ABRIK Wrap-Up#130
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ABRIK_speed_comparisons.cc and ABRIK_accuracy_analysis.cc both gain a num_runs
positional argument and an outer loop over runs that uses RNGState<RNG>(run) so
each run draws from a distinct seed. CSVs gain a leading 'run' column tagging
each data row with its run index. GESDD (deterministic) runs once and is
reported under run=0 in both benchmarks.
Speed_comparisons CLI: <prec> <outdir> <input> <target_rank> <run_gesdd>
<budget> <num_runs> <num_b_sz> <b_sz...> [sub_ratio] [use_cqrrt]
Accuracy_analysis CLI: <prec> <outdir> <input> <m> <n> <b_sz> <num_matmuls> <num_runs>
Previously the accuracy benchmark used RandLAPACK::gen::mat_gen with custom_input, which only handles whitespace-delimited text files. Feeding it the .bin matrices produced by gen_mat_alg971_paper crashed at the dimension query because the binary header was interpreted as ASCII rows. Switch to BenchIO::load_matrix (the same auto-detecting loader used by ABRIK_speed_comparisons and ABRIK_runtime_breakdown). It dispatches on file extension: .bin via read_bin_matrix, .txt via read_txt_matrix, .mtx via fast_matrix_market. Sparse input is now rejected explicitly with a clear error since accuracy_analysis runs a full GESDD. A is now owned by the LoadedMatrix and freed automatically; removed the matching new T[m*n] and delete[] A. CMakeLists.txt bumps the target's LINK_LIBS from Benchmark_libs to Benchmark_libs_external because ext_matrix_io.hh pulls in fast_matrix_market and Eigen headers, matching the other two ABRIK benchmark targets.
The summary `end_cols = iter * k / 2` truncates when iter*k is odd, which only
happens for odd block size k. For k=1, calling BK::call with max_krylov_iters=1
finishes the prelude + one odd half-step (Y_od[:,0:1] populated, R[0:1,0:1]
populated) but then returns end_cols=0 due to integer floor.
ABRIK::call_with_checkpoints then sees end_cols==0, emits the placeholder row
(total_matvecs=0, err=1), and breaks the entire checkpoint loop. Every
subsequent checkpoint (mv=2, 4, ..., 4096) is skipped, so the speed-comparison
CSVs contain only one sentinel row per run at b_sz=1.
The runtime-breakdown benchmark drives BK::call with fixed max_krylov_iters
>= 2 in every cell, so this path produced valid data — only call_with_checkpoints
at its first b_sz=1 checkpoint exposed the bug.
Fix: ceiling division `(iter * k + 1) / 2`. Bit-identical for even k (all
historical b_sz ∈ {4, 8, 16, 32, 64, 128} cases), and yields the correct
column count for odd k:
iter | k=1 floor | k=1 ceil | k=2 (no change) | k=4 (no change)
---- | --------- | -------- | --------------- | ---------------
1 | 0 (bug) | 1 | 1 | 2
2 | 1 | 1 | 2 | 4
3 | 1 (bug) | 2 | 3 | 6
4 | 2 | 2 | 4 | 8
No new tests added; the b_sz=1 path is now exercised by the existing
ABRIK_speed_comparisons benchmark at the bench level once Bergamo/SPR
campaigns rerun with this fix.
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WIP