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Factor out string decoder in insns.pl

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Factor out the string decoder into its own subroutine.  This will be
useful shortly ;)
This commit is contained in:
H. Peter Anvin 2008-05-12 10:17:27 -07:00
parent d58656f797
commit 387c1c2714
1 changed files with 29 additions and 16 deletions
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45
insns.pl
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@ -275,6 +275,34 @@ sub addprefix ($@) {
return @l;
}
#
# Turn a code string into a sequence of bytes
#
sub decodify($) {
# Although these are C-syntax strings, by convention they should have
# only octal escapes (for directives) and hexadecimal escapes
# (for verbatim bytes)
my($codestr) = @_;
my $c = $codestr;
my @codes = ();
while ($c ne '') {
if ($c =~ /^\\x([0-9a-f]+)(.*)$/i) {
push(@codes, hex $1);
$c = $2;
next;
} elsif ($c =~ /^\\([0-7]{1,3})(.*)$/) {
push(@codes, oct $1);
$c = $2;
next;
} else {
die "$0: unknown code format in \"$codestr\"\n";
}
}
return @codes;
}
# Here we determine the range of possible starting bytes for a given
# instruction. We need only consider the codes:
# \1 \2 \3 mean literal bytes, of course
@ -291,22 +319,7 @@ sub startseq($) {
my $c0, $c1, $i;
my $prefix = '';
# Although these are C-syntax strings, by convention they should have
# only octal escapes (for directives) and hexadecimal escapes
# (for verbatim bytes)
while ($c ne '') {
if ($c =~ /^\\x([0-9a-f]+)(.*)$/i) {
push(@codes, hex $1);
$c = $2;
next;
} elsif ($c =~ /^\\([0-7]{1,3})(.*)$/) {
push(@codes, oct $1);
$c = $2;
next;
} else {
die "$0: unknown code format in \"$codestr\"\n";
}
}
@codes = decodify($codestr);
while ($c0 = shift(@codes)) {
$c1 = $codes[0];