Apple M1 Microarchitecture Research by Dougall Johnson

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

FMULX (vector, 2S)

Test 1: uops

Code:

  fmulx v0.2s, v0.2s, v1.2s
  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)031e3a3f4e51inst issue (52)~issue fp/simd (54)~dispatch fp/simd (57)huge thing fp/simd (5b)60696b6d6edispatch 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
100440373000147340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
100440373000124340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038
10044037300061340725100010001000531908140180403740373258338951000100020004037403711100110000073116113473100040384038403840384038

Test 2: Latency 1->2

Code:

  fmulx v0.2s, v0.2s, v1.2s
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 4.0037

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)9fa8a9cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102044003730001364394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
10204400373000319394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
10204400373000361394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
102044003730001284394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
1020440037299082394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
102044003730001302394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
10204400373009407394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
102044003730031334394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
102044003730001353394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038
102044003730001310394072510100100100001001000050057069081400184003740037381083387451010020010172200200004003740037111020110099100100100001000071011611394790100001004003840038400384003840038

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0037

retire (01)cycle (02)0308090b18191e1f3f4e51inst 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)9fa0a8a9acbranch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024400373000000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006404163439473010000104003840038400384003840038
10024400372990000000613940725100101010000101000050570690840018400374003738130338767100102010000222032240037400371110021109101010000100000006402163439473010000104003840038400384003840038
10024400372990000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006403164339473010000104003840038400384003840038
10024400373000000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006402164339473010000104003840038400384003840038
10024400373000000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006403164339473010000104003840038400384003840038
10024400373000000000823940725100101010000101000050570690840088400854003738130338767100102010323222032440037400371110021109101010000100023790006635324439473110000104046340463404974046440356
1002440462303001891200880651939326199100421510054141118471571947240298404514027138169403893111049241139524222664051240458101100211091010100001001232060008208894539833310000104046740322404664046540467
1002440463303111991059792729539326216100651210060181133272571778040333404614008438165453894111348241159430229284046340465101100211091010100001021017788006403162439473010000104003840038400384003840038
10024400373000000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006404164439473010000104003840038400384003840038
10024400373000000000613940725100101010000101000050570690840018400374003738130338767100102010000202000040037400371110021109101010000100000006402162339473010000104003840038400384003840038

Test 3: Latency 1->3

Code:

  fmulx v0.2s, v1.2s, v0.2s
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 4.0037

retire (01)cycle (02)03080b18191e1f3a3f4e51inst 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)9fa0a1a6a8a9acc2branch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204400373000000000726394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000030071011611394790100001004003840077400384003840038
1020440037299000000061394072510100100100001001000050057069081400184003740037381083387451010020210000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071211611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037300000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038
1020440037299000000061394072510100100100001001000050057069081400184003740084381083387451010020010000200200004003740037111020110099100100100001000000000071011611394790100001004003840038400384003840038

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0037

retire (01)cycle (02)031e3a3f4e51inst 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)9fa1a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100244003730002623940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644101612103947310000104003840038400384003840038
100244003729902623940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644101610103947310000104003840038400384003840038
10024400373000262394072510010101000010100005057069081400184003740037381303387671001020100002020000400374003711100211091010100001000064451610103947310000104003840038400384003840038
100244003730002623940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644101610103947310000104003840038400384003840038
10024400373000262394072510010101000010100005057069081400184003740037381303387671001020100002020000400374003711100211091010100001000064410161053947310000104003840038400384003840038
100244003730002623940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644101610123947310000104003840038400384003840038
1002440037300027273940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644101610103947310000104003840038400384003840038
100244003730002623940725100101010000101000050570690814001840037400373813033876710010201000020200004003740037111002110910101000010000644121610123947310000104003840038400384003840038
100244003730002104394072510010101000010100005057069081400184003740037381303387671001020100002020000400374003711100211091010100001001064410161053947310000104003840038400384003840038
100244003730002623940725100101010000101000050570690814001840037400373813083876710010201000020200004003740037111002110910101000010000644101610103947310000104003840038400384003840038

Test 4: throughput

Count: 8

Code:

  fmulx v0.2s, v8.2s, v9.2s
  fmulx v1.2s, v8.2s, v9.2s
  fmulx v2.2s, v8.2s, v9.2s
  fmulx v3.2s, v8.2s, v9.2s
  fmulx v4.2s, v8.2s, v9.2s
  fmulx v5.2s, v8.2s, v9.2s
  fmulx v6.2s, v8.2s, v9.2s
  fmulx v7.2s, v8.2s, v9.2s
  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)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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420060150042258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051102161120037800001002004120041200412004120041
8020420040150942258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
802042004015004225801001008000010080000500640000120021020040200409973399988010020080000200160000200402004011802011009910010080000100014151101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400001200720200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400000200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
8020420040150042258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041
80204200401500707258010010080000100800005006400001200210200402004099733999880100200800002001600002004020040118020110099100100800001000051101161120037800001002004120041200412004120041

1000 unrolls and 10 iterations

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

retire (01)cycle (02)031e3a3f51inst 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)9fa6a8a9accfd0d2icache miss (d3)d5d6d9daddinst fetch restart (de)e0? int output thing (e9)eb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242004915000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001916001918200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001916001919200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001416001920200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200002116001719200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001916001520200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200002116001920200370080000102004120041200412004120041
80024200401500041258001010800001080000506400000200212004020040999631002080010208000020160000200402004011800211091010800001000053350200001916002219200370080000102004120041200412004120041
800242004015060412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050203002016002021200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001916001520200370080000102004120041200412004120041
800242004015000412580010108000010800005064000002002120040200409996310020800102080000201600002004020040118002110910108000010000050200001816001814200370080000102004120041200412004120041