forked from mirrors/linux
cf66bb93e0
Since GCC 4.4, there have been __builtin_bswap32() and __builtin_bswap16() intrinsics. A __builtin_bswap16() came a little later (4.6 for PowerPC, 48 for other platforms). By using these instead of the inline assembler that most architectures have in their __arch_swabXX() macros, we let the compiler see what's actually happening. The resulting code should be at least as good, and much *better* in the cases where it can be combined with a nearby load or store, using a load-and-byteswap or store-and-byteswap instruction (e.g. lwbrx/stwbrx on PowerPC, movbe on Atom). When GCC is sufficiently recent *and* the architecture opts in to using the intrinsics by setting CONFIG_ARCH_USE_BUILTIN_BSWAP, they will be used in preference to the __arch_swabXX() macros. An architecture which does not set ARCH_USE_BUILTIN_BSWAP will continue to use its own hand-crafted macros. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: H. Peter Anvin <hpa@linux.intel.com>
38 lines
901 B
C
38 lines
901 B
C
#ifndef __LINUX_COMPILER_H
|
|
#error "Please don't include <linux/compiler-intel.h> directly, include <linux/compiler.h> instead."
|
|
#endif
|
|
|
|
#ifdef __ECC
|
|
|
|
/* Some compiler specific definitions are overwritten here
|
|
* for Intel ECC compiler
|
|
*/
|
|
|
|
#include <asm/intrinsics.h>
|
|
|
|
/* Intel ECC compiler doesn't support gcc specific asm stmts.
|
|
* It uses intrinsics to do the equivalent things.
|
|
*/
|
|
#undef barrier
|
|
#undef RELOC_HIDE
|
|
|
|
#define barrier() __memory_barrier()
|
|
|
|
#define RELOC_HIDE(ptr, off) \
|
|
({ unsigned long __ptr; \
|
|
__ptr = (unsigned long) (ptr); \
|
|
(typeof(ptr)) (__ptr + (off)); })
|
|
|
|
/* Intel ECC compiler doesn't support __builtin_types_compatible_p() */
|
|
#define __must_be_array(a) 0
|
|
|
|
#endif
|
|
|
|
#define uninitialized_var(x) x
|
|
|
|
#ifndef __HAVE_BUILTIN_BSWAP16__
|
|
/* icc has this, but it's called _bswap16 */
|
|
#define __HAVE_BUILTIN_BSWAP16__
|
|
#define __builtin_bswap16 _bswap16
|
|
#endif
|
|
|