C++程序  |  131行  |  2.8 KB

/**************************************************************************
 * 
 * Copyright 2007-2008 VMware, Inc.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

#ifndef U_POINTER_H
#define U_POINTER_H

#include "pipe/p_compiler.h"

#ifdef __cplusplus
extern "C" {
#endif

static inline intptr_t
pointer_to_intptr( const void *p )
{
   union {
      const void *p;
      intptr_t i;
   } pi;
   pi.p = p;
   return pi.i;
}

static inline void *
intptr_to_pointer( intptr_t i )
{
   union {
      void *p;
      intptr_t i;
   } pi;
   pi.i = i;
   return pi.p;
}

static inline uintptr_t
pointer_to_uintptr( const void *ptr )
{
   union {
      const void *p;
      uintptr_t u;
   } pu;
   pu.p = ptr;
   return pu.u;
}

static inline void *
uintptr_to_pointer( uintptr_t u )
{
   union {
      void *p;
      uintptr_t u;
   } pu;
   pu.u = u;
   return pu.p;
}

/**
 * Return a pointer aligned to next multiple of N bytes.
 */
static inline void *
align_pointer( const void *unaligned, uintptr_t alignment )
{
   uintptr_t aligned = (pointer_to_uintptr( unaligned ) + alignment - 1) & ~(alignment - 1);
   return uintptr_to_pointer( aligned );
}


/**
 * Return a pointer aligned to next multiple of 16 bytes.
 */
static inline void *
align16( void *unaligned )
{
   return align_pointer( unaligned, 16 );
}

typedef void (*func_pointer)(void);

static inline func_pointer
pointer_to_func( void *p )
{
   union {
      void *p;
      func_pointer f;
   } pf;
   pf.p = p;
   return pf.f;
}

static inline void *
func_to_pointer( func_pointer f )
{
   union {
      void *p;
      func_pointer f;
   } pf;
   pf.f = f;
   return pf.p;
}


#ifdef __cplusplus
}
#endif

#endif /* U_POINTER_H */