Fix bug in read/write-bits! and make them work on the VAX.

diff --git a/v7/src/microcode/bitstr.c b/v7/src/microcode/bitstr.c
index 9c1f81da83ec3a100df88c6104995931a852aef2..520691a5088fee4988b9d2604ad57ed9037036d9 100644 (file)
--- a/v7/src/microcode/bitstr.c
+++ b/v7/src/microcode/bitstr.c
@@ -30,7 +30,7 @@ Technology nor of any adaptation thereof in any advertising,
 promotional, or sales literature without prior written consent from
 MIT in each case. */
 
-/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/bitstr.c,v 9.32 1987/08/06 19:58:57 jinx Exp $
+/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/bitstr.c,v 9.33 1987/08/17 19:31:42 jinx Exp $
 
    Bit string primitives. 
 
@@ -786,12 +786,16 @@ Built_In_Primitive( Prim_bit_string_to_unsigned, 1,
 \f
 #define read_bits_initialize()                                         \
   long end, end_mod, offset;                                           \
+  Pointer *start;                                                      \
   Primitive_3_Args ();                                                 \
                                                                        \
   CHECK_ARG (3, BIT_STRING_P);                                         \
   end = (bit_string_length (Arg3));                                    \
   end_mod = (end % POINTER_LENGTH);                                    \
-  offset = (arg_nonnegative_integer (2))
+  offset = (arg_nonnegative_integer (2));                              \
+  start = read_bits_ptr(Arg1, offset, end);                            \
+  compute_read_bits_offset(offset, end)
+
 
 /* (READ-BITS! pointer offset bit-string)
    Read the contents of memory at the address (POINTER,OFFSET)
@@ -801,7 +805,7 @@ Built_In_Primitive (Prim_read_bits_x, 3, "READ-BITS!", 0xDF)
 {
   read_bits_initialize();
 
-  copy_bits ((object_msw_ptr(Arg1, (offset + end))),
+  copy_bits (start,
             offset,
             (Nth_Vector_Loc (Arg3, (index_to_word (Arg3, (end - 1))))),
             ((end_mod == 0) ? 0 : (POINTER_LENGTH - end_mod)),
@@ -819,7 +823,7 @@ Built_In_Primitive (Prim_write_bits_x, 3, "WRITE-BITS!", 0xE0)
 
   copy_bits ((Nth_Vector_Loc (Arg3, (index_to_word (Arg3, (end - 1))))),
             ((end_mod == 0) ? 0 : (POINTER_LENGTH - end_mod)),
-            (object_msw_ptr(Arg1, (offset + end))),
+            start,
             offset,
             end);
   PRIMITIVE_RETURN( NIL);

diff --git a/v7/src/microcode/bitstr.h b/v7/src/microcode/bitstr.h
index c8977aaaffe31a11e63625ea137f86ea8088b802..c013290584c4e6f4b91af1122078506717b7c0b4 100644 (file)
--- a/v7/src/microcode/bitstr.h
+++ b/v7/src/microcode/bitstr.h
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/bitstr.h,v 1.3 1987/08/06 05:03:44 jinx Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/bitstr.h,v 1.4 1987/08/17 19:32:28 jinx Rel $
 
 Copyright (c) 1987 Massachusetts Institute of Technology
 
@@ -37,28 +37,28 @@ MIT in each case. */
 #define BIT_STRING_LENGTH_OFFSET       1
 #define BIT_STRING_FIRST_WORD          2                            
 
-#define bits_to_pointers(bits)                                 \
+#define bits_to_pointers(bits)                                         \
 (((bits) + (POINTER_LENGTH - 1)) / POINTER_LENGTH)
 
 #define low_mask(nbits) ((1 << (nbits)) - 1)
 #define any_mask(nbits, offset) ((low_mask (nbits)) << (offset))
 
-#define bit_string_length(bit_string)                          \
+#define bit_string_length(bit_string)                                  \
 (Fast_Vector_Ref (bit_string, BIT_STRING_LENGTH_OFFSET))
 
-#define bit_string_start_ptr(bit_string)                       \
+#define bit_string_start_ptr(bit_string)                               \
 (Nth_Vector_Loc (bit_string, BIT_STRING_FIRST_WORD))
 
-#define bit_string_end_ptr(bit_string)                         \
+#define bit_string_end_ptr(bit_string)                                 \
 (Nth_Vector_Loc (bit_string, ((Vector_Length (bit_string)) + 1)))
 
-#define bit_string_msw(bit_string)                             \
+#define bit_string_msw(bit_string)                                     \
 (bit_string_word(bit_string_high_ptr(bit_string)))
 
-#define bit_string_lsw(bit_string)                             \
+#define bit_string_lsw(bit_string)                                     \
 (bit_string_word(Nth_Vector_Loc(bit_string, index_to_word(bit_string, 0))))
 
-#define index_pair_to_bit_fixnum(string, word, bit)            \
+#define index_pair_to_bit_fixnum(string, word, bit)                    \
 (Make_Unsigned_Fixnum (index_pair_to_bit_number (string, word, bit)))
 \f
 /* Byte order dependencies. */
@@ -102,17 +102,24 @@ The "size in bits" is a C "long" integer.
 
 #define inc_bit_string_ptr(ptr)                ((ptr)++)
 
-#define object_msw_ptr(object, length)                         \
-(Get_Pointer(object) + bits_to_pointers(length - 1))
-
 /* This is off by one so bit_string_word will get the correct word. */
 
-#define index_to_word(bit_string, index)                       \
+#define index_to_word(bit_string, index)                               \
 ((BIT_STRING_FIRST_WORD + 1) + (index / POINTER_LENGTH))
 
-#define index_pair_to_bit_number(string, word, bit)            \
+#define index_pair_to_bit_number(string, word, bit)                    \
 (((word) * POINTER_LENGTH) + (bit))
 
+#define read_bits_ptr(object, offset, end)                             \
+(Nth_Vector_Loc(object, bits_to_pointers((offset + end) - 1)))
+
+#define compute_read_bits_offset(offset, end)                          \
+{                                                                      \
+  offset = ((offset + end) % POINTER_LENGTH);                          \
+  if (offset != 0)                                                     \
+    offset = (POINTER_LENGTH - offset);                                        \
+}
+
 
 \f
 #else /* not VAX_BYTE_ORDER */
@@ -153,18 +160,24 @@ The "size in bits" is a C "long" integer.
 
 #define inc_bit_string_ptr(ptr)                (--(ptr))
 
-#define object_msw_ptr(object, length) (Get_Pointer(object))
-
 /* 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)                       \
+#define index_to_word(bit_string, index)                               \
 ((Vector_Length (bit_string)) - (index / POINTER_LENGTH))
 
-#define index_pair_to_bit_number(string, word, bit)            \
+#define index_pair_to_bit_number(string, word, bit)                    \
 ((((Vector_Length (string)) - (word)) * POINTER_LENGTH) + (bit))
 
+#define read_bits_ptr(object, offset, end)                             \
+(Nth_Vector_Loc((object), ((offset) / POINTER_LENGTH)))
+
+#define compute_read_bits_offset(offset, end)                          \
+{                                                                      \
+  offset = (offset % POINTER_LENGTH);                                  \
+}
+
 
 #endif /* VAX_BYTE_ORDER */

diff --git a/v7/src/microcode/version.h b/v7/src/microcode/version.h
index 8e6b0baf73e4f622a5fab338a1ecbe37d963b129..fadf04b61f1765343da4465cb9ffbdc17c442f7c 100644 (file)
--- a/v7/src/microcode/version.h
+++ b/v7/src/microcode/version.h
@@ -30,7 +30,7 @@ Technology nor of any adaptation thereof in any advertising,
 promotional, or sales literature without prior written consent from
 MIT in each case. */
 
-/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/Attic/version.h,v 9.97 1987/08/12 21:22:33 jinx Exp $
+/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/Attic/version.h,v 9.98 1987/08/17 19:33:01 jinx Exp $
 
 This file contains version information for the microcode. */
 \f
@@ -46,7 +46,7 @@ This file contains version information for the microcode. */
 #define VERSION                9
 #endif
 #ifndef SUBVERSION
-#define SUBVERSION     97
+#define SUBVERSION     98
 #endif
 
 #ifndef UCODE_TABLES_FILENAME

diff --git a/v8/src/microcode/version.h b/v8/src/microcode/version.h
index c3aaae907b7ea29d41b1604eddbed973c26d00d3..cfc7757d13358b5967e6058ec606dadeb0e01228 100644 (file)
--- a/v8/src/microcode/version.h
+++ b/v8/src/microcode/version.h
@@ -30,7 +30,7 @@ Technology nor of any adaptation thereof in any advertising,
 promotional, or sales literature without prior written consent from
 MIT in each case. */
 
-/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v8/src/microcode/version.h,v 9.97 1987/08/12 21:22:33 jinx Exp $
+/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v8/src/microcode/version.h,v 9.98 1987/08/17 19:33:01 jinx Exp $
 
 This file contains version information for the microcode. */
 \f
@@ -46,7 +46,7 @@ This file contains version information for the microcode. */
 #define VERSION                9
 #endif
 #ifndef SUBVERSION
-#define SUBVERSION     97
+#define SUBVERSION     98
 #endif
 
 #ifndef UCODE_TABLES_FILENAME