Apple M1 Microarchitecture Research by Dougall Johnson

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

UCVTF (vector, integer, 8H from 8H)

Test 1: uops

Code:

  ucvtf v0.8h, v0.8h
  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)03091e3f4e51inst 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)a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
1004303723096125472510001000100039816003018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723106125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240126125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  ucvtf v0.8h, v0.8h
  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)03181e3f4e51inst 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)9fa0a8a9acc2c5cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372320061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372320061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
102043003723300612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000048017101161229777100001003003830038300383003830038
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372320061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000103007101161129633100001003003830038300383003830038
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038
10204300372330061295472510100100100001001000050042771601300183003730037282643287451010020010000200100003003730037111020110099100100100001000000007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)030708090b18191e1f3f4e51inst 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)9fa0a1a6a7a8a9acc2cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372390000000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000008015606403162229629010000103003830038300383003830038
1002430037225000000001882954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000110306402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716013001830037300372828632876710010201000020100003003730037111002110910101000010000000006402162229629010000103003830038300383003830038
1002430037225000000006129547251001010100001010000504277160130018300373003728286262876710010201000020100003003730037111002110910101000010000010006402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000010006402162229629010000103003830038300383003830038
1002430037225000000006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000206906402162229629010000103003830038300383003830038
100243003722500000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000010006401162229629010000103003830038300383003830038
100243003722400000000612954725100101010000101000050427716003001830037300372828632876710010201000020100003003730037111002110910101000010000010006402162229629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  ucvtf v0.8h, v8.8h
  ucvtf v1.8h, v8.8h
  ucvtf v2.8h, v8.8h
  ucvtf v3.8h, v8.8h
  ucvtf v4.8h, v8.8h
  ucvtf v5.8h, v8.8h
  ucvtf v6.8h, v8.8h
  ucvtf v7.8h, v8.8h
  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)030b1e3f51inst 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)9fa0a1a8acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042006115500161258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151181162220036800001002004020040200402004020040
802042003915600118258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162420036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162120036800001002004020040200402004020040
802042003915500337258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162120036800001002004020040200402004020040
802042003915501893258010810080008100800205006401320200202003920039997769990801202008024420080032200392003911802011009910010080000100000011151181162220036800001002004020040200402004020040
80204200391550073258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162120036800001002004020040200402004020040
802042003915500663258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162220036800001002004020040200402004020040
802042003915500118258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162120036800001002004020040200402004020040
802042003915500118258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151182162220036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200202003920039997769990801202008003220080032200392003911802011009910010080000100000011151181162220036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)030818191e1f3a3f51inst 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)9fa0a6a8a9acc2cfd5d6ddinst fetch restart (de)e0eaeb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420039155000207004025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000000502011611200360080000102004020040200402004020040
800242003915510000040258001010800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000300502011611200360080000102004020040200402004020040
80024200391550000004025800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010001000502011611200360080000102004020040200402004020040
80024200391550000008225800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000000502011611200360080000102004020040200402004020040
800242003915600000044925800101080000108000050640000200202003920039999631001980010208000020800002003920039118002110910108000010000000502011611200360080000102004020040200402004020040
800242003915500000040258001010800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000005020116112003602380000102004020040200402004020040
80024200391550000001182258001010800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000005020116112003601880000102004020040200402004020040
800242003915500000043258010710800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000005020116112003601880000102004020040200402004020040
800242003915500000040258001010800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000005020116112003602380000102004020040200402004020040
800242003915500000040258001010800001080000506400002002020039200399996310019800102080000208000020039200391180021109101080000100000005020116112003601880000102004020040200402004020040