Apple M1 Microarchitecture Research by Dougall Johnson

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

SQSHLU (vector, 4H)

Test 1: uops

Code:

  sqshlu v0.4h, v0.4h, #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)03080918191e1f3f4e51inst 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)a6a8a9acc2cfd5d6ddinst fetch restart (de)e0? fp/simd (ee)f5f6f7f8fd
10042037160000006116862510001000100026452102018203720371571318951000100010002037203711100110000003073216111786100020382038203820382038
10042037150000006116862510001000100026452112018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
10042037150000006116862510001000100026452102018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
100420371500000010316862510001000100026452102018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
10042037160000006116862510001000100026452112018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
10042037160000006116862510001000100026452112018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
10042037150000006116862510001000100026452102018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
10042037150000006116862510001000100026452112018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
100420371500000013716862510001000100026452102018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038
100420371500001206116862510001000100026452112018203720371571318951000100010002037203711100110000000073116111786100020382038203820382038

Test 2: Latency 1->2

Code:

  sqshlu v0.4h, v0.4h, #3
  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)030b18191e1f3f4e51inst 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
1020420037150000120061196862510100100100001001000062828475210200182003720037184213187451042820010000200100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820038
10204200371500000061196862510100100100001001000050028475210200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820038
10204200371500006061196752510100100100001001000050028475211200182003720037184243187451026220810000200100002003720037211020110099100100100001004000000071011611197910100001002003820038200382003820038
10204200371500003061196862510100100100001001015250028475211200182003720037184243187451010020410000212100002003720037111020110099100100100001000000100071011611197910100001002003820038200382003820038
10204200371500000061196862510100100100001001000050028475211200182003720037184213187451058120010000202100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820038
10204200371500000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000003071011611197910100001002003820038200382003820038
102042003715000012061196862510100100100001001000050028475210200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820038
1020420037150000396061196862510100100100001001000050028475210200182003720037184213187451010020010000200100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820038
10204200371500000061196862510100100100001001000050028475211200182003720037184213187451010020010000200100002003720037111020110099100100100001000000003071011611197910100001002003820038200382003820038
10204200371490009061196862510100100100001001000051728475211200182003720037184213187611010020010000200100002003720037111020110099100100100001000000000071011611197910100001002003820038200382003820086

1000 unrolls and 10 iterations

Result (median cycles for code): 2.0037

retire (01)cycle (02)0308090a0b18191e1f3f4e51inst 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
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037150000000001471968625100101010000101000050284752112001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100221010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000611968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
100242003715000000000821968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038
1002420037149000000001451968625100101010000101000050284752102001820037200371844331876710010201000020100002003720037111002110910101000010000000006402162219786010000102003820038200382003820038

Test 3: throughput

Count: 8

Code:

  sqshlu v0.4h, v8.4h, #3
  sqshlu v1.4h, v8.4h, #3
  sqshlu v2.4h, v8.4h, #3
  sqshlu v3.4h, v8.4h, #3
  sqshlu v4.4h, v8.4h, #3
  sqshlu v5.4h, v8.4h, #3
  sqshlu v6.4h, v8.4h, #3
  sqshlu v7.4h, v8.4h, #3
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2506

retire (01)cycle (02)030818191e1f3f51inst 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)9fa0a6a8a9acc2c5branch mispredict (cb)cdcfd5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
80204200571500008703425801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151184160020035800001002003920039200392003920039
80204200381500002102925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392011020039
80204200381500002402925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000100011151180160020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038201971180201100991001008000010000000011151180160020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392003920039
80204200381500000059925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180161020035800001002003920039200392003920039
8020420038150000002925801081008000810080020500640132120019200382003899776998980120200800322008003220038200381180201100991001008000010000000011151180160020035800001002003920039200392003920039

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)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)9fa8a9cficache miss (d3)d5d6ddinst fetch restart (de)e0? fp/simd (ee)gpr retires (ef)f5f6f7f8fd
8002420050150693925800101080000108000050640000120019200382003899963100188001020800002080000200382013811800211091010800001000502001916992003580000102003920039200392003920039
8002420038150039258001010800001080000506400001200192003820038999631001880010208000020800002003820038118002110910108000010005020010165112003580000102003920039200392003920039
80024200381500392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100050200716482003580000102003920039200392003920039
800242003815029439258001010800001080000506400001200192003820038999631001880010208000020800002003820038118002110910108000010005020011169102003580000102003920039200392003920039
800242003815003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000502008161092003580000102003920039200392003920039
80024200381509392580087108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100050200916892008580000102003920039200392003920039
80024200381500392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100050200516862003580000102003920039200392003920039
800242003815024392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100050200816952003580000102003920039200392003920039
800242003815003925800101080000108000050640000120019200382003899963100188001020800002080000200382003811800211091010800001000502009167102003580000102003920039200392003920039
80024200381500392580010108000010800005064000012001920038200389996310018800102080000208000020038200381180021109101080000100050200416472003580000102003920039200392003920039