+2004-04-18 Dirk Herrmann <dirk@dirk-herrmanns-seiten.de>
+
+ * tags.h (scm_tags, scm_tc8_tags, scm_tc9_flag, scm_tc8_flag,
+ scm_tc8_isym): Renamed scm_tags to scm_tc8_tags. Renamed
+ scm_tc9_flag to scm_tc8_flag. Introduced new identifier
+ scm_tc8_isym. Defined tc8-tags relative to scm_tc3_imm24.
+ Defined the tc8-tag for flags to be 0x04, which will mean that
+ SCM_BOOL_F will also have the value 0x04 instead of 0x013c. Due
+ to the reduced number of bits and the simpler bit pattern for
+ SCM_BOOL_F, certain machines may be able to use more efficient
+ processor instructions to deal with SCM_BOOL_F.
+
+ (SCM_ITAG9, SCM_MAKE_ITAG9, SCM_ITAG9_DATA): Removed. These have
+ never been defined in a released version, thus no need to
+ deprecate them.
+
+ (SCM_IFLAGP, SCM_MAKIFLAG, SCM_IFLAGNUM): Flags now use tc8
+ instead of tc9 tags.
+
+ (SCM_ISYMP, SCM_MAKISYM, SCM_ISYMNUM): Isyms now use tc8 instead
+ of tc9 tags.
+
+ (SCM_MAKSPCSYM): Removed. It is almost impossible that user code
+ could have used this definition.
+
+ (SCM_IM_AND, SCM_IM_BEGIN, SCM_IM_CASE, SCM_IM_COND, SCM_IM_DO,
+ SCM_IM_IF, SCM_IM_LAMBDA, SCM_IM_LET, SCM_IM_LETSTAR,
+ SCM_IM_LETREC, SCM_IM_OR, SCM_IM_QUOTE, SCM_IM_SET_X): Now encoded
+ as isyms, as special isyms don't exist any more.
+
2004-04-18 Kevin Ryde <user42@zip.com.au>
* filesys.c (scm_readdir): Use readdir_r when available, for thread
#ifndef SCM_TAGS_H
#define SCM_TAGS_H
-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
+ * Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* value and sign. Thus, the only scheme objects for which a further
* subdivision is of interest are the ones with tc3==100.
*
- * tc7, tc8, tc9 (for objects with tc3==100):
- * 00-0000-100: \ evaluator byte codes ('short instructions'). The byte
- * ... } code interpreter can dispatch on them in one step based
- * 00-1100-100: / on their tc7 value.
- * 00-1101-100: evaluator byte codes ('long instructions'). The byte code
- * interpreter needs to dispatch on them in two steps: The
- * first dispatch is based on the tc7-code. The second
- * dispatch is based on the actual byte code that is extracted
- * from the upper bits.
- * x1-1110-100: evaluator byte codes ('ilocs')
- * x1-1111-100: characters with x as their least significant bit
- * 10-1111-100: various constants ('flags')
+ * tc8 (for objects with tc3==100):
+ * 00000-100: special objects ('flags')
+ * 00001-100: characters
+ * 00010-100: evaluator byte codes ('ilocs')
+ * 00011-100: evaluator byte codes ('isyms')
*
*
* Summary of type codes on the heap
#define scm_tc_free_cell (scm_tc7_smob + 0 * 256L)
\f
+
/* {Immediate Values}
*/
-enum scm_tags
+enum scm_tc8_tags
{
- scm_tc8_iloc = 0xf4,
- scm_tc8_char = 0xfc,
- scm_tc9_flag = 0x17c
+ scm_tc8_flag = scm_tc3_imm24 + 0x00, /* special objects ('flags') */
+ scm_tc8_char = scm_tc3_imm24 + 0x08, /* characters */
+ scm_tc8_isym = scm_tc3_imm24 + 0x10, /* evaluator byte codes ('isyms') */
+ scm_tc8_iloc = scm_tc3_imm24 + 0x18 /* evaluator byte codes ('ilocs') */
};
#define SCM_ITAG8(X) (SCM_UNPACK (X) & 0xff)
#define SCM_MAKE_ITAG8(X, TAG) SCM_PACK (((X) << 8) + TAG)
#define SCM_ITAG8_DATA(X) (SCM_UNPACK (X) >> 8)
-#define SCM_ITAG9(X) (SCM_UNPACK (X) & 0x1ff)
-#define SCM_MAKE_ITAG9(X, TAG) SCM_PACK (((X) << 9) + TAG)
-#define SCM_ITAG9_DATA(X) (SCM_UNPACK (X) >> 9)
-
-
\f
-/* Flags (various constants and special objects). The indices of the flags
- * must agree with the declarations in print.c: iflagnames. */
-#define SCM_IFLAGP(n) (SCM_ITAG9 (n) == scm_tc9_flag)
-#define SCM_MAKIFLAG(n) SCM_MAKE_ITAG9 ((n), scm_tc9_flag)
-#define SCM_IFLAGNUM(n) (SCM_ITAG9_DATA (n))
+/* Flags (special objects). The indices of the flags must agree with the
+ * declarations in print.c: iflagnames. */
+
+#define SCM_IFLAGP(n) (SCM_ITAG8 (n) == scm_tc8_flag)
+#define SCM_MAKIFLAG(n) SCM_MAKE_ITAG8 ((n), scm_tc8_flag)
+#define SCM_IFLAGNUM(n) (SCM_ITAG8_DATA (n))
#define SCM_BOOL_F SCM_MAKIFLAG (0)
#define SCM_BOOL_T SCM_MAKIFLAG (1)
#define SCM_UNBNDP(x) (SCM_EQ_P ((x), SCM_UNDEFINED))
+\f
-/* Short instructions ('special symbols'), long instructions ('immediate
- * symbols'). The indices of the SCM_IM_ symbols must agree with the
- * declarations in print.c: scm_isymnames. */
+/* Evaluator byte codes ('immediate symbols'). These constants are used only
+ * in eval but their values have to be allocated here. The indices of the
+ * SCM_IM_ symbols must agree with the declarations in print.c:
+ * scm_isymnames. */
-#define SCM_MAKSPCSYM(n) SCM_PACK (((n) << 9) + ((n) << 3) + 4L)
-#define SCM_MAKISYM(n) SCM_PACK (((n) << 9) + 0x6cL)
+#define SCM_ISYMP(n) (SCM_ITAG8 (n) == scm_tc8_isym)
+#define SCM_MAKISYM(n) SCM_MAKE_ITAG8 ((n), scm_tc8_isym)
+#define SCM_ISYMNUM(n) (SCM_ITAG8_DATA (n))
-/* SCM_ISYMP tests for ISPCSYM and ISYM */
-#define SCM_ISYMP(n) ((0x187 & SCM_UNPACK (n)) == 4)
-#define SCM_ISYMNUM(n) (SCM_UNPACK (n) >> 9)
SCM_API char *scm_isymnames[]; /* defined in print.c */
#define SCM_ISYMCHARS(n) (scm_isymnames[SCM_ISYMNUM (n)])
-/* Evaluator bytecodes (short instructions): These are uniquely identified by
- * their tc7 value. This makes it possible for the evaluator to dispatch on
- * them in one step. However, the type system allows for at most 13 short
- * instructions. Consequently, the most frequent instructions are chosen to
- * be represented as short instructions. These constants are used only in
- * eval but their values have to be allocated here. */
-
-#define SCM_IM_AND SCM_MAKSPCSYM (0)
-#define SCM_IM_BEGIN SCM_MAKSPCSYM (1)
-#define SCM_IM_CASE SCM_MAKSPCSYM (2)
-#define SCM_IM_COND SCM_MAKSPCSYM (3)
-#define SCM_IM_DO SCM_MAKSPCSYM (4)
-#define SCM_IM_IF SCM_MAKSPCSYM (5)
-#define SCM_IM_LAMBDA SCM_MAKSPCSYM (6)
-#define SCM_IM_LET SCM_MAKSPCSYM (7)
-#define SCM_IM_LETSTAR SCM_MAKSPCSYM (8)
-#define SCM_IM_LETREC SCM_MAKSPCSYM (9)
-#define SCM_IM_OR SCM_MAKSPCSYM (10)
-#define SCM_IM_QUOTE SCM_MAKSPCSYM (11)
-#define SCM_IM_SET_X SCM_MAKSPCSYM (12)
-
-
-/* Evaluator bytecodes (long instructions): All these share a common tc7
- * value. Thus, the evaluator needs to dispatch on them in two steps. These
- * constants are used only in eval but their values have to be allocated
- * here. */
-
-/* Evaluator bytecode for (define ...) statements. We make it a long
- * instruction since the evaluator will see this bytecode only for a very
- * limited number of times, namely once for every top-level and internal
- * definition: Top-level definitions are only executed once and internal
- * definitions are converted to letrec expressions. */
+#define SCM_IM_AND SCM_MAKISYM (0)
+#define SCM_IM_BEGIN SCM_MAKISYM (1)
+#define SCM_IM_CASE SCM_MAKISYM (2)
+#define SCM_IM_COND SCM_MAKISYM (3)
+#define SCM_IM_DO SCM_MAKISYM (4)
+#define SCM_IM_IF SCM_MAKISYM (5)
+#define SCM_IM_LAMBDA SCM_MAKISYM (6)
+#define SCM_IM_LET SCM_MAKISYM (7)
+#define SCM_IM_LETSTAR SCM_MAKISYM (8)
+#define SCM_IM_LETREC SCM_MAKISYM (9)
+#define SCM_IM_OR SCM_MAKISYM (10)
+#define SCM_IM_QUOTE SCM_MAKISYM (11)
+#define SCM_IM_SET_X SCM_MAKISYM (12)
#define SCM_IM_DEFINE SCM_MAKISYM (13)
-
#define SCM_IM_APPLY SCM_MAKISYM (14)
#define SCM_IM_CONT SCM_MAKISYM (15)
#define SCM_IM_DISPATCH SCM_MAKISYM (16)
#define SCM_IM_CALL_WITH_VALUES SCM_MAKISYM (21)
#define SCM_IM_ELSE SCM_MAKISYM (22)
#define SCM_IM_ARROW SCM_MAKISYM (23)
-
-/* Multi-language support */
-
-#define SCM_IM_NIL_COND SCM_MAKISYM (24)
-#define SCM_IM_BIND SCM_MAKISYM (25)
+#define SCM_IM_NIL_COND SCM_MAKISYM (24) /* Multi-language support */
+#define SCM_IM_BIND SCM_MAKISYM (25) /* Multi-language support */
\f
HCoop / bpt / guile.git / commitdiff