[llvm] r223113 - Add support for ARM modified-immediate assembly syntax.

[Tim Northover]

On 11 February 2015 at 15:50, Steven Wu <stevenwu at apple.com> wrote:
> Couldn’t find anything related to tilde or how an expression gets evaluated
> to an immediate in ARM manual. Any authority over ARM assembly language?

I basically agree with Jim, but our ideas aren't really based on the
manual. The ARM manual says what immediates are permitted, just how
you get to write them is largely down to the individual assembler.
MASM might let you write ffh, GAS 0xff or ~0xffffff00 (or whatever
else).

So what I really think are two things:
  + In GAS syntax it's reasonable to parse an expression and interpret ~ as NOT.
  + For instructions operating on 32-bit registers it's reasonable for
that NOT to produce a 32-bit result by default.

Cheers.

Tim.