GCC compiler intrinsics.

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

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.

 

If I stumped you, I could use an email address for someone that actually works on the gcc/egcs team.

 

Andy