5 # This is a quick and dirty hack to potentially find a misoptimization
6 # problem. Mostly its to work around problems in bugpoint that prevent
7 # it from finding a problem unless the set of failing optimizations are
8 # known and given to it on the command line.
10 # Given a bytecode file that produces correct output (or return code),
11 # this script will run through all the optimizations passes that gccas
12 # uses (in the same order) and will narrow down which optimizations
13 # cause the program either generate different output or return a
14 # different result code. When the passes have been narrowed down,
15 # bugpoint is invoked to further refine the problem to its origin. If a
16 # release version of bugpoint is available it will be used, otherwise
20 # findmisopt bcfile outdir progargs [match]
24 # is the bytecode file input (the unoptimized working case)
26 # is a directory into which intermediate results are placed
28 # is a single argument containing all the arguments the program needs
30 # is a file name from which stdin should be directed
32 # if specified to any value causes the result code of the program to
33 # be used to determine success/fail. If not specified success/fail is
34 # determined by diffing the program's output with the non-optimized
37 if [ "$#" -lt 3 ] ; then
38 echo "usage: findmisopt bcfile outdir progargs [match]"
42 dir="${0%%/utils/findmisopt}"
43 if [ -x "$dir/Release/bin/bugpoint" ] ; then
44 bugpoint="$dir/Release/bin/bugpoint"
45 elif [ -x "$dir/Debug/bin/bugpoint" ] ; then
46 bugpoint="$dir/Debug/bin/bugpoint"
48 echo "findmisopt: bugpoint not found"
56 if [ ! -f "$input" ] ; then
60 name=`basename $bcfile .bc`
61 ll="$outdir/${name}.ll"
63 prog="$outdir/${name}"
64 out="$outdir/${name}.out"
65 optbc="$outdir/${name}.opt.bc"
66 optll="$outdir/${name}.opt.ll"
67 opts="$outdir/${name}.opt.s"
68 optprog="$outdir/${name}.opt"
69 optout="$outdir/${name}.opt.out"
70 ldflags="-lstdc++ -lm -ldl -lc"
72 echo "Test Name: $name"
73 echo "Unoptimized program: $prog"
74 echo " Optimized program: $optprog"
76 # Define the list of optimizations to run. This comprises the same set of
77 # optimizations that opt -std-compile-opts and gccld run, in the same order.
78 opt_switches=`llvm-as < /dev/null -o - | opt -std-compile-opts -disable-output -debug-pass=Arguments 2>&1 | sed 's/Pass Arguments: //'`
79 ld_switches=`llvm-as < /dev/null -o - | llvm-ld - -debug-pass=Arguments 2>&1 | sed 's/Pass Arguments: //'`
80 all_switches="$opt_switches $ld_switches"
81 echo "Passes : $all_switches"
83 # Create output directory if it doesn't exist
84 if [ -f "$outdir" ] ; then
85 echo "$outdir is not a directory"
89 if [ ! -d "$outdir" ] ; then
90 mkdir "$outdir" || exit 1
93 # Generate the disassembly
94 llvm-dis "$bcfile" -o "$ll" -f || exit 1
96 # Generate the non-optimized program and its output
97 llc "$bcfile" -o "$s" -f || exit 1
98 gcc "$s" -o "$prog" $ldflags || exit 1
99 "$prog" $args > "$out" 2>&1 <$input
102 # Current set of switches is empty
105 opt $switches_to_use "$bcfile" -o "$optbc" -f || exit
106 llvm-dis "$optbc" -o "$optll" -f || exit
107 llc "$optbc" -o "$opts" -f || exit
108 gcc "$opts" -o "$optprog" $ldflags || exit
109 "$optprog" $args > "$optout" 2>&1 <"$input"
112 if [ -n "$match" ] ; then
113 if [ "$ex1" -ne "$ex2" ] ; then
114 echo "Return code not the same with these switches:"
116 echo "Unoptimized returned: $ex1"
117 echo "Optimized returned: $ex2"
121 diff "$out" "$optout" > /dev/null
122 if [ $? -ne 0 ] ; then
123 echo "Diff fails with these switches:"
126 diff "$out" "$optout" | head
133 echo "Trying to find optimization that breaks program:"
134 for sw in $all_switches ; do
136 switches="$switches $sw"
137 if tryit "$switches" ; then
142 # Terminate the previous output with a newline
145 # Determine if we're done because none of the optimizations broke the program
146 if [ "$switches" == " $all_switches" ] ; then
147 echo "The program did not miscompile"
152 while [ ! -z "$switches" ] ; do
153 trimmed=`echo "$switches" | sed -e 's/^ *\(-[^ ]*\).*/\1/'`
154 switches=`echo "$switches" | sed -e 's/^ *-[^ ]* *//'`
155 echo "Trimmed $trimmed from left"
156 tryit "$final $switches"
157 if [ "$?" -eq "0" ] ; then
158 echo "Still Failing .. continuing ..."
161 echo "Found required early pass: $trimmed"
162 final="$final $trimmed"
168 if [ "$final" == " $all_switches" ] ; then
169 echo "findmisopt: All optimizations pass. Perhaps this isn't a misopt?"
172 echo "Smallest Optimization list=$final"
174 bpcmd="$bugpoint -run-llc -disable-loop-extraction --output "$out" --input /dev/null $bcfile $final --args $args"
176 echo "Running: $bpcmd"
178 echo "findmisopt finished."