Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTPU (scalar, S to S)

Test 1: uops

Code:

  fcvtpu s0, s0
  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)03191e1f3f4e51inst 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
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
10043037240006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372311328810325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
100430372300010325472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037230006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240006125472510001000100039816013018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240006125472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtpu s0, s0
  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)030a1e3f4e51inst 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)9fa0a1a8accdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102043003722505161295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038
102043003722501561295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000017102162229633100001003003830038300383003830038
10204300372250252119295472510100100100001001000050042771601300183003730037282647328745101002001000020410000300373003711102011009910010010000100002007102162229633100001003003830038300383003830038
10204300372250061295382510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038
10204300372260061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038
10204300372250061295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038
10204300372250961295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038
1020430037225045061295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100001007102162229633100001003003830038300383003830038
1020430037225028561295472510100100100001001000050042771601300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383008530038
102043003722403061295472510100100100001001000050042771600300183003730037282640328745101002001000020010000300373003711102011009910010010000100000007102162229633100001003003830038300383003830038

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)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)9fa8acc2branch mispredict (cb)cfd5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383008630038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243008422500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000016403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038
100243003722500000061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000006403163329629010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtpu s0, s8
  fcvtpu s1, s8
  fcvtpu s2, s8
  fcvtpu s3, s8
  fcvtpu s4, s8
  fcvtpu s5, s8
  fcvtpu s6, s8
  fcvtpu s7, s8
  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)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)9fa0a1a8a9acc5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200491500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
8020420039150020352580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915001562580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
802042003915002012580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160120036800001002004020040200402004020040
80204200391500932580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391500302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000011151180160020036800001002004020040200402004020040
80204200391780302580108100800081008002050064013202002020039200399977699908012020080032200800322003920039118020110099100100800001000000311151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire (01)cycle (02)030b1e3f5051inst 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)5f60696d6edispatch 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
80024200511500040025800101080000108009950640000612002020039200399996310019800102080000208000020039200391180021109101080000100050201216472003680000102004020040200402004020040
80024200391500040200232580010108000010800005064000051200202003920039999631001980010208000020800002003920039118002110910108000010005020616652003680000102004020040200402004020040
80024200391610040025800101080000108000050640000512002020039200399996310019800102080000208000020039200391180021109101080000100050209161042003680000102004020040200402004020040
800242003915000705025800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100050204161242003680000102004020040200402004020040
80024200391500040025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050205164142003680000102004020040200402004020040
800242003915000400258001010800001080000506400000120020200392003999963100198001020800002080000200392003911800211091010800001000502013161252003680000102004020040200402004020040
8002420039156004002580010108000010800005064000001200202003920039999631001980126208000020800002003920039118002110910108000010005020516882003680000102004020040200402004020040
8002420039150004002580010108000010800005064000001200202003920039999631001980010208000020800002003920039118002110910108000010005020616482003680000102004020040200402004020040
8002420039150004002580010108000010800005064000001200202003920039999631001980010208000020800002003920039118002110910108000010005020131613132003680000102004020091200402004020040
80024200391500040025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100050201316482003680000102004020040200402004020040