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

RBIT (32-bit)

Test 1: uops

Code:

  rbit w0, w0
  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)03mmu table walk data (08)1e3f4d51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)6d6emap 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
1004103570061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103570061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103570061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103580061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103570061862251000100010001691610351035728386810001000100010354111100110001073141119371000100010361036103610361036
1004103570061862251000100010001691610351035728386810001000100010354111100110001073141119371000100010361036103610361036
1004103580061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103580061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103580061862251000100010001691610351035728386810001000100010354111100110000073141119371000100010361036103610361036
1004103570061862251000100010001691610351035728386810001000100010354111100110001073141119371000100010361036103610361036

Test 2: Latency 1->2

Code:

  rbit w0, w0
  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)03mmu table walk instruction (07)l2 tlb miss data (0b)181e3f4d51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)696a6d6emap 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)9fld unit uop (a6)l1d cache writeback (a8)a9accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
1020410035750000103987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
1020410035760000619877251010010100101008866449695510035100358580387221010010200102001003541111020110099100101001000000710137111000910000101001003610036100361003610036
102041003575000082987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
1020410035750000145987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
102041003575000061987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
1020410035750000166987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
1020410035750001861987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
102041003575000061987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
102041003575000061987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036
102041003575000061987725101001010010100886644969551003510035858038722101001020010200100354111102011009910010100100000071013711994110000101001003610036100361003610036

1000 unrolls and 10 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)696a6d6emap 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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
100241003575061986368100101001010010927914969551003510035860238740100101002010020100354111100211091010010101364024122994010000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
1002410035750619863251001010010100108878449695510035100358602387401001010020100201003541111002110910100101000640241221000810000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
1002410035750187986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
100241003575061986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036
1002410035750103986325100101001010010887844969551003510035860238740100101002010020100354111100211091010010100064024122994010000100101003610036100361003610036

Test 3: throughput

Count: 8

Code:

  rbit w0, w8
  rbit w1, w8
  rbit w2, w8
  rbit w3, w8
  rbit w4, w8
  rbit w5, w8
  rbit w6, w8
  rbit w7, w8
  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)031e3f51schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)696a6d6emap 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 cache writeback (a8)branch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfmap dispatch bubble (d6)dde0? int output thing (e9)? int retires (ef)f5f6f7f8fd
80204134151002463127801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
80204133901002762827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010002827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010102827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001002011151191601338780036801001339113391133911339113391
802041339010092827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
8020413390100013727801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010002848801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010002827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010002827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391
802041339010002827801368013680148400710491031013390133903326633368014880264802641339039118020110099100801001000011151191601338780036801001339113391133911339113391

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)031e3f51schedule 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)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? int retires (ef)f5f6f7f8fd
80024133901000982580010800108001040005014910291133711337133303333680010800208002013371391180021109108001010005020219441336880133800101337213372133721337213372
800241337110004262580010800108001040005014910291133711337133303333980010800208002013371391180021109108001010005022419431336880000800101337213372133721337213372
800241337110002062580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005020419741336880000800101337213372133721337213372
80024133711000352580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005021419351336880000800101337213372133721337213372
800241337110002982580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005020619441336880000800101337213372133721337213372
800241337110001902580010800108001040005014910291133711337133303334080010800208002013371391180021109108001010005022419431336880000800101337213372133721337213372
80024133711000352580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005020319341336880000800101337213372133721337213372
800241337110002842580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005021419641336880000800101337213372133721337213372
80024133711000562580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005020619471336880000800101337213372133721337213372
80024133711000562580010800108001040005014910291133711337133303334280010800208002013371391180021109108001010005020319431336880000800101337213372133721337213372