[llvm-commits] CVS: llvm/utils/findmisopt

[Reid Spencer]

Changes in directory llvm/utils:

findmisopt added (r1.1)
---
Log message:

Add a utility script to find a mis-optimization problem. This sometimes 
helps when bugpoint can't find the problem directly because it needs the
set of optimizations that cause the program to fail.


---
Diffs of the changes:  (+125 -0)

 findmisopt |  125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 125 insertions(+)


Index: llvm/utils/findmisopt
diff -c /dev/null llvm/utils/findmisopt:1.1
*** /dev/null	Wed Nov  8 18:26:27 2006
--- llvm/utils/findmisopt	Wed Nov  8 18:26:17 2006
***************
*** 0 ****
--- 1,125 ----
+ #!/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.
+ #
+ #   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
+ #       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.
+ #       
+ bcfile="$1"
+ outdir="$2"
+ args="$3"
+ match="$4"
+ 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"
+ 
+ echo "Test Name: $name"
+ echo "Unoptimized program: $prog"
+ echo "  Optimized program: $optprog"
+ 
+ 
+ # Generate the disassembly
+ llvm-dis "$bcfile" -o "$ll" -f || exit 1
+ 
+ # Generate the non-optimized program
+ llc "$bcfile" -o "$s" -f || exit 1
+ gcc "$s" -o "$prog" || exit 1
+ 
+ # Define the list of optimizations to run
+ 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"
+ 
+ # 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 "$optprog" || exit
+   "$prog" $args > "$out"
+   ex1=$?
+   "$optprog" $args > "$optout"
+   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" 
+       return 0;
+     fi
+   fi
+   return 1
+ }
+ 
+ for sw in $all_switches ; do
+   switches="$switches $sw"
+   if tryit "$switches" ; then
+     break;
+   fi
+ done
+ 
+ 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
+ 
+ echo "Smallest Optimization list= $final"
+ bpcmd="bugpoint -run-llc --output "$out" --input /dev/null $bcfile $final --args $args"
+ 
+ echo "Running: $bpcmd"
+ $bpcmd
+ echo "Finished."