From: Richard W.M. Jones <rich@annexia.org>
Date: Tue, 26 Aug 2008 08:20:41 +0000 (+0000)
Subject: This patch adds the framework for including C code in bitstring.
X-Git-Url: http://git.annexia.org/?p=ocaml-bitstring.git;a=commitdiff_plain;h=42545798e1ada7e47d7ba56e1c9c2e32bc0e7129

This patch adds the framework for including C code in bitstring.
---

diff --git a/MANIFEST b/MANIFEST
index 688dd07..06cf900 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -3,6 +3,7 @@ benchmarks/parse_ext3_superblock.ml
 bitmatch.ml
 bitstring.ml
 bitstring.mli
+bitstring_c.c
 bitstring_config.ml.in
 bitstring_objinfo.ml
 bitstring_persistent.ml
diff --git a/Makefile.in b/Makefile.in
index 808146d..f3fed47 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -27,6 +27,8 @@ INSTALL		= @INSTALL@
 TIME		= @TIME@
 GPROF		= @GPROF@
 
+OCAMLLIB	= @OCAMLLIB@
+
 pkg_cil		= @pkg_cil@
 pkg_extlib	= @pkg_extlib@
 
@@ -37,6 +39,14 @@ OCAMLOPTPACKAGES =
 
 OCAMLDOCFLAGS	= -html -sort
 
+CC		= @CC@
+CFLAGS		= @CFLAGS@ -Wall -Werror -fPIC -I$(OCAMLLIB)
+
+LIBRARY_PATH	= @abs_top_builddir@
+LD_LIBRARY_PATH	= @abs_top_builddir@
+export LIBRARY_PATH
+export LD_LIBRARY_PATH
+
 SUBDIRS		=
 ifneq ($(pkg_cil),no)
 ifneq ($(pkg_extlib),no)
@@ -56,9 +66,9 @@ all:	bitstring.cma bitstring_persistent.cma \
 	bitstring-objinfo
 	@for d in $(SUBDIRS); do $(MAKE) -C $$d $@; done
 
-bitstring.cma: bitstring_types.cmo bitstring_config.cmo bitstring.cmo \
-	  bitmatch.cmo
-	$(OCAMLFIND) ocamlc -a -o $@ $^
+bitstring.cma: bitstring_types.cmo bitstring_config.cmo \
+	  bitstring_c.o bitstring.cmo bitmatch.cmo
+	$(OCAMLMKLIB) -o bitstring $^
 
 bitstring_persistent.cma: bitstring_persistent.cmo
 	$(OCAMLFIND) ocamlc -a -o $@ $^
@@ -67,9 +77,9 @@ bitstring_persistent.cmo: bitstring_persistent.ml
 	$(OCAMLFIND) ocamlc $(OCAMLCFLAGS) $(OCAMLCPACKAGES) \
 	  -I +camlp4 -pp camlp4of -c $<
 
-bitstring.cmxa: bitstring_types.cmx bitstring_config.cmx bitstring.cmx \
-	  bitmatch.cmx
-	$(OCAMLFIND) ocamlopt -a -o $@ $^
+bitstring.cmxa: bitstring_types.cmx bitstring_config.cmx \
+	  bitstring_c.o bitstring.cmx bitmatch.cmx
+	$(OCAMLMKLIB) -o bitstring $^
 
 bitstring_persistent.cmxa: bitstring_persistent.cmx
 	$(OCAMLFIND) ocamlopt -a -o $@ $^
@@ -207,7 +217,7 @@ endif
 # Install.
 
 install:
-	ocamlfind install bitstring META *.mli *.cmx *.cma *.cmxa *.a \
+	ocamlfind install bitstring META *.mli *.cmx *.cma *.cmxa *.a *.so \
 		bitstring.cmi \
 		bitstring_persistent.cmi \
 		pa_bitstring.cmo
diff --git a/bitstring.ml b/bitstring.ml
index fda9ad6..610c2b5 100644
--- a/bitstring.ml
+++ b/bitstring.ml
@@ -157,16 +157,8 @@ module I = struct
   let minus_one = -1
   let ff = 0xff
 
-  (* Create a mask so many bits wide. *)
-  let mask bits =
-    if bits < 30 then
-      pred (one << bits)
-    else if bits = 30 then
-      max_int
-    else if bits = 31 then
-      minus_one
-    else
-      invalid_arg "Bitstring.I.mask"
+  (* Create a mask 0-31 bits wide. *)
+  external mask : int -> int = "ocaml_bitstring_I_mask" "noalloc"
 
   (* Byte swap an int of a given size. *)
   let byteswap v bits =
diff --git a/bitstring_c.c b/bitstring_c.c
new file mode 100644
index 0000000..6faba8b
--- /dev/null
+++ b/bitstring_c.c
@@ -0,0 +1,42 @@
+/* Bitstring library.
+ * Copyright (C) 2008 Red Hat Inc., Richard W.M. Jones
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version,
+ * with the OCaml linking exception described in COPYING.LIB.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * $Id: bitstring.ml 146 2008-08-20 16:58:33Z richard.wm.jones $
+ */
+
+/* This file contains hand-coded, optimized C implementations of
+ * certain very frequently used functions.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <caml/mlvalues.h>
+#include <caml/fail.h>
+
+/* Return a mask of 0-31 bits wide. */
+CAMLprim value
+ocaml_bitstring_I_mask (value bitsv)
+{
+  int bits = Int_val (bitsv);
+
+  if (bits <= 31)
+    return Val_int ((1 << bits) - 1);
+  else
+    caml_invalid_argument ("Bitstring.I.mask");
+}