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

SCVTF (vector, integer, 4H from 4H)

Test 1: uops

Code:

  scvtf 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 uop (01)cycle (02)0318191e3f4e51schedule 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)ld unit uop (a6)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372200121032547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
10043037230012612547251000100010003981601301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
10043037230012612547251000100010003981600301830373037241432895100010001000303730371110011000001073116112629100030383038303830383038
10043037220012612547251000100010003981600301830373037241432895100010001000303730371110011000000373116112629100030383038303830383038
1004303723000612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
10043037220012612547251000100010003981600301830373037241432895100010001000303730371110011000901073116112629100030383038303830383038
1004303722000612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372300151032547251000100010003981600301830373037241432895100010001000303730371110011000001073116112629100030383038303830383038
10043037220001032547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
1004303723000612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf 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 uop (01)cycle (02)031e3f4e51schedule 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)9fld unit uop (a6)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037225123103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000137101161129633100001003003830038300383003830038
1020430037225459103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000137101161129633100001003003830038300383003830038
1020430037225297103295472510100100100001001000050042771601300183003730037282648287451010020010000200100003003730037111020110099100100100001002037101161129633100001003003830038300383003830038
10204300372251144011295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000107101161129633100001003003830038300383003830038
1020430037225255103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000007101161129633100001003003830038300383003830038
102043003722531261295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000137101161129633100001003003830038300383003830038
10204300372250103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000007101161129633100001003003830038300383003830038
102043003722530061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000107101161129633100001003003830038300383003830038
1020430037225361295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000007101161129633100001003003830038300383003830038
1020430037225961295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)18191e1f3f4e51schedule 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 tlb miss (a1)ld unit uop (a6)st unit uop (a7)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)eb? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000000064031622296290010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010163201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
1002430037225000085808429547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
100243003722500000025129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000000064021622296290010000103003830038300383003830038
10024300372250000006129475170100891410072131135010342879761303063046330462283134328936113632411484221148530461304671011002110910101000010003002235832832310143299534010000103045630463304633049930480
10024304642280091013208806129547251003710100481811411764290603130378301793046128326192893611518281156724114953046330462101100211091010100001022211227833481027233299712010000103051230509303213046330514

Test 3: throughput

Count: 8

Code:

  scvtf v0.4h, v8.4h
  scvtf v1.4h, v8.4h
  scvtf v2.4h, v8.4h
  scvtf v3.4h, v8.4h
  scvtf v4.4h, v8.4h
  scvtf v5.4h, v8.4h
  scvtf v6.4h, v8.4h
  scvtf 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 uop (01)cycle (02)031e1f3f51schedule 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 miss (a1)ld unit uop (a6)l1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204200581500030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001011151181160020036800001002004020040200402004020040
80204200391500030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001011151180160020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000035011151180160020036800001002004020040200402004020040
8020420039150003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000436611151180160020036800001002004020040200402004020040
802042003915000302580108100802081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000029011151180160020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000033311151180160020036800001002004020040200402004020040
8020420039150006952580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000030311151180160020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000040311151180160020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000028311151180160020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000044511151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)0318191e1f3a3f51schedule 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)696d6emap 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)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8002420050150001200402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001005020416342003680000102004020040200402004020040
8002420039150001200402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000035020316532003680000102004020040200402004020040
8002420039150001200402580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001035020516332003680000102004020040200402004020040
800242003915000000822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001035020416452003680000102004020040200402004020040
8002420039150001200822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001035020416332003680000102004020040200402004020040
8002420039150001200822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000035020316352003680000102004020040200402004020040
800242003915000000822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001005020416442003680000102004020040200402004020040
800242003915000000822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001000035020416432003680000102004020040200402004020040
8002420039150001200822580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001035020416342008680000102004020040200402004020040
8002420039150006007012580010108000010800005064000020020200392003999963100198001020800002080000200392003911800211091010800001001005020416422003680000102004020040200402004020040