rscrypto: adjusting thresholds for the Intel SPR triggers; adding the

CPU print to the comp benches.

Author: loadingalias

crates/checksum/bench_baseline/linux_arm64.txt

@@ -1,204 +1,179 @@
-Running benches/comp.rs (target/release/deps/comp-24ae1ad5b25f40af)
+Running benches/comp.rs (target/release/deps/comp-67526cd4db14de38)
 Gnuplot not found, using plotters backend
 crc64/xz/compare/rscrypto/aarch64/pmull-small/xs
-                        time:   [6.2976 ns 6.3893 ns 6.5079 ns]
-                        thrpt:  [9.1589 GiB/s 9.3288 GiB/s 9.4646 GiB/s]
-Found 3 outliers among 100 measurements (3.00%)
+                        time:   [7.7437 ns 7.8411 ns 7.9881 ns]
+                        thrpt:  [7.4617 GiB/s 7.6016 GiB/s 7.6972 GiB/s]
+Found 4 outliers among 100 measurements (4.00%)
+  1 (1.00%) low mild
   3 (3.00%) high severe
 crc64/xz/compare/crc64fast/auto/xs
-                        time:   [16.844 ns 16.866 ns 16.891 ns]
-                        thrpt:  [3.5288 GiB/s 3.5340 GiB/s 3.5386 GiB/s]
-Found 7 outliers among 100 measurements (7.00%)
-  2 (2.00%) high mild
-  5 (5.00%) high severe
+                        time:   [17.752 ns 17.939 ns 18.197 ns]
+                        thrpt:  [3.2755 GiB/s 3.3227 GiB/s 3.3577 GiB/s]
+Found 10 outliers among 100 measurements (10.00%)
+  2 (2.00%) low mild
+  4 (4.00%) high mild
+  4 (4.00%) high severe
 crc64/xz/compare/crc-fast/auto/xs
-                        time:   [17.541 ns 17.723 ns 17.883 ns]
-                        thrpt:  [3.3330 GiB/s 3.3631 GiB/s 3.3981 GiB/s]
-Found 22 outliers among 100 measurements (22.00%)
-  12 (12.00%) low severe
-  7 (7.00%) low mild
-  1 (1.00%) high mild
-  2 (2.00%) high severe
-crc64/xz/compare/rscrypto/aarch64/pmull-eor3/s
-                        time:   [8.5603 ns 8.5996 ns 8.6600 ns]
-                        thrpt:  [27.531 GiB/s 27.724 GiB/s 27.852 GiB/s]
+                        time:   [19.766 ns 19.910 ns 20.053 ns]
+                        thrpt:  [2.9724 GiB/s 2.9937 GiB/s 3.0155 GiB/s]
 Found 2 outliers among 100 measurements (2.00%)
-  2 (2.00%) high severe
+  2 (2.00%) high mild
+crc64/xz/compare/rscrypto/aarch64/pmull-eor3/s
+                        time:   [9.0965 ns 9.1473 ns 9.2309 ns]
+                        thrpt:  [25.828 GiB/s 26.064 GiB/s 26.210 GiB/s]
+Found 7 outliers among 100 measurements (7.00%)
+  1 (1.00%) low mild
+  3 (3.00%) high mild
+  3 (3.00%) high severe
 crc64/xz/compare/crc64fast/auto/s
-                        time:   [10.417 ns 10.426 ns 10.435 ns]
-                        thrpt:  [22.849 GiB/s 22.867 GiB/s 22.888 GiB/s]
-Found 18 outliers among 100 measurements (18.00%)
-  4 (4.00%) low severe
-  10 (10.00%) low mild
+                        time:   [10.605 ns 10.737 ns 11.009 ns]
+                        thrpt:  [21.657 GiB/s 22.206 GiB/s 22.481 GiB/s]
+Found 5 outliers among 100 measurements (5.00%)
+  2 (2.00%) low mild
   2 (2.00%) high mild
-  2 (2.00%) high severe
+  1 (1.00%) high severe
 crc64/xz/compare/crc-fast/auto/s
-                        time:   [13.214 ns 13.222 ns 13.231 ns]
-                        thrpt:  [18.020 GiB/s 18.032 GiB/s 18.043 GiB/s]
+                        time:   [17.298 ns 17.552 ns 17.814 ns]
+                        thrpt:  [13.383 GiB/s 13.583 GiB/s 13.783 GiB/s]
 Found 2 outliers among 100 measurements (2.00%)
-  2 (2.00%) low mild
-crc64/xz/compare/rscrypto/aarch64/pmull-eor3/m
-                        time:   [65.732 ns 65.786 ns 65.835 ns]
-                        thrpt:  [57.944 GiB/s 57.987 GiB/s 58.034 GiB/s]
-Found 16 outliers among 100 measurements (16.00%)
-  9 (9.00%) low severe
-  2 (2.00%) low mild
   1 (1.00%) high mild
-  4 (4.00%) high severe
+  1 (1.00%) high severe
+crc64/xz/compare/rscrypto/aarch64/pmull-eor3/m
+                        time:   [67.825 ns 68.594 ns 70.050 ns]
+                        thrpt:  [54.457 GiB/s 55.613 GiB/s 56.243 GiB/s]
+Found 3 outliers among 100 measurements (3.00%)
+  2 (2.00%) high mild
+  1 (1.00%) high severe
 crc64/xz/compare/crc64fast/auto/m
-                        time:   [67.372 ns 67.413 ns 67.447 ns]
-                        thrpt:  [56.558 GiB/s 56.587 GiB/s 56.621 GiB/s]
-Found 21 outliers among 100 measurements (21.00%)
-  7 (7.00%) low severe
-  1 (1.00%) low mild
-  4 (4.00%) high mild
-  9 (9.00%) high severe
+                        time:   [68.737 ns 68.923 ns 69.211 ns]
+                        thrpt:  [55.117 GiB/s 55.348 GiB/s 55.497 GiB/s]
+Found 9 outliers among 100 measurements (9.00%)
+  3 (3.00%) low mild
+  2 (2.00%) high mild
+  4 (4.00%) high severe
 crc64/xz/compare/crc-fast/auto/m
-                        time:   [69.514 ns 69.552 ns 69.582 ns]
-                        thrpt:  [54.823 GiB/s 54.847 GiB/s 54.877 GiB/s]
-Found 23 outliers among 100 measurements (23.00%)
-  11 (11.00%) low severe
-  2 (2.00%) low mild
-  5 (5.00%) high mild
-  5 (5.00%) high severe
+                        time:   [73.544 ns 73.902 ns 74.576 ns]
+                        thrpt:  [51.152 GiB/s 51.619 GiB/s 51.869 GiB/s]
+Found 11 outliers among 100 measurements (11.00%)
+  3 (3.00%) low mild
+  6 (6.00%) high mild
+  2 (2.00%) high severe
 crc64/xz/compare/rscrypto/aarch64/pmull-eor3-3way/l
-                        time:   [983.81 ns 984.23 ns 984.63 ns]
-                        thrpt:  [61.988 GiB/s 62.013 GiB/s 62.039 GiB/s]
-Found 14 outliers among 100 measurements (14.00%)
-  8 (8.00%) low severe
+                        time:   [1.0054 µs 1.0145 µs 1.0304 µs]
+                        thrpt:  [59.234 GiB/s 60.164 GiB/s 60.710 GiB/s]
+Found 11 outliers among 100 measurements (11.00%)
+  3 (3.00%) low mild
+  5 (5.00%) high mild
+  3 (3.00%) high severe
+crc64/xz/compare/crc64fast/auto/l
+                        time:   [1.0888 µs 1.1040 µs 1.1248 µs]
+                        thrpt:  [54.265 GiB/s 55.287 GiB/s 56.056 GiB/s]
+Found 10 outliers among 100 measurements (10.00%)
   2 (2.00%) low mild
   2 (2.00%) high mild
-  2 (2.00%) high severe
-crc64/xz/compare/crc64fast/auto/l
-                        time:   [1.0586 µs 1.0605 µs 1.0631 µs]
-                        thrpt:  [57.414 GiB/s 57.551 GiB/s 57.654 GiB/s]
-Found 3 outliers among 100 measurements (3.00%)
-  1 (1.00%) high mild
-  2 (2.00%) high severe
+  6 (6.00%) high severe
 crc64/xz/compare/crc-fast/auto/l
-                        time:   [1.0407 µs 1.0435 µs 1.0462 µs]
-                        thrpt:  [58.342 GiB/s 58.493 GiB/s 58.651 GiB/s]
-Found 1 outliers among 100 measurements (1.00%)
-  1 (1.00%) high mild
+                        time:   [1.0957 µs 1.0969 µs 1.0981 µs]
+                        thrpt:  [55.581 GiB/s 55.642 GiB/s 55.703 GiB/s]
 crc64/xz/compare/rscrypto/aarch64/pmull-eor3-3way/xl
-                        time:   [15.570 µs 15.573 µs 15.575 µs]
-                        thrpt:  [62.702 GiB/s 62.711 GiB/s 62.720 GiB/s]
-Found 11 outliers among 100 measurements (11.00%)
-  1 (1.00%) low severe
-  4 (4.00%) high mild
-  6 (6.00%) high severe
+                        time:   [15.909 µs 15.924 µs 15.940 µs]
+                        thrpt:  [61.265 GiB/s 61.325 GiB/s 61.385 GiB/s]
+Found 8 outliers among 100 measurements (8.00%)
+  3 (3.00%) low mild
+  3 (3.00%) high mild
+  2 (2.00%) high severe
 crc64/xz/compare/crc64fast/auto/xl
-                        time:   [17.354 µs 17.520 µs 17.871 µs]
-                        thrpt:  [54.644 GiB/s 55.739 GiB/s 56.274 GiB/s]
-Found 11 outliers among 100 measurements (11.00%)
-  4 (4.00%) low severe
-  2 (2.00%) low mild
+                        time:   [17.670 µs 17.894 µs 18.354 µs]
+                        thrpt:  [53.208 GiB/s 54.576 GiB/s 55.266 GiB/s]
+Found 5 outliers among 100 measurements (5.00%)
+  1 (1.00%) low mild
   2 (2.00%) high mild
-  3 (3.00%) high severe
+  2 (2.00%) high severe
 crc64/xz/compare/crc-fast/auto/xl
-                        time:   [17.346 µs 17.363 µs 17.381 µs]
-                        thrpt:  [56.187 GiB/s 56.244 GiB/s 56.300 GiB/s]
+                        time:   [17.693 µs 17.709 µs 17.725 µs]
+                        thrpt:  [55.094 GiB/s 55.144 GiB/s 55.195 GiB/s]
 Found 4 outliers among 100 measurements (4.00%)
   1 (1.00%) low mild
-  2 (2.00%) high mild
-  1 (1.00%) high severe
+  3 (3.00%) high mild
 
 crc64/nvme/compare/rscrypto/aarch64/pmull-small/xs
-                        time:   [6.2906 ns 6.2982 ns 6.3061 ns]
-                        thrpt:  [9.4519 GiB/s 9.4637 GiB/s 9.4752 GiB/s]
-Found 5 outliers among 100 measurements (5.00%)
-  5 (5.00%) high mild
-crc64/nvme/compare/crc64fast-nvme/auto/xs
-                        time:   [17.069 ns 17.238 ns 17.561 ns]
-                        thrpt:  [3.3941 GiB/s 3.4578 GiB/s 3.4920 GiB/s]
-Found 5 outliers among 100 measurements (5.00%)
-  4 (4.00%) high mild
+                        time:   [7.4442 ns 7.4569 ns 7.4713 ns]
+                        thrpt:  [7.9778 GiB/s 7.9932 GiB/s 8.0069 GiB/s]
+Found 2 outliers among 100 measurements (2.00%)
+  1 (1.00%) low mild
   1 (1.00%) high severe
+crc64/nvme/compare/crc64fast-nvme/auto/xs
+                        time:   [17.812 ns 17.836 ns 17.860 ns]
+                        thrpt:  [3.3373 GiB/s 3.3418 GiB/s 3.3464 GiB/s]
+Found 2 outliers among 100 measurements (2.00%)
+  2 (2.00%) low mild
 crc64/nvme/compare/crc-fast/auto/xs
-                        time:   [16.423 ns 16.609 ns 16.823 ns]
-                        thrpt:  [3.5430 GiB/s 3.5886 GiB/s 3.6293 GiB/s]
+                        time:   [19.992 ns 20.148 ns 20.310 ns]
+                        thrpt:  [2.9348 GiB/s 2.9583 GiB/s 2.9815 GiB/s]
 Found 1 outliers among 100 measurements (1.00%)
   1 (1.00%) low mild
 crc64/nvme/compare/rscrypto/aarch64/pmull-eor3/s
-                        time:   [8.5440 ns 8.5541 ns 8.5641 ns]
-                        thrpt:  [27.839 GiB/s 27.872 GiB/s 27.905 GiB/s]
-Found 3 outliers among 100 measurements (3.00%)
-  2 (2.00%) high mild
-  1 (1.00%) high severe
+                        time:   [9.1422 ns 9.1519 ns 9.1611 ns]
+                        thrpt:  [26.025 GiB/s 26.051 GiB/s 26.079 GiB/s]
+Found 7 outliers among 100 measurements (7.00%)
+  2 (2.00%) low mild
+  1 (1.00%) high mild
+  4 (4.00%) high severe
 crc64/nvme/compare/crc64fast-nvme/auto/s
-                        time:   [10.524 ns 10.548 ns 10.573 ns]
-                        thrpt:  [22.550 GiB/s 22.604 GiB/s 22.656 GiB/s]
-Found 3 outliers among 100 measurements (3.00%)
-  3 (3.00%) high mild
-crc64/nvme/compare/crc-fast/auto/s
-                        time:   [13.180 ns 13.189 ns 13.198 ns]
-                        thrpt:  [18.065 GiB/s 18.077 GiB/s 18.090 GiB/s]
-Found 6 outliers among 100 measurements (6.00%)
-  1 (1.00%) low severe
+                        time:   [10.627 ns 10.667 ns 10.718 ns]
+                        thrpt:  [22.245 GiB/s 22.350 GiB/s 22.436 GiB/s]
+Found 16 outliers among 100 measurements (16.00%)
   1 (1.00%) low mild
-  1 (1.00%) high mild
-  3 (3.00%) high severe
+  7 (7.00%) high mild
+  8 (8.00%) high severe
+crc64/nvme/compare/crc-fast/auto/s
+                        time:   [17.274 ns 17.502 ns 17.731 ns]
+                        thrpt:  [13.446 GiB/s 13.623 GiB/s 13.802 GiB/s]
 crc64/nvme/compare/rscrypto/aarch64/pmull-eor3/m
-                        time:   [65.781 ns 65.884 ns 66.003 ns]
-                        thrpt:  [57.796 GiB/s 57.900 GiB/s 57.990 GiB/s]
-Found 8 outliers among 100 measurements (8.00%)
-  1 (1.00%) low mild
-  6 (6.00%) high mild
-  1 (1.00%) high severe
+                        time:   [67.225 ns 67.976 ns 69.436 ns]
+                        thrpt:  [54.938 GiB/s 56.118 GiB/s 56.745 GiB/s]
+Found 4 outliers among 100 measurements (4.00%)
+  2 (2.00%) high mild
+  2 (2.00%) high severe
 crc64/nvme/compare/crc64fast-nvme/auto/m
-                        time:   [67.383 ns 67.445 ns 67.511 ns]
-                        thrpt:  [56.504 GiB/s 56.560 GiB/s 56.612 GiB/s]
-Found 8 outliers among 100 measurements (8.00%)
-  5 (5.00%) low mild
-  3 (3.00%) high severe
+                        time:   [67.657 ns 67.712 ns 67.776 ns]
+                        thrpt:  [56.284 GiB/s 56.337 GiB/s 56.383 GiB/s]
+Found 4 outliers among 100 measurements (4.00%)
+  2 (2.00%) high mild
+  2 (2.00%) high severe
 crc64/nvme/compare/crc-fast/auto/m
-                        time:   [69.533 ns 69.581 ns 69.629 ns]
-                        thrpt:  [54.786 GiB/s 54.824 GiB/s 54.862 GiB/s]
-Found 9 outliers among 100 measurements (9.00%)
-  1 (1.00%) low severe
-  2 (2.00%) low mild
-  5 (5.00%) high mild
-  1 (1.00%) high severe
+                        time:   [72.632 ns 72.737 ns 72.842 ns]
+                        thrpt:  [52.369 GiB/s 52.445 GiB/s 52.521 GiB/s]
+Found 4 outliers among 100 measurements (4.00%)
+  4 (4.00%) high mild
 crc64/nvme/compare/rscrypto/aarch64/pmull-eor3-3way/l
-                        time:   [983.84 ns 984.15 ns 984.40 ns]
-                        thrpt:  [62.002 GiB/s 62.018 GiB/s 62.037 GiB/s]
-Found 16 outliers among 100 measurements (16.00%)
-  3 (3.00%) low severe
-  2 (2.00%) low mild
-  6 (6.00%) high mild
-  5 (5.00%) high severe
+                        time:   [990.98 ns 995.89 ns 1.0052 µs]
+                        thrpt:  [60.720 GiB/s 61.287 GiB/s 61.591 GiB/s]
+Found 2 outliers among 100 measurements (2.00%)
+  2 (2.00%) high severe
 crc64/nvme/compare/crc64fast-nvme/auto/l
-                        time:   [1.0624 µs 1.0630 µs 1.0634 µs]
-                        thrpt:  [57.399 GiB/s 57.420 GiB/s 57.449 GiB/s]
-Found 16 outliers among 100 measurements (16.00%)
-  4 (4.00%) low severe
-  3 (3.00%) low mild
-  4 (4.00%) high mild
-  5 (5.00%) high severe
+                        time:   [1.0705 µs 1.0716 µs 1.0727 µs]
+                        thrpt:  [56.900 GiB/s 56.957 GiB/s 57.014 GiB/s]
+Found 5 outliers among 100 measurements (5.00%)
+  2 (2.00%) high mild
+  3 (3.00%) high severe
 crc64/nvme/compare/crc-fast/auto/l
-                        time:   [1.0447 µs 1.0474 µs 1.0499 µs]
-                        thrpt:  [58.135 GiB/s 58.272 GiB/s 58.424 GiB/s]
+                        time:   [1.0873 µs 1.0887 µs 1.0902 µs]
+                        thrpt:  [55.988 GiB/s 56.063 GiB/s 56.135 GiB/s]
 crc64/nvme/compare/rscrypto/aarch64/pmull-eor3-3way/xl
-                        time:   [15.567 µs 15.569 µs 15.572 µs]
-                        thrpt:  [62.713 GiB/s 62.723 GiB/s 62.731 GiB/s]
-Found 13 outliers among 100 measurements (13.00%)
-  2 (2.00%) low severe
-  1 (1.00%) low mild
-  4 (4.00%) high mild
-  6 (6.00%) high severe
+                        time:   [15.635 µs 15.765 µs 16.026 µs]
+                        thrpt:  [60.937 GiB/s 61.944 GiB/s 62.460 GiB/s]
+Found 5 outliers among 100 measurements (5.00%)
+  3 (3.00%) high mild
+  2 (2.00%) high severe
 crc64/nvme/compare/crc64fast-nvme/auto/xl
-                        time:   [17.352 µs 17.360 µs 17.367 µs]
-                        thrpt:  [56.230 GiB/s 56.254 GiB/s 56.279 GiB/s]
-Found 9 outliers among 100 measurements (9.00%)
-  2 (2.00%) low severe
-  2 (2.00%) low mild
-  1 (1.00%) high mild
-  4 (4.00%) high severe
+                        time:   [17.413 µs 17.432 µs 17.452 µs]
+                        thrpt:  [55.958 GiB/s 56.022 GiB/s 56.082 GiB/s]
+Found 3 outliers among 100 measurements (3.00%)
+  2 (2.00%) high mild
+  1 (1.00%) high severe
 crc64/nvme/compare/crc-fast/auto/xl
-                        time:   [17.373 µs 17.525 µs 17.849 µs]
-                        thrpt:  [54.712 GiB/s 55.724 GiB/s 56.211 GiB/s]
-Found 10 outliers among 100 measurements (10.00%)
-  1 (1.00%) low severe
-  3 (3.00%) low mild
+                        time:   [17.449 µs 17.468 µs 17.488 µs]
+                        thrpt:  [55.842 GiB/s 55.905 GiB/s 55.968 GiB/s]
+Found 1 outliers among 100 measurements (1.00%)
   1 (1.00%) high mild
-  5 (5.00%) high severe

crates/checksum/bench_baseline/linux_x86-64.txt

@@ -1,9 +1,33 @@
 use core::hint::black_box;
+use std::sync::Once;
 
 use checksum::{Checksum, Crc64, Crc64Nvme};
 use crc_fast::{CrcAlgorithm as CrcFastAlgorithm, Digest as CrcFastDigest};
 use criterion::{BenchmarkId, Criterion, Throughput, criterion_group, criterion_main};
 
+/// Print platform detection info once at benchmark start.
+fn print_platform_info() {
+  static ONCE: Once = Once::new();
+  ONCE.call_once(|| {
+    let tune = platform::tune();
+    eprintln!("╔══════════════════════════════════════════════════════════════╗");
+    eprintln!("║                   PLATFORM DETECTION INFO                    ║");
+    eprintln!("╠══════════════════════════════════════════════════════════════╣");
+    eprintln!("║ Platform: {}", platform::describe());
+    eprintln!("║ Tune Kind: {:?}", tune.kind());
+    eprintln!("║ PCLMUL threshold: {} bytes", tune.pclmul_threshold);
+    eprintln!("║ SIMD width: {} bits", tune.effective_simd_width);
+    eprintln!("║ Fast wide ops: {}", tune.fast_wide_ops);
+    eprintln!("║ Parallel streams: {}", tune.parallel_streams);
+    eprintln!("╠══════════════════════════════════════════════════════════════╣");
+    eprintln!("║ Kernel selection by size:");
+    for &(label, size) in CASES {
+      eprintln!("║   {:>3} ({:>7} B): {}", label, size, Crc64::kernel_name_for_len(size));
+    }
+    eprintln!("╚══════════════════════════════════════════════════════════════╝");
+  });
+}
+
 const CASES: &[(&str, usize)] = &[
   ("xs", 64),
   ("s", 256),
@@ -19,6 +43,7 @@ fn make_data(len: usize) -> Vec<u8> {
 }
 
 fn bench_crc64_xz_comp(c: &mut Criterion) {
+  print_platform_info();
   let base_rs = Crc64::new();
   let base_ref = crc64fast::Digest::new();
   let base_fast = CrcFastDigest::new(CrcFastAlgorithm::Crc64Xz);

crates/checksum/bench_baseline/macos_arm64.txt

@@ -283,10 +283,11 @@ fn default_pclmul_to_vpclmul_threshold(caps: Caps, tune: Tune) -> usize {
       return usize::MAX;
     }
 
-    // Heuristic default:
-    // - Fast wide ops (Zen4/5): low crossover.
-    // - Slow warmup (many Intel parts): require much larger buffers.
-    if tune.fast_wide_ops { 1024 } else { 16 * 1024 }
+    // Heuristic default based on benchmarks vs crc-fast-rust:
+    // - Fast wide ops (Zen4/5): low crossover (512B is sufficient).
+    // - Slow warmup (Intel SPR/GNR): 2KB is the practical crossover where VPCLMUL wins despite ZMM
+    //   warmup overhead. At 4KB, VPCLMUL is clearly faster.
+    if tune.fast_wide_ops { 512 } else { 2 * 1024 }
   }
 
   #[cfg(not(target_arch = "x86_64"))]