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Re: GAS .fpu directive
- From: Renato Golin <renato dot golin at linaro dot org>
- To: Matthew Fortune <Matthew dot Fortune at imgtec dot com>
- Cc: Peter Bergner <bergner at vnet dot ibm dot com>, Richard Earnshaw <rearnsha at arm dot com>, Nicholas Clifton <nickc at redhat dot com>, "binutils at sourceware dot org" <binutils at sourceware dot org>
- Date: Thu, 21 Aug 2014 10:20:47 +0100
- Subject: Re: GAS .fpu directive
- Authentication-results: sourceware.org; auth=none
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On 21 August 2014 10:02, Matthew Fortune <Matthew.Fortune@imgtec.com> wrote:
> FWIW given that behaviour my suggestion would be that for .fpu you would
> want to enforce just one .fpu directive and that should precede all code.
> I guess that might break some existing code though but I'd say that is a
> good thing.
That was my original proposal, and one that I'm ready to enforce in
LLVM's ARM assembler as soon as we reach consensus. :)
> Introducing a new directive to select the 'current' fpu may then be
> necessary for some use cases though. The current situation doesn't sound
> good from a hand-coded assembler nor compiler perspective. It seems fairly
> undesirable to allow an inline asm block to affect a module's attributes.
Other directives have the same problem: .cpu, .arch, .arch_extension,
.eabi_attribute, .syntax, etc.
> It seems less likely to occur in hand-written assembler but the results
> would be equally confusing if multiple .fpu directives did appear.
It does, and that's why I started this discussion. This has shown up
while compiling Chromium for Android with LLVM.