Re: [PULL 4/8] tests/tcg/s390x: Test BRASL and BRCL with large negative offsets

[Thomas Huth <thuth@redhat.com>]

On 15/03/2022 12.20, Thomas Huth wrote:
> From: Ilya Leoshkevich <iii@linux.ibm.com>
> 
> Add a small test in order to prevent regressions.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> Message-Id: <20220314104232.675863-4-iii@linux.ibm.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   tests/tcg/s390x/Makefile.target        |  1 +
>   tests/tcg/s390x/branch-relative-long.c | 68 ++++++++++++++++++++++++++
>   2 files changed, 69 insertions(+)
>   create mode 100644 tests/tcg/s390x/branch-relative-long.c
> 
> diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
> index 7aa502a557..f0d474a245 100644
> --- a/tests/tcg/s390x/Makefile.target
> +++ b/tests/tcg/s390x/Makefile.target
> @@ -15,6 +15,7 @@ TESTS+=mvc
>   TESTS+=shift
>   TESTS+=trap
>   TESTS+=signals-s390x
> +TESTS+=branch-relative-long
>   
>   ifneq ($(HAVE_GDB_BIN),)
>   GDB_SCRIPT=$(SRC_PATH)/tests/guest-debug/run-test.py
> diff --git a/tests/tcg/s390x/branch-relative-long.c b/tests/tcg/s390x/branch-relative-long.c
> new file mode 100644
> index 0000000000..94219afcad
> --- /dev/null
> +++ b/tests/tcg/s390x/branch-relative-long.c
> @@ -0,0 +1,68 @@
> +#include <stddef.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <sys/mman.h>
> +
> +#define DEFINE_ASM(_name, _code) \
> +    extern const char _name[]; \
> +    extern const char _name ## _end[]; \
> +    asm("    .globl " #_name "\n" \
> +        #_name ":\n" \
> +        "    " _code "\n" \
> +        "    .globl " #_name "_end\n" \
> +        #_name "_end:\n");
> +
> +DEFINE_ASM(br_r14, "br %r14");
> +DEFINE_ASM(brasl_r0, "brasl %r0,.-0x100000000");
> +DEFINE_ASM(brcl_0xf, "brcl 0xf,.-0x100000000");

  Hi Ilya,

I just noticed that this does not compile with Clang
(version 13.0.1):

<inline asm>:8:15: error: offset out of range
     brasl %r0,.-0x100000000
               ^
<inline asm>:13:14: error: offset out of range
     brcl 0xf,.-0x100000000
              ^
2 errors generated.

Any ideas how to fix this? Could we decrease the offset a little bit? Or 
maybe detect Clang and run with -no-integrated-as in that case?

  Thomas