> On Thu, Apr 1, 2021 at 6:54 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> >
> > Since uiret should be used only for user interrupt handler return, don't
> > generate uiret in interrupt handler return with -mcmodel=kernel even if
> > UINTR is enabled.
>
> NAK, -mcmodel should not affect ISAs, in the same way it doesn't switch off
> SSE.
Agreed, while kernel name might not be bit too suggestive, code models
was intended to be quite general, so it may make sense to compile things
that are not kernels with kernel cmodel...
Honza
>
> Uros.
>
> > gcc/
> >
> > PR target/99870
> > * config/i386/i386.md (interrupt_return): Don't generate uiret
> > for -mcmodel=kernel.
> >
> > gcc/testsuite/
> >
> > * gcc.target/i386/pr99870.c: New test.
> > ---
> > gcc/config/i386/i386.md | 3 ++-
> > gcc/testsuite/gcc.target/i386/pr99870.c | 19 +++++++++++++++++++
> > 2 files changed, 21 insertions(+), 1 deletion(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/pr99870.c
> >
> > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> > index 9ff35d9a607..1055b4187b2 100644
> > --- a/gcc/config/i386/i386.md
> > +++ b/gcc/config/i386/i386.md
> > @@ -13885,7 +13885,8 @@ (define_insn "interrupt_return"
> > (unspec [(const_int 0)] UNSPEC_INTERRUPT_RETURN)]
> > "reload_completed"
> > {
> > - return TARGET_64BIT ? (TARGET_UINTR ? "uiret" : "iretq") : "iret";
> > + return TARGET_64BIT ? ((TARGET_UINTR && ix86_cmodel != CM_KERNEL)
> > + ? "uiret" : "iretq") : "iret";
> > })
> >
> > ;; Used by x86_machine_dependent_reorg to avoid penalty on single byte RET
> > diff --git a/gcc/testsuite/gcc.target/i386/pr99870.c
> > b/gcc/testsuite/gcc.target/i386/pr99870.c
> > new file mode 100644
> > index 00000000000..0dafa001ba9
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr99870.c
> > @@ -0,0 +1,19 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -march=sapphirerapids -mgeneral-regs-only" } */
> > +/* { dg-additional-options "-mcmodel=kernel" { target { ! ia32 } } } */
> > +
> > +void
> > +__attribute__((interrupt))
> > +fn (void *frame)
> > +{
> > +}
> > +
> > +typedef void (*fn_t) (void *) __attribute__((interrupt));
> > +
> > +fn_t fns[] =
> > +{
> > + fn,
> > +};
> > +
> > +/* { dg-final { scan-assembler-times "\\tiret" 1 { target ia32 } } } */
> > +/* { dg-final { scan-assembler-times "\\tiretq" 1 { target { ! ia32 } } }
> > } */
> > --
> > 2.30.2
> >
