Apple M1 Microarchitecture Research by Dougall Johnson

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

SXTL (4S)

Test 1: uops

Code:

  sxtl v0.4s, v0.4h
  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)696d6edispatch 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)a8cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073216231786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073216331786100020382038203820382038
1004203716061168625100010001000264521201820372037157131895100010001000203720371110011000073316331786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073316331786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073316331786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073316331786100020382038203820382038
10042037151561168625100010001000264521201820372037157131895100010001000203720371110011000073216331786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073316331786100020382038203820382038
1004203715061168625100010001000264521201820372037157131895100010001000203720371110011000073216331786100020382038203820382038
10042037150170168625100010001000264521201820372037157131895100010001000203720371110011000073216331786100020382038203820382038

Test 2: Latency 1->2

Code:

  sxtl v0.4s, v0.4h
  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)030708090b18191e1f3a3f4e51inst 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)9fa0a1a6a8a9acc2cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1020420037150000000000611968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037150000000000611968625101001061000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037150000000000611968625101001001000010010000500284752112002220037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
10204200371500000000001051968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037149000000000611968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622200340100001002003820038200382003820038
10204200371500000000001451968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037150000000000611968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037150000000000611968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
10204200371500000000005361968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038
1020420037150000000000611968625101001001000010010000500284752112001820037200371842103187451010020010000200100002003720037111020110099100100100001000000000071021622197910100001002003820038200382003820038

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)60696b6d6edispatch 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)9fa6accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037150089196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037149061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
10024200371500580196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038
1002420037150061196864410010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010036402162219786010000102003820038200382003820038
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102008420038200382003820038
1002420037150061196862510010101000010100005028475210200180200372003718443031876710010201000020100002003720037111002110910101000010006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  sxtl v0.4s, v8.4h
  sxtl v1.4s, v8.4h
  sxtl v2.4s, v8.4h
  sxtl v3.4s, v8.4h
  sxtl v4.4s, v8.4h
  sxtl v5.4s, v8.4h
  sxtl v6.4s, v8.4h
  sxtl v7.4s, v8.4h
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2506

retire (01)cycle (02)03191e3f51inst 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)9facc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200381500029258010810080008100800205006401321200192003820038997769989801202008003220080032200382003821802011009910010080000100311151182160020035800001002003920039200392003920039
80204200381500071258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
802042003815000138258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151183290020035800001002003920039200392003920039
80204200381500029258010810080008100800205006401320200682003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
80204200381500029258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
80204200381510029258010810080100102800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
80204200381500029258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
802042003815000737258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151181160020035800001002003920039200392003920039
80204200381670029258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039
802042003815000134258010810080008100800205006401320200192003820038997769989801202008003220080032200382003811802011009910010080000100011151180160020035800001002003920039200392003920039

1000 unrolls and 10 iterations

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

retire (01)cycle (02)03040b1e1f3f51inst 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)9fa6a7a8a9acc2cfd0itlb miss (d4)d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200511500000392580010108000010800005064000002001920038200389996310018800102080000208000020038200381180021109101080000102100505050350016168172003580000102003920039200392003920039
80024200381500012039258001010800921080000506400000200192003820138999631002580207208000020800002003820086118002110910108000010000000502000171614172003580000102003920039200392003920039
8002420038150000039258001010800001080000506400000200192003820038999631001880108208000020800002003820038118002110910108000010000000502000171614172003580000102003920039200392003920039
800242003815000003925800101080000108000050640000020019200382003899963100188001020800002080000200382003811800211091010800001000000050220014161792003580000102003920039200392003920039
800242003815000003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000000050220016169172003580000102003920039200392003920039
8002420038150001206025800101080093108000050640000020019201912003899963100188010620800962080000200382009621800211091010800001000009860502000171613202003580000102003920039200392003920039
80024200381500000821258001010800001080000506400001200192003820038999631001880010208000020800002003820038118002110910108000010000030502000164014172003580000102003920039200392003920039
8002420038150000039258001010800001080000506400000200192003820038999631001880010208000020800002003820038118002110910108000010000000502000181616182003580000102003920039200392003920039
80024200381500012039258001010800001080000506400001200192003820038999631001880010208000020800002003820038118002110910108000010001000502000171616172003580000102003920039200392003920039
80024200381500000392580010108000010800005064000002001920038200389996310018800102080000208000020038200381180021109101080000100000005020009161792003580000102003920039200392003920039