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, 4 regs, 16B)

Test 1: uops

Code:

  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  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: 4.000

Integer unit issues: 0.001

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 ldst uop (58)simd uops in schedulers (5a)dispatch uop (78)map ldst uop (7d)map ldst uop inputs (80)? int output thing (e9)? ldst retires (ed)
640053002140091400840001200040004000400014000
640042952640011400040001200040004000400014000
640042959440011400040001200040004000400014000
640042970240011400040001200040004000400014000
640042980240011400040001200040004000400014000
640042967140011400040001200040004000400014000
640042974840011400040001200040004000400014000
640042975040011400040001200440004000400014000
640042969640011400040001200040004000400014000
640042983840011400040001200040004000400014000

Test 2: throughput

Count: 8

Code:

  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  ld1 { v0.16b, v1.16b, v2.16b, v3.16b }, [x6]
  mov x7, x6
  mov x8, x6
  mov x9, x6
  mov x10, x6
  mov x11, x6
  mov x12, x6
  mov x13, x6

(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)
3202051601793201371013200361003200103009921943201102003200162003200721320000100
32020416007232010710132000610032005830025441803201582003200722003200161320000100
32020416006332010110132000010032001030025602603201102003200162003200161320000100
32020416005432010110132000010032001030025603503201102003200162003200161320000100
32020416006032010110132000010032005830020894303201582003200722003200161320000100
32020416005732010110132000010032001030025602063201102003200162003200161320000100
32020416005432010110132000010032001030025602063201102003200162003200161320000100
32020416005732010110132000010032001030019202483201102003200162003200161320000100
32020416006332010110132000010025596167420517032560992642559902003200161320000100
32020416007132010110132000010032001030025602603201102003200162003200161320000100

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)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)? int retires (ef)
32002516017632004711320036103200583025429203200682032007219889338514126886032921810812722
3200241605453201331132012210320000302086878320010203200002032012801320000010
3200241600713200111132000010320000302560326320010203200002032000001320000010
3200241600603200111132000010320000302560218320010203200002032000001320000010
3200241600543200111132000010320000302560218320010203200002032007201320000010
3200241600543200111132000010320000302560218320010203200002032000001320000010
3200241600543200111132000010320000302560218320010203200002032000001320000010
3200241600543200111132000010320000302560218320010203200002032000001320000010
3200241600543200111132000010320058301987882320068203200722032000001320000010
3200241600543200111132000010320000302560218320010203200002032000001320000010