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Diffstat (limited to 'utils/findoptdiff')
| -rwxr-xr-x | utils/findoptdiff | 99 |
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diff --git a/utils/findoptdiff b/utils/findoptdiff new file mode 100755 index 0000000000..617ac04368 --- /dev/null +++ b/utils/findoptdiff @@ -0,0 +1,99 @@ +#!/bin/bash +# +# findoptdiff +# +# This script helps find the optimization difference between two llvm +# builds. It is useful when you have a build that is known to work and +# one that exhibits an optimization problem. Identifying the difference +# between the two builds can lead to discovery of the source of a +# mis-optimization. +# +# The script takes two llvm build paths as arguments. These specify the +# the two llvm builds to compare. It is generally expected that they +# are "close cousins". That is, they are the same except that the +# second build contains some experimental optimization features that +# are suspected of producing a misoptimization. +# +# The script takes two bytecode files, one from each build. They are +# presumed to be a compilation of the same program or program fragment +# with the only difference being the builds. +# +# The script operates by iteratively applying the optimizations that gccas +# and gccld run until there is a difference in the assembly resulting +# from the optimization. The difference is then reported with the set of +# optimization passes that produce the difference. +# +# To work around differences in the assembly language format, the script +# can also take two filter arguments that post-process the assembly +# so they can be differenced without making false positives for known +# differences in the two builds. These filters are optional. +# +# Usage: +# findoptdiff llvm1 llvm2 bc1 bc2 filter1 filter2 +# +# Where: +# llvm1 +# is the path to the first llvm build dir +# llvm2 +# is the path to the second llvm build dir +# bc1 +# is the bytecode file for the first llvm environment +# bc2 +# is the bytecode file for the second llvm environment +# filter1 +# is an optional filter for filtering the llvm1 generated assembly +# filter2 +# is an optional filter for filtering the llvm2 generated assembly +# +llvm1=$1 +llvm2=$2 +bc1=$3 +bc2=$4 +filt1=$5 +if [ -z "$filt1" ] ; then + filt1="cat" +fi +filt2=$6 +if [ -z "$filt2" ] ; then + filt2="cat" +fi +opt1=opt.$bc1 +opt2=opt.$bc2 +ll1=${bc1}.ll +ll2=${bc2}.ll +dir1="/proj/llvm/llvm-test-1/External/SPEC/CINT2000/300.twolf" +opt1="/proj/llvm/llvm-1/Debug/bin/opt" +dis1="/proj/llvm/llvm-1/Debug/bin/llvm-dis" +dir2="/proj/llvm/llvm-test-2/External/SPEC/CINT2000/300.twolf" +opt2="/proj/llvm/llvm-2/Debug/bin/opt" +dis2="/proj/llvm/llvm-2/Debug/bin/llvm-dis" +bcfile="Output/300.twolf.linked.rbc" +optll="opt.ll" + +all_switches="-verify -lowersetjmp -funcresolve -raiseallocs -simplifycfg -mem2reg -globalopt -globaldce -ipconstprop -deadargelim -instcombine -simplifycfg -prune-eh -inline -simplify-libcalls -argpromotion -raise -tailduplicate -simplifycfg -scalarrepl -instcombine -predsimplify -condprop -tailcallelim -simplifycfg -reassociate -licm -loop-unswitch -instcombine -indvars -loop-unroll -instcombine -load-vn -gcse -sccp -instcombine -condprop -dse -dce -simplifycfg -deadtypeelim -constmerge -funcresolve -internalize -ipsccp -globalopt -constmerge -deadargelim -inline -prune-eh -globalopt -globaldce -argpromotion -instcombine -predsimplify -scalarrepl -globalsmodref-aa -licm -load-vn -gcse -dse -instcombine -simplifycfg -verify" + +function tryit { + switches_to_use="$1" + cd $dir1 + $opt1 $switches_to_use "$bcfile" -o - | $dis1 | $filt1 > "$optll" + cd $dir2 + $opt2 $switches_to_use "$bcfile" -o - | $dis2 | $filt2 > "$optll" + diff "$dir1/$optll" "$dir2/$optll" > /dev/null + if [ $? -ne 0 ] ; then + echo + echo "Diff fails with these switches:" + echo $switches + echo "Differences:" + diff "$dir1/$optll" "$dir2/$optll" | head + exit 1 + fi + return 1 +} + +for sw in $all_switches ; do + echo -n " $sw" + switches="$switches $sw" + if tryit "$switches" ; then + break; + fi +done |