Re: [PATCH v2] tests/tcg/s390x: Test overflow conditions

[Thomas Huth]

On 31/05/2022 20.35, Gautam Agrawal wrote:
> Add a test to check for overflow conditions in s390x.
> This patch is based on the following patches :
> * https://git.qemu.org/?p=qemu.git;a=commitdiff;h=5a2e67a691501
> * https://git.qemu.org/?p=qemu.git;a=commitdiff;h=fc6e0d0f2db51
>
> Signed-off-by: Gautam Agrawal <gautamnagrawal@gmail.com>
> ---
> Changes since v1:
> - Corrected the "long" data type to "long long"
> - Changed local variable name in overflow function to "res"
>
>   tests/tcg/s390x/Makefile.target |  1 +
>   tests/tcg/s390x/overflow.c      | 58 +++++++++++++++++++++++++++++++++
>   2 files changed, 59 insertions(+)
>   create mode 100644 tests/tcg/s390x/overflow.c
>
> diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
> index 3124172736..7f86de85b9 100644
> --- a/tests/tcg/s390x/Makefile.target
> +++ b/tests/tcg/s390x/Makefile.target
> @@ -16,6 +16,7 @@ TESTS+=shift
>   TESTS+=trap
>   TESTS+=signals-s390x
>   TESTS+=branch-relative-long
> +TESTS+=overflow
>   
>   VECTOR_TESTS=vxeh2_vs
>   VECTOR_TESTS+=vxeh2_vcvt
> diff --git a/tests/tcg/s390x/overflow.c b/tests/tcg/s390x/overflow.c
> new file mode 100644
> index 0000000000..1c59c2cb70
> --- /dev/null
> +++ b/tests/tcg/s390x/overflow.c
> @@ -0,0 +1,58 @@
> +#include <stdio.h>
> +
> +int overflow_add_32(int x, int y)
> +{
> +    int res;
> +    return __builtin_add_overflow(x, y, &res);
> +}
> +
> +int overflow_add_64(long long x, long long y)
> +{
> +    long long res;
> +    return __builtin_add_overflow(x, y, &res);
> +}
> +
> +int overflow_sub_32(int x, int y)
> +{
> +    int res;
> +    return __builtin_sub_overflow(x, y, &res);
> +}
> +
> +int overflow_sub_64(long long x, long long y)
> +{
> +    long long res;
> +    return __builtin_sub_overflow(x, y, &res);
> +}
> +
> +int a1_add = -2147483648;
> +int b1_add = -2147483648;
> +long long a2_add = -9223372036854775808ULL;
> +long long b2_add = -9223372036854775808ULL;
> +
> +int a1_sub;
> +int b1_sub = -2147483648;
> +long long a2_sub = 0L;
> +long long b2_sub = -9223372036854775808ULL;
> +
> +int main()
> +{
> +    int ret = 0;
> +
> +    if (!overflow_add_32(a1_add, b1_add)) {
> +        fprintf(stderr, "data overflow while adding 32 bits\n");
> +        ret = 1;
> +    }
> +    if (!overflow_add_64(a2_add, b2_add)) {
> +        fprintf(stderr, "data overflow while adding 64 bits\n");
> +        ret = 1;
> +    }
> +    if (!overflow_sub_32(a1_sub, b1_sub)) {
> +        fprintf(stderr, "data overflow while subtracting 32 bits\n");
> +        ret = 1;
> +    }
> +    if (!overflow_sub_64(a2_sub, b2_sub)) {
> +        fprintf(stderr, "data overflow while subtracting 64 bits\n");
> +        ret = 1;
> +    }
> +    return ret;
> +}

Thinking a little bit more about this, there is nothing specific to s390x in 
here, so I think we could even move this test to tests/tcg/multiarch/ so 
that other architectures benefit from this test as well...

Alex, would that be OK for you?

 Thomas