On Thu, Aug 14, 2025 at 5:37 AM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> On Wed, Aug 13, 2025 at 11:33 PM Uros Bizjak <ubiz...@gmail.com> wrote:
> >
> > On Thu, Aug 14, 2025 at 6:58 AM H.J. Lu <hjl.to...@gmail.com> wrote:
> > >
> > > Add target("80387") attribute to enable and disable x87 instructions in a
> > > function.
> > >
> > > gcc/
> > >
> > > PR target/121541
> > > * config/i386/i386-options.cc
> > > (ix86_valid_target_attribute_inner_p): Add a bool argument to
> > > return if x87 is disabled by target("no-80387") attribute. Add
> > > and handle target("80387") attribute.
> > > (ix86_valid_target_attribute_tree): Get the x87 info from
> > > ix86_valid_target_attribute_inner_p and pass the info to
> > > ix86_option_override_internal.
> > > (ix86_option_override_internal): Add a bool argument to indicate
> > > if x87 should be disabled. Don't enable x87 if it should be
> > > disabled.
> > > (ix86_option_override): Pass false to
> > > ix86_option_override_internal.
> > > * doc/extend.texi: Document target("80387") function attribute.
> > >
> > > gcc/testsuite/
> > >
> > > PR target/121541
> > > * gcc.target/i386/pr121541-1a.c: New test.
> > > * gcc.target/i386/pr121541-1b.c: Likewise.
> > > * gcc.target/i386/pr121541-2.c: Likewise.
> > > * gcc.target/i386/pr121541-3.c: Likewise.
> > > * gcc.target/i386/pr121541-4.c: Likewise.
> > > * gcc.target/i386/pr121541-5a.c: Likewise.
> > > * gcc.target/i386/pr121541-5b.c: Likewise.
> > >
> > > Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
> > > ---
> > > gcc/config/i386/i386-options.cc | 42 +++++++++++++++------
> > > gcc/doc/extend.texi | 5 +++
> > > gcc/testsuite/gcc.target/i386/pr121541-1a.c | 11 ++++++
> > > gcc/testsuite/gcc.target/i386/pr121541-1b.c | 6 +++
> > > gcc/testsuite/gcc.target/i386/pr121541-2.c | 11 ++++++
> > > gcc/testsuite/gcc.target/i386/pr121541-3.c | 11 ++++++
> > > gcc/testsuite/gcc.target/i386/pr121541-4.c | 11 ++++++
> > > gcc/testsuite/gcc.target/i386/pr121541-5a.c | 11 ++++++
> > > gcc/testsuite/gcc.target/i386/pr121541-5b.c | 6 +++
> > > 9 files changed, 102 insertions(+), 12 deletions(-)
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-1a.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-1b.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-2.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-3.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-4.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-5a.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121541-5b.c
> > >
> > > diff --git a/gcc/config/i386/i386-options.cc
> > > b/gcc/config/i386/i386-options.cc
> > > index 09a35ef6298..30c10bed6bc 100644
> > > --- a/gcc/config/i386/i386-options.cc
> > > +++ b/gcc/config/i386/i386-options.cc
> > > @@ -825,7 +825,8 @@ STATIC_ASSERT (ARRAY_SIZE (processor_cost_table) ==
> > > PROCESSOR_max);
> > > static bool
> > > ix86_option_override_internal (bool main_args_p,
> > > struct gcc_options *opts,
> > > - struct gcc_options *opts_set);
> > > + struct gcc_options *opts_set,
> > > + bool disable_80387);
> >
> > m80387 option is a target option just like e.g. mrecip, so it should
> > be processed in the same way. A new bool argument should not be
> > needed, everything you need should be available via *opts and
> > *opts_set.
>
> It doesn't work because
>
> /* Don't enable x87 instructions if only general registers are
> allowed by target("general-regs-only") function attribute or
> -mgeneral-regs-only. */
> if (!(opts->x_ix86_target_flags & OPTION_MASK_GENERAL_REGS_ONLY)
> && !(opts_set->x_target_flags & MASK_80387))
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> When MASK_80387 in opts_set and opts are cleared by target("80387")
> function attribute, MASK_80387 will be turned on again without
> target("general-regs-only") function attribute nor -mgeneral-regs-only.
>
> {
> if (((processor_alias_table[i].flags & PTA_NO_80387) != 0))
> opts->x_target_flags &= ~MASK_80387;
> else
> opts->x_target_flags |= MASK_80387;
> }
>
Fixed in the v2 patch by updating opts_set->x_target_flags:
@@ -1281,6 +1285,8 @@ ix86_valid_target_attribute_inner_p (tree
fndecl, tree args, char *p_strings[],
else if (type == ix86_opt_yes || type == ix86_opt_no)
{
+ opts_set->x_target_flags |= mask;
+
if (type == ix86_opt_no)
opt_set_p = !opt_set_p;
--
H.J.
