Jackson's Technical Blog

📌 When Numerical Code Silently Fails: An Illustrative Example

[01/05/26]

DISCUSSED: finding exception-handling failures with my tool EXCVATE, exception spoofing, taint tracking, SMT solvers, opaque compiler transformations, the idiosyncracies of the x86 MAXSS instruction

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Short Update: Actually Understanding NVIDIA's ESC Calculation

[01/12/26]

DISCUSSED: misleading toy examples, hindsight being 20/20, lessons for the future

Grading the BLAS: Strassen vs Classical GEMM

[12/23/25]

DISCUSSED: floating-point rounding error, reconstruction of sparsity patterns, construction of inputs that maximize the degree of failure, some basic combinatorics

(Mis)understanding NVIDIA's ESC calculation

[12/03/25]

DISCUSSED: Ozaki-style emulation of DGEMM, Hadamard products, "Productization", FP64 dynamic range, implicit bits made explicit, my confusion

Why does BLIS SGEMM shatter my roofline?
(or, "Cache Rules Everything Around Me")

[12/02/25]

DISCUSSED: questionably memory-bound matmuls, warm vs cold caches, Agner Fog's meticulously constructed instruction tables, my trash test system, grad student email listservs