From: H. Peter Anvin <hpa@zytor.com>
Date: Thu, 30 Aug 2007 21:45:56 +0000 (+0000)
Subject: Generate a perfect hash for the token parser
X-Git-Tag: nasm-2.11.05~2032
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e9d1a97b88240132d452c45624880ddeacc842ac;p=platform%2Fupstream%2Fnasm.git

Generate a perfect hash for the token parser
---

diff --git a/tokhash.pl b/tokhash.pl
new file mode 100755
index 0000000..dfd7082
--- /dev/null
+++ b/tokhash.pl
@@ -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";