Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTMU (vector, 2S)

Test 1: uops

Code:

  fcvtmu v0.2s, v0.2s
  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)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
10043037240612547251000100010003981603018303730372414328951000100010003037303711100110000073216112629100030383038303830383038
10043037240612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723121072547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372401032547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230842547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240612547251000100010003981603018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtmu v0.2s, 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): 3.0037

retire (01)cycle (02)03080b191e1f3f4e51inst 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)9fa1a8accdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372330005706129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071021611296330100001003003830038300383003830038
102043003723300093526129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003723200042006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
10204300372320008706129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
10204300372320003006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003723300032108929547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003723300093526129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003723300026706129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003723300023706129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100006071011611296330100001003003830038300383003830038
10204300372320002106129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)031e1f3f4e51inst 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
100243003723200726295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640316222962910000103003830038300383003830038
10024300372330061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
1002430037233006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100064022422296291000013833003830038300863003830038
10024300372410061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
100243003723300103295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
100243003723312061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372320061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372330061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372330089295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038
10024300372330061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtmu v0.2s, v8.2s
  fcvtmu v1.2s, v8.2s
  fcvtmu v2.2s, v8.2s
  fcvtmu v3.2s, v8.2s
  fcvtmu v4.2s, v8.2s
  fcvtmu v5.2s, v8.2s
  fcvtmu v6.2s, v8.2s
  fcvtmu v7.2s, v8.2s
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2506

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)9fa8acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0ec? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042006116100363025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801610200360800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
802042003915520123025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
802042003915500012525801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010003111511801600200360800001002004020040200402004020040
80204200391560003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010013111511801600200360800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
80204200391610003025801081008000810080020500640132020020200392003999776999080338200800322008014120092200391180201100991001008000010000111511801600200360800001002004020040200402004020040
802042003915500961125801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
80204200391550007225801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03191e3f51inst 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)9fa8acc5cdcficache miss (d3)d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200391560364025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020016161772003680000102004020040200402004020040
800242003915609402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100000502008166172003680000102004020040200402004020040
800242003915500402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100000502008167172003680000102004020040200402004020040
800242003915506402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000100000502008161782003680000102004020040200402004020040
8002420039155064025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020017161572003680000102004020040200402004020040
8002420039161094025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020017161762003680000102004020040200402004020040
8002420039156004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020017166172003680000102004020040200402004020040
80024200391550340258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010000050200171616162003680000102004020040200402004020040
8002420039155004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020014161782003680000102004020040200402004020040
8002420039156004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020017168172003680000102004020040200402004020040