Apple Microarchitecture Research by Dougall Johnson

M1/A14 P-core (Firestorm): Overview | Base Instructions | SIMD and FP Instructions
M1/A14 E-core (Icestorm):  Overview | Base Instructions | SIMD and FP Instructions

FCVTAU (scalar, H to H)

Test 1: uops

Code:

  fcvtau h0, h0
  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 uop (01)cycle (02)03181e1f3f4e51schedule uop (52)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map simd uop (7e)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd alu (9a)l1d tlb access (a0)st unit uop (a7)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303724000612547251000100010003981601301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
10043037230906125472510001000100039816013018303730372414328951000100010003037303711100110000004573116112629100030383038303830383038
1004303724000752547251000100010003981601301830373037241432895100010001000303730371110011000003373116112629100030383038303830383038
100430372301802512547251000100010003981600301830373037241432895100010001000303730371110011000000673116112629100030383038303830383038
1004303724060612547251000100010003981600301830373037241432895100010001000303730371110011000005073116112629100030383038303830383038
1004303724000612547251000100010003981600301830373037241432895100010001000303730371110011000008073116112629100030383038303830383038
1004303724000612547251000100010003981600301830373037241432895100010001000303730371110011000000373116112629100030383038303830383038
10043037240006125472510001000100039816003018303730372414328951000100010003037303711100110000001873116112629100030383038303830383038
1004303724000612547251000100010003981600301830373037241432895100010001000303730371110011000200373116112629100030383038303830383038
1004303724000612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtau h0, h0
  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 uop (01)cycle (02)03mmu table walk instruction (07)191e1f3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fld unit uop (a6)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003723200006129547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010020007101161129633100001003003830038300383003830038
1020430037232001206129547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
1020430037233000034029547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010001007101161129633100001003003830038300383003830038
102043003723300006129547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000027101161229633100001003003830038300383003830038
1020430037233001206129547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
102043003723300008429547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000007103161129633100001003003830038300383003830038
1020430037232001206129547251010010010000010010000500427716003001830037300372826432874410100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
102043003723200006129547251010010010000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
102043003723200006129547251010010010000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038
102043003723310006129547251010012510000010010000500427716013001830037300372826432874510100200103292001000030037300371110201100991001001000010000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)1e3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d tlb access (a0)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372240049729547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640316222962910000103003830038300383003830038
10024300372250038229547251001010100001010000504277160130018300373008528286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372240014529547251001010100001010000504277160130018301813003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
100243003722509316629547251001010100001010000504277160130018300373003728286328805100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225063223329547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103008430038300383003830038
1002430037225008429547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250014929547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225006129547251001012100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
10024300372250017029547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtau h0, h8
  fcvtau h1, h8
  fcvtau h2, h8
  fcvtau h3, h8
  fcvtau h4, h8
  fcvtau h5, h8
  fcvtau h6, h8
  fcvtau h7, h8
  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 uop (01)cycle (02)03mmu table walk instruction (07)1e3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfmap dispatch bubble (d6)dde0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200591550060025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
80204200391610022625801081008000810080024500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155003025801081008010810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511837020036800001002004020040200402004020040
8020420039155063025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039156003025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155037225801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040
8020420039155103025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511816020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03191e3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)accfd0d2d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8002420039155004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502009316112003680000102004020040200402004020040
800242003915500166258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020011216112003680000102004020040200402004020040
80024200391550040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020011116112003680000102004020040200402004020040
8002420039155012705258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020011116112003680000102004020040200402004020040
80024200871550640258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010035020010216112003680000102004020040200402004020040
80024200391610040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010035020010216112003680000102004020040200402004020040
80024200391550040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020010116112003680000102004020040200402004020040
800242003915501240258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020010316112003680000102004020040200402004020040
80024200391550040258001010800001080000506407561200202003920039999631001980010208000020800002003920039118002110910108000010005020010116222003680000102004020040200402004020040
80024200391550082258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010005020010116112003680000102004020040200402004020040