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

LD4R (post-index, 8H)

Test 1: uops

Code:

  ld4r { 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): 5.000

Issues: 6.008

Integer unit issues: 1.001

Load/store unit issues: 1.000

SIMD/FP unit issues: 4.008

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)ldst uops in schedulers (5b)dispatch uop (78)map ldst uop (7d)map simd uop (7e)map ldst uop inputs (80)map simd uop inputs (81)? int output thing (e9)? ldst retires (ed)? simd retires (ee)
65005298336053100340481002100240081000300030003056860001000400020004000100110004000
65004295596009100140081000100040001000300030003056860001000400020004000100110004000
65004295686009100140081000100040001000300030003056860001000400020004000100110004000
65004295996009100140081000100040001000300030003056860001000400020004000100110004000
65004295686009100140081000100040001000300030003056860001000400020004000100110004000
65004295646009100140081000100040001000300030003056860001000400020004000100110004000
65004295556009100140081000100040001000300030003056860001000400020004000100110004000
65004295936009100140081000100040001000300030003057260001000400020004000100110004000
65004295486009100140081000100040001000300030003056860001000400020004000100110004000
65004295616009100140081000100040001000300030003056860001000400020004000100110004000

Test 2: throughput

Count: 8

Code:

  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { v0.8h, v1.8h, v2.8h, v3.8h }, [x6], x8
  ld4r { 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): 2.0006

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)schedule simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)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)
400205160164480219801123200968001180112320039800042403122400122427622480121200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800182403532400583006272480203200800183200712001600083200158000480000320000100
400204160066480135801043200288000380104320013800042403122400172889870480121200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100
400204160046480127801043200208000380104320012800042403122400173200264480120200800043200152001600083200158000480000320000100

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 simd uop (54)schedule ldst uop (55)dispatch int uop (56)dispatch simd uop (57)dispatch ldst uop (58)int uops in schedulers (59)simd uops in schedulers (5a)ldst uops in schedulers (5b)dispatch uop (78)map int uop (7c)map ldst uop (7d)map simd uop (7e)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)
400025160171480129800223200968001180022320039800182400832400533202074480112208001832007120160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010
400025160098480105800273200628001680028320066800002400302400033200336480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200080480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160036320071800178000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010
400024160052480039800113200288000080010320000800002400302400003200336480010208000032000020160000320000800018000032000010