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 (vector, 8H)

Test 1: uops

Code:

  fcvtas 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 uop (01)cycle (02)031e3f4e51schedule 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)c2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372396125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372308225472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372506125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372466125472510001000100039816003018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372406125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303721100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtas 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 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)60696b6d6emap 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)l1d cache writeback (a8)a9accdcfd5map dispatch bubble (d6)ddfetch restart (de)e0eb? simd retires (ee)? int retires (ef)f5f6f7f8fd
102053003723201732954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000100071011611296330100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723312612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372320612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
102043003723306312954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000074111611296330100001003003830038300383003830038
10204300372330612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372320612954725101001001000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038
10204300372320612954725101001021000010010000500427716003001803003730037282643287451010020010000200100003003730037111020110099100100100001000000071011611296330100001003003830038300383003830038

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)91inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d tlb access (a0)l1d tlb miss (a1)st unit uop (a7)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640616222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
100243003722501342954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110901010100001000000640216462962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372250612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038
10024300372240612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110901010100001000000640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtas v0.8h, v8.8h
  fcvtas v1.8h, v8.8h
  fcvtas v2.8h, v8.8h
  fcvtas v3.8h, v8.8h
  fcvtas v4.8h, v8.8h
  fcvtas v5.8h, v8.8h
  fcvtas v6.8h, v8.8h
  fcvtas 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 uop (01)cycle (02)03l2 tlb miss data (0b)191e3a3f51schedule 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)ld unit uop (a6)l1d cache writeback (a8)a9acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80204202151551000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402009120040
80204200391560300932580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391560000932580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204201041550000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550000522580108100800081008012550064013212008320039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500120742580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500002542580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391550000762580108100800081008002050064013202002020039200399977699908012020080350200800322003920039218020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500005412580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915500307225801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000302111151180160020036800001002004020040200402004020040

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)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)a9acc2branch mispred nonspec (cb)cfd5map dispatch bubble (d6)ddfetch restart (de)e0ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200391550000014625800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050207163320036080000102004020040200402004020040
80024200391550012009925800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050204163320036080000102004020040200402004020040
80024200391550000010925800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000030050203163320036080000102004020040200402004020040
800242003915500900182025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050204163320036080000102004020040200402004020040
8002420039155000008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203163720036080000102004020040200402004020040
80024200391550000055125800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203164720036080000102004020040200402004020040
80024200391610060064525800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203167420036080000102004020040200402004020040
8002420039155000008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203163320036080000102004020040200402004020040
8002420039155003600171225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000000050203163320036080000102004020040200402004020040
8002420039155000008225800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000030050203163320036080000102004020040200402009120040