Apple M1 Microarchitecture Research by Dougall Johnson

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

SQSHRN (2D)

Test 1: uops

Code:

  sqshrn v0.2s, v0.2d, #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)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)a8cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372301242547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037220612547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981601305430373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981601301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037239612547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981600301830373037241432895100010001000303730371110011000073116112706100030383038303830383038
10043037230612547251000100010003981601301830373037241432895100010001000303730371110011000073116112629100030383038303830383038
10043037230612547251000100010003981600301830373037241432895100010001000303730371110011000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  sqshrn v0.2s, v0.2d, #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)03181e1f3f4e51inst 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)9fa0a6a8accfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003722501320744295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100200071011611296330100001003003830038300383003830038
102043003722400061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500061295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
1020430037225012061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
1020430037225039061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038
102043003722500061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000371011611296330100001003003830038300383003830038
10204300372250270612954725101001001001613210000500427851213001830037300372826403287451010020010000200100003003730037111020110099100100100001000010710116112963314100001003003830086300863008630038
1020430037225027061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000071011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

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)696b6d6edispatch 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)9fa1a8acc2branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500006306129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722500002406129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300183300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722500002706129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722500003006129547251001010100001010000504277160300180300373003728286328767100102010339201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722500002406129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722400001206129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
10024300372250000006129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000006403163329629010000103003830038300383003830038
100243003722500003906129547251001010100001010000504277160300180300373003728286328767100102010000201000030037300371110021109101010000100000007675738529904410000103027430320303713036930367
10024301212281172948616513629484821006815100561510900504277160300180300373003728286328767100102010000201000030037300372110021109101010000100100006403163329629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  sqshrn v0.2s, v8.2d, #3
  sqshrn v1.2s, v8.2d, #3
  sqshrn v2.2s, v8.2d, #3
  sqshrn v3.2s, v8.2d, #3
  sqshrn v4.2s, v8.2d, #3
  sqshrn v5.2s, v8.2d, #3
  sqshrn v6.2s, v8.2d, #3
  sqshrn v7.2s, v8.2d, #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)0307080a0b18191e3f51inst 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)696b6d6edispatch 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)9fa6a8acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200581511010002730258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
802042003915010100003025801081008000810080020500640132200200200392003999776999080120200800322008003220039200391180201100991001008000010000470011151181161120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151361161120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
80204200391501010001230258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181161120036800001002004020040200402004020040
80204200391501010003030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100000011151181261120036800001002004020040200402004020040
8020420039150101000030258010810080008100800205006401322002002003920039997769990801202008003220080032200392003911802011009910010080000100040011151182161120036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)031e3a3f51inst 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)9fa8cfd5d6dbddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200511506040258001010800001080000506400000200202003920039999631001980010208000020800002003920039218002110910108000010050207160642003680000102004020040200402004020040
8002420039150147063258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050204160462003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200692003920039999631001980010208000020800002003920039118002110910108000010050207160652003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050206160462003680000102004020040200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010050206160642003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050204160462003680000102004020040200402004020040
80024200391500040258001010800001080000506400001200202003920039999631001980010208000020800002003920039118002110910108000010050206160562003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050206160642003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050205160462003680000102004020040200402004020040
80024200391500040258001010800001080000506400000200202003920039999631001980010208000020800002003920039118002110910108000010050204160642003680000102004020040200402004020040