| #!/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 |
