On Wed, Aug 13, 2025 at 3:44 PM H.J. Lu <[email protected]> wrote:
>
> On Mon, Jul 28, 2025 at 1:29 AM Uros Bizjak <[email protected]> wrote:
> >
> > On Sat, Jul 26, 2025 at 7:37 PM H.J. Lu <[email protected]> wrote:
> > >
> > > __tls_get_addr doesn't preserve vector registers. When a function
> > > with no_caller_saved_registers attribute calls __tls_get_addr, YMM
> > > and ZMM registers will be clobbered. Issue an error and suggest
> > > -mtls-dialect=gnu2 in this case.
> > >
> > > gcc/
> > >
> > > PR target/121208
> > > * config/i386/i386.cc (ix86_tls_get_addr): Issue an error for
> > > -mtls-dialect=gnu with no_caller_saved_registers attribute and
> > > suggest -mtls-dialect=gnu2.
> > >
> > > gcc/testsuite/
> > >
> > > PR target/121208
> > > * gcc.target/i386/pr121208-1a.c: New test.
> > > * gcc.target/i386/pr121208-1b.c: Likewise.
> > > * gcc.target/i386/pr121208-2a.c: Likewise.
> > > * gcc.target/i386/pr121208-2b.c: Likewise.
> > > * gcc.target/i386/pr121208-3a.c: Likewise.
> > > * gcc.target/i386/pr121208-3b.c: Likewise.
> > >
> > > Signed-off-by: H.J. Lu <[email protected]>
> > > ---
> > > gcc/config/i386/i386.cc | 22 +++++++++++++++++++++
> > > gcc/testsuite/gcc.target/i386/pr121208-1a.c | 15 ++++++++++++++
> > > gcc/testsuite/gcc.target/i386/pr121208-1b.c | 4 ++++
> > > gcc/testsuite/gcc.target/i386/pr121208-2a.c | 17 ++++++++++++++++
> > > gcc/testsuite/gcc.target/i386/pr121208-2b.c | 4 ++++
> > > gcc/testsuite/gcc.target/i386/pr121208-3a.c | 17 ++++++++++++++++
> > > gcc/testsuite/gcc.target/i386/pr121208-3b.c | 4 ++++
> > > 7 files changed, 83 insertions(+)
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-1a.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-1b.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-2a.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-2b.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-3a.c
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr121208-3b.c
> > >
> > > diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> > > index 4682db85ce4..036455a45a5 100644
> > > --- a/gcc/config/i386/i386.cc
> > > +++ b/gcc/config/i386/i386.cc
> > > @@ -12442,6 +12442,28 @@ static GTY(()) rtx ix86_tls_symbol;
> > > static rtx
> > > ix86_tls_get_addr (void)
> > > {
> > > + if (cfun->machine->call_saved_registers
> > > + == TYPE_NO_CALLER_SAVED_REGISTERS)
> > > + {
> > > + /* __tls_get_addr doesn't preserve vector registers. When a
> > > + function with no_caller_saved_registers attribute calls
> > > + __tls_get_addr, YMM and ZMM registers will be clobbered.
> > > + Issue an error and suggest -mtls-dialect=gnu2 in this case. */
> > > + if (cfun->machine->func_type != TYPE_NORMAL)
> >
> > Maybe just switch the arms of "if" statement to avoid negative logic here.
> >
>
> OK to backport this and
>
> commit c6d1f58da7eb72e8bac307d342e4655012b36a89
> Author: H.J. Lu <[email protected]>
> Date: Tue Jul 29 09:11:34 2025 -0700
>
> x86: Pass -mno-80387 to compile pr121208-1(a|b).c
>
> to release branches?
OK.
Thanks,
Uros.
>
> Thanks.
>
> > Uros.
> >
> > > + error (cfun->machine->func_type == TYPE_EXCEPTION
> > > + ? G_("%<-mtls-dialect=gnu2%> must be used with an"
> > > + " exception service routine")
> > > + : G_("%<-mtls-dialect=gnu2%> must be used with an"
> > > + " interrupt service routine"));
> > > + else
> > > + error (G_("%<-mtls-dialect=gnu2%> must be used with a function"
> > > + " with the %<no_caller_saved_registers%> attribute"));
> > > + /* Don't issue the same error twice. */
> > > + cfun->machine->func_type = TYPE_NORMAL;
> > > + cfun->machine->call_saved_registers
> > > + = TYPE_DEFAULT_CALL_SAVED_REGISTERS;
> > > + }
> > > +
> > > if (!ix86_tls_symbol)
> > > {
> > > const char *sym
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-1a.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-1a.c
> > > new file mode 100644
> > > index 00000000000..ac851cb50d8
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-1a.c
> > > @@ -0,0 +1,15 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
> > > +
> > > +extern __thread int bar;
> > > +extern void func (void);
> > > +
> > > +__attribute__((no_caller_saved_registers))
> > > +void
> > > +foo (int error)
> > > +{
> > > + bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
> > > + if (error == 0)
> > > + func ();
> > > + bar = 0;
> > > +}
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-1b.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-1b.c
> > > new file mode 100644
> > > index 00000000000..b97ac715c65
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-1b.c
> > > @@ -0,0 +1,4 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
> > > +
> > > +#include "pr121208-1a.c"
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-2a.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-2a.c
> > > new file mode 100644
> > > index 00000000000..c1891ae322c
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-2a.c
> > > @@ -0,0 +1,17 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
> > > +
> > > +typedef unsigned int uword_t __attribute__ ((mode (__word__)));
> > > +extern __thread int bar;
> > > +extern void func (void);
> > > +
> > > +__attribute__((target("general-regs-only")))
> > > +__attribute__((interrupt))
> > > +void
> > > +foo (void *frame, uword_t error)
> > > +{
> > > + bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
> > > + if (error == 0)
> > > + func ();
> > > + bar = 0;
> > > +}
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-2b.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-2b.c
> > > new file mode 100644
> > > index 00000000000..269b120f990
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-2b.c
> > > @@ -0,0 +1,4 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
> > > +
> > > +#include "pr121208-2a.c"
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-3a.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-3a.c
> > > new file mode 100644
> > > index 00000000000..26fe6870155
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-3a.c
> > > @@ -0,0 +1,17 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
> > > +
> > > +typedef unsigned int uword_t __attribute__ ((mode (__word__)));
> > > +extern __thread int bar;
> > > +extern void func (void);
> > > +
> > > +__attribute__((target("general-regs-only")))
> > > +__attribute__((interrupt))
> > > +void
> > > +foo (void *frame)
> > > +{
> > > + bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
> > > + if (frame == 0)
> > > + func ();
> > > + bar = 0;
> > > +}
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr121208-3b.c
> > > b/gcc/testsuite/gcc.target/i386/pr121208-3b.c
> > > new file mode 100644
> > > index 00000000000..b672d751d7f
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr121208-3b.c
> > > @@ -0,0 +1,4 @@
> > > +/* { dg-do compile { target *-*-linux* } } */
> > > +/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
> > > +
> > > +#include "pr121208-3a.c"
> > > --
> > > 2.50.1
> > >
>
>
>
> --
> H.J.
