mirrors/arti.git/crates/hashx/src/program.rs, branch arti-v1.1.8

hashx: Cleanup around Instruction and NUM_INSTRUCTIONS

2023-08-25T20:14:24Z

This patch tries to make some of the expressions around NUM_INSTRUCTIONS more convenient. We can import it directly where it's needed, but most uses are replaced by new type aliases for InstructionArray and InstructionVec. No change to any hashx_cachegrind iai benchmarks

RFC: hashx: Make Architecture::compile take an array ref

2023-08-25T17:12:56Z

generate_interp_1000x Instructions: 219216169 (No change) L1 Accesses: 278017243 (-0.000441%) L2 Accesses: 1257 (+4389.286%) RAM Accesses: 415 (-0.479616%) Estimated Cycles: 278038053 (+0.001744%) generate_interp_1000x_c Instructions: 272748034 (No change) L1 Accesses: 349932964 (No change) L2 Accesses: 76 (-1.298701%) RAM Accesses: 411 (+0.243902%) Estimated Cycles: 349947729 (+0.000009%) generate_compiled_1000x Instructions: 256896028 (+0.175731%) L1 Accesses: 342543838 (+0.131802%) L2 Accesses: 149273 (-10.34924%) RAM Accesses: 810 (-0.246305%) Estimated Cycles: 343318553 (+0.106328%) generate_compiled_1000x_c Instructions: 281855218 (No change) L1 Accesses: 362569035 (-0.000001%) L2 Accesses: 88 (+1.149425%) RAM Accesses: 473 (+0.211864%) Estimated Cycles: 362586030 (+0.000010%) interp_u64_hash_1000x Instructions: 13450926 (No change) L1 Accesses: 16622561 (+0.000024%) L2 Accesses: 28 (No change) RAM Accesses: 390 (-1.015228%) Estimated Cycles: 16636351 (-0.000817%) interp_8b_hash_1000x_c Instructions: 8618541 (No change) L1 Accesses: 12316160 (-0.000008%) L2 Accesses: 80 (No change) RAM Accesses: 433 (+0.231481%) Estimated Cycles: 12331715 (+0.000276%) compiled_u64_hash_100000x Instructions: 87311792 (+0.000520%) L1 Accesses: 94396598 (+0.000463%) L2 Accesses: 215 (+2.380952%) RAM Accesses: 774 (-0.641849%) Estimated Cycles: 94424763 (+0.000304%) compiled_8b_hash_100000x_c Instructions: 91547640 (No change) L1 Accesses: 98838166 (-0.000007%) L2 Accesses: 137 (+3.007519%) RAM Accesses: 488 (+0.618557%) Estimated Cycles: 98855931 (+0.000119%)

Rustfmt

2023-08-24T16:01:44Z

hashx: FixedCapacityVec: Replace .into_boxed_array method with Try

2023-08-24T12:50:29Z

This version pushes the panic into the call site, which seems much better. No change to the iai results.

hashx: FixedCapacityVec: Move into its own module

2023-08-24T12:50:20Z

Rustfmt

2023-08-23T11:02:24Z

RFC: hashx: Introduce FixedCapacityVec

2023-08-23T10:59:24Z

This is quite shoddy. It shouldn't be merged without some tidying up and unit tests and so on. Also I am confused about the difference between NUM_INSTRUCTIONS and model::REQUIRED_INSTRUCTIONS. However: generate_interp_1000x Instructions: 220115418 (-1.147100%) L1 Accesses: 278918725 (-0.936103%) L2 Accesses: 25 (-98.46248%) RAM Accesses: 414 (-0.956938%) Estimated Cycles: 278933340 (-0.938920%) generate_interp_1000x_c Instructions: 272748034 (No change) L1 Accesses: 349932970 (+0.000001%) L2 Accesses: 76 (-1.298701%) RAM Accesses: 405 (-0.491400%) Estimated Cycles: 349947525 (-0.000021%) generate_compiled_1000x Instructions: 257344624 (-0.982784%) L1 Accesses: 343007206 (-0.753942%) L2 Accesses: 152502 (-17.12839%) RAM Accesses: 809 (-0.369458%) Estimated Cycles: 343798031 (-0.797384%) generate_compiled_1000x_c Instructions: 281855218 (No change) L1 Accesses: 362569043 (+0.000002%) L2 Accesses: 87 (-4.395604%) RAM Accesses: 466 (-0.427350%) Estimated Cycles: 362585788 (-0.000023%) interp_u64_hash_1000x Instructions: 13451818 (-0.100680%) L1 Accesses: 16623452 (-0.105967%) L2 Accesses: 28 (No change) RAM Accesses: 392 (-1.507538%) Estimated Cycles: 16637312 (-0.107138%) interp_8b_hash_1000x_c Instructions: 8618541 (No change) L1 Accesses: 12316165 (+0.000032%) L2 Accesses: 80 (-2.439024%) RAM Accesses: 428 (-0.465116%) Estimated Cycles: 12331545 (-0.000616%) compiled_u64_hash_100000x Instructions: 87312230 (-1.358594%) L1 Accesses: 94397055 (-1.669415%) L2 Accesses: 212 (-0.469484%) RAM Accesses: 776 (-0.767263%) Estimated Cycles: 94425275 (-1.669144%) compiled_8b_hash_100000x_c Instructions: 91547640 (No change) L1 Accesses: 98838176 (+0.000009%) L2 Accesses: 134 (-4.964539%) RAM Accesses: 481 (-0.414079%) Estimated Cycles: 98855681 (-0.000097%)

RFC: hashx: Make Program a boxed array

2023-08-23T10:02:08Z

generate_interp_1000x Instructions: 222669662 (-0.146601%) L1 Accesses: 281554367 (+0.069275%) L2 Accesses: 1623 (-90.13494%) RAM Accesses: 418 (No change) Estimated Cycles: 281577112 (+0.042908%) generate_interp_1000x_c Instructions: 272748034 (No change) L1 Accesses: 349932970 (+0.000001%) L2 Accesses: 74 (No change) RAM Accesses: 407 (-0.731707%) Estimated Cycles: 349947585 (-0.000029%) generate_compiled_1000x Instructions: 259898868 (-0.124860%) L1 Accesses: 345603941 (+0.055045%) L2 Accesses: 193008 (-4.001910%) RAM Accesses: 812 (-0.490196%) Estimated Cycles: 346597401 (+0.043228%) generate_compiled_1000x_c Instructions: 281855218 (No change) L1 Accesses: 362569040 (+0.000000%) L2 Accesses: 88 (+2.325581%) RAM Accesses: 468 (-0.636943%) Estimated Cycles: 362585860 (-0.000026%) interp_u64_hash_1000x Instructions: 13465375 (-0.024687%) L1 Accesses: 16641089 (-0.028974%) L2 Accesses: 25 (+8.695652%) RAM Accesses: 398 (+0.505051%) Estimated Cycles: 16655144 (-0.028470%) interp_8b_hash_1000x_c Instructions: 8618541 (No change) L1 Accesses: 12316165 (+0.000016%) L2 Accesses: 78 (No change) RAM Accesses: 430 (-0.462963%) Estimated Cycles: 12331605 (-0.000551%) compiled_u64_hash_100000x Instructions: 88514787 (-0.000365%) L1 Accesses: 95999693 (+0.000196%) L2 Accesses: 208 (-0.952381%) RAM Accesses: 782 (-0.255102%) Estimated Cycles: 96028103 (+0.000112%) compiled_8b_hash_100000x_c Instructions: 91547640 (No change) L1 Accesses: 98838171 (-0.000002%) L2 Accesses: 137 (+3.007519%) RAM Accesses: 483 (-0.412371%) Estimated Cycles: 98855761 (-0.000053%)

hashx: Use a boxed slice for Program storage

2023-08-21T22:27:28Z

This is a very small change that converts our Vec cheaply into a boxed slice during program generation. Program generation speed shows no changes, and there's no change when using compiled hashes, but is a surprisingly effective 10% speedup to interpreted hash execution. Signed-off-by: Micah Elizabeth Scott

hashx: New approach to avoid memcpy in Program

2023-08-21T22:27:28Z

I was trying to eliminate all the places where we copied a Program (about 4100 bytes) except for the one final copy into a Box; but that approach was proving too annoying. Even returning a Program via Result will cause multiple unnecessary copies that don't optimize out. This patch switches approaches, and instead allocates a Vec presized to the correct capacity. This allocation is made as early as possible and retained for the lifetime of the program if necessary. This means we'll never avoid a heap allocation, but we can always avoid extra copies and we don't need a separate Box for interpreted programs. Performance effects are subtle. Overall wallclock time doesn't change much. Cachegrind shows some accesses moving up from RAM to L2 cache. Using GDB to probe memcpy sizes shows that large (>1024b) memcpy are now totally gone in the generate-interp test. Signed-off-by: Micah Elizabeth Scott