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 (scalar, integer, H from H)

Test 1: uops

Code:

  scvtf h0, h0
  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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303722012825472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
100430372206125472510001000100039816003018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
1004303723126125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372306125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723216125472510001000100039816003018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
100430372306125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723126125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372206125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  scvtf h0, h0
  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)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)? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037225000012061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000103071011611296330100001003003830038300383003830038
10204300372250000120103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000100071011611296330100001003003830038300383003830038
1020430037224000012061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000000071011611296330100001003003830038300383003830038
10204300372250000120726295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000000071011611296330100001003003830038300383003830038
1020430037225000030103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000103071011611296330100001003003830038300383003830038
10204300372250000120103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000003071011611296330100001003003830038300383003830038
10204300372250000120103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000103071011611296330100001003003830038300383003830038
102043003722500000061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000003071011611296330100001003003830038300383003830038
10204300372250000120103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000103071011611296330100001003003830038300383003830038
10204300372250000120103295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000100071011611296330100001003003830038300383003830038

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)18191e1f3a3f4e51schedule 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)st unit uop (a7)l1d cache writeback (a8)a9acc2cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003722400000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006403162229629010000103003830038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
1002430037225000000072629547251001010100001010000504277160130054300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000101000006402162229629010000103008330038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100000006402162229629010000103003830038300383003830038
100243003722500000006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100010006402162229629010000103003830038300383003830038
100243003722500000006129547251001910100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000101000006402162229629010000103003830038300383003830038
1002430037225000001760405929484152100721610056131100492428662413023430368303202831434288801106320111572211147303213036971100211091010100001001101966807906164629881410000103036930368303693036830361

Test 3: throughput

Count: 8

Code:

  scvtf h0, h8
  scvtf h1, h8
  scvtf h2, h8
  scvtf h3, h8
  scvtf h4, h8
  scvtf h5, h8
  scvtf h6, h8
  scvtf h7, h8
  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)1e3f51schedule 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)61696d6emap 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)acc2branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420058150012221258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511821600200360800001002004020040200402004020040
8020420039150012181258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
8020420039150012346258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
802042003915000179258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100100111511801600200360800001002004020040200402004020040
8020420039150012356258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100100111511801600200360800001002004020040200402004020040
8020420039150012271258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000111511801600200360800001002004020040200402004020040
802042003915001272258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
8020420039150012307258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
8020420039150012310258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040
8020420039150012135258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100130111511801600200360800001002004020040200402004020040

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)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200511500712258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010005020516442003680000102004020040200402004020040
8002420039150040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010805020316472003680000102004020040200402004020040
8002420039155040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135020316432003680000102004020040200402004020040
8002420039150044302580010108000010800005064000012002020039200399996310019800102080000208000020039200391180021109101080000101605020416642003680000102004020040200402004020040
8002420039150040258001010800001080000506400001200202003920039999671001980010208000020800002003920039118002110910108000010005020748742003680000102004020040200402004020040
800242003915012402580010108000010800005064000012002020039200399996310019800102080000208000020039200391180022109101080000101125020416632003680000102004020040200402004020040
80024200391501240258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010165020716342003680000102004020040200402004020040
80024200391501282258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010235020716672003680000102004020040200402004020040
800242003915012557258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010235020416432003680000102004020040200402004020040
8002420039150061258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010135020716472003680000102004020040200402004020040