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

ST4 (multiple, post-index, 4S)

Test 1: uops

Code:

  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [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, 0
  mov x8, 0

(no loop instructions)

1000 unrolls and 1 iteration

Retires (minus 60 nops): 12.000

Issues: 13.000

Integer unit issues: 1.001

Load/store unit issues: 4.000

SIMD/FP unit issues: 8.000

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)
720073026113027100380164008100280164000300044010400001300040008000900020000100140008000
720042989313001100180004000100080004000300044010400001300040008000900020000100140008000
720042989113001100180004000100080004000300044010400001300040008000900020000100140008000
720042989013001100180004000100080004000300044010400001300040008000900020000100140008000
720042993013001100180004000100080004000300044010400001300040008000900020000100140008000
720042988813001100180004000100080004000300044010400001300040008000900020000100140008000
720052995813001100180004000100080004000300044010400001300040008000900020000100140008000
720042993213001100180004000100080004000300044010400001300040008000900020000100140008000
720042993313001100180004000100080004000300044010400001300040008000900020000100140008000
720042991113001100180004000100080004000300044010400001300040008000900020000100140008000

Test 2: throughput

Count: 8

Code:

  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [x6], x8
  st4 { v0.4s, v1.4s, v2.4s, v3.4s }, [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): 4.0006

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)
96020732014810402178011264008432002180111640096320006240303396558132000511040117200320006640014200720013160003580002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320039240333510982032004611040243200320047640097200720018160004080002320000640000100
96020432005010401088010264000632000080101640012320002240303543996232000611040115200320008640016200720018160004080002320000640000100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 4.0006

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)
96002732013610401268002264008632001880021640100320000240030437595432000001040010203200006400002072010516002428001132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010
96002432005010400118001164000032000080010640000320042240063522535632004561040156203200476400972072000016000008000132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010
96002432005010400118001164000032000080010640000320042240063491354732004561040156203200476400972072000016000008000132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010
96002432005010400118001164000032000080010640000320042240063466232832004611040156203200476400972072000016000008000132000064000010
96002432005010400118001164000032000080010640000320000240030543995632000001040010203200006400002072000016000008000132000064000010