[PATCH] D103028: [llvm][ARM] Add CPU defs for arm2/3/6/7m

Tue Jun 1 11:41:16 PDT 2021

nickdesaulniers added a comment.

In D103028#2791630 <https://reviews.llvm.org/D103028#2791630>, @efriedma wrote:

> I found some discussion at https://patchwork.kernel.org/project/linux-arm-kernel/patch/20180930024904.14240-1-Jason@zx2c4.com/ .  Apparently, the kernel is actually intentionally building for "ARMv3M" by default,

(when targeting armv3 hardware, not in general)

> to support some ancient hardware that doesn't support all the armv4 instructions.  LLVM doesn't support this at the moment.  We shouldn't accept -march=armv3m unless we're actually going to generate correct code for it.
>
>> We don't yet support v4 or v4t FWIW.
>
> Not sure what you mean by this?

Folks building the Linux kernel with Clang do not have working configurations of the Linux kernel that target ARMv4 hardware.  I don't know the list of blockers, and it's not a high priority. Clang may support ARMv4, but that doesn't mean a kernel with such configuration with build let alone boot.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103028/new/

https://reviews.llvm.org/D103028