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

UMULH

Test 1: uops

Code:

  umulh x0, x0, x1
  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
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000
100430301001100110002585610001000200010011000

Test 2: Latency 1->2

Code:

  umulh x0, x0, x1
  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)
10204300301010110101101002601441010010206202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002602591011410228202161000110100
10205300601010610106101142601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
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)schedule ldst uop (55)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)
100243003010021100210100202599071002010020200781001610010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010
100243003010021100210100202599161002010020200201001110010

Test 3: Latency 1->3

Code:

  umulh x0, x1, x0
  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)
10204300301010110101101002601501010010206202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10204300301010110101101002601561010010208202161000110100
10205300601010610106101142601561010010208202161000110100
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)
10024300301002110021100202599071002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010
10024300301002110021100202599161002010020200201001110010

Test 4: throughput

Count: 8

Code:

  umulh x0, x8, x9
  umulh x1, x8, x9
  umulh x2, x8, x9
  umulh x3, x8, x9
  umulh x4, x8, x9
  umulh x5, x8, x9
  umulh x6, x8, x9
  umulh x7, x8, x9
  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)
802048003480104801048010524031580105802101602248000480100
802048003480104801048010524031580105802121602248000480100
802058006680120801208012424031580105802101602208000480100
802048004480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
802048003480104801048010524031580105802121602248000480100
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)
800248004680025800258002624007880026800341600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024013280045800601600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600488001580010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024006080020800201600208001180010
800248003280021800218002024013280045800601600208001180010