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, 1 reg, 4S)

Test 1: uops

Code:

  st1 { v0.4s }, [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, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 1.000

Issues: 1.000

Integer unit issues: 0.001

Load/store unit issues: 1.000

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)
61005296671003110021000400010001000200011000
61004292461001110001000400010001000200011000
61004292451001110001000400010001000200011000
61004292391001110001000400010001000200211000
61004294711001110001000400010001000200011000
61004299141001110001000400010001000200011000
61004292151001110001000400010001000200011000
61004292551001110001000400010001000200011000
61004292371001110001000400010001000200011000
61004292941001110001000400010001000200011000

Test 2: throughput

Count: 8

Code:

  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [x6]
  st1 { v0.4s }, [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): 1.0005

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)
802058014980119101800181008000130013599748010120080008200160016180000100
802048003980101101800001008003730013603128013720080052200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100
802048003980101101800001008003630013603358013620080051200160016180000100
802048003980101101800001008000130013598868010120080008200160016180000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.0005

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)
800258015180029118001810800013013598508001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016010418000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010
800248003980011118000010800013013598868001120800082016001618000010