[LLVMdev] CPUStringIsValid() into MCSubtargetInfo and use it for ARM .cpu parsing

[Tim Northover]

Hi Sumanth,

> Shouldn’t the eabi attributes be honored ?

EABI attributes are instructions for the linker on which object files
are compatible with each other, not instructions for the assembler
(and trying to make them so sounds like a recipe for confusion to me).
>From the ARM ABI addenda:

"Build attributes record data that a linker needs to reason
mechanically about the compatibility, or incompatibility, of a set of
relocatable files."

> What should be the approach to fix the issue which I am facing?

There are a few options here:
1. Specify an existing CPU that has hardware division (notably,
Cortex-A9 doesn't).
2. Teach LLVM & Clang about your CPU's features, either locally or upstream.
3. Pass "-mhwdiv=arm,thumb" to Clang (or less if you only have hwdiv
in one mode).

Cheers.

Tim.