Apple M1 Microarchitecture Research by Dougall Johnson

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

SQSHRUN (H)

Test 1: uops

Code:

  sqshrun b0, h0, #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)031e1f3f4e51inst 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)a0a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372300612547251000100010003981601301830373037241432895100010001000303730371110011000014073116112629100030383038303830383038
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037230061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
100430372200112254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
100430372212061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
100430372330612547251000100010003981601301830373037241432895100010001000303730371110011000019373116112629100030383038303830383038
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037230061254725100010001000398160130183037303724143289510001000100030373037111001100000073116112629100030383038303830383038
10043037220061254725100010001000398160130183037303724143289510001000100030373037111001100000373116112701100030383038303830383038

Test 2: Latency 1->2

Code:

  sqshrun b0, h0, #3
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)0307081e3f4e51inst 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)6061696b6d6edispatch 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)9fa6a8a9acc2cfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003722500061295472510100100100001001000050042771601530018030037300372826432874510100200100002041000030037300371110201100991001001000010005000710521622296330100001003003830038300383003830038
102043003722400061295472510100100100001001000050042798641530018030037300372826432874510100200100002001000030037300371110201100991001001000010000062710521622296330100001003003830038300383003830038
1020430037225000612954725101001001000010010000500427716015300180300373003728264328745101002001000020010000300373003711102011009910010010000100018000710521622296330100001003003830038300383003830038
1020430037224001261295472510100100100001001000050042771601530018030037300372826432874510100200100002001000030037300371110201100991001001000010000030710521622296330100001003003830038300383003830038
1020430037225000124295472510100100100001001000050042771601530018030037300372826432874510100200100002001000030037300371110201100991001001000010030000710521622296330100001003003830038300383003830038
1020430037225000726295472510100100100001001000050042798731530018030037300372826432874510100200100002001000030037300371110201100991001001000010000000710521622296330100001003003830038300383003830038
102043003722400061295472510100100100001001000050042771601530018030037300372826432874510100200100002001000030037300371110201100991001001000010000030710521622296330100001003003830038300383003830038
1020430037225001261295472510100100100001001000050042771601530018030037300372826432874510100200100002001000030037300371110201100991001001000010000030710521622296330100001003003830132300873003830038
1020430037225000612954725101001001000010010000500427716015300180300373003728264328745101002001000020010000300373003711102011009910010010000100030030710521622296330100001003003830038300383003830038
102043003722400061295472510100100100001001000050042771601530018030037300372826432874510100200100002001000030037300371110201100991001001000010000030710521622296330100001003013230038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)03191e1f3f4e51inst 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)9fa6a7a8acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372250006129547251001010100001010000604277160130018300373003728286328767100102010000201000030037300371110021109101010000100039006403162229629010000103003830038300383003830038
1002430037225000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010008006402162229629010000103017930038300383003830038
1002430037224000612954762100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010002006402162229629010000103003830038300383003830038
100243003722500010329547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100007506402162229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100007506402162229629010000103003830038300383003830038
10024300372250390612954725100101010024101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000606402162229629010000103003830038300383003830038
10024300372250001892954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000606403162229629010000103003830038300383003830038
10024300372250006129511251001010100001010000504277160130018300373003728286328767100102010000201000030037300371110021109101010000100006906402162229629010000103003830038300383003830038
10024300372250120612954725100101010000101000050427716013012630037300372828632876710010201000020100003003730037111002110910101000010004306402162229629010000103003830038300383003830038
100243003722500061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000017706402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  sqshrun b0, h8, #3
  sqshrun b1, h8, #3
  sqshrun b2, h8, #3
  sqshrun b3, h8, #3
  sqshrun b4, h8, #3
  sqshrun b5, h8, #3
  sqshrun b6, h8, #3
  sqshrun b7, h8, #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)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)9fa0a8acc5branch mispredict (cb)cdcfd5d6inst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042004915000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000161115118116020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118016020036800001002004020040200402004020040
80204200391500024125801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000121115118016020036800001002004020040200402004020040
802042003915100302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000001115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000101115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001000061115118016020036800001002004020040200402004020040
802042003915000302580108100800081008002050064013212002020039200399977699908012020080032200800322003920039118020110099100100800001002131115118016020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)031e3f51inst 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)9fa8accfd0d5d6dbddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
800242004015004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001010502004160242003680000102004020040200402004020040
800242003915004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502002160252003680000102004020040200402004020040
800242003915004025801091080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001003502002160242003680000102004020040200402004020040
800242003915004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502004160442003680000102004020040200402004020040
8002420039150013525800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502002160242003680000102004020040200402004020040
800242003915004025800101080000108000050640000020020200392003999963100198001020800002080000200392003911800211091010800001000502002160242003680000102004020040200402004020040
800242003915004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001013504534160432003680000102004020040200402004020040
800242003915004025800101080000108030450640000120020200392003999963100198001020800002080000200392003911800211091010800001010502004160422003680000102004020040200402004020040
800242003915004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001010502002160242003680000102004020040200402004020040
800242003915004025800101080000108000050640000120020200392003999963100198001020800002080000200392003911800211091010800001000502004160422003680000102004020040200402004020040