Apple M1 Microarchitecture Research by Dougall Johnson

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

USHLL (8H)

Test 1: uops

Code:

  ushll v0.8h, v0.8b, #3
  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)03181e1f3f4e51inst 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)a6a8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
1004203715000611686251000100010002645211201820372037157131895100010001000203720371110011000000075316221784100020382038203820382038
1004203716090611686251000100010002645211201820372037157131895100010001000203720371110011000000075116111786100020382038203820382038
10042037150120611686251000100010002645210201820372037157131895100010001000203720371110011000000073116111786100020382038203820382038
1004203715000611686251000100010002645210201820372037157131895100010001000203720371110011000000075116111849100020382038203820382038
1004203715000611686251000100010002645210201820372037157131895100010001000203720371110011000000073116111786100020382038203820382038
10042037160120611686251000100010002645210201820372037157131895100010001000203720371110011000000075116111786100020382038203820382038
1004203715030611686251000100010002645210201820372037157131895100010001000203720371110011000000073116111786100020382038203820382038
1004203716000821686251000100010002645211201820372037157131895100010001000203720371110011000000075216221784100020382038203820382038
1004203716000611686251000100010002645210201820372037157131895100010001000203720371110011000000073116111786100020382038203820382038
1004203716060611686251000100010002645211201820372037157031895100010001000203720371110011000000075116221784100020382038203820382038

Test 2: Latency 1->2

Code:

  ushll v0.8h, v0.8b, #3
  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)03181e1f3a3f4e51inst 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)9fa8a9accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037155000021519686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
10204200371560000210196862510100100100001001000050028475210200180200372003718421318745101002001000020010000200372003711102011009910010010000100650071011611197910100001002003820038200382003820038
1020420037155000061019686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037155000012919686251010011510000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037155000015119686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002008520038200382003820038
1020420037156000014919686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
102042003715500006119686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200372110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037155000037519686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010010071011611197910100001002003820038200382003820038
102042003715500008219686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038
1020420037156000012419686251010010010000100100005002847521020018020037200371842131874510100200100002001000020037200371110201100991001001000010000071011611197910100001002003820038200382003820038

1000 unrolls and 10 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)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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024200371500611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010440640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001013640316221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001000640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001010640216221978610000102003820038200382003820086
1002420037150061196862510010101000010100005028475211200182003720037184433187671001020100002010000200372003711100211091010100001000640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001013640216221978610000102003820038200382003820038
1002420037157061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001006640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001000640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001003640216221978610000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200182003720037184433187671001020100002010000200372003711100211091010100001013640216221978610000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  ushll v0.8h, v8.8b, #3
  ushll v1.8h, v8.8b, #3
  ushll v2.8h, v8.8b, #3
  ushll v3.8h, v8.8b, #3
  ushll v4.8h, v8.8b, #3
  ushll v5.8h, v8.8b, #3
  ushll v6.8h, v8.8b, #3
  ushll v7.8h, v8.8b, #3
  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)0318191e3f51inst 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)9fa8acc5branch mispredict (cb)cdcfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042003815500029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118041633200350800001002003920039200392003920039
802042003815500029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031633200350800001002003920039200392003920039
802042003816100029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031633200350800001002003920039200392003920039
8020420038155000132258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031633200350800001002003920039200392003920039
802042003815500029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031622200350800001002003920039200392003920039
8020420038150000292580108100800081008002050064013212001920038200389977259989801202008003220080032200382003811802011009910010080000100001115118031642200350800001002003920039200392003920039
802042003815000029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031633200350800001002003920039200392003920039
802042003815000029258010810080108100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031633200350800001002003920039200392003920039
802042003815000029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100001115118031623200350800001002003920039200392003920039
802042003815000029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003811802011009910010080000100031115118031644200350800001002003920039200392003920039

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0307191e3a3f51inst 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)9fa1a6a8a9acc9cfd0d5d6dbddinst fetch restart (de)dfe0ea? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242004015610003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000003050243116011320035080000102003920039200392003920039
800242003815500003925800101080000108000050640000020019200382003899963100188001020800002080000200382003811800211091010800001000000050243116011320035080000102003920039200392003920039
800242003815500003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050243116011320035080000102003920039200392003920039
8002420038155000014825800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050243116011320035080000102003920039200392003920039
800242003815500003925800101080000108000050640000020019200382003899963100188001020800002080000200382003811800211091010800001000000050243116011320035080000102003920039200392008820039
80024200381550013203925800101080000108000050640000020019200382003899963100188001020800002080000200382003811800211091010800001000000050243116011320035080000102003920039200392003920039
800242003816010003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050240216011320035080000102003920039200392003920039
8002420038155000016925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050240116011320035080000102003920039200392003920039
8002420038155000014625800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050240116011320035080000102003920039200392003920039
800242003815600003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050240116051320035080000102003920039200392003920112