Re: [PATCH 2/2] tests/tcg/s390x: Test LOAD ADDRESS EXTENDED

[Ilya Leoshkevich <iii@linux.ibm.com>]

On Thu, 2024-01-11 at 09:37 +0100, Thomas Huth wrote:
> On 10/01/2024 00.22, Ilya Leoshkevich wrote:
> > Add a small test to prevent regressions. Userspace runs in primary
> > mode, so LAE should always set the access register to 0.
> > 
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> >   tests/tcg/s390x/Makefile.target |  1 +
> >   tests/tcg/s390x/lae.c           | 25 +++++++++++++++++++++++++
> >   2 files changed, 26 insertions(+)
> >   create mode 100644 tests/tcg/s390x/lae.c
> > 
> > diff --git a/tests/tcg/s390x/Makefile.target
> > b/tests/tcg/s390x/Makefile.target
> > index 0e670f3f8b9..30994dcf9c2 100644
> > --- a/tests/tcg/s390x/Makefile.target
> > +++ b/tests/tcg/s390x/Makefile.target
> > @@ -44,6 +44,7 @@ TESTS+=clgebr
> >   TESTS+=clc
> >   TESTS+=laalg
> >   TESTS+=add-logical-with-carry
> > +TESTS+=lae
> >   
> >   cdsg: CFLAGS+=-pthread
> >   cdsg: LDFLAGS+=-pthread
> > diff --git a/tests/tcg/s390x/lae.c b/tests/tcg/s390x/lae.c
> > new file mode 100644
> > index 00000000000..661e95f9978
> > --- /dev/null
> > +++ b/tests/tcg/s390x/lae.c
> > @@ -0,0 +1,25 @@
> > +/*
> > + * Test the LOAD ADDRESS EXTENDED instruction.
> > + *
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + */
> > +#include <assert.h>
> > +#include <stdlib.h>
> > +
> > +int main(void)
> > +{
> > +    unsigned long long ar = -1, b2 = 100000, r, x2 = 500;
> > +    int tmp;
> > +
> > +    asm("ear %[tmp],%[r]\n"
> > +        "lae %[r],42(%[x2],%[b2])\n"
> > +        "ear %[ar],%[r]\n"
> > +        "sar %[r],%[tmp]"
> > +        : [tmp] "=&r" (tmp), [r] "=&r" (r), [ar] "+r" (ar)
> > +        : [b2] "r" (b2), [x2] "r" (x2)
> > +        : "memory");
> > +    assert(ar == 0xffffffff00000000ULL);
> > +    assert(r == 100542);
> > +
> > +    return EXIT_SUCCESS;
> > +}
> 
> I'm sorry, but it fails when building with Clang (version 17):
> 
> .../qemu/tests/tcg/s390x/lae.c:14:9: error: invalid operand for
> instruction
>     14 |     asm("ear %[tmp],%[r]\n"
>        |         ^
> <inline asm>:1:10: note: instantiated into assembly here
>      1 |         ear %r2,%r1
>        |                 ^
> .../qemu/tests/tcg/s390x/lae.c:16:10: error: invalid operand for
> instruction
>     16 |         "ear %[ar],%[r]\n"
>        |          ^
> <inline asm>:3:9: note: instantiated into assembly here
>      3 | ear %r0,%r1
>        |         ^
> .../qemu/tests/tcg/s390x/lae.c:17:10: error: invalid operand for
> instruction
>     17 |         "sar %[r],%[tmp]"
>        |          ^
> <inline asm>:4:5: note: instantiated into assembly here
>      4 | sar %r1,%r2
>        |     ^
> 3 errors generated.
> 
> Any suggestions how to fix it best?
> 
>   Thomas
> 

clang wants %aN there, and I don't see a way to convert %rN to %aN.
Seems like I'll have to hardcode the register number. I'll send a v2.