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, 8H)

Test 1: uops

Code:

  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [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)
64005297165011100340081002400030001200050004000500010014000
64004295125001100140001000400030001200050004000500010014000
64004295125001100140001000400030001200050004000500010014000
64004295095001100140001000400030001200050004000500010014000
64004294905001100140001000400030001200050004000500010014000
64004294945001100140001000400030001200050004000500010014000
64004294925001100140001000400030001200050004000500010014000
64004294965001100140001000400030001200050004000500010014000
64004294955001100140001000400030001200050004000500010014000
64004294915001100140001000400030001200050004000500010014000

Test 2: throughput

Count: 8

Code:

  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld1 { v0.8h, v1.8h, v2.8h, v3.8h }, [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)
3202051602974001468011632003080116320010240309100819440011320032001620040002080003320000100
3202041600554001038010332000080103320010240309113619440011320032001620040002080003320000100
3202051604374001468011632003080116320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320010240309256020640011320032001620040009080016320000100
3202041600554001038010332000080103320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320010240309256020640011320032001620040002080003320000100
3202041600554001038010332000080103320058240348210435840017420032007220040002080003320000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 2.0006

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)
3200251601584000568002632003080026320000240030256016440001020320000204000008000132000010
3200241600514000118001132000080010320000240030256016440001020320000204000008000132000010
3200241600514000118001132000080010320048240069256640040007120320056204000008000132000010
3200241600514000118001132000080010320000240030256016440001020320000204000008000132000010
3200241600514000118001132000080010320000240030256016440001020320000204000008000132000010
3200241605344000118001132000080010320144240147234838040019320320168204000008000132000010
3200251601104000548002432003080023320000240030256016440001020320000204000008000132000010
3200241600514000118001132000080010320240240225182885240031520320280204007008013132000010
3200241612884003988012832027080127320000240030256016440001020320000204000008000132000010
3200251601144000568002632003080026320000240030256016440001020320000204000008000132000010