source: parabix-LLVM/llvm_git/utils/codegen-diff @ 4136

Last change on this file since 4136 was 4078, checked in by linmengl, 5 years ago

checkin llvm-meng source

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Line 
1#!/usr/bin/perl
2
3use Getopt::Std;
4$DEBUG = 0;
5
6sub parse_objdump_file {
7  my ($filename) = @_;
8  my @result;
9  open (INPUT, $filename) or die "$filename: $!\n";
10  print "opened objdump output file $filename\n" if $DEBUG;
11  while (<INPUT>) {
12    if (/\s*([0-9a-f]*):\t(([0-9a-f]{2} )+) *\t(.*)$/) {
13      my ($addr, $bytes, $instr) = ($1, $2, $4);
14      $addr = "0x" . $addr;
15      $bytes =~ s/\s*(.*\S)\s*/$1/; # trim any remaining whitespace
16      $instr =~ s/\s*(.*\S)\s*/$1/;
17      push (@result, {'addr' => $addr, 'bytes' => $bytes, 'instr' => $instr});
18      print "addr=$addr bytes='$bytes' instr='$instr'\n" if $DEBUG;
19    }
20  }
21  close INPUT;
22  return @result;
23}
24
25sub parse_gdb_file {
26  my ($filename) = @_;
27  my @result;
28  my $got_addr;
29  open (INPUT, $filename) or die "$filename: $!\n";
30  print "opened gdb output file $filename\n" if $DEBUG;
31  while (<INPUT>) {
32    if (/^(0x[0-9a-f]*):\t([^\t]*)\t[^:]*:\t((0x[0-9a-f]{2}\s*)+)\s*$/) {
33      my ($addr, $bytes, $instr) = ($1, $3, $2);
34      $bytes =~ s/0x//g;
35      $bytes =~ s/\s+/ /g;           # regularize whitespace
36      $bytes =~ s/\s*(.*\S)\s*/$1/;  # trim any remaining whitespace
37      $instr =~ s/\s*(.*\S)\s*/$1/;
38      push (@result, {'addr' => $addr, 'bytes' => $bytes, 'instr' => $instr});
39      print "addr=$addr bytes='$bytes' instr='$instr'\n" if $DEBUG;
40    } elsif (/^(0x[0-9a-f]*):\t$/) { # deal with gdb's line breaker
41      $got_addr = $1;
42    } elsif ($got_addr && /^    ([^\t]*)\t[^:]*:\t((0x[0-9a-f]{2}\s*)+)\s*$/) {
43      my ($addr, $bytes, $instr) = ($got_addr, $2, $1);
44      $bytes =~ s/0x//g;
45      $bytes =~ s/\s+/ /g;           # regularize whitespace
46      $bytes =~ s/\s*(.*\S)\s*/$1/;  # trim any remaining whitespace
47      $instr =~ s/\s*(.*\S)\s*/$1/;
48      push (@result, {'addr' => $addr, 'bytes' => $bytes, 'instr' => $instr});
49      print "addr=$addr bytes='$bytes' instr='$instr'\n" if $DEBUG;
50      undef $got_addr;
51    }
52  }
53  close INPUT;
54  return @result;
55}
56
57sub binary_diffs {
58  my ($objdump_file, $gdb_file) = @_;
59  my @file1 = parse_objdump_file ($objdump_file);
60  my @file2 = parse_gdb_file ($gdb_file);
61  my $lastrecord = ($#file1 >= $#file2) ? ($#file1) : ($#file2);
62  for (my $i = 0; $i <= $lastrecord; ++$i) {
63    my $d1 = $file1[$i];
64    my $d2 = $file2[$i];
65    if ($d1->{'bytes'} ne $d2->{'bytes'}) {
66      next if (($d1->{'instr'} eq $d2->{'instr'}) && $opt_d);
67      printf "0x%08x:\t%30s \t%s\n", 0+$d1->{'addr'}, $d1->{'bytes'}, $d1->{'instr'};
68      printf "0x%08x:\t%30s \t%s\n\n", 0+$d2->{'addr'}, $d2->{'bytes'}, $d2->{'instr'};
69    }
70  }
71}
72
73&getopts('d');
74$objdump_file = $ARGV[0];
75$gdb_file = $ARGV[1];
76binary_diffs ($objdump_file, $gdb_file);
77exit (0);
78__END__
79=pod
80
81=head1 NAME
82
83codegen-diff
84
85=head1 SYNOPSIS
86
87codegen-diff [-d] I<OBJDUMP-OUTPUT-FILE> I<GDB-DISASSEMBLY-FILE>
88
89=head1 DESCRIPTION
90
91B<codegen-diff> is a program that tries to show you the differences
92between the code that B<llc> generated and the code that B<lli> generated.
93
94The way you use it is as follows: first, you create I<OBJDUMP-OUTPUT-FILE>
95by running B<objdump> on the B<llc> compiled and linked binary. You need to
96trim down the result so it contains only the function of interest.
97
98Second, you create I<GDB-DISASSEMBLY-FILE> by running B<gdb>, with my patch
99to print out hex bytes in the B<disassemble> command output, on
100B<lli>.  Set a breakpoint in C<Emitter::finishFunction()> and wait until
101the function you want is compiled.  Then use the B<disassemble> command
102to print out the assembly dump of the function B<lli> just compiled.
103(Use C<lli -debug> to find out where the function starts and ends in memory.)
104It's easiest to save this output by using B<script>.
105
106Finally, you run B<codegen-diff>, as indicated in the Synopsis section of
107this manpage. It will print out a two-line stanza for each mismatched
108instruction, with the  B<llc> version first, and the  B<lli> version second.
109
110=head1 OPTIONS
111
112=over 4
113
114=item -d
115
116Don't show instructions where the bytes are different but they
117disassemble to the same thing. This puts a lot of trust in the
118disassembler, but it might help you highlight the more egregious cases
119of misassembly.
120
121=back
122
123=head1 AUTHOR
124
125B<codegen-diff> was written by Brian Gaeke.
126
127=head1 SEE ALSO
128
129L<gdb(1)>, L<objdump(1)>, L<script(1)>.
130
131You will need my B<gdb> patch:
132
133  http://llvm.cs.uiuc.edu/~gaeke/gdb-disassembly-print-bytes.patch
134
135=cut
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