Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTZU (vector, fixed-point, 8H)

Test 1: uops

Code:

  fcvtzu v0.8h, v0.8h, #3
  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)03181e3f4e51inst 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
1004303724006125472510001000100039816003018303730372414328951000100010003037303711100110000073316222629100030383038303830383038
1004303723007025472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003085303711100110000073216222629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
10043037240010325472510001000100039816013018303730372414328951000100010003037303711100110000673216222629100030383038303830383038
10043037240010325472510001000100039816013018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110001073216222629100030383038303830383038
1004303724006125472510001000100039816003018303730372414328951000100010003037303711100110000073216222629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110001073216222629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110000073216222629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtzu v0.8h, v0.8h, #3
  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)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)9fa6a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372330612954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037211020110099100100100001000097101161129633100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000137101161129633100001003003830038300383003830038
10204300372320612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129633100001003003830038300383003830038
102043003723312612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000107101161129633100001003003830038300383003830038
10204300372333842954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129705100001003003830038300383003830038
10204300372336612954725101001001000010010600500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129633100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129633100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129633100001003003830038300383003830038
102043003723307262954725101001001000010010000500427716013001803003730037282643287451010020010000200100003003730037111020110099100100100001000007101161129633100001003003830038300383003830038
10204300372330892954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000067101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03071e3f4e51inst 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)9fa8acc5cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100306402162229631010000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300372110021109101010000100006402162229629010000103003830038300383003830038
10024300372251306129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
1002430037225008229547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
10024300372250025129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
1002430037225006129547251001012100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038
10024300372371017829547251001010100001010000604277160130018300373003728286328767100102010000201000030037300371110021109101010000100006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtzu v0.8h, v8.8h, #3
  fcvtzu v1.8h, v8.8h, #3
  fcvtzu v2.8h, v8.8h, #3
  fcvtzu v3.8h, v8.8h, #3
  fcvtzu v4.8h, v8.8h, #3
  fcvtzu v5.8h, v8.8h, #3
  fcvtzu v6.8h, v8.8h, #3
  fcvtzu v7.8h, v8.8h, #3
  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)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)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)9fa0a1a8acc5branch mispredict (cb)cdcfd5d6dde0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420039156023025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
8020420039155011425801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010002001115138016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
80204200391550100225801081008000810080020500640788120020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
8020420039156042725801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
8020420039155038725801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020040
802042003915503025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000101115118016020036800001002004020040200402004020040
8020420039155011425801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000101115118016020036800001002004020040200402004020040
8020420039155011525801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000001115118016020036800001002004020040200402004020088

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03080b18191e3f51inst 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)5f60696d6edispatch 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? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242003915500000612580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010002005020316242003680000102004020040200402004020040
800242003915500000822580010108000010804245064000011200202003920039999631001980010208000020800002003920039118002110910108000010426035020316442003680000102004020040200402004020040
8002420039155000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100000365020416422003680000102004020040200402004020040
800242003915600000402580010108000010800005064000011200202003920039999631001980010208000020800002003920039118002110910108000010000065020216242003680000102004020040200402004020040
80024200391550000040258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000001085020216522003680000102004020040200402004020040
800242003915500000402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010000065020416522003680000102004020040200402004020040
800242003915600000402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010000035020416422003680000102004020040200402004020040
8002420039155000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100030005020316252003680000102004020040200402004020040
80024200391550000040258001010800001080000506400000020020200392003999963100198001020800002080000200392003911800211091010800001000280125020416432003680000102004020040200402004020040
8002420039155000004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100033065020216252003680000102004020040200402004020040