jberryman

Pointer compression in GHC?

Can compiled Haskell programs benefit from any pointer compression schemes? The goal would be to lower memory residency significantly, while hopefully seeing an improvement in other runtime metrics. V8 Successfully implemented a pointer compression scheme; it seems the challenge for them was recovering the lost performance after the change; After optimizing they did observe single-digit improvements to CPU time.

In the analysis below I'm using

jberryman

``
$ cmake -B build && cmake --build build --parallel
-- Configuring done
-- Generating done
-- Build files have been written to: /home/me/Downloads/graphia/build
gmake[1]: Entering directory '/home/me/Downloads/graphia/build'
gmake[2]: Entering directory '/home/me/Downloads/graphia/build'
gmake[2]: Entering directory '/home/me/Downloads/graphia/build'
gmake[2]: Entering directory '/home/me/Downloads/graphia/build'
gmake[2]: Leaving directory '/home/me/Downloads/graphia/build'

jberryman

#!/bin/bash
set -euo pipefail
#
# A hack to get hasktags working with vim-gutentags
#
# In vimrc:
#
#     let g:gutentags_project_info = []
#     call add(g:gutentags_project_info, {'type': 'haskell', 'file': 'stack.yaml'})
#     call add(g:gutentags_project_info, {'type': 'haskell', 'glob': '*.cabal'})

jberryman

#!/usr/bin/zsh
# Not portable, sorry...
set -e 
set -o pipefail
# set -x

# Change to your command. Below we assume that this:
#  - deletes (or replaces) the original file
#  - the new/replacement object file must be in the same directory as the source file (need not be same name though)
COMMAND="ls -l"

jberryman

$('canvas').each(function(i,e){ var img = e.toDataURL("image/png"); $(e).replaceWith(  $('<img src="'+img+'"/>').attr({width: $(e).attr("width"), height: $(e).attr("height"), style: $(e).attr("style") }) ) });

jberryman

-- an optimized minimum edit distance function, using the 'vector' library.
-- By making careful use of the stream-fusing functions in Vector, we can
-- write an implementation that looks like idiomatic list-processing code
-- but runs like tight mutable array code.

import qualified Data.Vector.Unboxed.Safe as V

-- we use suffixes _W, _SW, etc. to indicate the cell to the west, southwest,
-- and so on in the more traditional matrix-based approach.
med :: String -> String -> Int