forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			102 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
#!/bin/bash
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#
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#  findoptdiff
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#
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#      This script helps find the optimization difference between two llvm
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#      builds. It is useful when you have a build that is known to work and
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#      one that exhibits an optimization problem. Identifying the difference
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#      between the two builds can lead to discovery of the source of a
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#      mis-optimization.
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#
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#      The script takes two llvm build paths as arguments. These specify the
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#      the two llvm builds to compare. It is generally expected that they
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#      are "close cousins".  That is, they are the same except that the 
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#      second build contains some experimental optimization features that
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#      are suspected of producing a misoptimization.
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#
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#      The script takes two bitcode files, one from each build. They are
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#      presumed to be a compilation of the same program or program fragment
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#      with the only difference being the builds.
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#
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#      The script operates by iteratively applying the optimizations that gccas
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#      and gccld run until there is a difference in the assembly resulting
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#      from the optimization. The difference is then reported with the set of
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#      optimization passes that produce the difference.  The processing 
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#      continues until all optimization passes have been tried. The differences
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#      for each pass, if they do differ, are placed in a diffs.# file.
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#
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#      To work around differences in the assembly language format, the script
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#      can also take two filter arguments that post-process the assembly 
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#      so they can be differenced without making false positives for known
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#      differences in the two builds. These filters are optional.
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#
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#   Usage:
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#      findoptdiff llvm1 llvm2 bc1 bc2 filter1 filter2
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#
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#   Where:
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#      llvm1
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#          is the path to the first llvm build dir
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#      llvm2
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#          is the path to the second llvm build dir
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#      bc1
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#          is the bitcode file for the first llvm environment
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#      bc2
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#          is the bitcode file for the second llvm environment
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#      filter1
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#          is an optional filter for filtering the llvm1 generated assembly
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#      filter2
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#          is an optional filter for filtering the llvm2 generated assembly
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#       
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llvm1=$1
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llvm2=$2
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bc1=$3
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bc2=$4
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filt1=$5
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filt2=$6
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if [ -z "$filt1" ] ; then
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  filt1="cat"
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fi
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if [ -z "$filt2" ] ; then
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  filt2="cat"
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fi
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opt1="${bc1}.opt"
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opt2="${bc2}.opt" 
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ll1="${bc1}.ll"
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ll2="${bc2}.ll"
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opt1ll="${bc1}.opt.ll"
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opt2ll="${bc2}.opt.ll"
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dis1="$llvm1/Debug/bin/llvm-dis"
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dis2="$llvm2/Debug/bin/llvm-dis"
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opt1="$llvm1/Debug/bin/opt"
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opt2="$llvm2/Debug/bin/opt"
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all_switches="-verify -lowersetjmp -simplifycfg -mem2reg -globalopt -globaldce -ipconstprop -deadargelim -instcombine -simplifycfg -prune-eh -inline -simplify-libcalls -argpromotion -tailduplicate -simplifycfg -sroa -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 -internalize -ipsccp -globalopt -constmerge -deadargelim -inline -prune-eh -globalopt -globaldce -argpromotion -instcombine -predsimplify -sroa -globalsmodref-aa -licm -load-vn -gcse -dse -instcombine -simplifycfg -verify"
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#counter=0
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function tryit {
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  switches_to_use="$1"
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  $opt1 $switches_to_use "$bc1" -o - | $dis1 | $filt1 > "$opt1ll"
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  $opt2 $switches_to_use "$bc2" -o - | $dis2 | $filt2 > "$opt2ll"
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  diffs="diffs."$((counter++))
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  diff "$opt1ll" "$opt2ll" > $diffs
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  if [ $? -ne 0 ] ; then
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    echo
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    echo "Diff fails with these switches:"
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    echo $switches
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    echo "Differences:"
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    head $diffs
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    echo 'Switches:' $switches_to_use >> $diffs
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  else
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    rm $diffs
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  fi
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  return 1
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}
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for sw in $all_switches ; do
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  echo -n " $sw"
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  switches="$switches $sw"
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  if tryit "$switches" ; then
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    break;
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  fi
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done
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