Build with CFLAGS='-DWIDE_EMACS_INT' to try them out. */
/* #undef WIDE_EMACS_INT */
-/* These are default choices for the types to use. */
+/* EMACS_INT - signed integer wide enough to hold an Emacs value
+ EMACS_INT_MAX - maximum value of EMACS_INT; can be used in #if
+ pI - printf length modifier for EMACS_INT
+ EMACS_UINT - unsigned variant of EMACS_INT */
#ifndef EMACS_INT
-# if BITS_PER_LONG < BITS_PER_LONG_LONG && defined WIDE_EMACS_INT
+# if LONG_MAX < LLONG_MAX && defined WIDE_EMACS_INT
# define EMACS_INT long long
-# define BITS_PER_EMACS_INT BITS_PER_LONG_LONG
+# define EMACS_INT_MAX LLONG_MAX
# define pI "ll"
-# elif BITS_PER_INT < BITS_PER_LONG
+# elif INT_MAX < LONG_MAX
# define EMACS_INT long
-# define BITS_PER_EMACS_INT BITS_PER_LONG
+# define EMACS_INT_MAX LONG_MAX
# define pI "l"
# else
# define EMACS_INT int
-# define BITS_PER_EMACS_INT BITS_PER_INT
+# define EMACS_INT_MAX INT_MAX
# define pI ""
# endif
#endif
-#ifndef EMACS_UINT
-# define EMACS_UINT unsigned EMACS_INT
-#endif
+#define EMACS_UINT unsigned EMACS_INT
+
+/* Number of bits in some machine integer types. */
+enum
+ {
+ BITS_PER_CHAR = CHAR_BIT,
+ BITS_PER_SHORT = CHAR_BIT * sizeof (short),
+ BITS_PER_INT = CHAR_BIT * sizeof (int),
+ BITS_PER_LONG = CHAR_BIT * sizeof (long int),
+ BITS_PER_EMACS_INT = CHAR_BIT * sizeof (EMACS_INT)
+ };
/* printmax_t and uprintmax_t are types for printing large integers.
These are the widest integers that are supported for printing.
variable VAR of type TYPE with the added requirement that it be
TYPEBITS-aligned. */
-#ifndef GCTYPEBITS
#define GCTYPEBITS 3
-#endif
-
-#ifndef VALBITS
#define VALBITS (BITS_PER_EMACS_INT - GCTYPEBITS)
-#endif
+
+/* The maximum value that can be stored in a EMACS_INT, assuming all
+ bits other than the type bits contribute to a nonnegative signed value.
+ This can be used in #if, e.g., '#if VAL_MAX < UINTPTR_MAX' below. */
+#define VAL_MAX (EMACS_INT_MAX >> (GCTYPEBITS - 1))
#ifndef NO_DECL_ALIGN
# ifndef DECL_ALIGN
|| defined DARWIN_OS || defined __sun)
/* We also need to be able to specify mult-of-8 alignment on static vars. */
# if defined DECL_ALIGN
-/* On hosts where VALBITS is greater than the pointer width in bits,
+/* On hosts where pointers-as-ints do not exceed VAL_MAX,
USE_LSB_TAG is:
a. unnecessary, because the top bits of an EMACS_INT are unused, and
b. slower, because it typically requires extra masking.
So, define USE_LSB_TAG only on hosts where it might be useful. */
-# if UINTPTR_MAX >> VALBITS != 0
+# if VAL_MAX < UINTPTR_MAX
# define USE_LSB_TAG
# endif
# endif
#else /* not USE_LSB_TAG */
-#define VALMASK ((((EMACS_INT) 1) << VALBITS) - 1)
+#define VALMASK VAL_MAX
/* One need to override this if there must be high bits set in data space
(doing the result of the below & ((1 << (GCTYPE + 1)) - 1) would work