Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTPU (vector, 8H)

Test 1: uops

Code:

  fcvtpu v0.8h, v0.8h
  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)030b18191e3f4e51inst 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)a0a8a9acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372400042612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000003073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240000612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037240009612547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038
10043037230000612547251000100010003981603018303730372414328951000100010003037303711100110000003073116112629100030383038303830383038
100430372300001032547251000100010003981603018303730372414328951000100010003037303711100110000000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtpu v0.8h, v0.8h
  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)030809181e3f4e51inst 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)9fa8cfd5d6ddinst fetch restart (de)e0eb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722400006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611297050100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009910010010000100071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030818191e1f3f4e51inst 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)9fa1a6a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250000061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000000640316332962910000103003830084300863003830038
100243003722400000300295472510020111000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000640316332962910000103003830038300383003830038
10024300372250100061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000640316332962910000103003830038300383003830038
10024300372250000061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000630640316332962910000103003830038300383003830038
100243003723200090520295472510010101000013100005042785120300183003730037282863287671001020100002010000300373003711100211091010100001000430640316332962910000103003830038300383003830038
10024300372250003061295472510010101000010100005042771601300183003730037282863287671001020100002010000300853008511100211091010100001002190661316332962910000103003830085300383003830085
100243003722600012061295472510010101000010100005042771600300183003730037282863287671001022100002010000300373003711100211091010100001000000640316332962910000103003830038300383003830038
10024300372250000061295472510010101000010100005042771600300543003730037282863287671001020100002010000300373003711100211091010100001000000640316332962910000103003830038300383003830038
10024300372250000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000640316332962910000103003830038300383003830038
10024300372250000061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000030640316332962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtpu v0.8h, v8.8h
  fcvtpu v1.8h, v8.8h
  fcvtpu v2.8h, v8.8h
  fcvtpu v3.8h, v8.8h
  fcvtpu v4.8h, v8.8h
  fcvtpu v5.8h, v8.8h
  fcvtpu v6.8h, v8.8h
  fcvtpu v7.8h, v8.8h
  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)03181e1f3f51inst 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)9fa8acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042003915000020025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391500003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391500003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
8020420039150057252119825801081008000810080020500640132020020200392003999770699908012020080032200800322003920195118020110099100100800001000011151180160020036800001002004020040200402004020040
8020420039150012088925801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
802042003915003303025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391500003025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391500005325801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001001011151180160020036800001002004020040200402004020040
80204200391500003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
802042003915000037025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040

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)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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420051150004025800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100050201416372003680000102004020040200402004020040
800242003915000402580010108000010800005064000000200202003920039999631001980010208014020800002003920039118002110910108000010065020316732003680000102004020040200402004020040
8002420039155001522580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002210910108000010005020716732003680000102004020040200402004020040
800242003915000402580010108000010800005064000001200202003920039999631001980010208000020800002003920039118002110910108000010005020416332003680000102004020040200402004020040
800242003915000402580010108000010800005064000001200202003920039999631001980010208000020800002003920039118002110910108000010005020416372003680000102004020040200402004020040
800242003915000402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020416332003680000102004020040200402004020040
800242003915000402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010035020316332003680000102004020040200402004020040
800242003915000402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020316372003680000102004020040200402004020040
800242003915060402580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010005020716732003680000102004020040200402004020040
80024200391572101392580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010135020316332003680000102004020040200402004020040