Dear Wolfgang Denk,
Dear Marek,
In message 201210312351.35977.marex@denx.de you wrote:
Could you please explain these supposed benefits in a bit more detail?
Yes, thanks for the review (I really needed one from you on this)!
So, here comes the list:
- It's cool to link with gcc, duh ;-)
Is it - and why exactly?
It's all the rage now (better ignore this point) ;-)
- You can enable LTO eventually -- long term plan -- which proved can
shrink the code size a bit
Do you have a workign example? You know, we don;t like adding dead code...
We've been digging with Albert, but nothing we can release just yet. This is a groundwork patch.
- Usage of LLVM/CLANG is now much more straightforward
Please elucidate?
Now you can simply replace gcc with clang and that _should_ work. Sure, I expect more work will be needed here, but this patch gives you all the ground to do that.
- Binutils usually lag behind the GCC development a bit, by using GCC to
do the link, we can remedy this problem
Grrrrghhhg. I lost you here. By not calling ld directly (where we know exactly what we are doing), but through a (somewhat unknown) GCC framework, we can magicly adjust any (claimed - by you) version differences? I cannot parse this.
GCC can do all the optimization magic (LTO ...) and then just let linker do the linking.
But actually, the 2) is the most important part. LTO will hopefully help us optimize U-Boot for size even better than it is now. But that will still need much more research. So this is only a patch that shall prepare the groundwork for this further research.
As is, it's just unused or dead code that adds a lot of complexity and buys nothing. Please submit as part of a patch series that makes successfull (and tested) use of LTO.
No, I won't, I don't have that part ready yet.
Besides, the sandbox target already uses gcc linking. Shall we also convert it to use LD instead then ?
Best regards, Marek Vasut