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

LD1 (multiple, post-index, 4 regs, 2S)

Test 1: uops

Code:

  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop ; nop
  mov x0, 1
  mov x1, 2
  mov x8, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 4.000

Issues: 5.000

Integer unit issues: 1.001

Load/store unit issues: 4.000

SIMD/FP unit issues: 0.000

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule ldst uop (55)dispatch int uop (56)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)dispatch uop (78)map ldst uop (7d)map ldst uop inputs (80)? int output thing (e9)? ldst retires (ed)
64005297685011100340081002400030001200050004000500010014000
64004295195001100140001000400030001200050004000500010014000
64004296945001100140001000400030001200050004000500010014000
64004295195001100140001000400030001200050004000500010014000
64004295165001100140001000400030001200050004000500010014000
64004295575001100140001000400030001200050004000500010014000
64004295385001100140001000400030001200050004000500010014000
64004295455001100140001000400030001200050004000500010014000
64004295495001100140001000400030001200050004000500010014000
64004295115001100140001000400030001200050004000500010014000

Test 2: throughput

Count: 8

Code:

  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  ld1 { v0.2s, v1.2s, v2.2s, v3.2s }, [x6], x8
  mov x7, x6
  mov x8, x6
  mov x9, x6
  mov x10, x6
  mov x11, x6
  mov x12, x6
  mov x13, x6
  mov x8, 0

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 2.0007

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule ldst uop (55)dispatch int uop (56)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)dispatch uop (78)map int uop (7c)map ldst uop (7d)map int uop inputs (7f)map ldst uop inputs (80)? int output thing (e9)? ldst retires (ed)? int retires (ef)
3202051601564001468011632003080116320010240309136024840011320032001620040002080003320000100
3202041600654001098010332000680103320010240309256024240011320032001620040002080003320000100
3202041600584001038010332000080103320058240348256552440017420032007220040002080003320000100
3202041600584001038010332000080103320010240309256026040011320032001620040002080003320000100
3202041600584001038010332000080103320010240309256026040011320032001620040002080003320000100
3202041600584001048010332000180103320010240309256026040011320032001620040002080003320000100
3202051601044001528011632003680116320010240309256026040011320032001620040002080003320000100
3202041600584001038010332000080103320010240309256026040011320032001620040002080003320000100
3202041600584001038010332000080103320010240309256026040011320032001620040002080003320000100
3202041600584001038010332000080103320010240309256026040011320032001620040002080003320000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 2.0007

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule ldst uop (55)dispatch int uop (56)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)dispatch uop (78)map int uop (7c)map ldst uop (7d)map int uop inputs (7f)map ldst uop inputs (80)? int output thing (e9)? ldst retires (ed)? int retires (ef)
3200251601764000628002632003680026320000240030144021840001020320000204000008000132000010
3200241600544000118001132000080010320058240078206776240008420320072204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200251601194000568002632003080026320000240030256021840001020320000204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200241600544000118001132000080010320000240030256021840001020320000204000008000132000010
3200251604004000568002632003080026320000240030256021840001020320000204000008000132000010