382003820038
1020420037155000000611968725101001001000010010000500284768002001820037200371842231874510100200100002002000020037200371110201100991001001000010000004803000071011611197910100001002003820038200382003820038
1020420037155000000611968725101001001000010010000500284768012001820037200371842231874510100200100002002000020037200371110201100991001001000010000004021000071011611197910100001002003820038200382003820038

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)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? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100242003715606119687251001010100001010000502847680120018200372003718444318767100102010000202000020037200371110021109101010000100246402162219785010000102003820038200382003820038
10024200371550611968725100101010000101000050284768012001820037200371844431876710010201000020200002003720037111002110910101000010096402162219785010000102003820038200382003820038
100242003715606119687251001010100001010000502847680020018200372003718444318767100102010000202000020037200371110021109101010000100156402162219785010000102003820038200382003820038
100242003715506119687251001010100001010000502847680020018200372003718444318767100102010000202000020037200371110021109101010000100156402162219785010000102003820038200382003820038
100242003715512611968725100101010000101000050284768002001820037200371844431876710010201000020200002003720037111002110910101000010006402162219785010000102003820038200382003820038
100242003715506119687251001010100001010000502847680020018200372003718444318767100102010000202000020037200371110021109101010000100186402162219785010000102003820038200382003820038
10024200371551225119687251001010100001010000502847680020018200372003718444318767100102010000202000020037200371110021109101010000100216402162219785010000102003820038200382003820038
10024200371550611968725100101010000101000050284768002001820037200371844431876710010201000020200002003720037111002110910101000010036402162219785010000102003820038200382003820038
10024200371560611968725100101010000101000050284768012001820037200371844431876710010201000020200002003720037111002110910101000010066402162219785010000102003820038200382003820038
10024200371550611968725100101010000101000050285152912001820037200371844431876710010201000020200002003720037111002110910101000010196402162219785010000102003820038200382003820038

Test 4: throughput

Count: 8

Code:

  usubw v0.8h, v8.8h, v9.8b
  usubw v1.8h, v8.8h, v9.8b
  usubw v2.8h, v8.8h, v9.8b
  usubw v3.8h, v8.8h, v9.8b
  usubw v4.8h, v8.8h, v9.8b
  usubw v5.8h, v8.8h, v9.8b
  usubw v6.8h, v8.8h, v9.8b
  usubw v7.8h, v8.8h, v9.8b
  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)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)9fa0a8accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042003815500402580100100800001008000050064000020019200382003899733999680100200800002001600002003820038118020110099100100800001000313511021611200350800001002003920039200392003920039
802042003815500402580100100800001008000050064000020019200382003899733999680100200800002001600002003820038118020110099100100800001000087511011611200350800001002003920039200392003920088
802042003815600402580100100800001218000050064000020019200382003899733999680100200800002001600002003820038118020110099100100800001000012511011612200950800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100043511011611200350800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100000511011611200350800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100003511011611200350800001002003920039200392003920039
80204200381550061258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100010511011611200350800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100010511011611200350800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100010511011611200350800001002003920039200392003920039
80204200381550040258010010080000100800005006400002001920038200389973399968010020080000200160000200382003811802011009910010080000100010511011611200350800001002003920039200392003920039

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03070b1e3f51inst 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)9fa0a6a8accfd0d2d5d6dbddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200401550012392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010002050200021603320035080000102003920039200392003920039
80024200381560003522580010108000012800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010001050200021602220035080000102003920039200392003920039
8002420038156000812580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010001050200021602320035080000102003920039200392003920039
8002420038155000392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010003050200021602320035080000102003920039200392003920039
8002420038155000392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010002650200021604420035080000102003920039200392003920039
8002420038155000392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010004050200031602220035080000102003920039200392003920039
80024200381550003925800101080000108000050640000020019200382003899963100188001020800002016000020038200381180021109101080000100003350200031602220035080000102003920039200392003920039
800242003815500123925800101080000108000050640000020019200382003899963100188001020800002016000020038200381180021109101080000100001850205021602220035080000102003920039200392003920039
8002420038155000392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010007350200021603520035080000102003920039200392003920039
8002420038161000392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010004350200021602320035080000102003920039200392003920039