Fix for hal_endian.h SWAP16() macro

[Grant Edwards]

The SWAP16() macro is broken.

  unsigned u = SWAP16(0x1234);

u will be 0x123412 instead of 0x3412.

Here's a fix.

I believe that the SWAP32() macro will also break in a similar
way on systems where "int" is larger than 32 bits, but I have
no way to test that conjecture.

-- 
Grant Edwards
[EMAIL PROTECTED]

? hal_endian.h--SWAP16.patch
Index: hal_endian.h
===================================================================
RCS file: /cvs/ecos/ecos/packages/hal/common/current/include/hal_endian.h,v
retrieving revision 1.3
diff -U10 -r1.3 hal_endian.h
--- hal_endian.h        23 May 2002 23:02:47 -0000      1.3
+++ hal_endian.h        24 Sep 2007 16:48:40 -0000
@@ -56,21 +56,21 @@
 #include <pkgconf/hal.h>                // CYGBLD_HAL_ENDIAN_H
 #include <cyg/infra/cyg_type.h>         // endian setting
 
 // Allow HALs to override the generic implementation of swap macros
 #ifdef CYGBLD_HAL_ENDIAN_H
 # include CYGBLD_HAL_ENDIAN_H
 #endif
 
 #ifndef CYG_SWAP16
 # define CYG_SWAP16(_x_)                                        \
-    ({ cyg_uint16 _x = (_x_); ((_x << 8) | (_x >> 8)); })
+    ({ cyg_uint16 _x = (_x_); (cyg_uint16)((_x << 8) | (_x >> 8)); })
 #endif
 
 #ifndef CYG_SWAP32
 # define CYG_SWAP32(_x_)                        \
     ({ cyg_uint32 _x = (_x_);                   \
        ((_x << 24) |                            \
        ((0x0000FF00UL & _x) <<  8) |            \
        ((0x00FF0000UL & _x) >>  8) |            \
        (_x  >> 24)); })
 #endif