Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTZS (scalar, integer, D to D)

Test 1: uops

Code:

  fcvtzs d0, d0
  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)03090b1e3f4e51inst 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)a8accfd5d6d9ddinst fetch restart (de)e0ea? fp/simd (ee)f5f6f7f8fd
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007331602326290100030383038303830383038
100430372300961254725100010001000398160301830373037241332895100010001000303730371110011000007321603326260100030383038303830383038
100430372300061254725100010001000398160301830373037241332895100010001000303730371110011000107321602226290100030383038303830383038
100430372400061254725100010001000398160301830373037241432895100010001000303730371110011000107321602326640100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007531602226290100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007321602226260100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007321602326260100030383038303830383038
10043037230012187254725100010001000398160301830373037241432895100010001000303730371110011000007321602226290100030383038303830383038
100430372400061254725100010001000398160301830373037241432895100010001000303730371110011000007321602226290100030383038303830383038
100430372300061254725100010001000398160301830373037241432895100010001000303730371110011000007321603226260100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtzs d0, d0
  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)03071e3a3f4e51inst 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)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)9fa8accfd5d6daddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020430037225000371295472510100100100001001000062642771601300180300373003728264032874510100200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
1020430037225000191295472510125100100001001000050042771601300180300373003728264032874510125200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
102043003722500084295472510100100100001001000050042771601300180300373003728264732874510100200100002001000030037300371110201100991001001000010003710116011296330100001003003830038300383003830038
102043003722400084295472510100100100001001000050042771601300180300373003728264032874510100200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
102043003722500061295472510100100100001001000050042771601300180300373003728264032874510100200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
10204300372250001492954725101251001000012510000500427716013001803003730037282640328745101002001000020010000300373003711102011009910010010000100107101160112963325100001003003830038300383003830038
102043003722400084295472510100100100001001000050042771601300180300373003728264032874510100200100002001000030037300371110201100991001001000010000712116011296330100001003003830038300383003830038
102043003722500084295472510100100100001001000050042771601300180300373003728264032874510125200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
1020430037225000168295474410130100100001001000050042771600300180300373003728264032874510252200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038
1020430037224000797295472510100100100001251000062642771600300180300373003728264032874510100200100002001000030037300371110201100991001001000010000710116011296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03191e1f3f4e51inst 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)9fa6a8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372240006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722510886129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500025129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722400025129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216252962910000103003830038300383003830038
10024300372250006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500015629547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722500072629547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216232962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtzs d0, d8
  fcvtzs d1, d8
  fcvtzs d2, d8
  fcvtzs d3, d8
  fcvtzs d4, d8
  fcvtzs d5, d8
  fcvtzs d6, d8
  fcvtzs d7, d8
  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)9fa0a6a8acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200391560005125801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151181160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915501203025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391560003025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000010011151180160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391610003025801081008000810080020500640132020020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550003025801081008000810080020500640132120020200392003999770699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040

1000 unrolls and 10 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)9fa0a1a6a8a9acc2cfd5d6d9ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242003915500000103258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010000000050201276112003680000102004020040200402004020040
80024200391550000068258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201160112003680000102004020040200402004020040
800242003915500048040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201162112003680000102004020040200402004020040
800242003915500000705258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201160112003680000102004020040200402004020040
80024200391550000040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010000000050201160112003680000102004020040200402004020040
80024200391550000040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000600050201160112003680000102004020040200402004020040
800242003915500012040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201162112003680000102004020040200402004020040
80024200391650000040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010000003050201160112003680000102004020040200402004020040
80024200391550000040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201160112003680000102004020040200402004020040
80024200391560000040378001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010000000050201160112003680000102004020040200402004020040