[PATCH] i386: support micro-levels in target{, _clone} attrs [PR101696]

H.J. Lu hjl.tools@gmail.com
Thu Aug 12 15:26:00 GMT 2021


On Thu, Aug 12, 2021 at 8:22 AM Martin Liška <mliska@suse.cz> wrote:
>
> On 8/12/21 4:51 PM, H.J. Lu wrote:
> > On Thu, Aug 12, 2021 at 7:39 AM Martin Liška <mliska@suse.cz> wrote:
> >>
> >> On 8/12/21 4:25 PM, H.J. Lu wrote:
> >>> Please send out the v2 patch with the enclosed patch.  I added some tests.
> >>
> >> Thanks, there's patch which includes your changes.
> >>
> >> Martin
> >
> > diff --git a/gcc/common/config/i386/i386-isas.h
> > b/gcc/common/config/i386/i386-isas.h
> > index 898c18f3dda..cd9523b8fbc 100644
> > --- a/gcc/common/config/i386/i386-isas.h
> > +++ b/gcc/common/config/i386/i386-isas.h
> > @@ -169,4 +169,8 @@ ISA_NAMES_TABLE_START
> >     ISA_NAMES_TABLE_ENTRY("aeskle", FEATURE_AESKLE, P_NONE, NULL)
> >     ISA_NAMES_TABLE_ENTRY("widekl", FEATURE_WIDEKL, P_NONE, "-mwidekl")
> >     ISA_NAMES_TABLE_ENTRY("avxvnni", FEATURE_AVXVNNI, P_NONE, "-mavxvnni")
> > +  ISA_NAMES_TABLE_ENTRY("x86-64", FEATURE_X86_64_BASELINE, P_NONE, NULL)
> > +  ISA_NAMES_TABLE_ENTRY("x86-64-v2", FEATURE_X86_64_V2, P_NONE, NULL)
> > +  ISA_NAMES_TABLE_ENTRY("x86-64-v3", FEATURE_X86_64_V3, P_NONE, NULL)
> > +  ISA_NAMES_TABLE_ENTRY("x86-64-v4", FEATURE_X86_64_V4, P_NONE, NULL)
> >
> > If they have proper feature_priority, can you avoid
>
> I don't think so. First we likely want supporting "arch=x86-64-v3" rather than
> "x86-64-v3" in e.g. 'target' attribute. That means a special handling by the code
> I added.

Will it hurt if they have proper feature_priorities you added?

> The following fails as there's no corresponding -m$option.
>
> pr101696.c:5:45: error: attribute ‘x86-64-v4’ argument ‘target’ is unknown
>
>      5 | __attribute__ ((target ("x86-64-v4"))) void foo () {  __builtin_printf ("arch=x86-64-v4\n"); }
>
>        |                                             ^~~
>
>
> Or do I miss something and we can do it in a simpler way?
>
> Cheers,
> Martin
>
> >
> > iff --git a/gcc/config/i386/i386-builtins.c b/gcc/config/i386/i386-builtins.c
> > index 204e2903126..492873bb076 100644
> > --- a/gcc/config/i386/i386-builtins.c
> > +++ b/gcc/config/i386/i386-builtins.c
> > @@ -1904,8 +1904,24 @@ get_builtin_code_for_version (tree decl, tree
> > *predicate_list)
> >    return 0;
> >         new_target = TREE_TARGET_OPTION (target_node);
> >         gcc_assert (new_target);
> > -
> > -      if (new_target->arch_specified && new_target->arch > 0)
> > +      enum ix86_builtins builtin_fn = IX86_BUILTIN_CPU_IS;
> > +
> > +      /* Special case x86-64 micro-level architectures.  */
> > +      const char *arch_name = attrs_str + strlen ("arch=");
> > +      if (startswith (arch_name, "x86-64"))
> > + {
> > +   arg_str = arch_name;
> > +   builtin_fn = IX86_BUILTIN_CPU_SUPPORTS;
> > +   if (strcmp (arch_name, "x86-64") == 0)
> > +     priority = P_X86_64_BASELINE;
> > +   else if (strcmp (arch_name, "x86-64-v2") == 0)
> > +     priority = P_X86_64_V2;
> > +   else if (strcmp (arch_name, "x86-64-v3") == 0)
> > +     priority = P_X86_64_V3;
> > +   else if (strcmp (arch_name, "x86-64-v4") == 0)
> > +     priority = P_X86_64_V4;
> > + }
> >
> >         if (predicate_list)
> >    {
> > -          predicate_decl = ix86_builtins [(int) IX86_BUILTIN_CPU_IS];
> > +   predicate_decl = ix86_builtins [(int) builtin_fn];
> >
> > Is this required?
> >
>


-- 
H.J.


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