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, 4S)

Test 1: uops

Code:

  fcvtas v0.4s, v0.4s
  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)03mmu table walk instruction (07)l2 tlb miss instruction (0a)191e3f4e51schedule 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
100430372500036125472510001000100039816013018303730372414328951000100010003037303711100110000073216212629100030383038303830383038
1004303726100310325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240002122925472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303725000186125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372500006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372400006125472510001000100039816013018303730372414328951000100010003037303711100110000373124112626100030383038303830383038
1004303724000156125472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
100430372400006225472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724100546125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372300006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtas v0.4s, v0.4s
  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)033f4e51schedule 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)simd prf full (72)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)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722561295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722461295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100107101161129633100001003003830084300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020210000300373003711102011009910010010000100007101161029633100001003003830038300383003830038
102043003722461295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
102043003722561295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038

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)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 access (a0)ld unit uop (a6)l1d cache writeback (a8)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372320612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640316222962910000103003830038300383003830038
100243003723207262954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000100640216222962910000103003830038300383003830038
10024300372330612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
100243003723307262954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
10024300372320612954725100101010000101000050427716003001803008530037282913287671001020100002010000300373003711100211091010100001000030640216222962910000103003830038300383003830038
10024300372330612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
100243003723307262954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
10024300372330822954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
10024300372320612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000000640216222962910000103003830038300383003830038
10024300372330612954725100101010000101000050427716003001803003730037282863287671001020100002010000300373003711100211091010100001000130640216222962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtas v0.4s, v8.4s
  fcvtas v1.4s, v8.4s
  fcvtas v2.4s, v8.4s
  fcvtas v3.4s, v8.4s
  fcvtas v4.4s, v8.4s
  fcvtas v5.4s, v8.4s
  fcvtas v6.4s, v8.4s
  fcvtas v7.4s, v8.4s
  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)0318191e1f3f51schedule 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)cdcfd5map dispatch bubble (d6)dde0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420049156000053258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100031115118116020036800001002004020040200402004020040
8020420039156000051258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
8020420039155000051258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
802042003915500001734258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
8020420039156000030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391550000102258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391550000169258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391550000505258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
8020420039155000030258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040
80204200391550000212258010810080008100800205006401321200202003920039997769990801202008003220080032200392003911802011009910010080000100001115118016020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03l2 tlb miss instruction (0a)191e3f51schedule 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)6061696d6emap 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)accfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)daddfetch restart (de)e0eaebec? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200511560004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000101050205002160112003600080000102004020040200402004020040
80024200391560006125800101080000108000050640000152002020039200399996310019800102080000208000020039200391180021109101080000100050205301160112003600080000102004020040202452004020040
8002420039155000182625800101080000108000050640000152002020039200399996310019800102080000208000020039200391180021109101080000100350205301160112003600080000102004020040200402010020154
800242003915500070525801071080000108000061640000152002020039200399996310019800102080000208000020039200391180021109101080000101050205401160112003600080000102004020040200402004020040
80024200391550006825800101080000108000050640000152002020039200399996310019800102080000208000020039200391180021109101080000102050200401160112003600080000102004020040200402004020040
80024200391550004025800101080000108000050640000152002020039200399996310019800102080000208000020039200391180021109101080000103050205401160112003600080000102004020040200402004020040
8002420039161101819425800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050200001160112003600080000102004020040200402004020040
80024200391560004025800101080000108000050640000102002020039200399996310019800102080000208000020039200391180021109101080000103050200001160112003600080000102004020040200402004020040
80024200391550004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050200001160112003600080000102004020040200402004020040
80024200391560004025800101080000108000050640000102006120039200391000531001980010208000020800002003920039118002110910108000010435020000116011200360023080000102004020040200402004020040