Re: [PATCH] target/ppc: Fix xvcmp* clearing FI bit

[Daniel Henrique Barboza]

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


Daniel

On 10/5/22 09:15, Víctor Colombo wrote:
> Vector instructions in general are not supposed to change the FI bit.
> However, xvcmp* instructions are calling gen_helper_float_check_status,
> which is leading to a cleared FI flag where it should be kept
> unchanged.
> As helper_float_check_status only affects inexact, overflow and
> underflow, and the xvcmp* instructions don't change these flags, this
> issue can be fixed by removing the call to helper_float_check_status.
> By doing this, the FI bit in FPSCR will be preserved as expected.
>
> Fixes: 00084a25adf ("target/ppc: introduce separate VSX_CMP macro for xvcmp* 
> instructions")
> Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
> ---
>   target/ppc/translate/vsx-impl.c.inc | 1 -
>   1 file changed, 1 deletion(-)
>
> diff --git a/target/ppc/translate/vsx-impl.c.inc 
> b/target/ppc/translate/vsx-impl.c.inc
> index 7acdbceec4..e6e5c45ffd 100644
> --- a/target/ppc/translate/vsx-impl.c.inc
> +++ b/target/ppc/translate/vsx-impl.c.inc
> @@ -810,7 +810,6 @@ static void gen_##name(DisasContext *ctx)                   
>                   \
>           gen_helper_##name(ignored, cpu_env, xt, xa, xb);                      
> \
>           tcg_temp_free_i32(ignored);                                           
> \
>       }                                                                         
> \
> -    gen_helper_float_check_status(cpu_env);                                   \
>       tcg_temp_free_ptr(xt);                                                    
> \
>       tcg_temp_free_ptr(xa);                                                    
> \
>       tcg_temp_free_ptr(xb);                                                    
> \