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

CRC32CW

Test 1: uops

Code:

  crc32cw w0, w0, w1
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 1.001

Load/store unit issues: 0.000

SIMD/FP unit issues: 0.000

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002595910141022200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000

Test 2: Latency 1->2

Code:

  crc32cw w0, w0, w1
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
10204300301010110101101002601501010010206202121000110100
10204300301010110101101002601501010010206202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002602591011410228202161000110100
10204300301010110101101002602591011410228202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
10024300301002110021100202599071002010030200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10025300601002610026100342599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010

Test 3: Latency 1->3

Code:

  crc32cw w0, w1, w0
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
10204300301010110101101002601501010010206202121000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002602591011410228202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002602441011610228202161000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0030

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
10024300301002110021100202599071002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200621001610010
10024300301002110021100202599161002010028200201001110010

Test 4: throughput

Count: 8

Code:

  crc32cw w0, w8, w9
  crc32cw w1, w8, w9
  crc32cw w2, w8, w9
  crc32cw w3, w8, w9
  crc32cw w4, w8, w9
  crc32cw w5, w8, w9
  crc32cw w6, w8, w9
  crc32cw w7, w8, w9
  mov x8, 9
  mov x9, 10

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 1.0004

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
802048005480104801048010524031580105802101602208000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602728002080100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 1.0004

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
800248003580025800258002624007880026800341600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024013280045800561600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010