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

FCVTAS (scalar, S to S)

Test 1: uops

Code:

  fcvtas s0, s0
  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)03181e3f4e51schedule 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 cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
10043037230010325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372301210625472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
1004303724008425472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230010325472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230010325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230010325472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
10043037240010325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtas s0, s0
  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)03l2 tlb miss data (0b)18191e3f4e51schedule 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)91inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d tlb access (a0)l1d tlb miss (a1)ld unit uop (a6)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ec? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037232000306129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
1020430037232000456129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
102043003723300006129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
1020430037233000336129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
1020430037233000666129547251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009901001001000010000200710216222963300100001003003830038300383003830038
1020430037232000246129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
10204300372320004206129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000003710216222963300100001003003830038300383003830038
1020430037232000336129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
1020430037233000666129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000000710216222963300100001003003830038300383003830038
1020430037232000636129547251010010010000100100005004277160130018300373003728264328745101002001000020010000300373003711102011009901001001000010000003710216222963300100001003003830038300383003830038

1000 unrolls and 10 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)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003722537262954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402162229629210000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402162229629010000103003830038300383003830038
10024300372250662954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010736402162229661010000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010221000020100003003730037111002110910101000010006402162229629010000103003830038300383003830038
10024300372240612954725100101010000101000061427716003001830037300372828632876710010201000020100003003730037111002110910101000010006682162229629010000103003830038300383003830038
10024300372320822954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402161229629010000103003830038300383003830038
100243003722505932954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402162229629010000103003830038300383003830038
100243003722501492954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402162229629010000103003830038300383003830038
10024300842240612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402163229629010000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtas s0, s8
  fcvtas s1, s8
  fcvtas s2, s8
  fcvtas s3, s8
  fcvtas s4, s8
  fcvtas s5, s8
  fcvtas s6, s8
  fcvtas s7, s8
  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 access (a0)st unit uop (a7)l1d cache writeback (a8)acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420061155300302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000003011151180160020036800001002004020040200402004020040
8020420039155603025801081008000810080020500640132020020200392003999779100158012020080032200800322003920039118020110099100100800001000013011151180160020036800001002004020040200402004020040
8020420039155330302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915530302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000010011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e3f51schedule 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)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242004015504025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020516432003680000102004020040200402004020040
800242003915504025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020416442003680000102004020040200402004020050
8002420039155214025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000005020416442003680000102004020040200402004020040
80024200391551959625800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020416442003680000102004020040200402004020040
8002420039161814025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020316432003680000102004020040200402004020040
800242003915504025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020316342003680000102004020040200402004020040
800242003916104025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020316432003680000102004020040200402004020040
800242003915604025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020416442003680000102004020040200402004020040
800242003915504025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000005020616442003680000102004020040200402004020040
8002420039155158225800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000305020416342003680000102004020040200402004020040