how to use libgcc2.c

[Jim Wilson]

qinfeng.zhang@philips.com wrote:
> In gcc source code, there is a file "libgcc2.c" in srcdir/gcc. It seems that this file is used to
> implement operation through software method. But I don't know using it, and I can't debug into this
> file.

libgcc contains compiler support routines.  It is used automatically by 
the compiler if the source code performs an arithmetic operation that 
requires calling a function to perform it.  For instance, a long long 
divide on many targets will generate a call to a libgcc function.

User source code should not call any routines in libgcc.

There shouldn't be any need to debug routines in libgcc, but it should 
be possible if you have a copy of the gcc sources available.  Some old 
versions of gcc compiled libgcc with -g1 which makes debugging 
difficult.  You can change the gcc Makefile to use -g instead if necessary.

Jim