Are you interested in merging std::simd enhanced and 2-4x faster code in general i'm working on?

[GrigoryEvko]

Hi, I'm working for my project on rust-decimal implementation with highly optimized operations, using std::simd, byte shifts, magic number usage, branch prediction optimized and branchless where reasonable code, with many fast path implementations for common real world cases, and with various features like Decimal GEMM implementation with optional avx2 and avx512 instructions, vector and matrix operations, maybe i will decide to make a GPU version later, i don't know for now.

Question is would you be interested in merging the code 2-4 times faster in general and up to 50x faster in some cases?

If you would, then I will try to maintain compatibility with your implementation, if you are not interested, I will just build it for myself.

[Tony-Samuels]

I'd be interested in seeing what it looked like, at least. Do you have a branch I can take a look at?

[zeroflaw]

I've been attempting to enhance the performance of rust-decimal on my own branch, there is definitely places where it can be improved. I've spent around 3 months full-time on this so far, still have some work to do.

rust_decimal = 1.37.2
optimised_decimal = local_branch

test add::b32::bench_equal_scale_rust_decimal                         ... bench:       9,672.95 ns/iter (+/- 134.50) = 1654 MB/s
test add::b32::bench_equal_scale_optimised_decimal                    ... bench:       2,110.79 ns/iter (+/- 50.91) = 8056 MB/s
test add::b32::bench_greater_scale_rust_decimal                       ... bench:      12,797.90 ns/iter (+/- 379.32) = 1250 MB/s
test add::b32::bench_greater_scale_optimised_decimal                  ... bench:       3,082.88 ns/iter (+/- 78.00) = 5515 MB/s
test add::b32::bench_less_scale_rust_decimal                          ... bench:      12,798.61 ns/iter (+/- 293.34) = 1250 MB/s
test add::b32::bench_less_scale_optimised_decimal                     ... bench:       3,087.82 ns/iter (+/- 145.77) = 5506 MB/s
test add::b64::bench_equal_scale_rust_decimal                         ... bench:      10,592.66 ns/iter (+/- 156.91) = 1510 MB/s
test add::b64::bench_equal_scale_optimised_decimal                    ... bench:       2,111.37 ns/iter (+/- 39.30) = 8053 MB/s
test add::b64::bench_greater_scale_rust_decimal                       ... bench:      13,281.24 ns/iter (+/- 639.66) = 1204 MB/s
test add::b64::bench_greater_scale_optimised_decimal                  ... bench:       3,087.73 ns/iter (+/- 71.87) = 5506 MB/s
test add::b64::bench_less_scale_rust_decimal                          ... bench:      13,312.21 ns/iter (+/- 493.53) = 1201 MB/s
test add::b64::bench_less_scale_optimised_decimal                     ... bench:       3,096.58 ns/iter (+/- 2,455.97) = 5490 MB/s
test add::b96::bench_equal_scale_rust_decimal                         ... bench:      10,421.87 ns/iter (+/- 511.14) = 1535 MB/s
test add::b96::bench_equal_scale_optimised_decimal                    ... bench:       2,109.75 ns/iter (+/- 47.18) = 8060 MB/s
test add::b96::bench_greater_scale_rust_decimal                       ... bench:      25,116.41 ns/iter (+/- 766.55) = 637 MB/s
test add::b96::bench_greater_scale_optimised_decimal                  ... bench:       3,077.07 ns/iter (+/- 88.05) = 5524 MB/s
test add::b96::bench_less_scale_rust_decimal                          ... bench:      25,433.42 ns/iter (+/- 658.55) = 629 MB/s
test add::b96::bench_less_scale_optimised_decimal                     ... bench:       3,088.02 ns/iter (+/- 77.12) = 5505 MB/s
test cmp::b32::bench_equal_scale_rust_decimal                         ... bench:       2,857.32 ns/iter (+/- 125.75) = 5600 MB/s
test cmp::b32::bench_equal_scale_optimised_decimal                    ... bench:       1,526.54 ns/iter (+/- 28.59) = 11140 MB/s
test cmp::b32::bench_greater_scale_rust_decimal                       ... bench:       4,250.53 ns/iter (+/- 69.47) = 3764 MB/s
test cmp::b32::bench_greater_scale_optimised_decimal                  ... bench:       3,327.77 ns/iter (+/- 99.42) = 5109 MB/s
test cmp::b32::bench_less_scale_rust_decimal                          ... bench:       4,265.66 ns/iter (+/- 109.52) = 3751 MB/s
test cmp::b32::bench_less_scale_optimised_decimal                     ... bench:       3,320.95 ns/iter (+/- 75.34) = 5120 MB/s
test div::b32::bench_equal_scale_rust_decimal                         ... bench:      18,763.15 ns/iter (+/- 552.83) = 852 MB/s
test div::b32::bench_equal_scale_optimised_decimal                    ... bench:       6,600.89 ns/iter (+/- 247.09) = 2575 MB/s
test div::b32::bench_greater_scale_rust_decimal                       ... bench:      18,239.59 ns/iter (+/- 565.22) = 877 MB/s
test div::b32::bench_greater_scale_optimised_decimal                  ... bench:       5,915.34 ns/iter (+/- 660.94) = 2874 MB/s
test div::b32::bench_less_scale_rust_decimal                          ... bench:      18,703.56 ns/iter (+/- 252.31) = 855 MB/s
test div::b32::bench_less_scale_optimised_decimal                     ... bench:       4,656.47 ns/iter (+/- 123.34) = 3651 MB/s
test div::b64::bench_equal_scale_rust_decimal                         ... bench:      12,318.88 ns/iter (+/- 459.85) = 1298 MB/s
test div::b64::bench_equal_scale_optimised_decimal                    ... bench:       5,466.46 ns/iter (+/- 297.66) = 3110 MB/s
test div::b64::bench_greater_scale_rust_decimal                       ... bench:      15,393.84 ns/iter (+/- 218.26) = 1039 MB/s
test div::b64::bench_greater_scale_optimised_decimal                  ... bench:       6,689.66 ns/iter (+/- 161.77) = 2541 MB/s
test div::b64::bench_less_scale_rust_decimal                          ... bench:      12,357.18 ns/iter (+/- 607.75) = 1294 MB/s
test div::b64::bench_less_scale_optimised_decimal                     ... bench:       4,701.60 ns/iter (+/- 44.43) = 3616 MB/s
test div::b96::bench_equal_scale_rust_decimal                         ... bench:      45,632.23 ns/iter (+/- 2,500.15) = 350 MB/s
test div::b96::bench_equal_scale_optimised_decimal                    ... bench:      12,392.93 ns/iter (+/- 331.95) = 1371 MB/s
test div::b96::bench_greater_scale_rust_decimal                       ... bench:      45,985.65 ns/iter (+/- 852.34) = 347 MB/s
test div::b96::bench_greater_scale_optimised_decimal                  ... bench:      18,363.01 ns/iter (+/- 655.54) = 925 MB/s
test div::b96::bench_less_scale_rust_decimal                          ... bench:      29,136.51 ns/iter (+/- 1,173.98) = 549 MB/s
test div::b96::bench_less_scale_optimised_decimal                     ... bench:      12,075.68 ns/iter (+/- 205.52) = 1407 MB/s
test eq::b32::bench_equal_scale_rust_decimal                          ... bench:       3,060.43 ns/iter (+/- 66.41) = 5228 MB/s
test eq::b32::bench_equal_scale_optimised_decimal                     ... bench:       1,427.18 ns/iter (+/- 84.00) = 11913 MB/s
test eq::b32::bench_greater_scale_rust_decimal                        ... bench:       4,291.56 ns/iter (+/- 146.30) = 3728 MB/s
test eq::b32::bench_greater_scale_optimised_decimal                   ... bench:       3,319.52 ns/iter (+/- 76.64) = 5122 MB/s
test eq::b32::bench_less_scale_rust_decimal                           ... bench:       4,308.64 ns/iter (+/- 88.32) = 3714 MB/s
test eq::b32::bench_less_scale_optimised_decimal                      ... bench:       3,325.01 ns/iter (+/- 75.55) = 5112 MB/s
test eq::b64::bench_equal_scale_rust_decimal                          ... bench:       3,056.20 ns/iter (+/- 73.14) = 5235 MB/s
test eq::b64::bench_equal_scale_optimised_decimal                     ... bench:       1,431.40 ns/iter (+/- 125.65) = 11879 MB/s
test eq::b64::bench_greater_scale_rust_decimal                        ... bench:       4,493.31 ns/iter (+/- 88.06) = 3561 MB/s
test eq::b64::bench_greater_scale_optimised_decimal                   ... bench:       3,338.00 ns/iter (+/- 92.83) = 5092 MB/s
test eq::b64::bench_less_scale_rust_decimal                           ... bench:       4,492.07 ns/iter (+/- 210.36) = 3561 MB/s
test eq::b64::bench_less_scale_optimised_decimal                      ... bench:       3,323.06 ns/iter (+/- 85.02) = 5115 MB/s
test eq::b96::bench_equal_scale_rust_decimal                          ... bench:       3,056.25 ns/iter (+/- 70.71) = 5235 MB/s
test eq::b96::bench_equal_scale_optimised_decimal                     ... bench:       1,416.15 ns/iter (+/- 69.76) = 12005 MB/s
test eq::b96::bench_greater_scale_rust_decimal                        ... bench:       4,500.51 ns/iter (+/- 217.01) = 3555 MB/s
test eq::b96::bench_greater_scale_optimised_decimal                   ... bench:       3,188.44 ns/iter (+/- 184.44) = 5332 MB/s
test eq::b96::bench_less_scale_rust_decimal                           ... bench:       4,513.98 ns/iter (+/- 232.05) = 3545 MB/s
test eq::b96::bench_less_scale_optimised_decimal                      ... bench:       3,325.58 ns/iter (+/- 69.24) = 5112 MB/s
test fmt::b32::bench_debug_3_significant_3_scale_rust_decimal         ... bench:      40,425.91 ns/iter (+/- 774.17) = 395 MB/s
test fmt::b32::bench_debug_3_significant_3_scale_optimised_decimal    ... bench:      36,666.33 ns/iter (+/- 1,091.88) = 463 MB/s
test fmt::b32::bench_format_3_significant_3_scale_rust_decimal        ... bench:      39,601.96 ns/iter (+/- 953.84) = 404 MB/s
test fmt::b32::bench_format_3_significant_3_scale_optimised_decimal   ... bench:      36,435.09 ns/iter (+/- 1,034.99) = 466 MB/s
test mul::b32::bench_equal_scale_rust_decimal                         ... bench:       9,854.37 ns/iter (+/- 113.25) = 1623 MB/s
test mul::b32::bench_equal_scale_optimised_decimal                    ... bench:       3,566.63 ns/iter (+/- 213.61) = 4767 MB/s
test mul::b32::bench_greater_scale_rust_decimal                       ... bench:       9,852.51 ns/iter (+/- 172.93) = 1624 MB/s
test mul::b32::bench_greater_scale_optimised_decimal                  ... bench:       3,545.20 ns/iter (+/- 96.68) = 4795 MB/s
test mul::b32::bench_less_scale_rust_decimal                          ... bench:       9,843.73 ns/iter (+/- 66.30) = 1625 MB/s
test mul::b32::bench_less_scale_optimised_decimal                     ... bench:       3,551.98 ns/iter (+/- 62.25) = 4787 MB/s
test mul::b64::bench_equal_scale_rust_decimal                         ... bench:      10,895.15 ns/iter (+/- 162.23) = 1468 MB/s
test mul::b64::bench_equal_scale_optimised_decimal                    ... bench:       3,567.06 ns/iter (+/- 86.48) = 4765 MB/s
test mul::b64::bench_greater_scale_rust_decimal                       ... bench:      10,913.55 ns/iter (+/- 129.18) = 1466 MB/s
test mul::b64::bench_greater_scale_optimised_decimal                  ... bench:       3,555.14 ns/iter (+/- 88.66) = 4781 MB/s
test mul::b64::bench_less_scale_rust_decimal                          ... bench:      10,926.43 ns/iter (+/- 214.70) = 1464 MB/s
test mul::b64::bench_less_scale_optimised_decimal                     ... bench:       3,564.06 ns/iter (+/- 110.92) = 4769 MB/s
test mul::b96::bench_equal_scale_rust_decimal                         ... bench:      10,420.90 ns/iter (+/- 164.49) = 1535 MB/s
test mul::b96::bench_equal_scale_optimised_decimal                    ... bench:       3,554.49 ns/iter (+/- 90.53) = 4783 MB/s
test mul::b96::bench_greater_scale_rust_decimal                       ... bench:      10,447.56 ns/iter (+/- 101.15) = 1531 MB/s
test mul::b96::bench_greater_scale_optimised_decimal                  ... bench:       3,531.92 ns/iter (+/- 159.83) = 4814 MB/s
test mul::b96::bench_less_scale_rust_decimal                          ... bench:      10,440.73 ns/iter (+/- 94.00) = 1532 MB/s
test mul::b96::bench_less_scale_optimised_decimal                     ... bench:       3,557.88 ns/iter (+/- 76.44) = 4779 MB/s
test normalize::b32::bench_00_scale_rust_decimal                      ... bench:       3,313.06 ns/iter (+/- 114.33) = 4829 MB/s
test normalize::b32::bench_00_scale_optimised_decimal                 ... bench:       2,607.70 ns/iter (+/- 102.52) = 6520 MB/s
test normalize::b32::bench_01_scale_rust_decimal                      ... bench:       5,020.11 ns/iter (+/- 116.13) = 3187 MB/s
test normalize::b32::bench_01_scale_optimised_decimal                 ... bench:       3,286.57 ns/iter (+/- 93.34) = 5173 MB/s
test normalize::b96::bench_00_scale_rust_decimal                      ... bench:       3,346.78 ns/iter (+/- 124.95) = 4781 MB/s
test normalize::b96::bench_00_scale_optimised_decimal                 ... bench:       2,605.38 ns/iter (+/- 66.01) = 6525 MB/s
test normalize::b96::bench_01_scale_rust_decimal                      ... bench:       4,984.72 ns/iter (+/- 37.98) = 3210 MB/s
test normalize::b96::bench_01_scale_optimised_decimal                 ... bench:       3,838.88 ns/iter (+/- 171.12) = 4429 MB/s
test normalize::b96::bench_03_scale_rust_decimal                      ... bench:       7,638.42 ns/iter (+/- 230.55) = 2094 MB/s
test normalize::b96::bench_03_scale_optimised_decimal                 ... bench:       4,789.56 ns/iter (+/- 137.68) = 3549 MB/s
test normalize::b96::bench_06_scale_rust_decimal                      ... bench:      12,492.48 ns/iter (+/- 612.77) = 1280 MB/s
test normalize::b96::bench_06_scale_optimised_decimal                 ... bench:       6,096.27 ns/iter (+/- 202.55) = 2788 MB/s
test normalize::b96::bench_09_scale_rust_decimal                      ... bench:      17,347.20 ns/iter (+/- 423.48) = 922 MB/s
test normalize::b96::bench_09_scale_optimised_decimal                 ... bench:      11,501.36 ns/iter (+/- 211.00) = 1478 MB/s
test normalize::b96::bench_12_scale_rust_decimal                      ... bench:      21,955.57 ns/iter (+/- 471.51) = 728 MB/s
test normalize::b96::bench_12_scale_optimised_decimal                 ... bench:      13,281.41 ns/iter (+/- 405.10) = 1280 MB/s
test other::floor::bench_06_scale_rust_decimal                        ... bench:      11,341.29 ns/iter (+/- 272.53) = 1410 MB/s
test other::floor::bench_06_scale_optimised_decimal                   ... bench:       4,271.91 ns/iter (+/- 224.42) = 3746 MB/s
test other::fract::bench_06_scale_rust_decimal                        ... bench:      15,306.17 ns/iter (+/- 361.14) = 1045 MB/s
test other::fract::bench_06_scale_optimised_decimal                   ... bench:       4,029.30 ns/iter (+/- 82.38) = 3971 MB/s
test other::sign::bench_set_sign_pos_from_neg_rust_decimal            ... bench:       6,145.74 ns/iter (+/- 161.26) = 2603 MB/s
test other::sign::bench_set_sign_pos_from_neg_optimised_decimal       ... bench:       1,781.00 ns/iter (+/- 119.29) = 8983 MB/s
test other::sign::bench_set_sign_pos_from_pos_rust_decimal            ... bench:       6,123.39 ns/iter (+/- 125.73) = 2613 MB/s
test other::sign::bench_set_sign_pos_from_pos_optimised_decimal       ... bench:       1,784.30 ns/iter (+/- 85.88) = 8968 MB/s
test other::trunc::bench_06_scale_rust_decimal                        ... bench:      11,070.23 ns/iter (+/- 651.62) = 1445 MB/s
test other::trunc::bench_06_scale_optimised_decimal                   ... bench:       4,011.32 ns/iter (+/- 82.18) = 3989 MB/s
test rem::b32::bench_equal_scale_rust_decimal                         ... bench:      12,457.92 ns/iter (+/- 673.25) = 1284 MB/s
test rem::b32::bench_equal_scale_optimised_decimal                    ... bench:       2,815.95 ns/iter (+/- 74.91) = 6039 MB/s
test rem::b32::bench_greater_scale_rust_decimal                       ... bench:      30,440.41 ns/iter (+/- 792.00) = 525 MB/s
test rem::b32::bench_greater_scale_optimised_decimal                  ... bench:       6,179.74 ns/iter (+/- 174.45) = 2751 MB/s
test rem::b32::bench_less_scale_rust_decimal                          ... bench:      12,294.52 ns/iter (+/- 461.78) = 1301 MB/s
test rem::b32::bench_less_scale_optimised_decimal                     ... bench:       5,171.60 ns/iter (+/- 154.01) = 3287 MB/s
test rem::b64::bench_equal_scale_rust_decimal                         ... bench:      10,553.57 ns/iter (+/- 123.40) = 1516 MB/s
test rem::b64::bench_equal_scale_optimised_decimal                    ... bench:       3,276.94 ns/iter (+/- 35.35) = 5189 MB/s
test rem::b64::bench_greater_scale_rust_decimal                       ... bench:      39,835.25 ns/iter (+/- 2,009.81) = 401 MB/s
test rem::b64::bench_greater_scale_optimised_decimal                  ... bench:       6,413.46 ns/iter (+/- 158.94) = 2650 MB/s
test rem::b64::bench_less_scale_rust_decimal                          ... bench:      12,702.23 ns/iter (+/- 414.40) = 1259 MB/s
test rem::b64::bench_less_scale_optimised_decimal                     ... bench:       5,423.78 ns/iter (+/- 231.49) = 3134 MB/s
test rem::b96::bench_equal_scale_rust_decimal                         ... bench:      14,239.58 ns/iter (+/- 310.91) = 1123 MB/s
test rem::b96::bench_equal_scale_optimised_decimal                    ... bench:       5,909.60 ns/iter (+/- 99.21) = 2876 MB/s
test rem::b96::bench_greater_scale_rust_decimal                       ... bench:      42,402.63 ns/iter (+/- 558.66) = 377 MB/s
test rem::b96::bench_greater_scale_optimised_decimal                  ... bench:       8,806.29 ns/iter (+/- 226.58) = 1930 MB/s
test rem::b96::bench_less_scale_rust_decimal                          ... bench:      12,354.15 ns/iter (+/- 730.74) = 1295 MB/s
test rem::b96::bench_less_scale_optimised_decimal                     ... bench:       5,642.74 ns/iter (+/- 135.91) = 3013 MB/s
test rescale::b32::bench_00_scale_rust_decimal                        ... bench:       3,547.20 ns/iter (+/- 69.78) = 4510 MB/s
test rescale::b32::bench_00_scale_optimised_decimal                   ... bench:       1,759.08 ns/iter (+/- 115.45) = 9664 MB/s
test rescale::b32::bench_01_scale_rust_decimal                        ... bench:       5,225.29 ns/iter (+/- 97.44) = 3062 MB/s
test rescale::b32::bench_01_scale_optimised_decimal                   ... bench:       4,737.55 ns/iter (+/- 135.05) = 3588 MB/s
test rescale::b32::bench_02_scale_rust_decimal                        ... bench:       7,016.96 ns/iter (+/- 219.10) = 2280 MB/s
test rescale::b32::bench_02_scale_optimised_decimal                   ... bench:       5,449.49 ns/iter (+/- 149.44) = 3119 MB/s
test rescale::b32::bench_12_scale_rust_decimal                        ... bench:      20,010.53 ns/iter (+/- 1,037.99) = 799 MB/s
test rescale::b32::bench_12_scale_optimised_decimal                   ... bench:       5,445.74 ns/iter (+/- 138.92) = 3122 MB/s
test rescale::b96::bench_12_scale_rust_decimal                        ... bench:      23,597.70 ns/iter (+/- 669.64) = 678 MB/s
test rescale::b96::bench_12_scale_optimised_decimal                   ... bench:       7,403.32 ns/iter (+/- 194.41) = 2296 MB/s
test round_dp::b32::bench_3_scale_2_round_rust_decimal                ... bench:      14,768.52 ns/iter (+/- 408.22) = 1083 MB/s
test round_dp::b32::bench_3_scale_2_round_optimised_decimal           ... bench:       4,490.29 ns/iter (+/- 285.88) = 3786 MB/s
test round_dp::b96::bench_12_scale_03_round_rust_decimal              ... bench:      19,845.35 ns/iter (+/- 584.19) = 806 MB/s
test round_dp::b96::bench_12_scale_03_round_optimised_decimal         ... bench:       8,206.47 ns/iter (+/- 126.35) = 2071 MB/s
test round_dp::b96::bench_12_scale_06_round_rust_decimal              ... bench:      17,987.94 ns/iter (+/- 629.79) = 889 MB/s
test round_dp::b96::bench_12_scale_06_round_optimised_decimal         ... bench:       8,740.54 ns/iter (+/- 138.83) = 1945 MB/s
test round_dp::b96::bench_12_scale_09_round_rust_decimal              ... bench:      16,449.32 ns/iter (+/- 692.90) = 972 MB/s
test round_dp::b96::bench_12_scale_09_round_optimised_decimal         ... bench:       8,751.68 ns/iter (+/- 189.51) = 1942 MB/s
test round_dp::b96::bench_12_scale_11_round_rust_decimal              ... bench:      15,700.49 ns/iter (+/- 355.46) = 1019 MB/s
test round_dp::b96::bench_12_scale_11_round_optimised_decimal         ... bench:       8,317.89 ns/iter (+/- 195.99) = 2044 MB/s
test round_sf::b32::bench_3_significant_2_round_rust_decimal          ... bench:      53,090.58 ns/iter (+/- 762.28) = 301 MB/s
test round_sf::b32::bench_3_significant_2_round_optimised_decimal     ... bench:      29,123.68 ns/iter (+/- 221.28) = 583 MB/s

[Tony-Samuels]

If you open an MR, others may be able to help or to comment on your approaches. Those look like solid improvements though.