Apple M1 Microarchitecture Research by Dougall Johnson

Firestorm: Overview | Base Instructions | SIMD and FP Instructions
Icestorm:  Overview | Base Instructions | SIMD and FP Instructions

SSUBW2 (vector, 8H)

Test 1: uops

Code:

  ssubw2 v0.8h, v0.8h, v1.16b
  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

retire (01)cycle (02)031e3f4e51inst issue (52)~issue fp/simd (54)~dispatch fp/simd (57)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op fp/simd (7e)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst neon or fp (9a)a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100420371506116872510001000100026468002018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
1004203715029816872510001000100026468012018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
100420371506116872510001000100026468012018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
100420371506116872510001000100026468002018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
1004203715011416872510001000100026468012018203720371572318951000100020002037203711100110001073116111787100020382038203820382038
100420371506116872510001000100026468012018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
1004203715156116872510001000100026468002018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
10042037151861168725100010001000264680020182037203715723189510001000200020372037111001100001573116111787100020382038203820382038
100420371506116872510001000100026468012018203720371572318951000100020002037203711100110000073116111787100020382038203820382038
1004203715061168725100010001000264680120182037203715723189510001000200020372037111001100002773116111787100020382038203820382038

Test 2: Latency 1->2

Code:

  ssubw2 v0.8h, v0.8h, v1.16b
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)031e3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696b6d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102042003715006119687251010010010000100100005002847680120018020037200371842231874510100200100002002000020037200371110201100991001001000010051007101161119791100001002003820038200382003820038
102042003715003461968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001000007101161119791100001002003820038200382003820038
10204200371500611968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001000007101161119791100001002003820038200382003820038
102042013215006119687251010010010000100100005002847680120054020086200371842231874510100200100002002000020037200371110201100991001001000010032007101161119791100001002003820038200382003820038
102042003715006119687251010010010000100100005002847680020018020037200371842231874510100200100002002000020037200371110201100991001001000010038007101161119791100001002003820038200382003820038
102042003715006119687251010010010000100100005002847680120018020037200371842231874510100200100002002000020037200371110201100991001001000010005407101161119791100001002003820038200382003820038
10204200371500611968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001000007101161119791100001002003820038200382003820038
10204200371500611968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001001007101161119791100001002003820038200382003820038
10204200371500611968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001007307101161119791100001002003820038200382003820038
10204200371500611968725101001001000010010000500284768012001802003720037184223187451010020010000200200002003720037111020110099100100100001000007101161119791100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)030b18191e3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a8accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024200371500000611968725100101010000101000050284768020018200372003718444318767100102010000202000020037200371110021109101010000100006402162219785010000102003820038200382003820038
10024200371500000611968725100101010000101000050284768020018200372003718444318767100102010000202000020037200371110021109101010000100006402162219785010000102003820038200382003820038
100242003715000006119687251001010100001010000502847680200182003720037184443187671001020100002020000200372003711100211091010100001004106402162219785010000102003820038200382003820038
100242003715000006119687251001010100001010000502847680200182003720037184443187671001020100002020000200372003711100211091010100001000216402162219785010000102003820038200382003820038
10024200371490000611968725100101010000101000050284768020018200372003718444318767100102010000202000020037200371110021109101010000100136402162219785010000102003820038200382003820038
1002420037150000126119687251001010100001010000502847680200182008520037184533187851001020100002020338201322003711100211091010100001002306402162219785310000102003820168200382003820038
100242003715011106119687251001010100001010000502847680200182003720037184443187671001020100002020000200372003711100211091010100001000276402162219785010000102003820038200382003820038
100242003715000006119687251001010100001010000502847680200182003720037184443187671001020100002020000200372003711100211091010100001000156402162219785110000102003820038200382003820038
100242003715000012611968725100101010000101000050284768020018200372003718444318767100102010000202000020037200371110021109101010000100166402162219785010000102003820038200382003820038
10024200371500000611968725100101010000101000050284768020018200372003718444318767100102010000202000020037200371110021109101010000100036402162219785010000102003820038200382003820038

Test 3: Latency 1->3

Code:

  ssubw2 v0.8h, v1.8h, v0.16b
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)030b181e1f3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696b6d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100237101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476801200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
10204200371500000611968725101001001000010010000500284768002005402003720037184223187451010020010000200200002003720037111020110099100100100001000667101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476801200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476800200180200372003718422318745101002001000020020000200372003711102011009910010010000100007101162119791100001002003820038200382003820038
1020420037150000061196872510100100100001001000050028476801200180200372003718422318745101002001000020020000200372003711102011009910010010000100107101161119791100001002003820038200382018220038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)03080918191e1f3a3f4e51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696d6edispatch stall (70)72scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a1a6a7a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002420037150000000061196872510010101000010100005028476801200182003720037184440318767100102010000202000020037200371110021109101010000100000320006406162219785010000102003820038200382003820038
100242003715000000006119687251001010100001010000502847680020018200372003718444731876710010201000020200002003720037111002110910101000010000000006402162219785010000102003820038200382003820038
100242003715000000006119687251001010100001010000502847680020018200842003718444031876710010201000020200002003720037111002110910101000010000010006402162219785010000102003820038200382003820038
100242003715000006006119687251001010100001010000502847680120018200372003718444031876710010201000020200002003720037111002110910101000010000080006402162219785010000102003820038200382003820038
100242003715100000006119687251001010100001010000502847680120018200372003718444031876710010201000020200002003720037111002110910101000010000000006402162219785010000102003820038200382003820038
100242003715000000006119687251001010100001010000502847680120018200372003718444031876710010201000020200002003720037111002110910101000010000000006402162219785010000102003820038200382003820038
1002420037150000000061196872510010101000010100005028476800200182003720037184440318767100102010000202000020037200371110021109101010000100000550306402162219785010000102003820038200382003820038
100242003715000000006119687251001010100001010000502847680020018200372003718444031876710010201000020200002003720037111002110910101000010000010006402162219785010000102003820038200382003820038
1002420037150000000025319687251001010100001010000502847680120018200372003718444031876710010201000020200002003720037111002110910101000010000000006402162219785010000102003820038200382003820038
100242003715000000006119687251001010100001010000502847680020018200372003718444031876710010201000020200002003720037111002110910101000010000010006402162219785010000102003820038200382003820038

Test 4: throughput

Count: 8

Code:

  ssubw2 v0.8h, v8.8h, v9.16b
  ssubw2 v1.8h, v8.8h, v9.16b
  ssubw2 v2.8h, v8.8h, v9.16b
  ssubw2 v3.8h, v8.8h, v9.16b
  ssubw2 v4.8h, v8.8h, v9.16b
  ssubw2 v5.8h, v8.8h, v9.16b
  ssubw2 v6.8h, v8.8h, v9.16b
  ssubw2 v7.8h, v8.8h, v9.16b
  movi v8.16b, 9
  movi v9.16b, 10

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2505

retire (01)cycle (02)0304080b18191e1f3f51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa0a1a6a7a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200601501000000402580100100800001008000050064000012001920038200389973399968010020080000200160000200382003811802011009910010080000100000000450511021611200350800001002003920039200392003920039
802042003815000000001548258010010080000100800005006400000200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400000200192003820038997339996801002008000020016000020038201111180201100991001008000010000000030511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400000200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400000200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400001200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400001200192003820038997339996801002008000020016000020038200381180201100991001008000010000001000511011612200350800001002003920039200392003920039
8020420038150000000040258010010080092100800005006400001200192003820038997339996801002008000020016000020038200381180201100991001008000010000000090511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400001200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039
8020420038150000000040258010010080000100800005006400000200192003820038997339996801002008000020016000020038200381180201100991001008000010000000000511011611200350800001002003920039200392003920039

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2505

retire (01)cycle (02)033f51inst issue (52)~issue int (53)~issue fp/simd (54)~dispatch int (56)~dispatch fp/simd (57)huge thing int (59)huge thing fp/simd (5b)60696d6edispatch stall (70)scheduler rewind (75)scheduler stall (76)~dispatch op (78)~map op int (7c)~map op fp/simd (7e)~map lookup int (7f)~map lookup fp/simd (81)8283pipeline redirect (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst b.cc (94)inst integer (97)inst neon or fp (9a)9fa8accfd5d6daddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200481503925800101080000108000050640000120019200382003899963100188001020800002016000020038200381180021109101080000100050201816016162003580000102003920039200392003920192
80024200381503925800101080000108000050640000120019200382003899963100188001020800002016000020038200381180021109101080000100050201316016162003580000102003920039200392003920039
800242003815039258001010800001080000506400000200192003820038999631001880010208000020160000200382003811800211091010800001010502061601662003580000102003920039200392003920039
8002420038150392580010108000010800005064000012001920038200389996310018800102080000201600002003820038118002110910108000010005020161601662003580000102003920039200392003920039
8002420038150392580010108000010800005064000012001920038200389996310018800102080000201600002003820038118002110910108000010005020161606162003580000102003920039200392003920039
800242003815039258001010800001080000506400001200192003820038999631001880010208000020160000200382003811800211091010800001000502061601662003580000102003920039200392003920237
8002420038150392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010005020161606162003580000102003920039200392003920039
8002420038150392580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010505020161601662003580000102003920039200392003920039
80024200381503925800101080000108000050640000020019200382003899963100188001020800002016000020038200381180021109101080000100050201616016162003580000102003920039200392003920039
80024200381504952580010108000010800005064000002001920038200389996310018800102080000201600002003820038118002110910108000010005020161601662003580000102003920039200392003920039