GCC compiler intrinsics

["Andy Hanson" <andrew_g_hanson at yahoo dot com>]

< I got a weird mail error back the last time I sent this, hopefully it
isn't hitting the list twice.

I've been doing a fair amount of linux coding for a web server, the last few
weeks, and recently I ran across a linker error claiming an unresolved
reference to memset.  Most of the link errors were my fault, but I was
simply shocked.  The fact that memset was unresolved, implied that memset
isn't a compiler intrinsic.  I mean, if strcpy is an intrinsic, why the hell
isn't memset.  (I'm using a semi-old version (egcs-2.91.66), so it might be
an intrinsic in newer versions.)

Which got me to thinking, now that I am free from relying on VC 6+, and the
compiler is open sourced, I can finally add my own compiler intrinsics.
Things like bsf (bit scan forward), or maybe a simple hash function.

Currently for quick and dirty asm functions, I typically use an
__attribute__((regparm(x))) style of function,  but an intrinsic would be so
much cleaner.

Now the big question is where to start.  I did a little digging through the
egcs release, and binutils, and I can't seem to see where intrinsics like
strcpy get processed by the compiler.  I did my traditional web search to
pick up any info on doing this, talked to all the linux coders I know, but I
haven't been able to find a thing.

Any help, or further guidance, direction pointing, examples, the source
file(s) I should look at etc. would be greatly appreciated.

Andy


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