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Diffstat (limited to 'utils/findmisopt')
| -rwxr-xr-x | utils/findmisopt | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/utils/findmisopt b/utils/findmisopt new file mode 100755 index 000000000000..b7ffbd9947d5 --- /dev/null +++ b/utils/findmisopt @@ -0,0 +1,178 @@ +#!/bin/bash +# +# findmisopt +# +# This is a quick and dirty hack to potentially find a misoptimization +# problem. Mostly its to work around problems in bugpoint that prevent +# it from finding a problem unless the set of failing optimizations are +# known and given to it on the command line. +# +# Given a bytecode file that produces correct output (or return code), +# this script will run through all the optimizations passes that gccas +# uses (in the same order) and will narrow down which optimizations +# cause the program either generate different output or return a +# different result code. When the passes have been narrowed down, +# bugpoint is invoked to further refine the problem to its origin. If a +# release version of bugpoint is available it will be used, otherwise +# debug. +# +# Usage: +# findmisopt bcfile outdir progargs [match] +# +# Where: +# bcfile +# is the bytecode file input (the unoptimized working case) +# outdir +# is a directory into which intermediate results are placed +# progargs +# is a single argument containing all the arguments the program needs +# proginput +# is a file name from which stdin should be directed +# match +# if specified to any value causes the result code of the program to +# be used to determine success/fail. If not specified success/fail is +# determined by diffing the program's output with the non-optimized +# output. +# +if [ "$#" -lt 3 ] ; then + echo "usage: findmisopt bcfile outdir progargs [match]" + exit 1 +fi + +dir="${0%%/utils/findmisopt}" +if [ -x "$dir/Release/bin/bugpoint" ] ; then + bugpoint="$dir/Release/bin/bugpoint" +elif [ -x "$dir/Debug/bin/bugpoint" ] ; then + bugpoint="$dir/Debug/bin/bugpoint" +else + echo "findmisopt: bugpoint not found" + exit 1 +fi + +bcfile="$1" +outdir="$2" +args="$3" +input="$4" +if [ ! -f "$input" ] ; then + input="/dev/null" +fi +match="$5" +name=`basename $bcfile .bc` +ll="$outdir/${name}.ll" +s="$outdir/${name}.s" +prog="$outdir/${name}" +out="$outdir/${name}.out" +optbc="$outdir/${name}.opt.bc" +optll="$outdir/${name}.opt.ll" +opts="$outdir/${name}.opt.s" +optprog="$outdir/${name}.opt" +optout="$outdir/${name}.opt.out" +ldflags="-lstdc++ -lm -ldl -lc" + +echo "Test Name: $name" +echo "Unoptimized program: $prog" +echo " Optimized program: $optprog" + +# Define the list of optimizations to run. This comprises the same set of +# optimizations that opt -std-compile-opts and gccld run, in the same order. +opt_switches=`llvm-as < /dev/null -o - | opt -std-compile-opts -disable-output -debug-pass=Arguments 2>&1 | sed 's/Pass Arguments: //'` +ld_switches=`llvm-as < /dev/null -o - | llvm-ld - -debug-pass=Arguments 2>&1 | sed 's/Pass Arguments: //'` +all_switches="$opt_switches $ld_switches" +echo "Passes : $all_switches" + +# Create output directory if it doesn't exist +if [ -f "$outdir" ] ; then + echo "$outdir is not a directory" + exit 1 +fi + +if [ ! -d "$outdir" ] ; then + mkdir "$outdir" || exit 1 +fi + +# Generate the disassembly +llvm-dis "$bcfile" -o "$ll" -f || exit 1 + +# Generate the non-optimized program and its output +llc "$bcfile" -o "$s" -f || exit 1 +gcc "$s" -o "$prog" $ldflags || exit 1 +"$prog" $args > "$out" 2>&1 <$input +ex1=$? + +# Current set of switches is empty +function tryit { + switches_to_use="$1" + opt $switches_to_use "$bcfile" -o "$optbc" -f || exit + llvm-dis "$optbc" -o "$optll" -f || exit + llc "$optbc" -o "$opts" -f || exit + gcc "$opts" -o "$optprog" $ldflags || exit + "$optprog" $args > "$optout" 2>&1 <"$input" + ex2=$? + + if [ -n "$match" ] ; then + if [ "$ex1" -ne "$ex2" ] ; then + echo "Return code not the same with these switches:" + echo $switches + echo "Unoptimized returned: $ex1" + echo "Optimized returned: $ex2" + return 0 + fi + else + diff "$out" "$optout" > /dev/null + if [ $? -ne 0 ] ; then + echo "Diff fails with these switches:" + echo $switches + echo "Differences:" + diff "$out" "$optout" | head + return 0; + fi + fi + return 1 +} + +echo "Trying to find optimization that breaks program:" +for sw in $all_switches ; do + echo -n " $sw" + switches="$switches $sw" + if tryit "$switches" ; then + break; + fi +done + +# Terminate the previous output with a newline +echo "" + +# Determine if we're done because none of the optimizations broke the program +if [ "$switches" == " $all_switches" ] ; then + echo "The program did not miscompile" + exit 0 +fi + +final="" +while [ ! -z "$switches" ] ; do + trimmed=`echo "$switches" | sed -e 's/^ *\(-[^ ]*\).*/\1/'` + switches=`echo "$switches" | sed -e 's/^ *-[^ ]* *//'` + echo "Trimmed $trimmed from left" + tryit "$final $switches" + if [ "$?" -eq "0" ] ; then + echo "Still Failing .. continuing ..." + continue + else + echo "Found required early pass: $trimmed" + final="$final $trimmed" + continue + fi + echo "Next Loop" +done + +if [ "$final" == " $all_switches" ] ; then + echo "findmisopt: All optimizations pass. Perhaps this isn't a misopt?" + exit 0 +fi +echo "Smallest Optimization list=$final" + +bpcmd="$bugpoint -run-llc -disable-loop-extraction --output "$out" --input /dev/null $bcfile $final --args $args" + +echo "Running: $bpcmd" +$bpcmd +echo "findmisopt finished." |