1 #!/bin/bash 2 # 3 # findmisopt 4 # 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. 9 # 10 # Given a bitcode 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 17 # debug. 18 # 19 # Usage: 20 # findmisopt bcfile outdir progargs [match] 21 # 22 # Where: 23 # bcfile 24 # is the bitcode file input (the unoptimized working case) 25 # outdir 26 # is a directory into which intermediate results are placed 27 # progargs 28 # is a single argument containing all the arguments the program needs 29 # proginput 30 # is a file name from which stdin should be directed 31 # match 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 35 # output. 36 # 37 if [ "$#" -lt 3 ] ; then 38 echo "usage: findmisopt bcfile outdir progargs [match]" 39 exit 1 40 fi 41 42 dir="${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" 47 else 48 echo "findmisopt: bugpoint not found" 49 exit 1 50 fi 51 52 bcfile="$1" 53 outdir="$2" 54 args="$3" 55 input="$4" 56 if [ ! -f "$input" ] ; then 57 input="/dev/null" 58 fi 59 match="$5" 60 name=`basename $bcfile .bc` 61 ll="$outdir/${name}.ll" 62 s="$outdir/${name}.s" 63 prog="$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" 71 72 echo "Test Name: $name" 73 echo "Unoptimized program: $prog" 74 echo " Optimized program: $optprog" 75 76 # Define the list of optimizations to run. This comprises the same set of 77 # optimizations that opt -O3 runs, in the same order. 78 opt_switches=`llvm-as < /dev/null -o - | opt -O3 -disable-output -debug-pass=Arguments 2>&1 | sed 's/Pass Arguments: //'` 79 all_switches="$opt_switches" 80 echo "Passes : $all_switches" 81 82 # Create output directory if it doesn't exist 83 if [ -f "$outdir" ] ; then 84 echo "$outdir is not a directory" 85 exit 1 86 fi 87 88 if [ ! -d "$outdir" ] ; then 89 mkdir "$outdir" || exit 1 90 fi 91 92 # Generate the disassembly 93 llvm-dis "$bcfile" -o "$ll" -f || exit 1 94 95 # Generate the non-optimized program and its output 96 llc "$bcfile" -o "$s" -f || exit 1 97 gcc "$s" -o "$prog" $ldflags || exit 1 98 "$prog" $args > "$out" 2>&1 <$input 99 ex1=$? 100 101 # Current set of switches is empty 102 function tryit { 103 switches_to_use="$1" 104 opt $switches_to_use "$bcfile" -o "$optbc" -f || exit 105 llvm-dis "$optbc" -o "$optll" -f || exit 106 llc "$optbc" -o "$opts" -f || exit 107 gcc "$opts" -o "$optprog" $ldflags || exit 108 "$optprog" $args > "$optout" 2>&1 <"$input" 109 ex2=$? 110 111 if [ -n "$match" ] ; then 112 if [ "$ex1" -ne "$ex2" ] ; then 113 echo "Return code not the same with these switches:" 114 echo $switches 115 echo "Unoptimized returned: $ex1" 116 echo "Optimized returned: $ex2" 117 return 0 118 fi 119 else 120 diff "$out" "$optout" > /dev/null 121 if [ $? -ne 0 ] ; then 122 echo "Diff fails with these switches:" 123 echo $switches 124 echo "Differences:" 125 diff "$out" "$optout" | head 126 return 0; 127 fi 128 fi 129 return 1 130 } 131 132 echo "Trying to find optimization that breaks program:" 133 for sw in $all_switches ; do 134 echo -n " $sw" 135 switches="$switches $sw" 136 if tryit "$switches" ; then 137 break; 138 fi 139 done 140 141 # Terminate the previous output with a newline 142 echo "" 143 144 # Determine if we're done because none of the optimizations broke the program 145 if [ "$switches" == " $all_switches" ] ; then 146 echo "The program did not miscompile" 147 exit 0 148 fi 149 150 final="" 151 while [ ! -z "$switches" ] ; do 152 trimmed=`echo "$switches" | sed -e 's/^ *\(-[^ ]*\).*/\1/'` 153 switches=`echo "$switches" | sed -e 's/^ *-[^ ]* *//'` 154 echo "Trimmed $trimmed from left" 155 tryit "$final $switches" 156 if [ "$?" -eq "0" ] ; then 157 echo "Still Failing .. continuing ..." 158 continue 159 else 160 echo "Found required early pass: $trimmed" 161 final="$final $trimmed" 162 continue 163 fi 164 echo "Next Loop" 165 done 166 167 if [ "$final" == " $all_switches" ] ; then 168 echo "findmisopt: All optimizations pass. Perhaps this isn't a misopt?" 169 exit 0 170 fi 171 echo "Smallest Optimization list=$final" 172 173 bpcmd="$bugpoint -run-llc -disable-loop-extraction --output "$out" --input /dev/null $bcfile $final --args $args" 174 175 echo "Running: $bpcmd" 176 $bpcmd 177 echo "findmisopt finished." 178
