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, 3 regs, 8H)

Test 1: uops

Code:

  ld1 { v0.8h, v1.8h, v2.8h }, [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): 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)
63005300903019130183000900030003000300013000
63004293943001130003000900030003000300013000
63004293413001130003000900030003000300013000
63004293433001130003000900030003000300013000
63004293493001130003000900030003000300013000
63004293453001130003000900030003000300013000
63004293473001130003000900030003000300213000
63004293483001130003000900030003000300013000
63004293433001130003000900030003000300013000
63004293413001130003000900030003000300013000

Test 2: throughput

Count: 8

Code:

  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [x6]
  ld1 { v0.8h, v1.8h, v2.8h }, [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): 1.5007

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)
2402051201692401351012400341002400083008401882401082002400122002400121240000100
24020412005324010110124000010024005730017425912401572002400682002400121240000100
24020412005324010110124000010024000830019203022401082002400122002400121240000100
24020412005624010110124000010024000830019201942401082002400122002400121240000100
24020412005924010110124000010024000830019201942401082002400122002400121240000100
24020412005324010110124000010024000830019201942401082002400122002400121240000100
24020412005324010110124000010024005730012520792401572002400672002400121240000100
24020412005324010110124000010024000830019205182401082002400122002400121240000100
24020412005324010110124000010024000830019201942401082002400122002400121240000100
24020412005324010110124000010024000830019201942401082002400122002400121240000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.5005

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)
24002612069324007111240060102400103012263062400202024001420240000124000010
24002412005124001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412012424001111240000102400003019200362400102024000020240000124000010
24002412004324001111240000102400593018998022400692024007220240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002512027624004111240030102400583013182602400682024006920240000124000010