This is the mail archive of the gcc-help@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

RE: builtin assembler constraints


This is really strange that such option does not exist. VLE instruction set does not use r8-r24 for many 16bit instructions. How do people use inline assembly with these? Or does compiler recognize these limitations for "known" instructions by itself?

Alex. 

-----Original Message-----
From: Ian Lance Taylor [mailto:iant@google.com] 
Sent: Friday, February 08, 2013 3:19 PM
To: Grobman Alexander-R53196
Cc: gcc-help@gcc.gnu.org
Subject: Re: builtin assembler constraints

On Fri, Feb 8, 2013 at 10:15 AM, Grobman Alexander-R53196 <R53196@freescale.com> wrote:
>
> I'm trying to incorporate new PPC instructions into a C code. These 
> instructions use limited set of GPRs as operands i.e. only even 
> registers can be used as a source,
>
> Is there way to specify that in the asm() statement?

As far as I know there is no constraint that describes only the even registers of the general register set.  It would not be very difficult to add one to the PPC backend.  I can't think of any other way to approach this.

Ian



Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]