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

SUB (uxth, 32-bit)

Test 1: uops

Code:

  sub w0, w0, w1, uxth
  mov x0, 1
  mov x1, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 2.000

Integer unit issues: 2.001

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)
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000
100420302001200110005226510001000200020011000

Test 2: Latency 1->2

Code:

  sub w0, w0, w1, uxth
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0030

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)int uops in schedulers (59)dispatch uop (78)map int uop (7c)map int uop inputs (7f)? int output thing (e9)? int retires (ef)
10204200302010120101001010405291001010410210202202000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212203062001510100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100
10204200302010120101001010405291861010410212202242000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0030

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)
10024200302002120021100255291971002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010

Test 3: Latency 1->3

Code:

  sub w0, w1, w0, uxth
  mov x0, 1
  mov x1, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0030

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)
10204200302010120101101045291001010410210202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045294801013710252202242000110100
10204200302010120101101045295241013710252202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045291861010410212202242000110100
10204200302010120101101045291861010410212202242000110100

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0030

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)
10024200302002120021100255295581005810074200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010
10024200302002120021100205292531002010020200202001110010

Test 4: throughput

Count: 8

Code:

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

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.6675

retire uop (01)cycle (02)schedule uop (52)schedule int uop (53)dispatch int uop (56)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)? int output thing (e9)? int retires (ef)
802045342916011816011880131013602970080129802340016027216001780100
802045341516011616011680129013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016037816008380100
802045340416011716011780130013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016037216005980100
802045340416011716011780130013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016027216001780100
802045340416011716011780130013608380080130802360016027216001780100

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.6671

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)
8002453405160039160039800511359975800518005816002016001180010
8002453371160021160021800201359903800208002016002016001180010
8002453409160039160039800511359975800518005816002016001180010
8002453371160021160021800201359903800208002016002016001180010
8002453371160021160021800201359903800208002016002016001180010
8002453371160021160021800201359903800208002016002016001180010
8002453371160021160021800201359903800208002016002016001180010
8002453371160021160021800201359903800208002016020416007480010
8002453371160021160021800201359903800208002016002016001180010
8002453371160021160021800201359903800208002016002016001180010