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, 4S)

Test 1: uops

Code:

  ld1 { v0.4s, v1.4s, v2.4s }, [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)
63005295193007130063000900030003000300013000
63004293443001130003000900030003000300013000
63004293173001130003000900030003000300013000
63004293333001130003000900030003000300013000
63004293533001130003000900030003000300013000
63004293293001130003000900030003000300013000
63004293053001130003000900030003000300013000
63004293353001130003000900030003000300013000
63004293303001130003000900030003000300013000
63004293543001130003000900030003000300013000

Test 2: throughput

Count: 8

Code:

  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [x6]
  ld1 { v0.4s, v1.4s, v2.4s }, [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): 1.5006

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)? simd retires (ee)? int retires (ef)
240205120170240135101240034100240059300103972624015920024007120024001412400000100
240204120056240101101240000100240008300192002824010820024001220024001212400000100
240204120047240101101240000100240008300192002824010820024001220024001212400000100
240204120047240101101240000100240008300192002824010820024001220024001212400000100
240204120047240101101240000100240008300192002824010820024001220024001212400000100
240204120047240101101240000100240057300129104524015720024006820024001212400000100
240204120047240101101240000100240008300192002824010820024001220024001212400000100
240204120067240101101240000100240008300192002824010820024001220024001212400000100
240204120047240101101240000100240008300192152224010820024001220024001212400000100
240204120559240223103240120102240008300192770024010820024001220024001212400000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.5006

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)
24002512024024004111240030102400003019199822400102024000020240000124000010
24002412005524001111240000102400003019200722400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019199822400102024000020240000124000010
24002412004324001111240000102400003019235462400102024000020240000124000010
24002412005824001111240000102400003019199822400102024000020240000124000010
24002412004924001111240000102400563018154602400662024006820240000124000010
24002412006124001111240000102400003019201062400102024000020240000124000010
24002512027124004111240030102400003019206462400102024000020240012124000010
24002412006224001111240000102400593018103982400692024007220240000124000010