--- a/src/mule-charset.h	Mon Aug 13 11:35:05 2007 +0200
+++ b/src/mule-charset.h	Mon Aug 13 11:36:19 2007 +0200
@@ -401,19 +401,19 @@
 
 /* Is this a prefix for a private leading byte? */
 
-INLINE_HEADER int LEADING_BYTE_PREFIX_P (unsigned char lb);
+INLINE_HEADER int LEADING_BYTE_PREFIX_P (Bufbyte lb);
 INLINE_HEADER int
-LEADING_BYTE_PREFIX_P (unsigned char lb)
+LEADING_BYTE_PREFIX_P (Bufbyte lb)
 {
   return (lb == PRE_LEADING_BYTE_PRIVATE_1 ||
 	  lb == PRE_LEADING_BYTE_PRIVATE_2);
 }
 
 /* Given a private leading byte, return the leading byte prefix stored
-   in a string */
+   in a string. */
 
 #define PRIVATE_LEADING_BYTE_PREFIX(lb)	\
-  ((lb) < MIN_LEADING_BYTE_PRIVATE_2 ?	\
+  ((unsigned int) (lb) < MIN_LEADING_BYTE_PRIVATE_2 ?	\
    PRE_LEADING_BYTE_PRIVATE_1 :		\
    PRE_LEADING_BYTE_PRIVATE_2)
 
@@ -423,13 +423,12 @@
 /*                             of any format                            */
 /************************************************************************/
 
-/* Argument `c' should be (unsigned int) or (unsigned char). */
-/* Note that SP and DEL are not included. */
+/* These are carefully designed to work if BYTE is signed or unsigned. */
+/* Note that SPC and DEL are considered ASCII, not control. */
 
-#define BYTE_ASCII_P(c) ((c) < 0x80)
-#define BYTE_C0_P(c) ((c) < 0x20)
-/* Do some forced casting just to make *sure* things are gotten right. */
-#define BYTE_C1_P(c) ((unsigned int) ((unsigned int) (c) - 0x80) < 0x20)
+#define BYTE_ASCII_P(byte) (((byte) & ~0x7f) == 0)
+#define BYTE_C0_P(byte)    (((byte) & ~0x1f) == 0)
+#define BYTE_C1_P(byte)    (((byte) & ~0x1f) == 0x80)
 
 
 /************************************************************************/
@@ -437,13 +436,13 @@
 /*                       in a Mule-formatted string                     */
 /************************************************************************/
 
-/* Does this byte represent the first byte of a character? */
+/* Does BYTE represent the first byte of a character? */
 
-#define BUFBYTE_FIRST_BYTE_P(c) ((c) < 0xA0)
+#define BUFBYTE_FIRST_BYTE_P(byte) ((byte) < 0xA0)
 
-/* Does this byte represent the first byte of a multi-byte character? */
+/* Does BYTE represent the first byte of a multi-byte character? */
 
-#define BUFBYTE_LEADING_BYTE_P(c) BYTE_C1_P (c)
+#define BUFBYTE_LEADING_BYTE_P(byte) BYTE_C1_P (byte)
 
 
 /************************************************************************/
@@ -561,29 +560,33 @@
   Bufbyte next_allocated_2_byte_leading_byte;
 };
 
-extern struct charset_lookup *chlook;
+INLINE_HEADER Lisp_Object CHARSET_BY_LEADING_BYTE (Bufbyte lb);
+INLINE_HEADER Lisp_Object
+CHARSET_BY_LEADING_BYTE (Bufbyte lb)
+{
+  extern struct charset_lookup *chlook;
 
 #ifdef ERROR_CHECK_TYPECHECK
-/* int not Bufbyte even though that is the actual type of a leading byte.
-   This way, out-of-range values will get caught rather than automatically
-   truncated. */
-INLINE_HEADER Lisp_Object CHARSET_BY_LEADING_BYTE (int lb);
-INLINE_HEADER Lisp_Object
-CHARSET_BY_LEADING_BYTE (int lb)
-{
-  assert (lb >= 0x80 && lb <= 0xFF);
+  /* When error-checking is on, x86 GCC 2.95.2 -O3 miscompiles the
+     following unless we introduce `tem'. */
+  int tem = lb;
+  type_checking_assert (tem >= 0x80 && tem <= 0xFF);
+#endif
   return chlook->charset_by_leading_byte[lb - 128];
 }
 
-#else
-
-#define CHARSET_BY_LEADING_BYTE(lb) (chlook->charset_by_leading_byte[(lb) - 128])
+INLINE_HEADER Lisp_Object
+CHARSET_BY_ATTRIBUTES (unsigned int type, unsigned char final, int dir);
+INLINE_HEADER Lisp_Object
+CHARSET_BY_ATTRIBUTES (unsigned int type, unsigned char final, int dir)
+{
+  extern struct charset_lookup *chlook;
 
-#endif
-
-#define CHARSET_BY_ATTRIBUTES(type, final, dir) \
-  (chlook->charset_by_attributes[type][final][dir])
-
+  type_checking_assert (type  < countof (chlook->charset_by_attributes) &&
+			final < countof (chlook->charset_by_attributes[0]) &&
+			dir   < countof (chlook->charset_by_attributes[0][0]));
+  return chlook->charset_by_attributes[type][final][dir];
+}
 
 /* Table of number of bytes in the string representation of a character
    indexed by the first byte of that representation.
@@ -594,13 +597,11 @@
 extern const Bytecount rep_bytes_by_first_byte[0xA0];
 
 /* Number of bytes in the string representation of a character. */
-INLINE_HEADER int REP_BYTES_BY_FIRST_BYTE (int fb);
+INLINE_HEADER int REP_BYTES_BY_FIRST_BYTE (Bufbyte fb);
 INLINE_HEADER int
-REP_BYTES_BY_FIRST_BYTE (int fb)
+REP_BYTES_BY_FIRST_BYTE (Bufbyte fb)
 {
-#ifdef ERROR_CHECK_TYPECHECK
-  assert (0 <= fb && fb < 0xA0);
-#endif
+  type_checking_assert (fb < 0xA0);
   return rep_bytes_by_first_byte[fb];
 }