Generate a perfect hash for the token parser

This commit is contained in:
H. Peter Anvin 2007-08-30 21:45:56 +00:00
parent 67858426e4
commit e9d1a97b88

184
tokhash.pl Executable file
View File

@ -0,0 +1,184 @@
#!/usr/bin/perl
#
# Generate a perfect hash for token parsing
#
# Usage: tokenhash.pl insns.dat regs.dat tokens.dat
#
require 'phash.ph';
my($insns_dat, $regs_dat, $tokens_dat) = @ARGV;
%tokens = ();
@tokendata = ();
#
# List of condition codes
#
@conditions = ('a', 'ae', 'b', 'be', 'c', 'e', 'g', 'ge', 'l', 'le',
'na', 'nae', 'nb', 'nbe', 'nc', 'ne', 'ng', 'nge', 'nl',
'nle', 'no', 'np', 'ns', 'nz', 'o', 'p', 'pe', 'po', 's', 'z');
#
# Read insns.dat
#
open(ID, "< ${insns_dat}") or die "$0: cannot open $insns_dat: $!\n";
while (defined($line = <ID>)) {
if ($line =~ /^([A-Z0-9_]+)(|cc)\s/) {
$insn = $1.$2;
($token = $1) =~ tr/A-Z/a-z/;
if ($2 eq '') {
# Single instruction token
if (!defined($tokens{$token})) {
$tokens{$token} = scalar @tokendata;
push(@tokendata, "\"${token}\", TOKEN_INSN, I_${insn}, 0");
}
} else {
# Conditional instruction
foreach $cc (@conditions) {
if (!defined($tokens{$token.$cc})) {
$tokens{$token.$cc} = scalar @tokendata;
push(@tokendata, "\"${token}${cc}\", TOKEN_INSN, I_${insn}, C_\U$cc\E");
}
}
}
}
}
close(ID);
#
# Read regs.dat
#
open(RD, "< ${regs_dat}") or die "$0: cannot open $regs_dat: $!\n";
while (defined($line = <RD>)) {
if ($line =~ /^([a-z0-9_-]+)\s/) {
$reg = $1;
if ($reg =~ /^(.*[^0-9])([0-9]+)\-([0-9]+)(|[^0-9].*)$/) {
$nregs = $3-$2+1;
$reg = $1.$2.$4;
$reg_nr = $2;
$reg_prefix = $1;
$reg_suffix = $4;
} else {
$nregs = 1;
undef $reg_prefix, $reg_suffix;
}
while ($nregs--) {
if (defined($tokens{$reg})) {
die "Duplicate definition: $reg\n";
}
$tokens{$reg} = scalar @tokendata;
push(@tokendata, "\"${reg}\", TOKEN_REG, R_\U${reg}\E, 0");
if (defined($reg_prefix)) {
$reg_nr++;
$reg = sprintf("%s%u%s", $reg_prefix, $reg_nr, $reg_suffix);
} else {
# Not a dashed sequence
die if ($nregs);
}
}
}
}
close(RD);
#
# Read tokens.dat
#
open(TD, "< ${tokens_dat}") or die "$0: cannot open $tokens_dat: $!\n";
while (defined($line = <TD>)) {
if ($line =~ /^\%\s+(.*)$/) {
$pattern = $1;
} elsif ($line =~ /^([a-z0-9_-]+)/) {
$token = $1;
if (defined($tokens{$reg})) {
die "Duplicate definition: $token\n";
}
$tokens{$token} = scalar @tokendata;
$data = $pattern;
$data =~ s/\*/\U$token/g;
push(@tokendata, "\"$token\", $data");
}
}
close(TD);
#
# Actually generate the hash
#
@hashinfo = gen_perfect_hash(\%tokens);
if (!defined(@hashinfo)) {
die "$0: no hash found\n";
}
# Paranoia...
verify_hash_table(\%tokens, \@hashinfo);
($n, $sv, $f1, $f2, $g) = @hashinfo;
$sv2 = $sv+2;
die if ($n & ($n-1));
print "#include \"nasm.h\"\n";
print "#include \"insns.h\"\n";
print "\n";
print "#define rot(x,y) (((uint32_t)(x) << (y))+((uint32_t)(x) >> (32-(y))))\n";
print "\n";
print "struct tokendata {\n";
print "\tconst char *string;\n";
print "\tint tokentype;\n";
print "\tint i1, i2;\n";
print "};\n";
print "\n";
print "int nasm_token_hash(const char *token, struct tokenval *tv)\n";
print "{\n";
print "\tstatic const int hash1[$n] =\n";
print "\t{\n";
for ($i = 0; $i < $n; $i++) {
print "\t\t", ${$g}[${$f1}[$i]], ",\n";
}
print "\t};\n\n";
print "\tstatic const int hash2[$n] =\n";
print "\t{\n";
for ($i = 0; $i < $n; $i++) {
print "\t\t", ${$g}[${$f2}[$i]], ",\n";
}
print "\t};\n\n";
printf "\tstatic const struct tokendata tokendata[%d] =\n", scalar(@tokendata);
print "\t{\n";
foreach $d (@tokendata) {
print "\t\t{ ", $d, " },\n";
}
print "\t};\n\n";
print "\tuint32_t k1 = 0, k2 = 0;\n";
print "\tuint8_t c;\n";
print "\tconst struct tokendata *data;\n";
print "\tconst char *p = token;\n";
print "\n";
print "\twhile ((c = *p++) != 0) {\n";
printf "\t\tk1 = rot(k1,%2d) - rot(k2,%2d) + c;\n", ${$sv}[0], ${$sv}[1];
printf "\t\tk2 = rot(k2,%2d) - rot(k1,%2d) + c;\n", ${$sv}[2], ${$sv}[3];
print "\t}\n";
print "\n";
printf "\tdata = &tokendata[(k1+k2) & 0x%08x];\n", $n-1;
printf "\tif (data >= &tokendata[%d] || strcmp(data->string, token))\n",
scalar(@tokendata);
print "\t\treturn -1;\n";
print "\n";
print "\ttv->t_integer = data->i1;\n";
print "\ttv->t_inttwo = data->i2;\n";
print "\treturn tv->t_type = data->tokentype;\n";
print "}\n";