On Sun, Feb 25, 2024 at 8:54 AM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> On Sun, Feb 25, 2024 at 5:01 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> >
> > ix86_set_func_type checks noreturn attribute to avoid incompatible
> > attribute error in LTO1 on interrupt functions. Since TREE_THIS_VOLATILE
> > is set also for _Noreturn without noreturn attribute, check interrupt
> > attribute for interrupt functions instead.
>
> Please also adjust the comment above the change. The current comment
> even explains why the "noreturn" attribute is checked instead of
> "interrupt" attribute.
How about this?
NB: Can't use just TREE_THIS_VOLATILE to check if this is a noreturn
function. The local-pure-const pass turns an interrupt function
into a noreturn function by setting TREE_THIS_VOLATILE. Normally
the local-pure-const pass is run after ix86_set_func_type is called.
When the local-pure-const pass is enabled for LTO, the interrupt
function is marked with TREE_THIS_VOLATILE in the IR output, which
leads to the incompatible attribute error in LTO1. Ignore the
interrupt function in this case.
Thanks.
> Uros.
>
> >
> > gcc/
> >
> > PR target/114097
> > * config/i386/i386-options.cc (ix86_set_func_type): Check
> > interrupt instead of noreturn attribute.
> >
> > gcc/testsuite/
> >
> > PR target/114097
> > * gcc.target/i386/pr114097-1.c: New test.
> > ---
> > gcc/config/i386/i386-options.cc | 3 ++-
> > gcc/testsuite/gcc.target/i386/pr114097-1.c | 26 ++++++++++++++++++++++
> > 2 files changed, 28 insertions(+), 1 deletion(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/pr114097-1.c
> >
> > diff --git a/gcc/config/i386/i386-options.cc
> > b/gcc/config/i386/i386-options.cc
> > index 93a01146db7..82fe0d228cd 100644
> > --- a/gcc/config/i386/i386-options.cc
> > +++ b/gcc/config/i386/i386-options.cc
> > @@ -3395,7 +3395,8 @@ ix86_set_func_type (tree fndecl)
> > incompatible attribute error in LTO1. */
> > bool has_no_callee_saved_registers
> > = ((TREE_THIS_VOLATILE (fndecl)
> > - && lookup_attribute ("noreturn", DECL_ATTRIBUTES (fndecl))
> > + && !lookup_attribute ("interrupt",
> > + TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))
> > && optimize
> > && !optimize_debug
> > && (TREE_NOTHROW (fndecl) || !flag_exceptions))
> > diff --git a/gcc/testsuite/gcc.target/i386/pr114097-1.c
> > b/gcc/testsuite/gcc.target/i386/pr114097-1.c
> > new file mode 100644
> > index 00000000000..b14c7b6214d
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr114097-1.c
> > @@ -0,0 +1,26 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -mtune-ctrl=^prologue_using_move,^epilogue_using_move
> > -fomit-frame-pointer" } */
> > +
> > +#define ARRAY_SIZE 256
> > +
> > +extern int array[ARRAY_SIZE][ARRAY_SIZE][ARRAY_SIZE];
> > +extern int value (int, int, int)
> > +#ifndef __x86_64__
> > +__attribute__ ((regparm(3)))
> > +#endif
> > +;
> > +
> > +void
> > +_Noreturn
> > +no_return_to_caller (void)
> > +{
> > + unsigned i, j, k;
> > + for (i = ARRAY_SIZE; i > 0; --i)
> > + for (j = ARRAY_SIZE; j > 0; --j)
> > + for (k = ARRAY_SIZE; k > 0; --k)
> > + array[i - 1][j - 1][k - 1] = value (i, j, k);
> > + while (1);
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "push" } } */
> > +/* { dg-final { scan-assembler-not "pop" } } */
> > --
> > 2.43.2
> >
--
H.J.
