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Re: Do not define -mlong-double-128 on ppc when --without-fp specified?
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: Roland McGrath <roland at redhat dot com>
- Cc: libc-alpha at sourceware dot org
- Date: Thu, 16 Mar 2006 22:12:44 +0000 (UTC)
- Subject: Re: Do not define -mlong-double-128 on ppc when --without-fp specified?
- References: <20060316215013.C2FEF180AB5@magilla.sf.frob.com>
On Thu, 16 Mar 2006, Roland McGrath wrote:
> > Note that the function-call ABI for soft-float and hard-float PowerPC is
> > in any case incompatible, you can't mix soft-float binaries with
> > hard-float libc or vice versa.
>
> Do you mean that the calling conventions use FPU registers in hard-float
> and not in soft-float?
Yes, exactly, the standard psABI uses FPU registers for arguments and
return values, but with -msoft-float the FPU registers aren't available
(hence some users using -msoft-float to avoid the compiler deciding to use
them in non-fp code) and there's a different ABI using general purpose
registers instead.
--
Joseph S. Myers
joseph@codesourcery.com