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

SXTW

Test 1: uops

Code:

  sxtw x0, x0
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 1.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 0.000

retire uop (01)cycle (02)031e3f4d5051schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)606d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst int alu (97)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
10041035706186210192510001000100016916010351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035706186210192510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035806186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035706186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035808286202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035706186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035806186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035806186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035706186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036
10041035706186202510001000100016916110351035728386810001000100010354111100110000073141119371000100010361036103610361036

Test 2: Latency 1->2

Code:

  sxtw x0, x0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 1.0035

retire uop (01)cycle (02)031e3f4d51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)60696a6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9faccfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
1020410035756619877251010010100101008866404969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866404969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866404969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071023711994110000101001003610036100361003610036
1020410035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035760619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020410035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036
1020510035750619877251010010100101008866414969551003510035858038722101001020010200100354111102011009910010100100071013711994110000101001003610036100361003610036

1000 unrolls and 10 iterations

Result (median cycles for code): 1.0035

retire uop (01)cycle (02)03091e3f4d51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)60696a6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9fl1d tlb miss (a1)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
10024100357500829863251001010010100108878414969551003510035860238740100101002010020100354111100211091010010100010264034122994010000100101003610036100361003610036
100241003575006198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
100241003575006198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
100241003576006198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
1002410035750061986325100101001010010887841496955100351003586023874010010100201002010035411110021109101001010015064024122994010000100101003610036100361003610036
100241003575006198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
100241003575008298632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
100241003575006198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
1002410035750029198632510010100101001088784149695510035100358602387401001010020100201003541111002110910100101000064024122994010000100101003610036100361003610036
1002410035750061986325100101001010010887841496955100351003586023874010010100201002010035411110021109101001010011064024122994010000100101003610036100361003610036

Test 3: throughput

Count: 8

Code:

  sxtw x0, x8
  sxtw x1, x8
  sxtw x2, x8
  sxtw x3, x8
  sxtw x4, x8
  sxtw x5, x8
  sxtw x6, x8
  sxtw x7, x8
  mov x8, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.1674

retire uop (01)cycle (02)03191e3f51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)60696a6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9fl1d cache writeback (a8)branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfmap dispatch bubble (d6)fetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
8020413413100002827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
80204133901000272827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100111151191601338780036801001345113391133911345513391
8020413390100002827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191621338780036801001339113391133911339113454
802041339010104232827801368013680277400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
802041339010001825927801368013680148400710149103101345013390332663336801488038780264133903911802011009910080100100011151191601338780036801001339113391133911339113391
8020413390100002827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
8020413390100002827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
80204133901010122827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
802041339010012162827801368013680149400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391
8020413390101002827801368013680148400710149103101339013390332663336801488026480264133903911802011009910080100100011151191601338780036801001339113391133911339113391

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.1671

retire uop (01)cycle (02)03mmu table walk data (08)l2 tlb miss data (0b)1e3f51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)60696a6d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map int uop inputs (7f)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)9fl1d tlb access (a0)l1d tlb miss (a1)l1d cache writeback (a8)a9accdcfl1i cache miss demand (d3)d5map dispatch bubble (d6)daddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
8002413390100000982580010800108001040005014910291133711337133303334880010800208002013371391180021109108001010000000502001196111336880000800101337213372133721337213372
8002413371100000352580010800108001040005014910291133711337133303334880010800208002013371391180021109108001010200000502001196111336880000800101337213372133721337213372
8002413371100000588080010800108001040005014910291133711337133303334880010800208002013371391180021109108001010000000502001195111336880000800101337213372133721337213372
8002413371100000352580010800108001040005014910291133711337133303334880010800208002013371391180021109108001010000001502001195111336880000800101337213372133721337213372
8002413371100000352580010800108001040005004910291133711337133303334880010800208002013371391180021109108001010000000502001195111336880000800101337213372133721337213372
8002413371100000562580010800108001040005004910291133711337133303334880010800208002013371391180021109108001010000030502001195111336880000800101337213372133721337213372
8002413371100000352580010800108001040005004910291133711337133303334880010800208002013371391180021109108001010000000502001195111336880000800101337213372133721337213372
800241337110100032025800108001080010400050049102911337113371333033348800108002080020133713911800211091080010100011000502001195111336880000800101337213372133721337213372
8002413371100000352580010800108001040005014910291133711337133303334880010800208002013371391180021109108001010000030502001195111336880000800101337213372133721337213372
8002413371100000352580010800108001040005014910291133711337133303334880010800208002013371391180021109108001010000000502001195111336880000800101337213372133721337213372