AndreasPK

Andi@Horzube MINGW64 /e/pan-os-syslog
$ cabal new-run bench -w /e/ghc_layout/_quick/stage1/bin/ghc.exe --allow-newer="*"
Up to date
benchmarking 8-1-Traffic-A ...
benchmarked 8-1-Traffic-A
time                 626.4 ns   (611.3 ns .. 647.4 ns)
                     0.987 R²   (0.971 R² .. 0.997 R²)
mean                 618.7 ns   (610.2 ns .. 634.3 ns)
std dev              38.10 ns   (25.20 ns .. 65.38 ns)
variance introduced by outliers: 39% (moderately inflated)

AndreasPK

compiler\nativeGen\X86\CodeGen.hs:169:1: warning: [-Wincomplete-patterns]
    Pattern match(es) are non-exhaustive
    In an equation for `verifyBasicBlock':
        Patterns not matched: _ :: [Instr]
    |
169 | verifyBasicBlock instrs


-- Verifying basic blocks is cheap, but not cheap enough to enable it unconditionally.
verifyBasicBlock :: [Instr] -> ()

AndreasPK

        Tue Aug 27 19:56 2019 Time and Allocation Profiling Report  (Final)

           ghc.exe +RTS -p -RTS Main.hs --make -O -fforce-recomp

        total time  =        7.72 secs   (7721 ticks @ 1000 us, 1 processor)
        total alloc = 9,747,651,160 bytes  (excludes profiling overheads)

COST CENTRE              MODULE      SRC                                                 %time %alloc

simplIdF                 Simplify    compiler\simplCore\Simplify.hs:899:61-79             16.9   18.1

AndreasPK

        Tue Aug 27 19:56 2019 Time and Allocation Profiling Report  (Final)

           ghc.exe +RTS -p -RTS Main.hs --make -O -fforce-recomp

        total time  =        7.72 secs   (7721 ticks @ 1000 us, 1 processor)
        total alloc = 9,747,651,160 bytes  (excludes profiling overheads)

COST CENTRE              MODULE      SRC                                                 %time %alloc

simplIdF                 Simplify    compiler\simplCore\Simplify.hs:899:61-79             16.9   18.1

AndreasPK

#!/usr/bin/env stack
{-
    stack
    script
    --resolver lts-12.20
    --package text,trifecta,containers,parsers,mtl,vector,deepseq
-}
{-# LANGUAGE RecordWildCards, BangPatterns #-}
{-# OPTIONS_GHC -O2 #-}

AndreasPK

        
        
    | x == A = e1
    | x == B = e2
    | predFunc(x) = e3
        
      case (case x of { C1 -> (Weight: 1000) A;
                        C2 -> (Weight: 1000) B;
                        C3 -> (Weight: 1000) e3; } ) of
            {

AndreasPK

Consider a simple definition using guards:

      foo x
        | x == C1 =   { -# LIKELY 10 #- } e1
        | otherwise = { -# LIKELY  0 #- } e2
        
    with C1 being defined by T using uniform default weights:

    data T = {-# LIKELY 1000 #-} C1

AndreasPK

Improvements to GHCs Code Generator

This is a writeup of the work done by me (Andreas Klebinger) during my SoC 2018 Project.

Improved code layout for GHC

The vast majority of my time was spent working on this part of the Project. While the patch was not yet merged there is not much missing.

AndreasPK

#!/usr/bin/env bash

LOGNAME=$1
LOG_DIR=~/logs4
TREE_DIR=~/trees4
RUNS=7


if [ -z "$1" ]
then

AndreasPK

{-# LANGUAGE OverloadedStrings #-}

module Main where

import qualified Data.Text as T
import Data.Text (Text(..))


longestCommonSubstring :: [Text] -> Text
longestCommonSubstring entries = go [""] "" where