Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTZS (vector, integer, 4H)

Test 1: uops

Code:

  fcvtzs v0.4h, v0.4h
  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)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
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306225472510081000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723010325472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724010325472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372468425472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtzs v0.4h, v0.4h
  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)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)9fa8acbbc5cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037233061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000219307101161129633100001003003830038300383003830038
1020430037233061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000156007101161129633100001003003830038300383003830038
1020430037232061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000150007101161129633100001003003830038300383003830038
102043003723306129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100015007101161129633100001003003830038300383003830038
1020430037233061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001001129007101161129633100001003003830038300383003830038
1020430037233061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000159007101161129633100001003003830038300383003830038
1020430037233061295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000117007101161129633100001003003830038300383003830038
1020430037233061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000126007101161129633100001003003830038300383003830038
10204300372330726295472510100100100001001000050042771600300183003730037282643287451010020010000200100003003730037111020110099100100100001000117007101161129633100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03183f4e51inst 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)9faccfd5d6ddinst fetch restart (de)dfe0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006404164502962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405165522962910000103003830038300383003830038
100243003722404322954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405164502962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405165402962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300842828603287671001020100002010000300373003711100211091010100001006405164502962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405165402962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006404164502962910000103003830038300383003830038
10024300372240612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405164502962910000103003830038300383003830038
10024300372330612954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006404165402962910000103003830038300383003830038
100243003722507262954725100101010000101000050427716013001830037300372828603287671001020100002010000300373003711100211091010100001006405165402962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtzs v0.4h, v8.4h
  fcvtzs v1.4h, v8.4h
  fcvtzs v2.4h, v8.4h
  fcvtzs v3.4h, v8.4h
  fcvtzs v4.4h, v8.4h
  fcvtzs v5.4h, v8.4h
  fcvtzs v6.4h, v8.4h
  fcvtzs v7.4h, v8.4h
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

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

retire (01)cycle (02)030818191e1f3f51inst 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)9fa0a1a6a8a9acc2c5branch mispredict (cb)cdcfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)ea? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200581560000030258010810080008100801205006401321200202003920039997769990801202008003220080032200392008911802011009910010080000100000000011151180016002003600800001002004020040200402004020040
80204200391560000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016022003600800001002004020040200402004020040
80204200391550005713230258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002004020040200402004020040
802042003915500000600258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002004020040200402004020040
80204200391550000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002004020040200402004020040
80204200391550000051258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002004020040200402004020088
802042003915500000555258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002005020050200492004920049
80204200491550000064278011610080016100800285006401961200292004820049997699986801282008003820080038200482004811802011009910010080000100000000021151180016012003600800001002004020040200402004020040
802042003916100000184258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100000000011151180016002003600800001002004020040200402004020040
80204200391560000042258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000003011151180016002003600800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03041e1f3f51inst 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)91inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa8acc2branch mispredict (cb)cfitlb miss (d4)d5d6d9daddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200511611001522580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109010108000010033005020023169025252003680000102004020040200402004020040
800242003916100040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110901010800001000005020023258014242003680000102004020040200402004020040
800242003915500082258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110901010800001000005020026166025142003680000102004020040200402004020040
8002420039155000402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109010108000010000050200281610029282003680000102004020040200402004020040
800242003915500040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110901010800001010005020024168124142003680000102004020040200402004020040
800242003915509040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110901010800001000005020028168026162003680000102004020040200402004020040
800242003915500040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110901010800001000005020027167026172003680000102004020040200402004020040
800242003915500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110901010800001000005020027166030142003680000102004020040200402004020040
8002420039155012040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110901010800001000005020026166027162003680000102004020040200402004020040
800242003915500040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110901010800001000005020016166027262003680000102004020040200402004020040