Apple M1 Microarchitecture Research by Dougall Johnson

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

FMSUB (scalar, H)

Test 1: uops

Code:

  fmsub h0, h0, h1, h2
  movi v0.16b, 1
  movi v1.16b, 2
  movi v2.16b, 3

(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)03091e3f4e51inst 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)a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10044037300061340725100010001000531908140184037403732583389510001000300040374037111001100030073116113473100040384038403840384038
10044037300061340725100010001000531908140184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
100440373000149340725100010001000531908140184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037300061340725100010001000531908140184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037300061340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037310061340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037300061340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037310061340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
100440373000105340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038
10044037300061340725100010001000531908040184037403732583389510001000300040374037111001100000073116113473100040384038403840384038

Test 2: Latency 1->2

Code:

  fmsub h0, h0, h1, h2
  movi v0.16b, 1
  movi v1.16b, 2
  movi v2.16b, 3

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 4.0037

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)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)9fa0a1a6a8a9acc2c5branch mispredict (cb)cdcfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020440037300000000613940725101001001000010010000500570690814001840037400373811506387401010020010008200300244003740037111020110099100100100001000000000111718011600394890100001004003840038400384003840038
10204400373000003001613940725101001001000010010000500570690804001840037400373811507387411010020010008200300244003740037111020110099100100100001000000000111717001600394900100001004003840038400384003840038
1020440037300000000613940725101001001000010010000500570690804001840037400373811507387401010020010008200300244003740037111020110099100100100001000000000111718001600394900100001004003840038400384003840038
10204400373000000006139407251010010010000100100005005706908040018400374003738115063874110100200100082003002440037400371110201100991001001000010000038000000710121622394790100001004003840038400384003840038
10204400373000000002513940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038
1020440037300000000613940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038
1020440037300000000613940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038
1020440037300000000613940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038
1020440037299000000613940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038
1020440037299000000613940725101001001000010010000500570690804001840037400373810803387451010020010000200300004003740037111020110099100100100001000000000000710121622394790100001004003840038400384003840038

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0037

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)9fa6a8acc2branch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100244003729900061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000000640216223947310000104003840038400384003840038
100244003731011061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001006000640216223947310000104003840038400384003840038
100244003729900061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003721100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057074391400184003740037381303387671001020100002030000400374008411100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000000640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000000640216323947310000104003840038400384003840038
1002440037300000726394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001001000640216223947310000104003840038400384003840038

Test 3: Latency 1->3

Code:

  fmsub h0, h1, h0, h2
  movi v0.16b, 1
  movi v1.16b, 2
  movi v2.16b, 3

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 4.0037

retire (01)cycle (02)0318191e1f3a3f4e51inst 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)9fa8a9acc2cfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204400373000234288061394072510100100100001001000050057069081400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710021622394790100001004003840038400384003840038
10204400373000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121632394790100001004003840038400384003840038
10204400373000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121622394790100001004003840038400384003840038
10204400373000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121622394790100001004003840038400384003840038
10204400373000000061394072510100100100001001000050057069081400184003740037381083387451010020010000200300004003740037111020110099100100100001000004712121622394790100001004003840038400384003840038
10204400372990000061394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121623394790100001004003840038400384003840038
102044003730000000968394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710131622394790100001004003840038400384003840038
10204400372990000061394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121622394790100001004003840038400384003840038
10204400372990060061394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121622394790100001004003840038400384003840038
10204400372990000061394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000000710121622394790100001004003840038400384003840038

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0037

retire (01)cycle (02)03080b1e3f4e51inst 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)9fa1a8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316333947310000104003840038400384003840038
100244003730000072639407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000102000640316333947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316333947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100400640416333947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316333947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316333947310000104003840038400384003840038
10024400372990006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316343947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316233947310000104003840038400384003840038
10024400372990006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316433947310000104003840038400384003840038
10024400373000006139407251001010100001010000505706908140018400374003738130338767100102010000203000040037400371110021109101010000100000640316333947310000104003840038400384003840038

Test 4: Latency 1->4

Code:

  fmsub h0, h1, h2, h0
  movi v0.16b, 1
  movi v1.16b, 2
  movi v2.16b, 3

(fused SUBS/B.cc loop)

100 unrolls and 100 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)9fa8acbranch mispredict (cb)cfd0d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102044003730000613940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071202162239479100001004003840038400384003840038
102044003730000613940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071002162239479100001004003840038400384003840038
102044003730000613940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071002162239479100001004003840038400384003840038
1020440037300006139407251010010010000100100005005706908040018400374003738108338745101002001000020030000400374003711102011009910010010000100099071012162239479100001004003840038400384003840038
10204400373000082394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000177071012162239479100001004003840038400384003840038
10204400373000061394072510100100100001001000050057069080400184003740037381083387451010020010000200300004003740037111020110099100100100001000168071012162239479100001004003840038400384003840038
102044003730000613940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071012162239479100001004003840038400384003840038
102044003730000613940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071012162239479100001004003840038400384003840038
102044003730000813940725101001001000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071012163239479100001004003840038400384003840038
102044003730000613940725101001171000010010000500570690804001840037400373810833874510100200100002003000040037400371110201100991001001000010000071012162239479100001004003840038400384003840038

1000 unrolls and 10 iterations

Result (median cycles for code): 4.0037

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)9fa0a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100244003730000061394072510010101000010100006157069081400184003740037381303387671001020100002030000400374003711100211091010100001000840640216223947310000104003840038400384003840038
100244003729900061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000600640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000750640216253947310000104013440133400864008540038
100244003729912061394072510010101001212101485057069081400884003740037381303387671001020100002030000400374003711100211091010100001000600684232243947310000104003840038400384003840038
10024400372990006139407251001010100001010000505706908140018400374003738144338767100102010000203000040037400371110021109101010000100160640216223947310000104003840038400384003840038
100244008430000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000630640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000240640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069081400184003740037381303387671001020100002030000400374003711100211091010100001000480640216223947310000104003840038400384003840038
100244003730000061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000690640216223947310000104003840038400384003840038
100244003729900061394072510010101000010100005057069080400184003740037381303387671001020100002030000400374003711100211091010100001000782640216223947310000104003840038400384003840085

Test 5: throughput

Count: 8

Code:

  fmsub h0, h8, h9, h10
  fmsub h1, h8, h9, h10
  fmsub h2, h8, h9, h10
  fmsub h3, h8, h9, h10
  fmsub h4, h8, h9, h10
  fmsub h5, h8, h9, h10
  fmsub h6, h8, h9, h10
  fmsub h7, h8, h9, h10
  movi v8.16b, 9
  movi v9.16b, 10
  movi v10.16b, 11

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

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

retire (01)cycle (02)03090b18191e1f3f51inst 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)9fa0a1a8a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420049150200000468125801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511021611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000006511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511011611200370800001002004120041200412004120041
802042004015000000042258010010080000100800005006400002002120040200409973399988010020080000200240000200402004011802011009910010080000100001090511011611200370800001002004120041200412004120041
80204200401510000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000100511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000000511011611200370800001002004120041200412004120041
80204200401500000004225801001008000010080000500640000200212004020040997339998801002008000020024000020040200401180201100991001008000010000200511011611200370800001002004120041200412004120041

1000 unrolls and 10 iterations

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

retire (01)cycle (02)031e1f3f51inst 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)9fa8a9acc5cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242004015030412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001000005020171617142003780000102004120041200412004120041
800242004015500412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001000905020141617102003780000102004120041200412004120041
800242004015000242258001010800001080000506400001200210200402004099963100208001020800002024000020040200401180021109101080000100000502014161792003780000102004120041200412004120041
80024200401500051625800101080000108000050640000120021020040200409996310020800102080000202400002004020040118002110910108000010120905020161614172003780000102004120041200412004120041
800242004015000412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001000005020171614172003780000102004120041200412004120041
8002420040150004125800101080000108000050640000120021020040200409996310020800102080000202400002004020040118002110910108000010560305020171617172003780000102004120041200412004120041
80024200401500069258001010800001080000506400001200210200402004099963100208001020800002024000020040200401180021109101080000100000502017168172003780000102004120041200412004120041
800242004015000412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001017017705020161616172003780000102004120041200412004120041
800242004015000412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001000005020151616172003780000102004120041200412004120041
800242004015000412580010108000010800005064000012002102004020040999631002080010208000020240000200402004011800211091010800001000305020171617132003780000102004120041200412004120041