Messages in this thread | | | Date | Tue, 7 Feb 2006 13:00:11 +0100 (CET) | From | Roman Zippel <> | Subject | Re: Cleanup possibility in asm-i386/string.h |
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Hi,
On Tue, 7 Feb 2006, Andi Kleen wrote:
> If you feel the need to remove some more code: Now that gcc 2.95 isn't supported > anymore there isn't really a need to keep the handwritten inline string functions > in asm-i386/string.h around. Just declaring them as normal externs will cause > gcc to use its builtin expansions, which are typically better than these old inline > functions with inline assembly. > > For out of line the C versions in lib/string.c can be used (by not setting __ARCH_*) > x86-64 did it like this forever and I guess it would be valuable cleanup for i386 too.
The only problem is that we compile with -ffreestanding which implies -fno-builtin, so just declaring them as normal externs is not enough and you have to something like this:
#define __HAVE_ARCH_MEMSET extern void *memset(void *, int, __kernel_size_t); #define memset(d, c, n) __builtin_memset(d, c, n)
(BTW you do this already in x86-64.)
Another problem here is because of -fno-builtin it's not easy to use the generic functions as fallback. x86-64 basically does this:
#define strlen __builtin_strlen size_t strlen(const char * s);
#ifndef __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); #endif
This means you define a prototype for the builtin function and not for the normal function. I'm not sure this is really intended.
bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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