https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89397
--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to jos...@codesourcery.com from comment #3)
> On Tue, 19 Feb 2019, marxin at gcc dot gnu.org wrote:
>
> > Before the revision it was rejected with:
> >
> > atomic2.c: In function ‘func’:
> > atomic2.c:49:8: error: x87 register return with x87 disabled
> > ald1 = d1;
> > ^
> > atomic2.c:51:8: error: SSE register return with SSE disabled
> > acd1 += ab1;
> > ^
>
> The code doesn't appear to involve such a return, so I don't see why it
> should be rejected at all.
'-mno-80387'
'-msoft-float'
Generate output containing library calls for floating point.
*Warning:* the requisite libraries are not part of GCC. Normally
the facilities of the machine's usual C compiler are used, but this
cannot be done directly in cross-compilation. You must make your
own arrangements to provide suitable library functions for
cross-compilation.
On machines where a function returns floating-point results in the
80387 register stack, some floating-point opcodes may be emitted
even if '-msoft-float' is used.
In this case, library calls return floating point in SSE register.
