> On Sat, Jun 29, 2013 at 12:55 AM, Sriraman Tallam <tmsri...@google.com> wrote:
>
> > Inlining sse* functions into avx is broken? Here is an example:
> >
> > __attribute__((always_inline,target("sse3")))
> > inline int callee ()
> > {
> > return 0;
> > }
> >
> > __attribute__((target("avx")))
> > inline int caller ()
> > {
> > return callee ();
> > }
> >
> > main ()
> > {
> > return caller ();
> > }
> >
> > $ g++ -O2 foo.cc
> > error: inlining failed in call to always_inline 'int callee()': target
> > specific option mismatch
> >
> > This patch fixes the problem:
> >
> > Index: gcc/config/i386/i386.c
> > ===================================================================
> > --- gcc/config/i386/i386.c (revision 200497)
> > +++ gcc/config/i386/i386.c (working copy)
> > @@ -4520,8 +4520,9 @@ ix86_can_inline_p (tree caller, tree callee)
> > != callee_opts->x_ix86_isa_flags)
> > ret = false;
> >
> > - /* See if we have the same non-isa options. */
> > - else if (caller_opts->x_target_flags != callee_opts->x_target_flags)
> > + /* Callee's non-isa options should be a subset of the caller's. */
> > + else if ((caller_opts->x_target_flags & callee_opts->x_target_flags)
> > + != callee_opts->x_target_flags)
> > ret = false;
> >
> >
> > Setting avx as ISA has side-effects on some target flags and directly
> > comparing them seems incorrect. This is also breaking the usage of
What target flags are enabled by AVX? Assumming that all target flags are
positive seems incorrect to me (like -mno-red-zone function can not be inlined
into -mred-zone). Does those conditionally enabled AVX codegen flags have any
effect when AVX is disabled? Perhaps we can set them unconditionally?
Honza
> > mmintrinsic headers. An intrinsic in avxintrin.h is calling an
> > intrinsic in another header. The call is not inlinable for the same
> > reason.
> >
> > Is this ok?
>
> This looks correct to me.
>
> Do we need to backport this change?
>
> Uros.
