On 24 May 2016 at 17:05, Jim Wilson jim.wilson@linaro.org wrote:
Cisco is trying to use clang/lto on big-endian arm, which apparently requires gold, and gold does not support the --be8 option which is required for ARMv7 big-endian support. Does anyone here care about this?
Hi Jim,
Using Clang with LTO on ARMv7 is already risky business, since not many people are testing it (we're not), but running it on BE8 is Terra Incognita. We'd have to care about many other things first to get there...
For one, validate BE8, which probably needs QEMU, but we don't have x86_64 hardware where QEMU would be remotely useful. Another, make a decision between implementing LTO in BFD, Gold, or LLD and stick to it, as well as extend to support BE8.
I don't know much about the BFD vs Gold, but I remember that ARM folks weren't happy about relying on Gold for AArch64. Also, LLD has reasonable AArch64 support (mostly only TLS missing), and ARM can (maybe) link (but not run) "hello world" on Peter's development tree, but otherwise doesn't exist.
The best decision, IMHO, would be to have it working on at least one GNU linker and one LLVM linker. The order in which they come doesn't matter.
But that's a year's plan, at least, unless we pick someone to focus solely on that, in which case it could be a few months' plan.
cheers, --renato