Re: [PATCH 13/25] tests/tcg: fix constraints in test-i386-adcox

[Richard Henderson <richard.henderson@linaro.org>]

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~