From: mdw <mdw>
Date: Sat, 17 Jun 2000 10:36:06 +0000 (+0000)
Subject: Support for 24-bit types.
X-Git-Tag: 2.0.4~182
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/commitdiff_plain/6a0129ea8c11c4fd12a6198dac1a3c4ab8af4ecc

Support for 24-bit types.
---

diff --git a/bits.h b/bits.h
index 21abb59..34f5f1f 100644
--- a/bits.h
+++ b/bits.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: bits.h,v 1.4 1999/12/10 23:42:04 mdw Exp $
+ * $Id: bits.h,v 1.5 2000/06/17 10:36:06 mdw Exp $
  *
  * Portable bit-level manipulation macros
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: bits.h,v $
+ * Revision 1.5  2000/06/17 10:36:06  mdw
+ * Support for 24-bit types.
+ *
  * Revision 1.4  1999/12/10 23:42:04  mdw
  * Change header file guard names.
  *
@@ -72,6 +75,14 @@
   typedef unsigned long uint32;
 #endif
 
+/* --- Decide on a 24-bit type --- */
+
+#if UINT_MAX >= 0x00ffffffu
+  typedef unsigned int uint24;
+#else
+  typedef unsigned long uint24;
+#endif
+
 /* --- Decide on 16-bit and 8-bit types --- *
  *
  * This is more for brevity than anything else.
@@ -92,12 +103,14 @@ typedef unsigned char octet;
 
 #define MASK8 0xffu
 #define MASK16 0xffffu
+#define MASK24 0xffffffu
 #define MASK32 0xffffffffu
 
 /* --- Type coercions --- */
 
 #define U8(x) ((octet)((x) & MASK8))
 #define U16(x) ((uint16)((x) & MASK16))
+#define U24(x) ((uint24)((x) & MASK24))
 #define U32(x) ((uint32)((x) & MASK32))
 
 /* --- Safe shifting macros --- */
@@ -106,6 +119,8 @@ typedef unsigned char octet;
 #define LSR8(v, s) U8(U8(v) >> ((s) & 7u))
 #define LSL16(v, s) U16(U16(v) << ((s) & 15u))
 #define LSR16(v, s) U16(U16(v) >> ((s) & 15u))
+#define LSL24(v, s) U24(U24(v) << ((s) % 24u))
+#define LSR24(v, s) U24(U24(v) >> ((s) % 24u))
 #define LSL32(v, s) U32(U32(v) << ((s) & 31u))
 #define LSR32(v, s) U32(U32(v) >> ((s) & 31u))
 
@@ -115,6 +130,8 @@ typedef unsigned char octet;
 #define ROR8(v, s) (LSR8((v), (s)) | (LSL8((v), 8u - (s))))
 #define ROL16(v, s) (LSL16((v), (s)) | (LSR16((v), 16u - (s))))
 #define ROR16(v, s) (LSR16((v), (s)) | (LSL16((v), 16u - (s))))
+#define ROL24(v, s) (LSL24((v), (s)) | (LSR24((v), 24u - (s))))
+#define ROR24(v, s) (LSR24((v), (s)) | (LSL24((v), 24u - (s))))
 #define ROL32(v, s) (LSL32((v), (s)) | (LSR32((v), 32u - (s))))
 #define ROR32(v, s) (LSR32((v), (s)) | (LSL32((v), 32u - (s))))
 
@@ -142,6 +159,26 @@ typedef unsigned char octet;
    PUTBYTE((p), 1, (uint16)(v) >> 8))
 #define STORE16(p, v) STORE16_B((p), (v))
 
+#define LOAD24_B(p)							\
+  (((uint24)GETBYTE((p), 0) << 16) |					\
+   ((uint24)GETBYTE((p), 1) <<  8) |					\
+   ((uint24)GETBYTE((p), 2) <<  0))
+#define LOAD24_L(p)							\
+  (((uint24)GETBYTE((p), 0) <<  0) |					\
+   ((uint24)GETBYTE((p), 1) <<  8) |					\
+   ((uint24)GETBYTE((p), 2) << 16))
+#define LOAD24(p) LOAD24_B((p))
+
+#define STORE24_B(p, v)							\
+  (PUTBYTE((p), 0, (uint24)(v) >> 16),					\
+   PUTBYTE((p), 1, (uint24)(v) >>  8),					\
+   PUTBYTE((p), 2, (uint24)(v) >>  0))
+#define STORE24_L(p, v)							\
+  (PUTBYTE((p), 0, (uint24)(v) >>  0),					\
+   PUTBYTE((p), 1, (uint24)(v) >>  8),					\
+   PUTBYTE((p), 2, (uint24)(v) >> 16))
+#define STORE24(p, v) STORE24_B((p), (v))
+
 #define LOAD32_B(p)							\
   (((uint32)GETBYTE((p), 0) << 24) |					\
    ((uint32)GETBYTE((p), 1) << 16) |					\