[LLVMdev] porting glibc

[Francesco Spadini]

> Note that compiling glibc with LLVM does not give you a solution to THIS
> problem: you'd still have to write a new backend for your ISA. There is
> currently a Sparc backend and an X86 backend. Depending on how similar
> your architecture is to one or the other, you might be able to leverage
> existing code. Take a look at llvm/lib/Target/{Sparc,X86}, though the
> X86 target codebase is smaller.

Yeah, that's the easy part.  My ISA is going to have a near 1:1 mapping to 
LLVM bytecode.

> 
> Also note that having glibc compiled by LLVM isn't a prerequisite for
> your new ISA, as long as you either emulate the library calls or you
> have it compiled in some other manner for your target architecture.
> 

The nasty thing about this, is that from my experience SPECInt spends a 
considerable amount of time in standard library calls (esp. the memory and 
string manipulation functions).   I think I'll try playing around with glibc 
for a bit.  At worst I'll end up adding a compatibility mode and hand-code 
some of the common simple ones (memcpy, memset, etc.).  Thanks for your help.

-- 
Francesco Spadini
http://www.crhc.uiuc.edu/~spadini
spadini at crhc.uiuc.edu

"The universe is full of magical 
things, patiently waiting for our 
wits to grow sharper."
	- Eden Phillpots