Re: [PATCH] target/ppc: fix unreachable code in fpu_helper.c

[Daniel Henrique Barboza <danielhb413@gmail.com>]

Queued in gitlab.com/danielhb/qemu/tree/ppc-next. Thanks,


Daniel

On 6/2/22 16:10, Daniel Henrique Barboza wrote:
> Commit c29018cc7395 added an env->fpscr OR operation using a ternary
> that checks if 'error' is not zero:
> 
>      env->fpscr |= error ? FP_FEX : 0;
> 
> However, in the current body of do_fpscr_check_status(), 'error' is
> granted to be always non-zero at that point. The result is that Coverity
> is less than pleased:
> 
>    Control flow issues  (DEADCODE)
> Execution cannot reach the expression "0ULL" inside this statement:
> "env->fpscr |= (error ? 1073...".
> 
> Remove the ternary and always make env->fpscr |= FP_FEX.
> 
> Cc: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Fixes: Coverity CID 1489442
> Fixes: c29018cc7395 ("target/ppc: Implemented xvf*ger*")
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>   target/ppc/fpu_helper.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
> index fed0ce420a..7ab6beadad 100644
> --- a/target/ppc/fpu_helper.c
> +++ b/target/ppc/fpu_helper.c
> @@ -464,7 +464,7 @@ static void do_fpscr_check_status(CPUPPCState *env, uintptr_t raddr)
>       }
>       cs->exception_index = POWERPC_EXCP_PROGRAM;
>       env->error_code = error | POWERPC_EXCP_FP;
> -    env->fpscr |= error ? FP_FEX : 0;
> +    env->fpscr |= FP_FEX;
>       /* Deferred floating-point exception after target FPSCR update */
>       if (fp_exceptions_enabled(env)) {
>           raise_exception_err_ra(env, cs->exception_index,