Apple M1 Microarchitecture Research by Dougall Johnson

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

FCMLT (scalar, zero, H)

Test 1: uops

Code:

  fcmlt h0, h0, #0
  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)03081e3f4e51inst 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)a6a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10042037150961168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150961168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
100420371500103168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
100420371500168168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150084168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037160061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038
10042037150061168625100010001000264521120182037203715713189510001000100020372037111001100000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  fcmlt h0, h0, #0
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 2.0037

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)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)9fa8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
102042003715000661968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715000611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038
102042003715009611968625101001001000010010000500284752120018200372003718421318745101002001000020010000200372003711102011009910010010000100007101161119791100001002003820038200382003820038

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

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)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)9fa1a8accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
1002420037150001031968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010010640216221978610000102003820038200382003820038
1002420037150120611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010010640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010013640216221978610000102003820038200382003820038
1002420037150001661968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
1002420037150007491968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038
100242003715000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000640216221978610000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  fcmlt h0, h8, #0
  fcmlt h1, h8, #0
  fcmlt h2, h8, #0
  fcmlt h3, h8, #0
  fcmlt h4, h8, #0
  fcmlt h5, h8, #0
  fcmlt h6, h8, #0
  fcmlt h7, h8, #0
  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)0318191e3f51inst 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)9fa8a9acc2c5branch mispredict (cb)cdcfd5d6e0? int output thing (e9)? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
802042003815000012425801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118416200350800001002003920039200392003920039
802042003815000152925801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392003920039
802042003815000074625801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392003920039
802042003815000066225801081008000810080020500640132020019200492003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392003920039
8020420038150000292580108100800081008002050064013212001920038200389977699898012020080032200800322003820038118020110099100100800001005501201115118016200350800001002003920039200392003920039
802042003815000029125801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000301115118016200350800001002003920039200392003920039
80204200381500002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392003920039
80204200381500002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392009120039
80204200381500002925801081008000810080020500640132020019200382003899776998980120200800322008003220038200921180201100991001008000010000001115118016200350800001002003920039200392003920039
802042003815000069425801081008000810080020500640132020019200382003899776998980120200800322008003220038200381180201100991001008000010000001115118016200350800001002003920039200392003920039

1000 unrolls and 10 iterations

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

retire (01)cycle (02)0308191e3f51inst 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)9fa8a9accfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80024200391500003925800101080000108000050640000020019200382003899960310018800102080000208000020038200381180021109101080000100005032116112003580000102003920039200392003920039
80024200381500003925800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005032116122003580000102003920039200392003920039
80024200381500003925800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039
80024200381500063925800101080000108000050640000120019200382003899967310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039
800242003815000025225800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005032316312003580000102003920039200392003920039
800242003815001012725800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005032116112003580000102003920039200392003920039
80024200381500003925800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039
80024200381500003925800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039
80024200381500003925800101080000108000050640000020019200382003899960310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039
80024200381500003925800101080000108000050640000120019200382003899960310018800102080000208000020038200381180021109101080000100005030116112003580000102003920039200392003920039