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

FCVT (S to D)

Test 1: uops

Code:

  fcvt d0, 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)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)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073216112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372396125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303722025125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372396125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013022303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvt d0, 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)0309l2 tlb miss data (0b)1e3a3f4e51schedule 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)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 tlb miss (a1)l1d cache writeback (a8)a9accfd2d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373008411102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002041000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722400006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129703100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003721102011009910010010000100000071001161129701100001003003830038300383003830038
102043003722500006129547251010010010000100100005004277160300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071001161129633100001003003830038300383003830038

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)acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003722400000061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000000326403162229629010000103003830038300383003830038
10024300372250000906129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300372110021109101010000100000203606402162229629010000103003830038300383003830038
10024300372240000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000010506402162229629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000306402162229629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000606402162229629010000103003830038300383003830038
100243003722500000061295472510010101000010100005542771601300183003730037282863287671001020100002010000300373003711100211091010100001000000006682162229629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000006402162229629010000103003830038300383003830038
100243003722400000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000000606402162229629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000000306402162229629010000103003830038300383003830038
1002430037225000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000017006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvt d0, s8
  fcvt d1, s8
  fcvt d2, s8
  fcvt d3, s8
  fcvt d4, s8
  fcvt d5, s8
  fcvt d6, s8
  fcvt d7, 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)033f51schedule 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)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)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420059151302580108100800081008002050064013220020200392003999770699908012020080032200800322003920039118020110099100100800001000611151181160020036800001002004020040200402004020040
8020420039150302580108100800081008002050064013220020201402003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
8020420039150302580108100800081008002050064013220020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
802042003915010425801081008000810080020500640132200202003920039997776999080120200800322008003220039200391180201100991001008000010001811151180160020036800001002004020040200402004020040
80204200391503025801081008000810080020500640132200202003920039997706999080120200800322008003220039200391180201100991001008000010002411151180160020036800001002004020040200402004020040
802042003915030258010810080008100800205006401322002020039200399977069990801202008003220080032200392003911802011009910010080000100025511151180160020036800001002004020040200402004020040
8020420039150302580108100800081008002050064342820020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
8020420039150302580108100800081008002050064013220020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391503025801081008000810080020500640132200202003920039997706999080120200800322008003220039200391180201100991001008000010001211151180160020036800001002004020040200402004020040
8020420039150302580108100800081008002050064013220020200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160120036800001002004020040200402004020040

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)9faccfd2d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200511510402580010108000010800005064000002002020039200399996310019800102080000208000020039200391180021109101080000101250200141614142003680000102004020040200402004020040
8002420039150040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010050205121612102003680000102004020040200402004020040
800242003915054344192580010108000010800005064000002002420039200391000631001980010208000020800002003920039118002110910108000010050200131611142003680000102011420040201122010020040
8002420039150244025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001011150200161614122003680000102004020040200402004020040
8002420039150040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050200131613152003680000102004020040200402004020040
800242003915004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001035020091617132003680000102004020040200402004020040
8002420039150040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010050200131614142003680000102004020040200402004020040
8002420039150040258001010800001080000506416561200202003920039999631001980010208000020800002003920039118002110910108000010050200131615162003680000102004020040200402004020040
8002420039150940258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050200161616132003680000102004020040200402004020040
8002420039150040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050200151614122003680000102004020040200402004020040