iPXE
compiler.h
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1 #ifndef _BITS_COMPILER_H
2 #define _BITS_COMPILER_H
3 
4 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
5 
6 /** Dummy relocation type */
7 #define RELOC_TYPE_NONE R_386_NONE
8 
9 #ifndef ASSEMBLY
10 
11 /** Declare a function with standard calling conventions */
12 #define __asmcall __attribute__ (( used, cdecl, regparm(0) ))
13 
14 /**
15  * Declare a function with libgcc implicit linkage
16  *
17  * It seems as though gcc expects its implicit arithmetic functions to
18  * be cdecl, even if -mrtd is specified. This is somewhat
19  * inconsistent; for example, if -mregparm=3 is used then the implicit
20  * functions do become regparm(3).
21  *
22  * The implicit calls to memcpy() and memset() which gcc can generate
23  * do not seem to have this inconsistency; -mregparm and -mrtd affect
24  * them in the same way as any other function.
25  *
26  * Update (25/4/14): it appears that more recent gcc versions do allow
27  * -mrtd to affect calls to the implicit arithmetic functions. There
28  * is nothing obvious in the gcc changelogs to indicate precisely when
29  * this happened. From experimentation with available gcc versions,
30  * the change occurred sometime between v4.6.3 and v4.7.2. We assume
31  * that only versions up to v4.6.x require the special treatment.
32  */
33 #if ( __GNUC__ < 4 ) || ( ( __GNUC__ == 4 ) && ( __GNUC_MINOR__ <= 6 ) )
34 #define __libgcc __attribute__ (( cdecl ))
35 #else
36 #define __libgcc
37 #endif
38 
39 #endif /* ASSEMBLY */
40 
41 #endif /* _BITS_COMPILER_H */
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)