Re: [Qemu-devel] [PATCH v2 04/27] target/sh4: Keep env->flags clean

[Philippe Mathieu-Daudé]

On 07/06/2017 11:20 PM, Richard Henderson wrote:
> If we mask off any out-of-band bits before we assign to the
> variable, then we don't need to clean it up when reading.
>
> Signed-off-by: Richard Henderson <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>   target/sh4/cpu.h | 2 +-
>   target/sh4/cpu.c | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/sh4/cpu.h b/target/sh4/cpu.h
> index 240ed36..6d179a7 100644
> --- a/target/sh4/cpu.h
> +++ b/target/sh4/cpu.h
> @@ -391,7 +391,7 @@ static inline void cpu_get_tb_cpu_state(CPUSH4State *env, 
> target_ulong *pc,
>   {
>       *pc = env->pc;
>       *cs_base = 0;
> -    *flags = (env->flags & TB_FLAG_ENVFLAGS_MASK) /* Bits  0-2 */
> +    *flags = env->flags                                        /* Bits  0-2 */
>               | (env->fpscr & (FPSCR_FR | FPSCR_SZ | FPSCR_PR))  /* Bits 19-21 
> */
>               | (env->sr & ((1u << SR_MD) | (1u << SR_RB)))      /* Bits 29-30 
> */
>               | (env->sr & (1u << SR_FD))                        /* Bit 15 */
> diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c
> index 9da7e1e..8536f6d 100644
> --- a/target/sh4/cpu.c
> +++ b/target/sh4/cpu.c
> @@ -39,7 +39,7 @@ static void superh_cpu_synchronize_from_tb(CPUState *cs, 
> TranslationBlock *tb)
>       SuperHCPU *cpu = SUPERH_CPU(cs);
>   
>       cpu->env.pc = tb->pc;
> -    cpu->env.flags = tb->flags;
> +    cpu->env.flags = tb->flags & TB_FLAG_ENVFLAGS_MASK;
>   }
>   
>   static bool superh_cpu_has_work(CPUState *cs)