From 97f93ea2cb05c7a4b4ed021e8fd03bb40c00314c Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Sun, 20 May 2018 12:41:16 +0100 Subject: [PATCH] update slides --- simple_v_extension/simple_v_chennai_2018.tex | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/simple_v_extension/simple_v_chennai_2018.tex b/simple_v_extension/simple_v_chennai_2018.tex index 34bda04e6..f8e2ee26e 100644 --- a/simple_v_extension/simple_v_chennai_2018.tex +++ b/simple_v_extension/simple_v_chennai_2018.tex @@ -87,15 +87,16 @@ \frame{\frametitle{Implementation Options} \begin{itemize} - \item Absolute minimum: Exceptions (CSRs needed)\vspace{10pt} + \item Absolute minimum: Exceptions (if CSRs indicate "V", trap)\vspace{10pt} \item Hardware loop, single-instruction issue\vspace{10pt} \item Hardware loop, parallel (multi-instruction) issue\vspace{10pt} \item Hardware loop, full parallel ALU (not recommended)\vspace{10pt} \end{itemize} - Considerations:\vspace{10pt} + Notes:\vspace{10pt} \begin{itemize} - \item OoO may split off 4+ single-instructions at a time\vspace{10pt} - \item Minimum VL MUST be sufficient to cover regfile LD/ST\vspace{10pt} + \item 4 (or more?) options above may be deployed on per-op basis + \item Minimum MVL MUST be sufficient to cover regfile LD/ST + \item OoO may split off 4+ single-instructions at a time \end{itemize} } @@ -114,7 +115,10 @@ \item Implementor free to choose (API remains the same)\vspace{10pt} \end{itemize} } - +% With multiple SIMD ALUs at for example 32-bit wide they can be used +% to either issue 64-bit or 128-bit or 256-bit wide SIMD operations +% or they can be used to cover several operations on totally different +% vectors / registers. \frame{\frametitle{What's the deal / juice / score?} @@ -158,8 +162,9 @@ \end{itemize} Considerations:\vspace{10pt} \begin{itemize} - \item Complex not really impacted, Simple impacted a LOT\vspace{10pt} - \item Please don't use Vectors for "security" (use Sec-Ext)\vspace{10pt} + \item Complex not really impacted, Simple impacted a LOT + \item Overlapping "Vectors" may issue overlapping ops + \item Please don't use Vectors for "security" (use Sec-Ext) \end{itemize} } -- 2.30.2