Apple Microarchitecture Research by Dougall Johnson

M1/A14 P-core (Firestorm): Overview | Base Instructions | SIMD and FP Instructions
M1/A14 E-core (Icestorm):  Overview | Base Instructions | SIMD and FP Instructions

FCVTNS (vector, 4S)

Test 1: uops

Code:

  fcvtns v0.4s, v0.4s
  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 uop (01)cycle (02)03mmu table walk data (08)191e1f3f4e51schedule uop (52)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map simd uop (7e)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd alu (9a)l1d tlb access (a0)l1d cache writeback (a8)accfd5map dispatch bubble (d6)daddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
100430372400002642547251000100010003981600301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
100430372400001032547251000100010003981601301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
100430372400003712547251000100010003981600301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
100430372400006262547251000100010003981600301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
10043037230000612547251000100010003981601301830373037241432895100010001000303730371110011000400731160112629100030383038303830383038
10043037230000612547251000100010003981601301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
10043037240000612547251000100010003981600301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
10043037240000612547251000100010003981601301830373037241432895100010001000303730371110011000000731160112629100030383038303830383038
1004303723001201032547251000100010003981601301830373037241432895100010001000303730371110011000000731160112629100030383038307430383038
10043037240000612547251000100010003981601301830373037241432895100010001000303730371110011000019731160112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtns v0.4s, v0.4s
  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 uop (01)cycle (02)031e3f4e5051schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
10204300372320442295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100107101161129777100001003003830038300383003830038
102043003723302512954730021251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100107101161129633100001003003830038300383003830038
10204300372330612954730021251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
10204300372330612954730021251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
10204300372320612954730021251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
1020430037233061295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129742100001003003830038300383003830038
1020430037233061295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
1020430037233061295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
1020430037233061295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038
1020430037232061295470251010010010000100100005004277160030018300373003728264328745101002001000020010000300373003711102011009910010010000100007101161129633100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)031e3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)acbranch cond mispred nonspec (c5)cfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
10024300372330147295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000064041634296290010000103003830038300383003830038
10024300372330208295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000064041644296290010000103003830038300383003830038
1002430037233061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000064041634296290010000103003830038300383003830038
1002430037233061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000064041643296290010000103003830038300383003830038
1002430037233061295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001040064041643296290010000103003830038300383003830038
1002430037233084295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000064031644296290010000103003830038300383003830038
10024300372320166295472510010101000010100005042771601300183003730037282863287671001020100002010000300373003711100211091010100001000064041634296290010000103003830038300383003830038
1002430037232061295472510010101000010100005042771600300183003730037282863287671015820100002010000300373003711100211091010100001005570264031634296290010000103003830038300383003830038
1002430037232061295472510010101000010100005042771600300183003730037282863287671001020100002010000300373003711100211091010100001000064041622296290010000103003830038300383003830038
10024300372330189295472510010101000010100005042771601300183003730037282863287671016220100002010000300373003711100211091010100001003064041644296293010000103003830038300383003830038

Test 3: throughput

Count: 8

Code:

  fcvtns v0.4s, v8.4s
  fcvtns v1.4s, v8.4s
  fcvtns v2.4s, v8.4s
  fcvtns v3.4s, v8.4s
  fcvtns v4.4s, v8.4s
  fcvtns v5.4s, v8.4s
  fcvtns v6.4s, v8.4s
  fcvtns v7.4s, v8.4s
  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 uop (01)cycle (02)031e3a3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155007225801081008000810080020500640132020020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039156003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
80204200391550030225801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040
8020420039155003025801081008000810080020500640132120020200392003999776999080120200800322008003220039200391180201100991001008000010000111511801600200360800001002004020040200402004020040

1000 unrolls and 10 iterations

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

retire uop (01)cycle (02)03mmu table walk instruction (07)l2 tlb miss instruction (0a)191e1f3a3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)5f60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)accdcfd0d2l1i cache miss demand (d3)d5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
80024200511561100028951800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100015024000161614162003680000102004020040200402004020040
80024200391551100024725800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005024000171616132003680000102004020040200402004020040
800242003915611022510824725800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005024000161613152003680000102004020040200402004020040
80024200391561100024725800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100005024000151615132003680000102004020040200402004020040
8002420039155110002472580010108000010800005064000000200202003920039999631001980010208000020800002003920039118002110910108000010230506200016168152003680000102004020040200402004020040
80024200391551100024725800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005024000171616142003680000102004020040200402004020040
80024200391561100024725800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100005024000171617132003680000102004020040200402004020040
80024200391551100024725800101080000108000050640000002002020039200399996310019800102080000208000020039200391180021109101080000100005024000151616142003680000102004020040200402004020040
80024200391551100024725800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000100005024000131615142003680000102004020040200402004020040
800242003915511000224525800101080000108000050640000012002020039200399996310019800102080000208000020039200391180021109101080000101005024000231611122003680000102004020040200402004020040