Clang complains:

  clang -O2 -m64 -mcx16 /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c -o test-i386-adcox -static
  /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:32:26: error: invalid input constraint '0' in asm
          : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
                           ^
  /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:57:26: error: invalid input constraint '0' in asm
          : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
                           ^
  2 errors generated.

Pointing out a numbered input constraint can't point to a read/write
output [1]. Convert to a read-only input constraint to allow this.

[1] https://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20101101/036036.html

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
---
 tests/tcg/i386/test-i386-adcox.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/tcg/i386/test-i386-adcox.c b/tests/tcg/i386/test-i386-adcox.c
index 16169efff8..b56dbc00f2 100644
--- a/tests/tcg/i386/test-i386-adcox.c
+++ b/tests/tcg/i386/test-i386-adcox.c
@@ -28,7 +28,7 @@ void test_adox_adcx(uint32_t in_c, uint32_t in_o, REG adcx_operand, REG adox_ope
         "adox %3, %2;"
         "adcx %3, %1;"
         "pushf; pop %0"
-        : "+r" (flags), "+r" (out_adcx), "+r" (out_adox)
+        : "=r"(flags), "=r"(out_adcx), "=r"(out_adox)
         : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
 
     assert(out_adcx == in_c + adcx_operand - 1);
@@ -53,7 +53,7 @@ void test_adcx_adox(uint32_t in_c, uint32_t in_o, REG adcx_operand, REG adox_ope
         "adcx %3, %1;"
         "adox %3, %2;"
         "pushf; pop %0"
-        : "+r" (flags), "+r" (out_adcx), "+r" (out_adox)
+        : "=r"(flags), "=r"(out_adcx), "=r"(out_adox)
         : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
 
     assert(out_adcx == in_c + adcx_operand - 1);
-- 
2.39.5

On 2/26/25 06:03, Alex Bennée wrote:
> Clang complains:
> 
>    clang -O2 -m64 -mcx16 /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c -o test-i386-adcox -static
>    /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:32:26: error: invalid input constraint '0' in asm
>            : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>                             ^
>    /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:57:26: error: invalid input constraint '0' in asm
>            : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>                             ^
>    2 errors generated.
> 
> Pointing out a numbered input constraint can't point to a read/write
> output [1]. Convert to a read-only input constraint to allow this.
> 
> [1] https://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20101101/036036.html
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>   tests/tcg/i386/test-i386-adcox.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/tcg/i386/test-i386-adcox.c b/tests/tcg/i386/test-i386-adcox.c
> index 16169efff8..b56dbc00f2 100644
> --- a/tests/tcg/i386/test-i386-adcox.c
> +++ b/tests/tcg/i386/test-i386-adcox.c
> @@ -28,7 +28,7 @@ void test_adox_adcx(uint32_t in_c, uint32_t in_o, REG adcx_operand, REG adox_ope
>           "adox %3, %2;"
>           "adcx %3, %1;"
>           "pushf; pop %0"
> -        : "+r" (flags), "+r" (out_adcx), "+r" (out_adox)
> +        : "=r"(flags), "=r"(out_adcx), "=r"(out_adox)
>           : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));

Alternately, drop all of the matching constraints as redundant.
That's what "+r" does, anyway.


r~

Richard Henderson <richard.henderson@linaro.org> writes:

> On 2/26/25 06:03, Alex Bennée wrote:
>> Clang complains:
>>    clang -O2 -m64 -mcx16
>> /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c -o
>> test-i386-adcox -static
>>    /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:32:26: error: invalid input constraint '0' in asm
>>            : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>>                             ^
>>    /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:57:26: error: invalid input constraint '0' in asm
>>            : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>>                             ^
>>    2 errors generated.
>> Pointing out a numbered input constraint can't point to a read/write
>> output [1]. Convert to a read-only input constraint to allow this.
>> [1]
>> https://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20101101/036036.html
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
>> ---
>>   tests/tcg/i386/test-i386-adcox.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>> diff --git a/tests/tcg/i386/test-i386-adcox.c
>> b/tests/tcg/i386/test-i386-adcox.c
>> index 16169efff8..b56dbc00f2 100644
>> --- a/tests/tcg/i386/test-i386-adcox.c
>> +++ b/tests/tcg/i386/test-i386-adcox.c
>> @@ -28,7 +28,7 @@ void test_adox_adcx(uint32_t in_c, uint32_t in_o, REG adcx_operand, REG adox_ope
>>           "adox %3, %2;"
>>           "adcx %3, %1;"
>>           "pushf; pop %0"
>> -        : "+r" (flags), "+r" (out_adcx), "+r" (out_adox)
>> +        : "=r"(flags), "=r"(out_adcx), "=r"(out_adox)
>>           : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>
> Alternately, drop all of the matching constraints as redundant.
> That's what "+r" does, anyway.

You mean like this:

    asm("push %0; popf;"
        "adox %3, %2;"
        "adcx %3, %1;"
        "pushf; pop %0"
        : "+r"(flags), "+r"(out_adcx), "+r"(out_adox));

Because that breaks the test:

  test-i386-adcox: /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:33: test_adox_adcx: Assertion `out_adcx == in_c + adcx_operand - 1' failed.

>
>
> r~

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

On 2/28/25 03:35, Alex Bennée wrote:
> Richard Henderson <richard.henderson@linaro.org> writes:
> 
>> On 2/26/25 06:03, Alex Bennée wrote:
>>> Clang complains:
>>>     clang -O2 -m64 -mcx16
>>> /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c -o
>>> test-i386-adcox -static
>>>     /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:32:26: error: invalid input constraint '0' in asm
>>>             : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>>>                              ^
>>>     /home/alex/lsrc/qemu.git/tests/tcg/i386/test-i386-adcox.c:57:26: error: invalid input constraint '0' in asm
>>>             : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>>>                              ^
>>>     2 errors generated.
>>> Pointing out a numbered input constraint can't point to a read/write
>>> output [1]. Convert to a read-only input constraint to allow this.
>>> [1]
>>> https://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20101101/036036.html
>>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>>> Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
>>> ---
>>>    tests/tcg/i386/test-i386-adcox.c | 4 ++--
>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>> diff --git a/tests/tcg/i386/test-i386-adcox.c
>>> b/tests/tcg/i386/test-i386-adcox.c
>>> index 16169efff8..b56dbc00f2 100644
>>> --- a/tests/tcg/i386/test-i386-adcox.c
>>> +++ b/tests/tcg/i386/test-i386-adcox.c
>>> @@ -28,7 +28,7 @@ void test_adox_adcx(uint32_t in_c, uint32_t in_o, REG adcx_operand, REG adox_ope
>>>            "adox %3, %2;"
>>>            "adcx %3, %1;"
>>>            "pushf; pop %0"
>>> -        : "+r" (flags), "+r" (out_adcx), "+r" (out_adox)
>>> +        : "=r"(flags), "=r"(out_adcx), "=r"(out_adox)
>>>            : "r" ((REG)-1), "0" (flags), "1" (out_adcx), "2" (out_adox));
>>
>> Alternately, drop all of the matching constraints as redundant.
>> That's what "+r" does, anyway.
> 
> You mean like this:
> 
>      asm("push %0; popf;"
>          "adox %3, %2;"
>          "adcx %3, %1;"
>          "pushf; pop %0"
>          : "+r"(flags), "+r"(out_adcx), "+r"(out_adox));
> 
> Because that breaks the test:

You dropped the 4th argument: "r"((REG)-1).


r~