Apple M1 Microarchitecture Research by Dougall Johnson

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

FCVTZS (vector, fixed-point, 2D)

Test 1: uops

Code:

  fcvtzs v0.2d, 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)03071e3f4e51inst 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)a0a6a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
100430372400612547251000100010003981601301830373037241432895100010001000303730371110011000000073216112629100030383038303830383038
100430372300612547251000100010003981601301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372300612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372400612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372300612547251000100010003981601301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372400612547251000100010003981600301830373037241432895100010001000303730371110011000000073116112629100030383038303830383038
100430372300612547251000100010003981601301830373037241432895100010001000303730371110011000001073116112629100030383038303830383038
100430372400612547251000100010003981601301830373037241432895100010001000303730371110011000001073116112629100030383038303830383038
1004303723012612547251000100010003981601301830373037241432895100010001000303730371110011000005073116112629100030383038303830383038
10043037230061254725100010001000398160130183037303724143289510001000100030373037111001100000015373116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtzs v0.2d, 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)0307080a0b18191e1f3a3f4e51inst 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)9fa0a1a6a7a8a9acc2cfd0d5d6ddinst fetch restart (de)e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10204300372320000000007262954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000710021611296330100001003003830038300383003830038
1020430037233000000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000710011611296330100001003003830038300383003830038
1020430037233000000000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000002000710011611296330100001003003830038300383003830038
10204300372330000006000612954725101001001000010010000500427716013001830037300372826432876310100200100002001000030037300371110201100991001001000010000001060710011611297058100001003003830038300383003830038
10204300372330000000001032954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000710011611296330100001003003830038300383003830038
10204300372320000000002452954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000000710011613296330100001003003830038300383003830038
10204300372330000003000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000003000710011611296330100001003003830038300383003830038
1020430037233000004000612954725101001281000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000000030710011621296330100001003003830038300383003830038
10204300372320000000001032954796101001001000010010000500427716013001830037301792826432874510100200100002001000030037300371110201100991001001000010000300000710011611296330100001003003830038300383003830038
10204300372330000000001032954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037302161110201100991001001000010000000000710011611296330100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire (01)cycle (02)031e1f3f4e51inst 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)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)9fa1acc5cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
10024300372253008229547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316432962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316332962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316332962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316432962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316332962910000103008530038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316342962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316332962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316432962910000103003830038300383003830038
1002430037225006129547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316332962910000103003830038300383003830038
100243003722412025029547251001010100001010000504277160300183003730037282860328767100102010000201000030037300371110021109101010000100000640316432962910000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtzs v0.2d, v8.2d, #3
  fcvtzs v1.2d, v8.2d, #3
  fcvtzs v2.2d, v8.2d, #3
  fcvtzs v3.2d, v8.2d, #3
  fcvtzs v4.2d, v8.2d, #3
  fcvtzs v5.2d, v8.2d, #3
  fcvtzs v6.2d, v8.2d, #3
  fcvtzs v7.2d, 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)031e3f5051inst 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)9fa8acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042006815514130025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182162220036800001002004020040200402004020040
80204200391562730025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010003011151182162220036800001002004020040200402004020040
8020420039155030025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000211151182161220036800001002004020040200402004020040
80204200391553030025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182162120036800001002004020040200402004020040
802042003915527630025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182161220036800001002004020040200402004020040
802042003915545030025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151181162120036800001002004020040200402004020040
8020420039156030025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182161220036800001002004020040200402004020040
8020420039156030025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182163220036800001002004020040200402004020040
8020420039156630025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000011151181162220036800001002004020040200402004020040
80204200391552730025801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000011151182161220036800001002004020040200402004020040

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)6061696d6edispatch 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)9fa6a8accfd0d2d5d6ddinst fetch restart (de)e0eb? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420039155010325800101080000108000050640000002002020039200399995310019800102080000208000020039200391180021109101080000100005020006163520036080000102004020040200402004020040
800242003915504025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020005163520036080000102004020040200402017420040
800242003915504025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020005163520036080000102004020040200402004020040
800242003915504025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020003163520036080000102004020040200402004020040
8002420039155364025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020003165320036429380000102004020040200402004020040
800242003918704025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020003163520036080000102004020040200402004020040
800242003916004025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020003163520036080000102004020040200402004020040
800242003915504025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020005163520036080000102004020040200402004020040
800242003915504025800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020005165320036080000102004020040200402004020040
800242003915506125800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005020005163520036080000102004020040200402004020040