Apple M1 Microarchitecture Research by Dougall Johnson

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

SXTL (2D)

Test 1: uops

Code:

  sxtl v0.2d, v0.2s
  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)a8acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
1004203716061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037151261168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715061168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037151261168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037151261168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203716061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
1004203715661168625100010001000264521020182037203715713189510001000100020372037111001100000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  sxtl v0.2d, v0.2s
  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)0318191e1f3f4e5051inst 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)9fa8acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204200371500072061196862002125101001001000010010000500284752112001820037200371842806187401010020010008200100082003720037111020110099100100100001000011171801600198000100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752102001820037200371842807187401010020010008200100082003720037111020110099100100100001000011171801600198000100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752112001820037200371842807187401010020010008200100082003720037111020110099100100100001000011171801600198010100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752102001820037200371842806187401010020010008200100082003720037111020110099100100100001000011171701600198000100001002003820038200382003820038
10204200371500000168719686025101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001001000071011611197910100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752102001820037200371842103187451010020010000200100002003720037111020110099100100100001000000071011611197910100001002003820038200382003820038
1020420037150001806119686025101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000071011611197910100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000071011611197910100001002003820038200382003820038
1020420037150000015619686025101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000071011611197910100001002003820038200382003820038
102042003715000006119686025101001001000010010000500284752102001820037200371842103187451010020010000200100002003720037111020110099100100100001000000071011611197910100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)03080b18191e1f3f4e51inst 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)9fa0a1a6a8a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100242003715000001770611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
1002420037150000030611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
10024200371500000270611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
1002420037150000060611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
10024200371500000150611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
1002420037150000090611968643100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
1002420037150000000611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
10024200371500000180611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038
10024200371500000390611968625100101010000101000050284752120018200372003718443318767100102010000201000020037200371110021109101010000100000006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  sxtl v0.2d, v8.2s
  sxtl v1.2d, v8.2s
  sxtl v2.2d, v8.2s
  sxtl v3.2d, v8.2s
  sxtl v4.2d, v8.2s
  sxtl v5.2d, v8.2s
  sxtl v6.2d, v8.2s
  sxtl v7.2d, v8.2s
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

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

retire (01)cycle (02)031e1f3f51inst 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)9fa8c2c5branch mispredict (cb)cdcfd6inst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8020420061150007325801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150302925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
80204200381503028125801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150006225801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150302925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000111511816020035800001002003920039200392003920039
8020420038150002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010070111511816020035800001002003920039200392003920039

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03080a0b18191e1f3f51inst 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)9fa0a1a6a8acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242003915000000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050206165420035080000102003920039200392003920039
800242003815000000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050205165320035080000102003920039200392003920039
8002420038150000001803925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050205163520035080000102003920039200392003920039
800242003815000000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050205165320035080000102003920039200392003920039
800242003815000000906025800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050203163520035080000102003920039200392003920039
8002420038150000004503925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000010050205165520035080000102003920039200392003920039
800242003815000000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050203163520035080000102003920039200392003920039
8002420038150000005103925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050205165320035080000102003920039200392003920039
8002420038150000000060925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050203165620035080000102003920039200392003920039
800242003815000000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050203165320035080000102003920039200392003920039