From: Chris Hanson <org/chris-hanson/cph>
Date: Sat, 25 Apr 1987 20:24:49 +0000 (+0000)
Subject: Initial revision
X-Git-Tag: 20090517-FFI~13583
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=16e5dac64be6f8538f4f17b3f857f0984715a443;p=mit-scheme.git

Initial revision
---

diff --git a/v7/src/microcode/bitstr.h b/v7/src/microcode/bitstr.h
new file mode 100644
index 000000000..4832bc446
--- /dev/null
+++ b/v7/src/microcode/bitstr.h
@@ -0,0 +1,81 @@
+/* -*-C-*-
+
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/bitstr.h,v 1.1 1987/04/25 20:24:49 cph Exp $
+
+Copyright (c) 1987 Massachusetts Institute of Technology
+
+This material was developed by the Scheme project at the Massachusetts
+Institute of Technology, Department of Electrical Engineering and
+Computer Science.  Permission to copy this software, to redistribute
+it, and to use it for any purpose is granted, subject to the following
+restrictions and understandings.
+
+1. Any copy made of this software must include this copyright notice
+in full.
+
+2. Users of this software agree to make their best efforts (a) to
+return to the MIT Scheme project any improvements or extensions that
+they make, so that these may be included in future releases; and (b)
+to inform MIT of noteworthy uses of this software.
+
+3. All materials developed as a consequence of the use of this
+software shall duly acknowledge such use, in accordance with the usual
+standards of acknowledging credit in academic research.
+
+4. MIT has made no warrantee or representation that the operation of
+this software will be error-free, and MIT is under no obligation to
+provide any services, by way of maintenance, update, or otherwise.
+
+5. In conjunction with products arising from the use of this material,
+there shall be no use of the name of the Massachusetts Institute of
+Technology nor of any adaptation thereof in any advertising,
+promotional, or sales literature without prior written consent from
+MIT in each case. */
+
+/* Bit string macros. */
+
+#define bit_string_p(P) ((pointer_type (P)) == TC_BIT_STRING)
+
+#define guarantee_bit_string_arg_1()				\
+if (! (bit_string_p (Arg1))) error_wrong_type_arg_1 ()
+
+#define guarantee_bit_string_arg_2()				\
+if (! (bit_string_p (Arg2))) error_wrong_type_arg_2 ()
+
+#define guarantee_bit_string_arg_3()				\
+if (! (bit_string_p (Arg3))) error_wrong_type_arg_3 ()
+
+#define guarantee_bit_string_arg_4()				\
+if (! (bit_string_p (Arg4))) error_wrong_type_arg_4 ()
+
+#define guarantee_bit_string_arg_5()				\
+if (! (bit_string_p (Arg5))) error_wrong_type_arg_5 ()
+
+#define bit_string_length(bit_string)				\
+(Fast_Vector_Ref (bit_string, NM_ENTRY_COUNT))
+
+#define bit_string_start_ptr(bit_string)			\
+(Nth_Vector_Loc (bit_string, NM_DATA))
+
+#define bit_string_end_ptr(bit_string)				\
+(Nth_Vector_Loc (bit_string, ((Vector_Length (bit_string)) + 1)))
+
+#define any_mask(nbits, offset) ((low_mask (nbits)) << (offset))
+#define low_mask(nbits) ((1 << (nbits)) - 1)
+
+/* This is especially clever.  To understand it, note that the index
+   of the last pointer of a vector is also the GC length of the
+   vector, so that all we need do is subtract the zero-based word
+   index from the GC length. */
+
+#define index_to_word(bit_string, index)			\
+((Vector_Length (bit_string)) - (index / POINTER_LENGTH))
+
+#define bits_to_pointers(bits)					\
+(((bits) + (POINTER_LENGTH - 1)) / POINTER_LENGTH)
+
+#define index_pair_to_bit_number(string, word, bit)		\
+((((Vector_Length (string)) - (word)) * POINTER_LENGTH) + (bit))
+
+#define index_pair_to_bit_fixnum(string, word, bit)		\
+(Make_Unsigned_Fixnum (index_pair_to_bit_number (string, word, bit)))