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authorJeremy Fitzhardinge <jeremy@goop.org>2008-01-30 07:32:42 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:32:42 -0500
commit74ef649fe847fdfbd3e1732d21b923f59ca04e8c (patch)
treecef6615597cc78bb507ff971f409530f14b962ff /include/linux/const.h
parent345b904c3f7c24fbfadfee7cddd5896d13b176d9 (diff)
x86: add _AT() macro to conditionally cast
# HG changeset patch # User Jeremy Fitzhardinge <jeremy@xensource.com> # Date 1199317452 28800 # Node ID f7e7db3facd9406545103164f9be8f9ba1a2b549 # Parent 4d9a413a0f4c1d98dbea704f0366457b5117045d x86: add _AT() macro to conditionally cast Define _AT(type, value) to conditionally cast a value when compiling C code, but not when used in assembler. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/const.h')
-rw-r--r--include/linux/const.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/const.h b/include/linux/const.h
index 07b300bfe34b..c22c707c455d 100644
--- a/include/linux/const.h
+++ b/include/linux/const.h
@@ -7,13 +7,18 @@
7 * C code. Therefore we cannot annotate them always with 7 * C code. Therefore we cannot annotate them always with
8 * 'UL' and other type specifiers unilaterally. We 8 * 'UL' and other type specifiers unilaterally. We
9 * use the following macros to deal with this. 9 * use the following macros to deal with this.
10 *
11 * Similarly, _AT() will cast an expression with a type in C, but
12 * leave it unchanged in asm.
10 */ 13 */
11 14
12#ifdef __ASSEMBLY__ 15#ifdef __ASSEMBLY__
13#define _AC(X,Y) X 16#define _AC(X,Y) X
17#define _AT(T,X) X
14#else 18#else
15#define __AC(X,Y) (X##Y) 19#define __AC(X,Y) (X##Y)
16#define _AC(X,Y) __AC(X,Y) 20#define _AC(X,Y) __AC(X,Y)
21#define _AT(T,X) ((T)(X))
17#endif 22#endif
18 23
19#endif /* !(_LINUX_CONST_H) */ 24#endif /* !(_LINUX_CONST_H) */