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

ST1 (multiple, 3 regs, 16B)

Test 1: uops

Code:

  st1 { v0.16b, v1.16b, v2.16b }, [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, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 3.000

Issues: 3.000

Integer unit issues: 0.001

Load/store unit issues: 3.000

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)
630052958830071300630001200030003000600013000
630042969730011300030001200030003000600013000
630043001730011300030001200030003000600013000
630042931930011300030001200030003000600013000
630042931630011300030001200030003000600013000
630042934230011300030001200030003000600013000
630042931630011300030001200030003000600013000
630042932430011300030001200030003000600013000
630042932130011300030001200030003000600013000
630042931330011300030001200030003000600013000

Test 2: throughput

Count: 8

Code:

  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [x6]
  st1 { v0.16b, v1.16b, v2.16b }, [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): 3.0006

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)
24020524015024011910124001810024000130040799122401012002400082004801041240000100
24020424005424010110124000010024000130040800462401012002400082004800161240000100
24020424004724010110124000010024000130040800462401012002400082004800161240000100
24020424004724010110124000010024003730040801682401372002400522004800161240000100
24020424004724010110124000010024000130040800462401012002400082004800161240000100
24020424004724010110124000010024000130040800462401012002400082004800161240000100
24020524007524011810124001710024000130040800462401012002400082004800161240000100
24020424004724010110124000010024000130040800462401012002400082004800161240000100
24020424004724010110124000010024003530040801592401352002400482004800161240000100
24020424004724010110124000010024000130040800462401012002400082004800161240000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 3.0005

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)
24002524015024002911240018102400013040798502400112024000820480000124000010
24002424003924001111240000102400003040798832400102024000020480000124000010
24002424003924001111240000102400343040799962400442024004820480000124000010
24002424003924001111240000102400003040798832400102024000020480000124000010
24002424003924001111240000102400003040798832400102024000020480096124000010
24002424004624001111240000102400003040798832400102024000020480000124000010
24002424003924001111240000102400003040798832400102024000020480000124000010
24002424003924001111240000102400353040799992400452024004820480000124000010
24002424004724001111240000102400003040798832400102024000020480000124000010
24002424003924001111240000102400003040798832400102024000020480000124000010