conferences/fosdem2024/fosdem2024_bigint/fosdem2024_bigint.tex

   1 % Copyright 2024 Jacob Lifshay
   2
   3 \documentclass{beamer}
   4 \usepackage{beamerthemesplit}
   5 \usetheme{default}
   6 \usepackage[english]{babel}
   7 \usepackage{tikz}
   8
   9 \title[Fast Big-Integer Arithmetic on SVP64 ...]{
  10     Fast Big-Integer Arithmetic on SVP64 at up to 256-bits/cycle and beyond
  11 }
  12
  13 \author{Jacob R. Lifshay}
  14
  15 \date{FOSDEM 2024}
  16
  17 \logo{\includegraphics[height=0.5cm]{../../../images/lsoclogo.png}}
  18
  19 \begin{document}
  20
  21 \begin{frame}
  22     \titlepage
  23 \end{frame}
  24
  25 \begin{frame}[fragile]
  26     \frametitle{What is SVP64?}
  27     \begin{itemize}
  28         \item Vectorization Extension for PowerISA developed by \href{https://libre-soc.org}{Libre-SOC}
  29         \pause
  30         \item Basically, a way to modify nearly any PowerISA instruction to run it in a HW loop.
  31         \pause \\
  32         \medskip
  33         Simple Example:
  34         \begin{semiverbatim}
  35 setvl 0, 0, 3, 0, 1, 1 # makes stuff run 3 times
  36 sv.add *r3, *r15, r12  # adds 3 times
  37 \pause
  38 # expands to:
  39 add r3, r15, r12  \only<+(1)->{# no * means r12 doesn't increment}
  40 add r4, r16, r12  \only<+(1)->{# * means r3 and r15 increment}
  41 add r5, r17, r12
  42         \end{semiverbatim}
  43     \end{itemize}
  44 \end{frame}
  45
  46 \begin{frame}[fragile]
  47     \frametitle{Big-Integer Addition on SVP64}
  48     How can we use SVP64 to add 192-bit integers?
  49     \pause
  50     \begin{semiverbatim}
  51 setvl 0, 0, 4, 0, 1, 1 # makes stuff run 4 times
  52 addic 0, 0, 0  # clear CA (carry flag)
  53 sv.adde *r4, *r4, *r8  # carry-propagating add
  54 \pause
  55 # expands to:
  56 addic 0, 0, 0  # clear CA (carry flag)
  57 adde r4, r4, r8
  58 adde r5, r5, r9
  59 adde r6, r6, r10
  60 adde r6, r6, r11
  61     \end{semiverbatim}
  62 \end{frame}
  63
  64 \begin{frame}
  65     \input{test.dia-tex}
  66 \end{frame}
  67
  68 \end{document}